303 results on '"Lacs"'
Search Results
2. Genome-wide expression analysis of LACS gene family implies GhLACS25 functional responding to salt stress in cotton
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Yuchen Xu, Shouyang Fu, Yiwen Huang, Dayun Zhou, Yuzhen Wu, Jun Peng, and Meng Kuang
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LACS ,Abiotic stress ,Yeast ,VIGS ,Cotton ,Botany ,QK1-989 - Abstract
Abstract Background Long-chain acyl-coenzyme A synthetase (LACS) is a type of acylating enzyme with AMP-binding, playing an important role in the growth, development, and stress response processes of plants. Results The research team identified different numbers of LACS in four cotton species (Gossypium hirsutum, Gossypium barbadense, Gossypium raimondii, and Gossypium arboreum). By analyzing the structure and evolutionary characteristics of the LACS, the GhLACS were divided into six subgroups, and a chromosome distribution map of the family members was drawn, providing a basis for further research classification and positioning. Promoter cis-acting element analysis showed that most GhLACS contain plant hormones (GA, MeJA) or non-biological stress-related cis-elements. The expression patterns of GhLACS under salt stress treatment were analyzed, and the results showed that GhLACS may significantly participate in salt stress response through different mechanisms. The research team selected 12 GhLACSs responsive to salt stress for tissue expression analysis and found that these genes are expressed in different tissues. Conclusions There is a certain diversity of LACS among different cotton species. Analysis of promoter cis-acting elements suggests that GhLACS may be involved in regulating plant growth, development and stress response processes. GhLACS25 was selected for in-depth study, which confirmed its significant role in salt stress response through virus-induced gene silencing (VIGS) and induced expression in yeast cells.
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- 2024
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3. Genome-wide expression analysis of LACS gene family implies GhLACS25 functional responding to salt stress in cotton
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Xu, Yuchen, Fu, Shouyang, Huang, Yiwen, Zhou, Dayun, Wu, Yuzhen, Peng, Jun, and Kuang, Meng
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- 2024
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4. Les immersions de munitions dans les lacs suisses et français (1919-aujourd’hui), de l’oubli à un statu quo évolutif
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Charrière, Elodie
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aujourd’hui ,Charrière ,Dépots ,Elodie ,environmental issue ,évolutif ,français ,immersions ,l’oubli ,lacs ,military waste ,munitions ,munitions/arms and armour ,statu ,suisses ,Thierry ,Waser ,bic Book Industry Communication::J Society & social sciences::JW Warfare & defence::JWM Weapons & equipment ,bic Book Industry Communication::H Humanities::HB History::HBW Military history ,bic Book Industry Communication::J Society & social sciences::JF Society & culture: general::JFF Social issues & processes ,bic Book Industry Communication::J Society & social sciences::JP Politics & government::JPF Political ideologies ,bic Book Industry Communication::R Earth sciences, geography, environment, planning::RN The environment::RNH Waste management ,bic Book Industry Communication::R Earth sciences, geography, environment, planning::RN The environment::RNT Social impact of environmental issues - Abstract
Cet ouvrage explore un dossier politico-scientifique aujourd’hui encore méconnu, celui du dépôt des munitions produites durant la Seconde Guerre mondiale par la Suisse et immergées, la paix revenue, par les autorités dans les lacs helvétiques. À une époque où les enjeux écologiques sont primordiaux pour notre avenir collectif planétaire, il s’agit à la fois de comprendre les motivations et raisons de ce choix qui nous parait désormais antiécologique et les enjeux actuels de gestion ou non de ces déchets militaires. Fondé sur une approche interdisciplinaire, ce livre rend compte, dans une double perspective d’historien des sciences et des sciences de la société, à la fois des décisions publiques ayant conduites à l’immersion, des modalités techniques mises en œuvre pour y parvenir, des conditions de production de l’oubli sociétal de ce méfait environnemental, du contexte de la redécouverte de ses dépôts et enfin des débats publics engagés autour d’un risque jugé scientifiquement encore incertain. Sans préjuger des solutions techniques potentielles si les craintes d’un risque potentiel ou avéré pour la santé humaine des riverains et pour les écosystèmes lacustres se confirmaient, ce livre rassemble pour le lecteur passionné par les questions environnementales toutes les informations et connaissances aujourd’hui en notre possession pour œuvrer activement à l’engagement durable citoyen.
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- 2023
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5. Longer Duration of Active Oil Biosynthesis during Seed Development Is Crucial for High Oil Yield—Lessons from Genome-Wide In Silico Mining and RNA-Seq Validation in Sesame.
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Nawade, Bhagwat, Kumar, Ajay, Maurya, Rasna, Subramani, Rajkumar, Yadav, Rashmi, Singh, Kuldeep, and Rangan, Parimalan
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SEED development ,BIOSYNTHESIS ,REGULATOR genes ,AMINO acid sequence ,OILSEEDS ,PETROLEUM - Abstract
Sesame, one of the ancient oil crops, is an important oilseed due to its nutritionally rich seeds with high protein content. Genomic scale information for sesame has become available in the public databases in recent years. The genes and their families involved in oil biosynthesis in sesame are less studied than in other oilseed crops. Therefore, we retrieved a total of 69 genes and their translated amino acid sequences, associated with gene families linked to the oil biosynthetic pathway. Genome-wide in silico mining helped identify key regulatory genes for oil biosynthesis, though the findings require functional validation. Comparing sequences of the SiSAD (stearoyl-acyl carrier protein (ACP)-desaturase) coding genes with known SADs helped identify two SiSAD family members that may be palmitoyl-ACP-specific. Based on homology with lysophosphatidic acid acyltransferase (LPAAT) sequences, an uncharacterized gene has been identified as SiLPAAT1. Identified key regulatory genes associated with high oil content were also validated using publicly available transcriptome datasets of genotypes contrasting for oil content at different developmental stages. Our study provides evidence that a longer duration of active oil biosynthesis is crucial for high oil accumulation during seed development. This underscores the importance of early onset of oil biosynthesis in developing seeds. Up-regulating, identified key regulatory genes of oil biosynthesis during early onset of seed development, should help increase oil yields. [ABSTRACT FROM AUTHOR]
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- 2022
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6. Quand la non-activation des règles devient la règle : regard de géographe sur un problème public qui s’éternise. Le cas de la déprivatisation des rives lacustres (Annecy, Léman).
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Nikolli, Alice
- Abstract
Copyright of VertigO is the property of La Revue Electronique en Sciences de l'Environnement VertigO and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2022
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7. Impacts potentiels et détection de l'hybride (Myriophyllum spicatum X Myriophyllum sibiricum) dans les lacs des Laurentides
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Matte-Richer, Chrystelle, Carignan, Richard, Matte-Richer, Chrystelle, and Carignan, Richard
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L’objectif principal de cet essai est de déterminer la distribution et les impacts potentiels de l’hybride (Myriophyllum spicatum X Myriophyllum sibiricum) dans la région des Laurentides. Le myriophylle à épis est une plante aquatique exotique envahissante (PAEE) présente en Amérique du Nord. Elle est originaire d’Asie et elle a probablement été introduite comme plante d’aquarium dans les années 1940 aux États-Unis. Elle est présente dans la région du Québec depuis au moins 1958. Le myriophylle à épis (Myriophyllum spicatum) peut avoir des impacts environnementaux et socioéconomiques importants. Le Myriophyllum spicatum peut s’hybrider avec une espèce indigène (Myriophyllum sibiricum). Ce phénomène est documenté aux États-Unis ainsi qu’en Ontario depuis 2002. Selon plusieurs études, l’espèce hybride aurait des caractéristiques plus envahissantes que le myriophylle à épis. Son caractère plus invasif pourrait avoir une incidence sur les méthodes de contrôle utilisées sur la plante. En 2022, dans le cadre d’un projet pilote, un hybride semblait avoir été découvert au lac René à Prévost dans les Laurentides. Outre ce projet pilote, l’hybridation (Myriophyllum spicatum X Myriophyllum sibiricum) n’a reçu aucune attention au Québec. Les hybrides peuvent répondre différemment de leurs parents aux conditions écologiques locales. De plus, l’hybridation entre le M. spicatum et le M. sibiricum pourrait entrainer la perte de lignée génétique du M. sibiricum à travers la compétition ou la contamination génomique. L’échantillonnage et les analyses génétiques de ce projet ont finalement permis d’identifier un seul hybride dans un autre lac, soit le lac Grenville. De plus, il a été constaté qu’il existe deux groupes génétiques de Myriophyllum spicatum dans la région des Laurentides. L’information sur la présence de l’hybride ainsi que sa potentielle distribution grâce à une détection précoce est particulièrement importante pour la gestion des stratégies de lutte et pour la conservat
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- 2024
8. Left atrial strain predicts incident atrial fibrillation in the general population: the Copenhagen City Heart Study.
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Hauser, Raphael, Nielsen, Anne Bjerg, Skaarup, Kristoffer Grundtvig, Lassen, Mats Christian Højbjerg, Duus, Lisa Steen, Johansen, Niklas Dyrby, Sengeløv, Morten, Marott, Jacob Louis, Jensen, Gorm, Schnohr, Peter, Søgaard, Peter, Møgelvang, Rasmus, and Biering-Sørensen, Tor
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ECHOCARDIOGRAPHY ,CONFIDENCE intervals ,MULTIVARIATE analysis ,ATRIAL fibrillation ,DESCRIPTIVE statistics ,LEFT heart atrium ,LONGITUDINAL method ,PROPORTIONAL hazards models - Abstract
Background Left atrial (LA) strain parameters have been demonstrated to be valuable predictors of atrial fibrillation (AF) in several patient cohorts. The purpose of this study was to investigate whether LA strain, assessed by two-dimensional speckle-tracking echocardiography, can be used to predict the development of AF in the general population. Methods and results This prospective longitudinal study included 4466 participants from the fifth Copenhagen City Heart Study. All participants underwent a health examination, including echocardiographic measurements of LA strain. Participants with prevalent AF at baseline were excluded. The primary endpoint was incident AF. During a median follow-up period of 5.3 years, 154 (4.3%) participants developed AF. In univariable analysis, peak atrial longitudinal strain (PALS), peak atrial contraction strain (PACS), and LA strain during the conduit phase were significantly associated with the development of AF. PALS [hazard ratio (HR) 1.05, 95% confidence interval (CI) (1.03–1.07), P < 0.001, per 1% decrease] and PACS (HR 1.08, 95% CI (1.05–1.12), P < 0.001, per 1% decrease] remained independent predictors of AF in multivariable analysis. In addition, PALS and PACS remained significantly associated with AF development even in participants with normal-sized atria and normal left ventricular (LV) systolic function. Conclusion In the general population, PALS and PACS independently predict incident AF. These findings remained consistent even in participants with normal-sized LA and normal LV systolic function. [ABSTRACT FROM AUTHOR]
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- 2022
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9. Engager les pratiquants de loisirs dans la gestion des invasions biologiques : une co-production territoriale.
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DEHEZ, JEOFFREY
- Abstract
Copyright of VertigO is the property of La Revue Electronique en Sciences de l'Environnement VertigO and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2021
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10. Genome-wide comparative analysis of long-chain acyl-CoA synthetases (LACSs) gene family: A focus on identification, evolution and expression profiling related to lipid synthesis.
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Ayaz, Asma, Saqib, Saddam, Huang, Haodong, Zaman, Wajid, Lü, Shiyou, and Zhao, Huayan
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GENE families , *LIPID synthesis , *LIGASES , *ACYL coenzyme A , *GENES - Abstract
In plants, Long-chain acyl-CoA synthetases (LACSs) play key roles in activating fatty acids to fatty acyl-CoA thioesters, which are then further involved in lipid synthesis and fatty acid catabolism. LACSs have been intensively studied in Arabidopsis , but its evolutionary relationship in green plants is unexplored. In this study, we performed a comprehensive genome-wide analysis of the LACS gene family across green plants followed by phylogenetic clustering analysis, gene structure determination, detection of conserved motifs, gene expression in tissues and subcellular localization. Our results identified LACS genes in 122 plant species including algae, low land plants (i.e., mosses and lycophytes), monocots, and eudicots. In total, 697 sequences were identified, and 629 sequences were selected because of alignment and some duplication errors. The retrieved amino acid sequences ranged from 271 to 1056 residues and diversified in intron/exon patterns in different LACSs. Phylogenetic clustering grouped LACS gene family into six major clades with distinct potential functions. This classification is well supported by examining gene structure and conserved motifs. Also, gene expression analysis and subcellular localization substantiate with clade division in the phylogeny, indicating that the evolutionary pattern is visible in their functionality. Additionally, experimental analysis of lacs2 mutant validated that LACS2 plays key roles in suberin synthesis. Thus, our study not only provides an evolutionary mechanism underlying functional diversification but also lays the foundation for further elucidation of the LACS gene family. • This is the first genome-wide identification of 629 LACSs genes in 122 plant species. • Phylogenetic analysis of LACSs genes shows six major clades with potential distinct functions. • LACSs genes present specific expression patterns across different tissues with different level. [ABSTRACT FROM AUTHOR]
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- 2021
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11. Comparison of surgical parameters using different lens fragmentation patterns in eyes undergoing laser-assisted cataract surgery.
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Uy, Harvey S., Chan, Pik Sha, Gil-Cazorla, Raquel, and Shah, Sunil
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Purpose: To compare surgical parameters among eyes undergoing laser-assisted cataract surgery (LACS) using different lens fragmentation patterns (LFP). Methods: Prospective, randomized, unmasked clinical trial. One-hundred eyes underwent LACS and were randomly assigned to 1 of 3 LFP treatment groups: (1) laser capsulotomy only; no lens fragmentation (NLF) (n = 34); (2) three-plane chop (TPC) (n = 33); and, (3) pie-cut pattern (PCP) fragmentation (n = 33). Prechop phacoemulsification (PHACO) was performed on all eyes using the same femtosecond (FS) laser and active-fluidics PHACO machine. Main outcome measures: FS laser dock time (s), PHACO time (s), PHACO power (%), cumulative dissipated energy (CDE) (%-s), irrigating fluid volume, and operative time. Results: The 3 treatment groups were comparable in terms of patient age (P = 0.164) and nuclear density (P = 0.669). FS dock time was higher in the PCP group (184.18 ± 25.86) compared to the TPC (145.09 ± 14.15) group (P < 0.001). PHACO time was significantly shorter in the PCP (23.19 ± 17.20 s) compared to TPC (35.27 ± 17.70) and NLF (46.15 ± 23.72) groups (P < 0.001). PHACO power was lower in the PCP (11.81 ± 3.71) compared to the NLF (14.41 ± 1.88) and TPC (14.04 ± 2.46) groups (P < 0.001). CDE was lower in the PCP (2.85 ± 2.32) compared to NLF (6.55 ± 3.32) and TPC (6.55 ± 5.45) groups (P < 0.001). Fluid volumes and operative times were similar. Conclusion: LFP can influence PHACO surgical parameters. Extensive fragmentation patterns such as PCP appear to lower PHACO time, power, and CDE and may potentially reduce the risk of PHACO related complications. [ABSTRACT FROM AUTHOR]
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- 2019
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12. Toujours les problèmes du lac de Besse-sur-Issole !
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Nicod, Jean
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Hydrogéologie ,Sources karstic ,Karst ,Hydrogeology ,Geomorphology ,drought ,lacs ,General Medicine ,gypsum karst ,gypse ,lakes ,Hydrology ,Karstic springs ,Géomorphologie ,Hydrologie ,sécheresse - Abstract
Le lac karstique de Besse-sur-Issole (Var) s'est vidé par un entonnoir, en raison de la sécheresse persistante au cours de l'été et de l'automne 2007. Ce phénomène pose le problème du rôle respectif des facteurs climatiques et anthropiques dans l'évolution des lacs des karsts du gypse. The karstic lake of Besse-sur-Issole (Var) empty by a funnel, because the persistent drought in summer and autumn 2007. This phenomenon put the problem of the respective part of the climatic and anthropic impacts in the evolution af the gypsum karst lakes.
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- 2022
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13. De la déglaciation à l’agriculture moderne :histoire environnementale du sud du Groenland
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Emilie Gauthier, Vincent Bichet, Charly Massa, Typhaine Guillemot, Laurent Millet, Christophe Petit, and Hervé Richard
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Groenland ,lacs ,Holocène ,Vikings ,analyses multi-proxy ,Archaeology ,CC1-960 - Abstract
Palaeoenvironmentalists from the Chrono-environment laboratory in Besançon have been working in Greenland since 2006. The Study area is located in southern Greenland, within the Norse Eastern settlement occupied from 986 to 1450 cal. BC. The study aims at characterizing the impact of this first colonization on a pristine environment. The lacustrine sequence was studied with the help of different proxies (palynology, Non Pollen Palynomorph, Diatoms, sedimentology, geochemical and isotope analyses) and, in some site, the Norse settlement was integrated in the Holocene context. About 20 sediment cores were collected during 5 fieldtrips from 2006 to 2013. The Holocene sequence from Igaliku, the medieval Garðar, starts at 8000 cal. AD and the record of pollen rain start at about 6100 cal. AD ; it is one of the best radiocarbon dated sequence of this area. From 6100 to 2500 cal. AD, pollen diagram from Lake Igaliku shows that vegetation is dominated by juniper and willow. Starting in 2500 cal. AD, with the beginning of the neoglacial period, Juniper pollen decreases while dwarf birch and white birch become the dominant tree taxa. Decrease in birch and juniper and the rise in coprophilous fungi are the first evidences of the Norse settlement. The presence of settlers and livestock is clearly recorded: increasing soil erosion frequencies Norse apophytes (sheep sorrel, dandelion, buttercup) and coprophilous fungi. This colonization phase is followed by a period of decreasing human impact at the beginning of the 14th century, with a decrease in coprophilous fungi suggesting a reduced grazing pressure. The regrowth of willow and birch and the disappearance of anthropogenic indicators except sheep sorrel type between the 15th and 18th century demonstrate the abandonment of the settlement, until the development of contemporary agriculture in the 20th century. Impact of modern agriculture on vegetation is comparable to the Norse impact. However, mechanization and fertilization have heavily increased soil erosion and transformed the lake ecosystem.
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- 2015
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14. Environmental drivers of plant assemblages: are there differences between palustrine and lacustrine wetlands? A case study from the northern Apennines (Italy).
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Angiolini, Claudia, Viciani, Daniele, Bonari, Gianmaria, Zoccola, Antonio, Bottacci, Alessandro, Ciampelli, Paola, Gonnelli, Vincenzo, and Lastrucci, Lorenzo
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WETLANDS ,WETLAND soils ,SPECIES distribution ,WATER depth ,PLANT species ,AQUATIC plants ,SOIL moisture - Abstract
Copyright of Knowledge & Management of Aquatic Ecosystems is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2019
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15. Contribution of 3D coupled hydrodynamic-ecological modeling to assess the representativeness of a sampling protocol for lake water quality assessment.
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Soulignac, Frédéric, Anneville, Orlane, Bouffard, Damien, Chanudet, Vincent, Dambrine, Etienne, Guénand, Yann, Harmel, Tristan, Ibelings, Bastiaan W, Trevisan, Dominique, Uittenbogaard, Rob, and Danis, Pierre-Alain
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WATER quality ,LAKE ecology ,ECOLOGICAL heterogeneity ,LAKES ,CHLOROPHYLL in water ,FREEWARE (Computer software) ,ECOLOGICAL assessment ,WATER quality monitoring - Abstract
Copyright of Knowledge & Management of Aquatic Ecosystems is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2019
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16. Production of microhomologous-mediated site-specific integrated LacS gene cow using TALENs.
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Su, Xiaohu, Wang, Shenyuan, Su, Guanghua, Zheng, Zhong, Zhang, Jiaqi, Ma, Yunlong, Liu, Zongzheng, Zhou, Huanmin, Zhang, Yanru, and Zhang, Li
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GENOME editing , *NUCLEASES , *ESTERASES , *LACTOSE , *DISACCHARIDES - Abstract
Gene editing tools (Zinc-Finger Nucleases, ZFN; Transcription Activator-Like Effector Nucleases, TALEN; and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated (Cas)9, CRISPR-Cas9) provide us with a powerful means of performing genetic engineering procedures. A combinational approach that utilizes both somatic cell nuclear transfer (SCNT) and somatic cell gene editing facilitates the generation of genetically engineered animals. However, the associated research has utilized markers and/or selected genes, which constitute a potential threat to biosafety. Microhomologous-mediated end-joining (MMEJ) has showed the utilization of micro-homologous arms (5–25 bp) can mediate exogenous gene insertion. Dairy milk is a major source of nutrition worldwide. However, most people are not capable of optimally utilizing the nutrition in milk because of lactose intolerance. Sulfolobus solfataricus β-glycosidase (LacS) is a lactase derived from the extreme thermophilic archaeon Sulfolobus solfataricus . Our finally aim was to site-specific integrated LacS gene into cow's genome through TALEN-mediated MMEJ and produce low-lactose cow. Firstly, we constructed TALENs vectors which target to the cow's β-casein locus and LacS gene expression vector which contain TALEN reorganization sequence and micro-homologous arms. Then we co-transfected these vectors into fetal derived skin fibroblasts and cultured as monoclone. Positive cell clones were screened using 3′ junction PCR amplification and sequencing analysis. The positive cells were used as donors for SCNT and embryo transfer (ET). Lastly, we detected the genotype through PCR of blood genomic DNA. This resulted in a LacS knock-in rate of 0.8% in TALEN-treated cattle fetal fibroblasts. The blastocyst rate of SCNT embryo was 27%. The 3 months pregnancy rate was 20%. Finally, we obtained 1 newborn cow (5%) and verified its genotype. We obtained 1 site-specific marker-free LacS transgenic cow. It provides a basis to solve lactose intolerance by gene engineering breeding. This study also provides us with a new strategy to facilitate gene knock-ins in livestock using techniques that exhibit improved biosafety and intuitive methodologies. [ABSTRACT FROM AUTHOR]
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- 2018
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17. Left atrial strain predicts incident atrial fibrillation in the general population: the Copenhagen City Heart Study
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Mats Christian Højbjerg Lassen, Jacob Louis Marott, Morten Sengeløv, Peter Schnohr, Peter Søgaard, Rasmus Mogelvang, Tor Biering-Sørensen, Gorm B. Jensen, Niklas Dyrby Johansen, Anne Bjerg Nielsen, Lisa Steen Duus, Raphael Hauser, and Kristoffer Grundtvig Skaarup
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medicine.medical_specialty ,Longitudinal study ,Population ,Left atrial strain ,Risk Assessment ,two-dimensional speckle-tracking echocardiography ,Left atrial ,Internal medicine ,Atrial Fibrillation ,medicine ,Clinical endpoint ,Humans ,atrial fibrillation ,Radiology, Nuclear Medicine and imaging ,Heart Atria ,Longitudinal Studies ,Prospective Studies ,LACS ,education ,PACS ,education.field_of_study ,business.industry ,Hazard ratio ,Atrial fibrillation ,General Medicine ,medicine.disease ,Confidence interval ,PALS ,Cardiology ,Cardiology and Cardiovascular Medicine ,business - Abstract
Background Left atrial (LA) strain parameters have been demonstrated to be valuable predictors of atrial fibrillation (AF) in several patient cohorts. The purpose of this study was to investigate whether LA strain, assessed by two-dimensional speckle-tracking echocardiography, can be used to predict the development of AF in the general population. Methods and results This prospective longitudinal study included 4466 participants from the fifth Copenhagen City Heart Study. All participants underwent a health examination, including echocardiographic measurements of LA strain. Participants with prevalent AF at baseline were excluded. The primary endpoint was incident AF. During a median follow-up period of 5.3 years, 154 (4.3%) participants developed AF. In univariable analysis, peak atrial longitudinal strain (PALS), peak atrial contraction strain (PACS), and LA strain during the conduit phase were significantly associated with the development of AF. PALS [hazard ratio (HR) 1.05, 95% confidence interval (CI) (1.03–1.07), P Conclusion In the general population, PALS and PACS independently predict incident AF. These findings remained consistent even in participants with normal-sized LA and normal LV systolic function.
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- 2021
- Full Text
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18. Chronologie des phases glaciaires et de la formation des lacs de montagnes dans les secteurs de l’OHM Pyrénées (Projet OHM 'Néolacs')
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Chapron, Emmanuel, Jomelli, Vincent, Lacou, Alexandre, Le Roux, G., van Beek, Pieter, Géographie de l'environnement (GEODE), Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire Ecologie Fonctionnelle et Environnement (LEFE), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT), Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), CNRS UMR 5602 GEODE, and ANR-11-LABX-0010,DRIIHM / IRDHEI,Dispositif de recherche interdisciplinaire sur les Interactions Hommes-Milieux(2011)
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Changement climatique ,OHM Pyrenees ,datations 10Be ,[SDE]Environmental Sciences ,datations 14C ,Lacs ,impacts anthropiques ,datations 137Cs ,LABEX DRIIHM ,Glaciers ,Pyrénées françaises - Abstract
National audience; La synthèse des données géomorphologiques, stratigraphiques et géochronologiques collectées ces dernières années notamment dans le cadre du projet OHM Pyrénées "Néolacs" (2020-2021), et des données scientifiques disponibles dans les secteurs de l'OHM Pyrénées (vallée du Haut Vicdessos en Ariège et Parc National des Pyrénées dans les Pyrénées Centrales) permet aujourd'hui de mieux contraindre la chronologie des dernières phases glaciaires et de la formation des lacs de montagnes dans ces deux secteurs des Pyrénées françaises. Cette présentation résume (i) les ages 10Be disponibles sur les blocs erratiques associés à des cordons morainiques ou sur des roches moutonnées; (ii) les ages 14C disponibles dans les remplissages lacustres de montagne localisés à proximité de formations glaciaires et parfois encore des derniers glaciers pyrénéens (notamment dans le cirque de Troumouze, et dans le bassin versant des Oulettes de Gaube) et (iii) les ages radionucléides (137Cs) obtenus dans les sédiments lacustres récents de quelques lacs. Les travaux en cours et programmés dans le cadre du projet "Néo Pyrénées" permettront d'harmoniser la base de données paléoenvironnementales à disposition dans les deux secteurs de l'OHM Pyrénées pour préciser la chronologie du retrait et de la fonte des glaciers würmiens, de la mise en place d'une néoglaciation dans les Pyrénées ainsi que leur influence sur la formation et la dynamique sédimentaire des environnements lacustres d'altitude.
- Published
- 2022
19. Estimating sensible and latent heat fluxes over an inland water body using optical and microwave scintillometers
- Author
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Pierre, Adrien, Isabelle, Pierre-Erik, Nadeau, Daniel, Thiboult, Antoine, Perelet, Alexei, Rousseau, Alain N., Anctil, François, Deschamps, Jaril, Pierre, Adrien, Isabelle, Pierre-Erik, Nadeau, Daniel, Thiboult, Antoine, Perelet, Alexei, Rousseau, Alain N., Anctil, François, and Deschamps, Jaril
- Abstract
Les flux de chaleurs turbulents sont encore trop rarement observés au-dessus des plans d’eau continentaux comme les lacs ou les réservoirs, alors que cela demeure essentiel pour le paramétrage des modèles de prévisions météorologiques et de projections climatiques. La scintillométrie permet d’estimer à l’échelle régionale (~km2) les flux turbulents, mais peu d’études ont évalué sa performance au-dessus de plans d’eau. Cette étude compare les flux de chaleurs turbulents issus de la méthode de scintillométrie avec ceux issus d’un système de covariance des tourbillons installé sur un quai flottant, au-dessus d’un réservoir hydroélectrique boréal, dimictique, de 85 km2, situé dans l’est du Canada (50.59°N, 63.24°O). À notre connaissance, il s'agit de l'une des premières études à quantifier l'évaporation sur un plan d'eau intérieur à l'aide d'un ensemble de scintillomètres optiques et micro-ondes. Du 14 août au 9 octobre 2019, les faisceaux des scintillomètres ont sondé l’atmosphère sur une distance de 1.7 km au-dessus du réservoir (10 m) dans une zone ayant jusqu’à 100 m de profondeur. Quarante-neuf jours de données ont été récoltés. Cette étude quantifie l'impact de la stabilité atmosphérique sur les flux calculés et explore l'utilisation des différences de température à l'interface eau-air à proximité du centre du faisceau du scintillomètre pour estimer correctement la direction du flux de chaleur sensible. Les méthodes de scintillométrie corrèlent bien avec les estimations de la covariance des tourbillons pour les flux de chaleur sensible (R2 jusqu'à 0.86, 43% de biais), tandis que la concordance diminue pour les flux de chaleur latente (R2 jusqu'à 0,58, 70% de biais). Le scintillomètre a mesuré des flux de chaleur latente beaucoup plus importants que le système de covariance des tourbillons. Ces résultats peuvent être dus à l'empreinte plus grande des scintillomètres qui captent une plus grande hétérogénéité des flux., Observations of turbulent heat fluxes over inland water bodies are scarce despite being critical to adequate lake parametrization for numerical weather forecast and climate models. Scintillometry has allowed for the regional (~ km2) estimation of turbulent heat fluxes, but few studies have assessed its performance over water. We compare scintillometry-derived turbulent heat fluxes over an 85-km2 dimictic boreal hydropower reservoir in eastern Canada (50.69° N, 63.24° W) with data from a raft-based eddy-covariance system. To the best of our knowledge, this is one of the first studies to quantify evaporation over an inland water body using a set of optical and microwave scintillometers. The scintillometer beam path extended 1.7 km over a section of the reservoir with depths of up to 100 m, from 14 August to 9 October 2019. Forty-nine days of data were retained. This study quantifies the impact of atmospheric stability on the derived fluxes and explores the use of temperature differences at the water–air interface from a point close to the centre of the scintillometer beam to properly estimate the direction of the sensible heat flux. The scintillometry approaches were well correlated with the eddy-covariance estimations for sensible heat fluxes (R2 up to 0.86, 32% bias), while the agreement decreased for latent heat fluxes (R2 up to 0.59, 69% bias). The scintillometer measured much larger latent heat fluxes than the eddy-covariance set-up. These results may be due to the larger footprint of the scintillometers capturing greater heterogeneity in the fluxes.
- Published
- 2022
20. Left atrial strain predicts incident atrial fibrillation in the general population:the Copenhagen City Heart Study
- Author
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Hauser, Raphael, Nielsen, Anne Bjerg, Skaarup, Kristoffer Grundtvig, Lassen, Mats Christian Højbjerg, Duus, Lisa Steen, Johansen, Niklas Dyrby, Sengeløv, Morten, Marott, Jacob Louis, Jensen, Gorm, Schnohr, Peter, Søgaard, Peter, Møgelvang, Rasmus, Biering-Sørensen, Tor, Hauser, Raphael, Nielsen, Anne Bjerg, Skaarup, Kristoffer Grundtvig, Lassen, Mats Christian Højbjerg, Duus, Lisa Steen, Johansen, Niklas Dyrby, Sengeløv, Morten, Marott, Jacob Louis, Jensen, Gorm, Schnohr, Peter, Søgaard, Peter, Møgelvang, Rasmus, and Biering-Sørensen, Tor
- Abstract
Background: Left atrial (LA) strain parameters have been demonstrated to be valuable predictors of atrial fibrillation (AF) in several patient cohorts. The purpose of this study was to investigate whether LA strain, assessed by two-dimensional speckle-tracking echocardiography, can be used to predict the development of AF in the general population. Methods and results: This prospective longitudinal study included 4466 participants from the fifth Copenhagen City Heart Study. All participants underwent a health examination, including echocardiographic measurements of LA strain. Participants with prevalent AF at baseline were excluded. The primary endpoint was incident AF. During a median follow-up period of 5.3 years, 154 (4.3%) participants developed AF. In univariable analysis, peak atrial longitudinal strain (PALS), peak atrial contraction strain (PACS), and LA strain during the conduit phase were significantly associated with the development of AF. PALS [hazard ratio (HR) 1.05, 95% confidence interval (CI) (1.03-1.07), P < 0.001, per 1% decrease] and PACS (HR 1.08, 95% CI (1.05-1.12), P < 0.001, per 1% decrease] remained independent predictors of AF in multivariable analysis. In addition, PALS and PACS remained significantly associated with AF development even in participants with normal-sized atria and normal left ventricular (LV) systolic function. Conclusion: In the general population, PALS and PACS independently predict incident AF. These findings remained consistent even in participants with normal-sized LA and normal LV systolic function.
- Published
- 2022
21. Deux lacs à problèmes du Centre-Var : le Grand Loucien de La Roquebrussanne et le Lac de Besse-sur-Issole
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Jean Nicod
- Subjects
Hydrogéologie ,Sources karstic ,Karst ,Hydrogeology ,Geomorphology ,General Medicine ,lacs ,gypsum ,gypses ,lakes ,Hydrology ,Géomorphologie ,Karstic springs ,Hydrologie - Abstract
Les petits lacs du Centre-Var sont situés dans des dépressions karstiques produites par la dissolution des gypses et de l'anhydrite des terrains triasiques. Leur évolution récente pose d'importants problèmes typiques, hydrologiques et environnementaux The little lakes of Middle Var Department are located in karstic depressions produced by solution of gypsum or anhydrite in the triassic formations. Their new evolution show main typical, hydrological and environmental problems.
- Published
- 2022
22. Littoral chironomids of a large Alpine lake: spatial variation and variables supporting diversity.
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Frossard, Victor and Marchand, Philippe
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CHIRONOMIDAE ,SPECIES diversity ,FISH conservation ,AUTOCORRELATION (Statistics) ,HYDRODYNAMICS - Abstract
Copyright of Knowledge & Management of Aquatic Ecosystems is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2018
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23. Long Chain Acyl-Coenzyme A Synthetase 4 (BnLACS4) Gene from Brassica napus Enhances the Yeast Lipid Contents
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Xiao-li TAN, Xiang-feng ZHENG, Zhi-yan ZHANG, Zheng WANG, Heng-chuan XIA, Changming LU, and Shou-lai GU
- Subjects
Brasscia napus ,LACS ,lipid ,subcellular localization ,yeast ,Agriculture (General) ,S1-972 - Abstract
Long-chain acyl-Coenzyme A (CoA) synthetases (LACSs) catalyze the formation of long-chain acyl-CoA, and play important roles in fatty acid metabolism including phospholipids, triacylglycerol (TAG) biosynthesis and fatty acid β-oxidation. Here, we report the characterization of a LACS gene from Brassica napus. It is highly homologous to Arabidopsis LACS4 and thus designated as BnLACS4. The cloned gene BnLACS4 could complement a LACS-deficient yeast strain YB525. It is mainly expressed in flowers and developing seeds where lipid biosynthesis is at high rate in Brassica napus. When transiently expressed in tobacco leaves, BnLACS4 is localized in endoplasmic reticulum (ER), the common site for eukaryotic pathway of lipid biosynthesis. Expression of BnLACS4 in the yeast strain pep4 increased its lipid content. Taken together, our results suggest that BnLACS4 may be involved in lipid biosynthesis in B. napus.
- Published
- 2014
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24. The ecological impacts of lakewater calcium decline on softwater boreal ecosystems.
- Author
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Jeziorski, Adam and Smol, John P.
- Subjects
- *
CLADOCERA , *ECOLOGICAL impact , *ACIDIFICATION , *CALCIUM , *ECOSYSTEMS - Abstract
In recent decades, marked declines in calcium (Ca) concentrations have been noted in many softwater boreal lakes, and are believed to be a long-term consequence of acid deposition as well as other stressors (such as timber harvesting). Reduced Ca availability may act as a potent environmental stressor. Investigations of the direct ecological impacts of lower Ca concentrations in freshwater systems have largely focused on Ca-rich members of the Cladocera; however, a growing body of work, spanning several scientific fields, suggests Ca decline will have profound direct and indirect consequences for aquatic ecosystems. Here, we synthesize recent laboratory analyses and field surveys to provide an overview of these consequences, while highlighting paleolimnological investigations that provide some long-term perspective on the phenomenon. However, considerable questions remain regarding 'baseline' or pre-impact conditions, due to the accelerated leaching of Ca from watershed soils during the period of anthropogenic influence. Furthermore, catchment-specific differences in both leaching rates and the initial size of the Ca pool in watershed soils complicate determination of the eventual endpoints of the declines. Despite these uncertainties, persistent low Ca concentrations are anticipated to impede biological recovery from lake acidification, and that ongoing declines will have cascading effects throughout aquatic ecosystems due to the loss of vulnerable taxa. To better understand how reduced Ca availability will continue to change affected surface waters and how these changes will interact with other environmental stressors will require continued investigation of the declines from multiple scientific perspectives. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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25. Écologie fonctionnelle du phytoplancton des lacs tempérés et boréaux : le rôle des facteurs environnementaux sur les communautés nanophytoplanctoniques et la prévalence des stratégies d’acquisition de ressources alternatives
- Author
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Le Noac'h, Philippe
- Subjects
- Phytoplancton d'eau douce, Écologie, Distribution verticale, Nutrition, Communautés, Biodiversité, Compétition, Traits fonctionnels, Lacs, Amérique du Nord
- Abstract
La diversité des communautés nanoplanctoniques des lacs est contrôlée par une variété de facteurs biotiques et biotiques, y compris la compétition interspécifique pour les ressources. La diversité des communautés se maintient lorsque les taxons peuvent éviter l'exclusion compétitive, les taxons évitent l'exclusion compétitive s'ils peuvent atténuer la compétition interspécifique au sein de la communauté. En théorie, les taxons peuvent réduire la compétition en se séparant spatialement le long des gradients de ressources verticaux généralement présents dans les systèmes stratifiés. Certains taxons utilisent également des stratégies alternatives d’acquisition des ressources, en particulier la phago-mixotrophie, pour compléter leurs apports en carbone et en nutriments. Cependant, ces deux mécanismes ne sont pas bien étudiés dans les lacs. La structure physique des lacs contrôle la répartition spatiale du nanophytoplancton, et la diversité des communautés est déterminée par une variété de facteurs biotiques et abiotiques en plus de la compétition pour les ressources. Cela limite notre capacité à déterminer si la répartition verticale de la communauté affecte réellement la diversité dans les systèmes naturels. Notre compréhension de la phago-mixotrophie nanophytoplanctonique est également incomplète. D’un point de vue théorique, il n’est pas si évident qu’une stratégie généraliste comme la mixotrophie puisse être viable face à des phago-hétérotrophes et des photo-autotrophes spécialisés. Nous savons également peu de choses sur les facteurs biotiques et abiotiques qui façonnent les assemblages de stratégie de nutrition nanoplanctoniques dans les systèmes d'eau douce. L'objectif de cette thèse est donc d'approfondir notre compréhension des effets de ces processus sur l’assemblage des communautés. Dans le premier chapitre de cette thèse, nous avons étudié comment la répartition spatiale du nanophytoplancton contrôle la diversité taxonomique et fonctionnelle des communautés en conjonction avec la structure de stratification de la colonne d'eau et les interactions de prédations (c.a.d. le broutage par le zooplancton). Le niveau d’agrégation spatiale au sein de la communauté nanophytoplanctonique d'un lac stratifié a été modifié en perturbant sélectivement la structure thermique du lac. Des modèles en équations structurelles ont révélé que des niveaux accrus d’agrégation spatiale n'avaient pas d'effet détectable sur la diversité taxonomique et fonctionnelle de la communauté. L'effet de la compétition interspécifique induite par l'augmentation de l'agrégation spatiale sur la diversité de la communauté était marginal comparé à l'effet de la composition de la communauté zooplanctonique et à la stratification de la colonne d'eau. Dans une deuxième étude, nous avons testé la viabilité de la phago-mixotrophie nanoplanctonique en tant que stratégie d’acquisition des ressources du point de vue de la compétition pure pour les ressources. Nous avons développé un modèle mathématique de compétition spatiale entre trois stratégies nanoplanctoniques d'acquisition de ressources (phagotrophie pure, mixotrophie et phototrophie pure) et avons étudié les assemblages trophiques prédits par le modèle pour une variabilité des conditions de disponibilité en lumière et en nutriments. Nos résultats montrent qu'une stratégie de nutrition mixotrophique généraliste est viable face aux stratégies spécialisées et que le mixotrophe peut dominer la communauté s'il présente un équilibre fonctionnel mixotrophique adéquat. La position verticale des compétiteurs était également contrastée dans l'espace, et le mixotrophe peut se développer sur une plus grande partie de la colonne d'eau par rapport aux spécialistes. La variabilité fonctionnelle au sein du trait mixotrophe pourrait expliquer pourquoi les stratégies de nutrition alternatives sont omniprésentes dans les environnements aquatiques. Dans le dernier chapitre de cette thèse, nous avons analysé des données de composition de communautés nanophytoplanctoniques provenant de deux campagnes d’échantillonnage de lacs à grande échelle, l'EPA National Lake Assessment aux États-Unis et le projet du NSERC Canadian Lake Pulse Network au Canada. Après avoir évalué le potentiel de mixotrophie des divers genres de nanophytoplancton identifiés dans les deux enquêtes, nous avons estimé la prévalence de la mixotrophie dans des centaines de lacs grâce à des relevés de composition taxonomique. Les mixotrophes se sont avérés omniprésents dans les lacs d'Amérique du Nord, bien qu'ils ne soient pas distribués uniformément dans les écorégions échantillonnées. La disponibilité des nutriments est le principal moteur des assemblages de stratégies de nutrition nanophytoplanctoniques dans les eaux de surface, avec une prévalence plus élevée de mixotrophie dans les lacs plus oligotrophes. L'état trophique du lac contrôle également la composition et la diversité de la partie mixotrophe de la communauté. L'effet de la disponibilité de la lumière sur la prévalence de la mixotrophie est marginal comparé à l'effet de la disponibilité des nutriments. La répartition verticale des taxons et la mixotrophie sont des caractéristiques peu étudiées des communautés de nanophytoplancton dans les lacs, ces résultats sont donc des contributions importantes pour comprendre les mécanismes contrôlant l'assemblage de ces communautés dans les lacs. Ce travail a été conduit à l’aide d’une variété de méthodes numériques, de la modélisation mathématique mécaniste aux analyses multivariées approfondies de grands ensembles de données écologiques, soulignant l'importance des outils numériques pour les études écologiques. _____________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : écologie des communautés, nanoplancton, diversité, traits fonctionnels, phago-mixotrophie, gradients environnementaux
- Published
- 2023
26. Storm impacts on phytoplankton community dynamics in lakes
- Author
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Vijay P. Patil, Wim Thiery, Emily R. Nodine, Stephen J. Thackeray, Aleksandra M. Lewandowska, Alfred Theodore Nutefe Kwasi Kpodonu, Francesco Pomati, Maria Eugenia del Rosario Llames, Ruchi Bhattacharya, Tanner J. Williamson, Orlane Anneville, Patrick Venail, Cayelan C. Carey, Nico Salmaso, Marc J. Lajeunesse, Harriet L. Wilson, Josef Hejzlar, Lisette N. de Senerpont Domis, Jason D. Stockwell, B.W. Ibelings, Rita Adrian, Gaël Dur, R. Iestyn Woolway, James A. Rusak, Lars G. Rudstam, Peeter Nõges, Christian Torsten Seltmann, Pablo Urrutia-Cordero, Piet Verburg, Laurence Carvalho, Karsten Rinke, Dietmar Straile, Shin-ichiro S. Matsuzaki, Hans-Peter Grossart, Tamar Zohary, Marieke A. Frassl, Jonathan P. Doubek, Nasime Janatian, Mikkel René Andersen, University of Vermont [Burlington], Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Institute of Biology at the Department of Biology, Chemistry and Pharmacy, Free University of Berlin (FU), Centre Alpin de Recherche sur les Réseaux Trophiques et Ecosystèmes Limniques (CARRTEL), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Virginia Tech [Blacksburg], Netherlands Institute of Ecology (NIOO-KNAW), Netherlands Institute of Ecology - NIOO-KNAW (NETHERLANDS), Shizuoka University of Art and Culture (SUAC), Griffith University [Brisbane], State University of New York at Potsdam (SUNY Potsdam), State University of New York (SUNY), Tata Memorial Centre, Helmholtz Zentrum für Umweltforschung = Helmholtz Centre for Environmental Research (UFZ), Fdn Edmund Mach, IASMA Research and Innovation Centre, Limnological Institute, University of Konstanz, Konstanz, Germany, G17AC00044U.S. Geological SurveyNE/J024279/1Natural Environment Research CouncilFondation pour la Recherche sur la BiodiversiteG16AP00087Vermont Water Resources and Lake Studies CenterOIA-1556770U.S. National Science FoundationEF-1702506U.S. National Science FoundationCNS-1737424U.S. National Science FoundationICER-1517823U.S. National Science FoundationDEB-1753639U.S. National Science FoundationH2020-MSCA-ITN-2016MANTELPBA/FS/16/02Irish Government791812European UnionU.S. Department of StateCentre Alpin de Recherche sur les Reseaux Trophiques des Ecosystemes Limniques2017-06421Swedish Research Council, AKWA, Aquatic Ecology (AqE), Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Hydrology and Hydraulic Engineering, Biological stations, Marine Ecosystems Research Group, and Tvärminne Zoological Station
- Subjects
0106 biological sciences ,010504 meteorology & atmospheric sciences ,Biodiversity & Conservation ,Oceanografi, hydrologi och vattenresurser ,01 natural sciences ,Oceanography, Hydrology and Water Resources ,Water column ,ddc:550 ,functional traits ,watershed ,General Environmental Science ,ddc:333.7-333.9 ,DIFFERENT CLIMATIC CONDITIONS ,changement climatique ,Global and Planetary Change ,Plan_S-Compliant-TA ,Ecology ,SPECIES-DIVERSITY ,Research Review ,lacs ,tempête ,climate change ,Oceanography ,WATER-QUALITY ,WIND-EXPOSED LAKE ,International ,1181 Ecology, evolutionary biology ,articles ,Biodiversity Conservation ,climate change, environmental disturbance, extreme events, functional traits, mixing, nutrients, stability, watershed ,Life Sciences & Biomedicine ,extreme events ,Biogeochemical cycle ,environmental disturbance ,mixing ,nutrients ,stability ,Storms ,Climate Change ,Climate change ,Environmental Sciences & Ecology ,010603 evolutionary biology ,Ecology and Environment ,Extreme weather ,Rivers ,Settore BIO/07 - ECOLOGIA ,ddc:570 ,Phytoplankton ,Environmental Chemistry ,DISSOLVED ORGANIC-CARBON ,CYANOBACTERIAL BLOOM FORMATION ,Ecosystem ,0105 earth and related environmental sciences ,Functional ecology ,Science & Technology ,LARGE SHALLOW LAKE ,phytoplancton ,nutriment ,Storm ,15. Life on land ,Lakes ,Invited Research Review ,FUNCTIONAL TRAITS ,13. Climate action ,Environmental science ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,THERMAL STRATIFICATION ,Surface runoff ,Environmental Sciences - Abstract
In many regions across the globe, extreme weather events such as storms have increased in frequency, intensity, and duration due to climate change. Ecological theory predicts that such extreme events should have large impacts on ecosystem structure and function. High winds and precipitation associated with storms can affect lakes via short‐term runoff events from watersheds and physical mixing of the water column. In addition, lakes connected to rivers and streams will also experience flushing due to high flow rates. Although we have a well‐developed understanding of how wind and precipitation events can alter lake physical processes and some aspects of biogeochemical cycling, our mechanistic understanding of the emergent responses of phytoplankton communities is poor. Here we provide a comprehensive synthesis that identifies how storms interact with lake and watershed attributes and their antecedent conditions to generate changes in lake physical and chemical environments. Such changes can restructure phytoplankton communities and their dynamics, as well as result in altered ecological function (e.g., carbon, nutrient and energy cycling) in the short‐ and long‐term. We summarize the current understanding of storm‐induced phytoplankton dynamics, identify knowledge gaps with a systematic review of the literature, and suggest future research directions across a gradient of lake types and environmental conditions., Our understanding of ecosystem‐scale responses to storm events is fragmented, and terminological variability in defining a “storm” hinders resolution of generalizable impacts. We provide a comprehensive synthesis of the interactions between physical properties and biological responses in lakes that demonstrates the context‐dependency of storm impacts; lake/watershed attributes and their antecedent conditions mediate the extent to which storms impact lake ecosystems. We develop a framework which conceptualizes how abrupt, storm‐induced changes in the lake environment influence phytoplankton community dynamics through functional traits, identifies current limitations, and highlights several avenues of research to narrow knowledge gaps in synthetic and interdisciplinary ways.
- Published
- 2020
- Full Text
- View/download PDF
27. Engager les pratiquants de loisirs dans la gestion des invasions biologiques : une co-production territoriale
- Author
-
Jeoffrey Dehez
- Subjects
outdoor recreation ,stakeholder coordination ,loisirs de nature ,General Earth and Planetary Sciences ,biological invasion ,lacs ,lake ,invasions biologiques ,General Environmental Science ,coordination d’acteurs - Abstract
Engager les pratiquants de loisirs dans la gestion du milieu naturel suppose d’être en capacité d’imaginer des modes de coordination adéquats, jusqu’à présent plutôt conçus par et pour les experts de la profession. Dans cet article, nous proposons de réfléchir à cette question à partir du cas des plantes aquatiques invasives, en étudiant les dispositifs mis en place sur les lacs Aquitains, dans le Sud Ouest de la France. Nous abordons ces dispositifs comme des processus de co-production territoriale, grâce à des outils d’analyse empruntés à l’économie des services. Nous montrons que les expérimentations ayant réussi à impliquer des pratiquants valorisent tout d’abord leurs compétences opérationnelles et relationnelles, et assez peu (voire pas) expertes. Ces formes d’actions collectives sont autant conditionnées par les plantes que par les supports sur lesquels celles-ci se développent. Dans ce contexte, l’implication des pratiquants de loisirs va largement contribuer à façonner la nature des actions mises en place et, par ce fait, conférer une dimension territoriale à la gestion. Ce processus s’accompagne néanmoins d’une tendance à la micro-localisation des tâches, ainsi que d’une certaine spécialisation des responsabilités, finalement assez peu compatibles avec les dynamiques spatiales des plantes, et que seuls les techniciens et les gestionnaires traditionnels de l’espace semblent en mesure de dépasser. Ces premières initiatives n’en conservent pas moins un caractère pionnier, véritable source d’inspiration pour de futures expériences de gestion participative. Involving recreational users in the management of environmental issues implies imagining new modes of cooperative actions, which have been built for professional managers. In this article, we propose to reflect on this question from the case of invasive aquatic plants on the shore lakes of Aquitaine in South Western France. We analyze these collective actions as territorial coproduction processes, relying on service economics analytical tools. We show that the collective actions that have succeeded in involving outdoor recreationists value first their operational and relational skills and rather little (if any) expertise. These actions are strongly conditioned by the type of support where the plants develop, at least as much as by the plants on which they are supposed to intervene. The involvement of recreational users will largely contribute to shaping the nature of the collective action and, as a result, add a territorial dimension. However, such a process favours the micro-localization of operations and responsibilities specialization. The latter is not adapted to the spatial dynamics of the plants. Technicians and traditional managers currently seem to be the only ones to overcome such difficulties. Neverthelss, these first initiatives are pioneering in character and a trustworthy source of inspiration for future experiments in participatory management.
- Published
- 2022
28. Transcatheter aortic valve implantation under conscious sedation – the first Indian experience
- Author
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Syed Maqbool, Vijay Kumar, Vishal Rastogi, and Ashok Seth
- Subjects
TAVI ,SAVR ,LACS ,Surgery ,RD1-811 ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Transcatheter aortic valve implantation (TAVI) is maturing strongly as an alternative to surgical aortic valve replacement (SAVR) in patients who are inoperable/high risk for open heart surgery. General anesthesia (GA) is the usual mode of anesthesia in these patients, but local anesthesia with conscious sedation (LACS) has recently been described as a safe alternative with some added advantages. We report 2 cases who were unfit for GA and were done successfully under LACS.
- Published
- 2014
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- View/download PDF
29. Longer Duration of Active Oil Biosynthesis during Seed Development Is Crucial for High Oil Yield—Lessons from Genome-Wide In Silico Mining and RNA-Seq Validation in Sesame
- Author
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Bhagwat Nawade, Ajay Kumar, Rasna Maurya, Rajkumar Subramani, Rashmi Yadav, Kuldeep Singh, and Parimalan Rangan
- Subjects
Ecology ,Plant Science ,longer duration ,early onset ,sesame ,oil biosynthesis ,Kennedy pathway ,ACCase ,KAS ,SAD ,FAD ,LACS ,DGAT ,LPAAT ,Ecology, Evolution, Behavior and Systematics - Abstract
Sesame, one of the ancient oil crops, is an important oilseed due to its nutritionally rich seeds with high protein content. Genomic scale information for sesame has become available in the public databases in recent years. The genes and their families involved in oil biosynthesis in sesame are less studied than in other oilseed crops. Therefore, we retrieved a total of 69 genes and their translated amino acid sequences, associated with gene families linked to the oil biosynthetic pathway. Genome-wide in silico mining helped identify key regulatory genes for oil biosynthesis, though the findings require functional validation. Comparing sequences of the SiSAD (stearoyl-acyl carrier protein (ACP)-desaturase) coding genes with known SADs helped identify two SiSAD family members that may be palmitoyl-ACP-specific. Based on homology with lysophosphatidic acid acyltransferase (LPAAT) sequences, an uncharacterized gene has been identified as SiLPAAT1. Identified key regulatory genes associated with high oil content were also validated using publicly available transcriptome datasets of genotypes contrasting for oil content at different developmental stages. Our study provides evidence that a longer duration of active oil biosynthesis is crucial for high oil accumulation during seed development. This underscores the importance of early onset of oil biosynthesis in developing seeds. Up-regulating, identified key regulatory genes of oil biosynthesis during early onset of seed development, should help increase oil yields.
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- 2022
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30. Gestion des débits d'un barrage en milieu urbanisé.
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Roy-Gosselin, Philippe-Hubert, Chouinard, Bastien, Morse, Brian, and Pelletier, Geneviève
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- *
DAMS , *RESERVOIRS , *SEDIMENTATION & deposition , *WATERSHED management , *DISSOLVED oxygen in water , *SIMULATION methods & models - Abstract
The Joseph-Samson Dam is located on the St. Charles River near the confluence with the St. Lawrence River in the Lower Town of Quebec City. The dam creates a 3.7 km long reservoir, with a very popular linear park running alongside. This water body has esthetic value and allows recreational boating. With its anti-tidal gates, the dam protects from flooding during very high spring tides in the St. Lawrence. However, the dam has completely changed the formerly natural estuary into a channel with sedimentation formed from the organic and inorganic sediment influx coming from the semi-urban, urban and forest watershed. Highly productive fish runs up the St. Charles are a thing of the past and significant reduction in dissolved oxygen is now often observed. Furthermore, the dam may actually increase the risk of flooding in the Lower Town under high flows. One-dimensional simulations (HEC-RAS) were performed to assess the dam's impact on flood risks for different bottom gate settings and two-dimensional simulations (RIVER 2D) were performed to assess the dam's impact on river velocities and sedimentation processes. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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31. Déterminants de l'expression du polymorphisme associé aux ressources chez l'omble de fontaine, Salvelinus Fontinalis, dans les lacs du Bouclier laurentien.
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Rainville, Vincent and Rainville, Vincent
- Published
- 2021
32. Water column gradients beneath the summer ice of a High Arctic freshwater lake as indicators of sensitivity to climate change
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Bégin, Paschale Noël, Culley, Alexander, Vincent, Warwick F., Bégin, Paschale Noël, Culley, Alexander, and Vincent, Warwick F.
- Abstract
Ice cover persists throughout summer over many lakes at extreme polar latitudes but is likely to become increasingly rare with ongoing climate change. Here we addressed the question of how summer ice-cover affects the underlying water column of Ward Hunt Lake, a freshwater lake in the Canadian High Arctic, with attention to its vertical gradients in limnological properties that would be disrupted by ice loss. Profiling in the deepest part of the lake under thick mid-summer ice revealed a high degree of vertical structure, with gradients in temperature, conductivity and dissolved gases. Dissolved oxygen, nitrous oxide, carbon dioxide and methane rose with depth to concentrations well above air-equilibrium, with oxygen values at >150% saturation in a mid water column layer of potential convective mixing. Fatty acid signatures of the seston also varied with depth. Benthic microbial mats were the dominant phototrophs, growing under a dim green light regime controlled by the ice cover, water itself and weakly colored dissolved organic matter that was mostly autochthonous in origin. In this and other polar lakes, future loss of mid-summer ice will completely change many water column properties and benthic light conditions, resulting in a markedly different ecosystem regime.
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- 2021
33. Water column gradients beneath the summer ice of a High Arctic freshwater lake as indicators of sensitivity to climate change
- Author
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Culley, Alexander, Bégin, Paschale Noël, Vincent, Warwick F., Culley, Alexander, Bégin, Paschale Noël, and Vincent, Warwick F.
- Abstract
Ice cover persists throughout summer over many lakes at extreme polar latitudes but is likely to become increasingly rare with ongoing climate change. Here we addressed the question of how summer ice-cover affects the underlying water column of Ward Hunt Lake, a freshwater lake in the Canadian High Arctic, with attention to its vertical gradients in limnological properties that would be disrupted by ice loss. Profiling in the deepest part of the lake under thick mid-summer ice revealed a high degree of vertical structure, with gradients in temperature, conductivity and dissolved gases. Dissolved oxygen, nitrous oxide, carbon dioxide and methane rose with depth to concentrations well above air-equilibrium, with oxygen values at >150% saturation in a mid water column layer of potential convective mixing. Fatty acid signatures of the seston also varied with depth. Benthic microbial mats were the dominant phototrophs, growing under a dim green light regime controlled by the ice cover, water itself and weakly colored dissolved organic matter that was mostly autochthonous in origin. In this and other polar lakes, future loss of mid-summer ice will completely change many water column properties and benthic light conditions, resulting in a markedly different ecosystem regime.
- Published
- 2021
34. La connectivité hydrologique comme vecteur de la composition et de la production des communautés de zooplancton dans les lacs et les étangs d’eau douce du Sud de l’Île Victoria, Nunavut
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Blackburn-Desbiens, Pénélope and Blackburn-Desbiens, Pénélope
- Abstract
Les paysages arctiques se caractérisent par la présence de nombreux lacs et étangs. Avec l’augmentation des températures annuelles moyennes en raison des changements climatiques, plusieurs perturbations sont attendues pour ces masses d'eau, notamment au niveau de leur connectivité hydrologique et leur l'écologie. Nous avons échantillonné 22 lacs hydrologiquement reliés et 13 lacs isolés pour l'abondance, la biomasse et la production de zooplancton près de Cambridge Bay, Nunavut (69' 07'00.71''N; 105' 03'34.85''W) dans le but de déterminer dans quelle mesure la connectivité hydrologique par rapport aux caractéristiques environnementales spécifiques au lac (nutriments, carbone organique dissous, chlorophylle-a, température, conductivité, profondeur, superficie) ont expliqué la composition, l'abondance et la production des communautés de zooplancton qui sont essentielles pour les niveaux trophiques supérieurs comme les poissons. Les lacs hydrologiquement reliés allaient de lacs situés en amont, à des lacs collecteurs fortement interconnectés recevant l'eau de 1 à 765 lacs. Les communautés de zooplancton dans les systèmes étudiés étaient plus similaires dans les lacs proches les uns des autres et différaient significativement des communautés dans les systèmes hydrologiquement isolés. Dans les systèmes isolés, la distance entre les plans d'eau ne contribuait pas à la similarité entre les communautés. Au total, 81 espèces de zooplancton ont été trouvées dont 57 rotifères, 9 copépodes, 11 cladocères, deux crevettes arctiques, un mysidacé et une crevette têtard. La richesse en espèces entre les lacs connectés et isolés n'était pas différente, respectivement de 63 et 61 espèces. Au total, vingt espèces étaient uniques aux lacs connectés et 17 aux lacs isolés. L'abondance du zooplancton était plus élevée dans les lacs connectés (255 ind L-1 dans les lacs connectés contre 65 ind L-1 dans les systèmes isolés). Cela était dû au nombre plus élevé de rotifères qui représentaient p
- Published
- 2021
35. Introduction : les lacs au prisme des sciences humaines et sociales
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Mélanie Duval, Alice Nikolli, Christophe Gauchon, Environnements, Dynamiques et Territoires de la Montagne (EDYTEM), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), coordinateurs : Alice Nikolli, Mélanie Duval et Christophe Gauchon, and duval, mélanie
- Subjects
[SDE] Environmental Sciences ,[SHS.GEO] Humanities and Social Sciences/Geography ,[SDE]Environmental Sciences ,[SHS] Humanities and Social Sciences ,lacs ,[SHS.GEO]Humanities and Social Sciences/Geography ,usages ,ComputingMilieux_MISCELLANEOUS ,aménagements ,accessibilité ,tourisme ,sociétés ,[SHS]Humanities and Social Sciences - Abstract
International audience
- Published
- 2021
36. Carbon budgets of boreal lakes: state of knowledge, challenges, and implications.
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Anas, M.U. Mohamed, Scott, Kenneth A., and Wissel, Björn
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- *
CARBON cycle , *BIOLOGICAL transport , *ECOSYSTEMS , *ENVIRONMENTAL protection , *BIOGEOCHEMICAL cycles - Abstract
Converging evidence suggests that freshwater systems play an important role in the carbon cycles at both regional and global scales. In addition, there are serious concerns that ongoing and future changes to the environment could alter these dynamics. This is particularly important in the boreal forest biome, which contains a very high density of lakes. In this review, we synthesize the current state of research to provide a critical overview of ( i) the role of boreal lakes as emitters versus sinks of carbon, ( ii) their contribution to the regional carbon balance, ( iii) knowledge gaps that may inhibit an accurate evaluation of the role of boreal lakes in a landscape context, and ( iv) impacts of environmental perturbations on carbon dynamics in boreal lakes. Several recent studies indicate that boreal lakes are actively processing, emitting, and storing carbon rather than being passive transport conduits. Yet, generalizing the role of lake ecosystems for the overall carbon balance of the boreal forest biome is challenging because of the scarcity of studies on lake carbon budgets in a landscape context that can capture the potential temporal and spatial variability and uncertainties associated with the available estimates of carbon pools and fluxes. Further, environmental perturbations, such as climate change, acidic deposition, and nutrient enrichment, likely affect both carbon export to lakes and in-lake carbon processing in boreal regions. Predicting their overall impacts on lake carbon budgets is particularly difficult, not only because individual environmental stressors likely affect multiple processes involved in carbon cycling, but also because often multiple stressors act synergistically or antagonistically at the landscape level. Accordingly, long-term, system-wide approaches are required to accurately evaluate the importance of lakes for boreal carbon budgets in a changing environment. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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37. Discovery of Living Populations of a Purported Fossil Diatom: Aulacoseira scalaris from Two Lakes in the Vosges Mountains (France).
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Heudre, David, Moreau, Laura, Wetzel, Carlos E., and Ector, Luc
- Subjects
- *
FOSSIL diatoms , *ALGAL populations , *CLASSIFICATION of algae , *WATERSHEDS - Abstract
Dans le cadre du Programme de Surveillance répondant à la Directive européenne Cadre sur l'Eau, un suivi du phytoplancton des plans d'eau de plus de 50 hectares est réalisé dans le bassin Rhin-Meuse. C'est lors de ce suivi que la diatomée centrique Aulacoseira scalaris (Grunow in Van Heurck) Houk, Klee & Passauer a été identifiée dans les lacs de Longemer en 2010 (Xonrupt-Longemer, France) et de Gérardmer en 2011 (Gérardmer, France). Sa présence a été à nouveau détectée dans les échantillons prélevés en 2014 sur ces deux lacs. Aulacoseira scalaris n'avait été jusqu'à présent trouvée que dans des échantillons fossiles à subfossiles des U.S.A. (État de l'Oregon, et Virginia City de l'État du Nevada) et de France (Lac de Gérardmer, Vosges, France). Cette espèce ayant été retrouvée vivante dans le phytoplancton de ces deux lacs des Vosges, elle ne doit plus être considérée comme uniquement une diatomée fossile. Des informations sur son autécologie sont proposées grâce aux données physicochimiques des deux lacs, et sa morphologie est comparée avec les espèces d' Aulacoseira semblables présentes dans la littérature. As a part of the Monitoring Program of the European Water Framework Directive, the phytoplankton of water bodies over 50 hectares have been studied in the Rhine-Meuse river basin. During the analysis, the centric diatom Aulacoseira scalaris (Grunow in Van Heurck) Houk, Klee & Passauer was identified from Longemer Lake in 2010 (Xonrupt-Longemer, France) and Gérardmer Lake in 2011 (Gérardmer, France). The presence of this diatom was again confirmed in samples collected in 2014 from both lakes. Interestingly, Aulacoseira scalaris until recently has been found only in fossil to subfossil materials from U.S.A. (State of Oregon and Virginia City, State of Nevada) and France (Vosges Mountains, Gérardmer Lake). The species has been observed for the first time in live material and should no longer be considered as strictly fossil or subfossil. Information on its autecology is provided using the physicochemical data of the lakes, and its morphology is compared with similar species of Aulacoseira in available literature. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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38. Diverse galactooligosaccharides consumption by bifidobacteria: implications of β-galactosidase--LacS operon.
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Takuya Akiyama, Kazumasa Kimura, and Hiroshi Hatano
- Subjects
- *
BIFIDOBACTERIUM , *PREBIOTICS , *OPERONS , *MEMBRANE proteins , *GALACTOSIDASES - Abstract
The article discusses the contribution of an operon consisted of LacS symporter, integral membrane protein, and β-galactosidase to bifidobacterial galactooligosaccharides (GOS), a prebiotics, consumption. Topics discussed include analysis of GOS consumption by 14 bifidobacterial strains; transcription analysis of GOS consumer; and the growth of bifidobacteria on GOS.
- Published
- 2015
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39. Comparison of hand-assisted laparoscopic surgery and conventional laparotomy for colorectal cancer: Interim results from a single institution.
- Author
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TAKAYUKI TAJIMA, MASAYA MUKAI, MASASHI YAMAZAKI, SHIGEO HIGAMI, SOUICHIROU YAMAMOTO, SAYURI HASEGAWA, EIJI NOMURA, SOTARO SADAHIRO, SEIEI YASUDA, and HIROYASU MAKUUCHI
- Subjects
- *
COLON cancer patients , *ABDOMINAL surgery , *LAPAROSCOPIC surgery , *CANCER relapse - Abstract
The present study aimed to compare the results of hand-assisted laparoscopic surgery (HALS) and conventional laparotomy (CL) at a single institution in Japan. Of the 212 patients with stage I/II/III colorectal cancer who received a curative resection, 98 patients underwent HALS and 114 patients underwent CL. The clinical background and post-operative management did not differ between the two groups. There were no significant differences in the 3-year relapse-free and 3-year overall survival rates between the HALS and CL groups for the patients in any stage. Blood loss during surgery was 250.1 and 135.5 ml (mean and median; the same hereafter) in stage I patients receiving HALS versus 608.2 and 315.5 ml in stage I CL patients (P=0.006), while it was 277.6 and 146 ml in stage II patients receiving HALS versus 548.6 and 347 ml in stage II CL patients (P=0.004). Post-operative hospital stay was recorded at 16.8 and 15 days in stage III patients receiving HALS versus 23.1 and 21 days in stage III CL patients (P=0.001). There were no significant differences in the operating time or complications between the two groups. These results indicate that the survival rate was comparable for HALS and CL, while HALS caused less surgical stress and achieved a better cosmetic outcome. The results of the final analysis of this cohort are awaited. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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40. Jointly thinking the post-dam future: exchange of local and scientific knowledge on the lakes of the Lower Rufiji, Tanzania.
- Author
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Duvail, S., Mwakalinga, A.B., Eijkelenburg, A., Hamerlynck, O., Kindinda, K., and Majule, A.
- Subjects
- *
LAKES , *FLOODPLAINS , *WATER levels , *WATER balance (Hydrology) , *SCIENTIFIC knowledge ,STIEGLER'S Gorge Dam (Tanzania) - Abstract
A large dam is planned at Stiegler’s Gorge in Tanzania. The change in the Rufiji River flood pattern will affect downstream ecosystems. This paper concentrates on the highly productive floodplain lakes that play a vital role in local livelihoods. A participatory monitoring system with village-based observers collected water level, rainfall, fisheries and food data from 2001 to 2011. Water balances of the lakes show dependence on the Rufiji River flood, with varying vulnerability. With the dam design flood of 2500 m3 s-1, lakes with a high threshold and small catchment will dry out quickly. Lakes with a lower threshold and substantial catchment are more robust but may still dry out during prolonged local drought. Analysis of rainfall (1923–2012) indicates a recent decrease. The data were analysed through feedback workshops with local observers, government technical staff and researchers. Through this collaborative approach, local capacity in preparing for the post-dam future was enhanced.Editor D. Koutsoyiannis; Guest editor M. AcremanCitation Duvail, S., Mwakalinga, A.B., Eijkelenburg, A., Hamerlynck, O., Kindinda, K., and Majule, A., 2014. Jointly thinking the post-dam future: exchange of local and scientific knowledge on the lakes of the Lower Rufiji, Tanzania. Hydrological Sciences Journal, 59 (3–4), 713–730. [ABSTRACT FROM PUBLISHER]
- Published
- 2014
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41. Méthodes de Monte-Carlo pour estimer l'incertitude associée à l'utilisation des indices multimétriques prédictifs
- Author
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Christine Argillier, Anthony Maire, Maxime Logez, Risques, Ecosystèmes, Vulnérabilité, Environnement, Résilience (RECOVER), Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), POLE HYDROECOLOGIE DES PLANS D'EAU AIX EN PROVENCE FRA, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), EDF (EDF), and European Project: 0226273(2002)
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0106 biological sciences ,Index (economics) ,Monte Carlo method ,BIOINDICATION ,General Decision Sciences ,010501 environmental sciences ,Expected value ,010603 evolutionary biology ,01 natural sciences ,Statistics ,DCE ,14. Life underwater ,LACS ,Ecology, Evolution, Behavior and Systematics ,0105 earth and related environmental sciences ,Mathematics ,Ecology ,EVALUATION ÉCOLOGIQUE ,INDICE MULTIMÉTRIQUE ,Sampling (statistics) ,Statistical model ,Water Framework Directive ,[SDE]Environmental Sciences ,Probability distribution ,Metric (unit) ,POISSON - Abstract
[Departement_IRSTEA]Eaux [TR1_IRSTEA]QUASARE [ADD1_IRSTEA]Systèmes aquatiques soumis à des pressions multiples; International audience; The publication of the Water Framework Directive by the European commission in 2000 has promoted the development of many multimetric biological indices to assess the ecological status of European waterbodies. These ecological assessments are based on the measurement of deviations between a metric's (characteristic of assemblages) observed values (obtained by sampling) and a metric's expected values in the absence of anthropogenic stressors (reference conditions). In addition, the confidence in the ecological status evaluation provided by the different biological indices is required. Numerous sources of uncertainty due to sampling variability or operator bias, for example, are often considered on observed metric values, whereas uncertainty associated with expected metric values are seldom discussed. In this study, we developed a methodology based on Monte-Carlo methods to assess the uncertainty associated with the establishment of reference values for multimetric predictive indices. This was done by randomly generating reference values and propagating the uncertainty throughout the computation of the index. This methodology can be applied to a wide variety of indices as long as it is possible to make assumptions about the statistical distributions of some of the index's numerical components (e.g. coefficients of the statistical models, metric values). The European Lake Fish Index was used to illustrate the methodology and show how this method can provide valuable information on the confidence in the ecological status defined by the index. These results also revealed that the degree of uncertainty varied between the ecological classes, which were highest for the "Moderate" class and lowest for the "Poor" and "High" classes for the ELFI.
- Published
- 2019
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42. Les lacs d’Hanoï, quelle place pour une pièce urbaine endémique ?
- Author
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Martin Jaillais Neliaz
- Subjects
Social Sciences ,lacs ,espace public ,public space ,geography ,géographie ,Hanoi ,lakes ,General Earth and Planetary Sciences ,urbain ,urban ,Hanoï ,General Environmental Science - Abstract
La ville de Hanoï s’est établie au sein d’un réseau hydrographique complexe : la plaine du delta du fleuve Rouge, un entremêlement de rivières offrant voies de communication et remparts naturels. Ce réseau s’est complexifié́ avec sa domestication par l’homme : un système de digues protégeant les villes des crues des fleuves, et la constitution de nombreux lacs et cours d’eau pour temporiser et d’évacuer les pluies. Ces lacs jouent un rôle important, à la fois technique, en luttant contre les risques d’inondation, mais aussi culturel, en déterminant l’emplacement de la ville et de nombreux édifices spirituels. À ces deux fonctions s’ajoute, au début du xxe siècle, celle de l’espace public : leurs réaménagements sont planifiés à l’échelle de la ville, pour en faire de véritables parcs et jardins créés durant la période coloniale, ou aménagés après l’indépendance. À partir des années 1992, avec le développement intense de l’urbanisation de la capitale, la qualité de ces lacs se dégrade. Ceux-ci deviennent parfois un obstacle, et sont asséchés par la construction de nouvelles infrastructures de transport, ou la réalisation de grandes opérations immobilières… Seuls les principaux lacs du centre-ville sont préservés. Les autres, plus modestes, sont grignotés. Face aux enjeux contemporains, les lacs ont pourtant un rôle et un potentiel remarquable. Corridors écologiques à l’échelle de la ville, espaces publics de proximité dans un îlot dense d’habitations, ils sont primordiaux pour pérenniser l’infiltration de la nature en ville et la conservation d’espaces continus de verdure, permettant de lutter plus durablement contre les effets de microclimat urbain, et d’îlots de chaleur. Ils doivent être intégrés et mieux pris en compte dans les réflexions urbaines, et représenter un véritable angle d’approche pour l’aménagement de la ville et de quartiers. The city of Hanoi was established within the complex hydrographic network of the Red River Delta plain, a web of rivers providing transport routes and natural boundaries. This network became more complex with its domestication: a system of dikes protecting built-up areas from river floods and the creation of many lakes and rivers to delay and evacuate rainfall runoff. These lakes play an important role technically against flood risks and culturally in determining the location of the city as well as that of many religious buildings. In addition to these two functions the lakes started to play a role as public spaces in the beginning of the 20th century with their redevelopment which was planned throughout the city. Some of them were included in the development of city parks and gardens during the colonial period and others were developed after the country’s independence. From 1992, with the intense urbanization of the capital the quality of these lakes deteriorated. If they presented obstacles, they were dried up to make way for new transport infrastructures or to enable the completion of major real estate operations. Only the main lakes in the city centre were preserved. Others smaller lakes were gradually encroached upon. Faced with contemporary challenges, however, these lakes play a remarkable role and have great potential. As ecological corridors for the city and local public spaces within a dense residential area they are essential in sustaining the infiltration of nature within the city and the conservation of uninterrupted green spaces, making it possible to fight more sustainably against the effects of urban micro-climates and heat islands. There is a need to take them into account and better integrate them within local and city-wide urban planning and development projects.
- Published
- 2020
43. La région des lacs de Kurtna : un joyau naturel sujet aux pressions anthropiques
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Marko Vainu, Jaanus Terasmaa, and Quentin Choffel
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extraction de schistes bitumineux ,formation de sulfures ,Isoetes lacustris ,découpe de tourbe ,lacs ,General Medicine ,extraction d’eau souterraine ,Estonie ,Lobelia dortmanna ,influence anthropique ,changement des niveaux d’eau ,Directive Habitats ,afflux d’eau souterraine - Abstract
La région des lacs de Kurtna, située dans le nord-est de l’Estonie, compte le plus grand nombre de lacs par km2 du pays : 38 lacs naturels sur une superficie de 30 km2. Cette zone unique a subi une forte influence anthropique au milieu du 20e siècle et cette influence est encore d’actualité. L’extraction de schiste bitumineux, de sable et de tourbe, le captage d’eau souterraine et d’eau de surface : tout cela a affecté les lacs de la région. Les niveaux d’eau des lacs ont baissé, la chimie des lacs et, par conséquent, les écosystèmes lacustres, se sont transformés. Pour certains lacs, les effets ont été plus importants, tandis que pour d’autres, presque aucun changement ne s’est fait ressentir. En 1987, une zone de protection du paysage a été créée, mais cela n’a pas résolu les problèmes. La région des lacs comptait auparavant cinq lacs d’eau claire rares à faible teneur en nutriments et en minéraux (L. Valgejärv, L. Liivjärv, L. Ahnejärv, L. Martiska, L. Kuradijärv). Aujourd’hui, la plupart d’entre eux ont subi un processus d’eutrophisation, dû à la baisse du niveau de l’eau, mais le lac Valgejärv, avec ses communautés végétales uniques préservées, est toujours considéré comme l’un des lacs les plus précieux sur le plan écologique en Estonie. La région des lacs compte également le seul lac sidérotrophe (riche en fer) d’Estonie, le lac Räätsma. Les lacs Nõmmejärv et Konsu ont vu leur régime hydrique changer de façon considérable. Le lac Nõmmejärv reçoit l’afflux d’eau minière riche en sulfates, et le lac Konsu a été transformé en réservoir d’eau de surface pour une usine de traitement du schiste bitumineux. Le lac Kihljärv, en revanche, s’est effectivement asséché au cours des dernières années. Dans le même temps, le pittoresque lac Saarejärv n’a, quant à lui, pas subi de transformation majeure. Par conséquent, la région des lacs de Kurtna est une zone de forts contrastes : elle a conservé une partie de son état originel, soit une nature vierge, et il s’agit en partie d’un triste exemple de consommation excessivement avide des ressources naturelles.
- Published
- 2018
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44. Les territoires limniques estoniens : une originalité baltique ?
- Author
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Pascal Bartout
- Subjects
Baltique ,territoire limnique ,lacs ,General Medicine ,Estonie ,géographie - Abstract
Lieu de présence des principaux lacs européens par leur superficie, l’espace limnique baltique ne peut pour autant pas se résumer à ses dizaines de lacs d’ampleur continentale car il abrite des dizaines de milliers de lacs morainiques, thermokarstiques et autres plans d’eau artificiels. Au travers d’approches limnosystémiques et limnorégionales, des dimensions temporelles, spatiales et anthroposystémiques, l’auteur s’attache à cadrer les 5 articles présents dans cette sous-partie thématique et questionne les territoires limniques estoniens au prisme de leurs indicateurs d’empreinte limnique.
- Published
- 2018
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45. Effects of bark beetle disturbance on soil nutrient retention and lake chemistry in glacial catchment
- Author
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Oulehle, Filip, Couture, Raoul-Marie, Wright, Richard F., Svoboda, Miroslav, Bače, Radek, Matĕjka, Karel, Kaňa, Jiří, Hruška, Jakub, Kopáček, Jiří, Oulehle, Filip, Couture, Raoul-Marie, Wright, Richard F., Svoboda, Miroslav, Bače, Radek, Matĕjka, Karel, Kaňa, Jiří, Hruška, Jakub, and Kopáček, Jiří
- Abstract
Forest ecosystems worldwide are subjected to human-induced stressors, including eutrophication and acidification, and to natural disturbances (for example, insect infestation, windstorms, fires). The occurrence of the later is expected to increase due to the ongoing climate change. These multi-stressor forcings modify ecosystem biogeochemistry, including the retention of limiting nutrients, with implications for terrestrial and aquatic biodiversity. Here we present whole ecosystem nutrient (N, Ca, Mg, K) mass balances in the forested catchment of Plešné Lake, CZ, which has undergone transient changes linked to the recovery from anthropogenic acidification and to the forest disturbances caused by severe infestations by the bark beetle (Ips typographus). Measured fluxes and storage of nutrients in the lake-catchment ecosystem were used to constrain the process-oriented biogeochemical model MAGIC (Model of Acidification of Groundwater In Catchments). Simulated lake water chemistry and changes in soil nutrient pools fitted observed data and revealed that (1) the ecosystem N retention declined, thus nitrate leaching increased for 10 years following the bark beetle disturbance, with transient adverse effects on the acid–base status of lake water, (2) the kinetics of nutrient mineralisation from decaying biomass coupled with nutrient immobilisation in regrowing vegetation constrained the magnitude and duration of ecosystem losses of N, Ca and Mg, (3) the excess of mineralised base cations from decomposing biomass replenished the soil cation exchange matrix, which led to increased soil base saturation, and (4) the improvement of the catchment soil acid–base status led to an increase of lake water pH and acid neutralising capacity. Forested ecosystems underlain by nutrient-poor soils and bedrock are prone to human-induced damages caused by acidification and eutrophication, and any natural disturbance may further lead to nutrient imbalances. We demonstrated that in this natur
- Published
- 2020
46. Distribution of subfossil ostracod assemblages in lacustrine profundal sediments of north-eastern Poland.
- Author
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Namiotko, Tadeusz, Namiotko, Lucyna, and Wysocka, Anna
- Subjects
OSTRACODA ,ARCHAEOLOGICAL assemblages ,LAKE hydrology ,SEDIMENTS ,EUTROPHICATION - Abstract
Copyright of Revue de Micropaleontologie is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2012
- Full Text
- View/download PDF
47. Extreme ecosystems and geosystems in the Canadian High Arctic: Ward Hunt Island and vicinity.
- Author
-
VINCENT, Warwick F., FORTIER, Daniel, LÉVESQUE, Esther, BOULANGER-LAPOINTE, Noémie, TREMBLAY, Benoît, SARRAZIN, Denis, ANTONIADES, Dermot, and MUELLER, Derek R.
- Abstract
Copyright of Ecoscience (Ecoscience) is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2011
- Full Text
- View/download PDF
48. Acidic calcium stores of Saccharomyces cerevisiae.
- Author
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Cunningham, Kyle W.
- Subjects
SACCHAROMYCES cerevisiae ,FUNGAL cell walls ,LYSOSOMES ,CALMODULIN ,CALCIUM ions ,EFFECT of calcium on plants ,CELL physiology - Abstract
Abstract: Fungi and animals constitute sister kingdoms in the eukaryotic domain of life. The major classes of transporters, channels, sensors, and effectors that move and respond to calcium ions were already highly networked in the common ancestor of fungi and animals. Since that time, some key components of the network have been moved, altered, relocalized, lost, or duplicated in the fungal and animal lineages and at the same time some of the regulatory circuitry has been dramatically rewired. Today the calcium transport and signaling networks in fungi provide a fresh perspective on the scene that has emerged from studies of the network in animal cells. This review provides an overview of calcium signaling networks in fungi, particularly the model yeast Saccharomyces cerevisiae, with special attention to the dominant roles of acidic calcium stores in fungal cell physiology. [Copyright &y& Elsevier]
- Published
- 2011
- Full Text
- View/download PDF
49. How frequent is metapopulation structure among butterflies in grasslands? Occurrence patterns in a forest-dominated landscape in southern Sweden1.
- Author
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Ranius, Thomas, Nilsson, Sven G., and Franzén, Markus
- Abstract
Copyright of Ecoscience (Ecoscience) is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2011
- Full Text
- View/download PDF
50. How frequent is metapopulation structure among butterflies in grasslands? Occurrence patterns in a forest-dominated landscape in southern Sweden1.
- Author
-
Ranius, Thomas, Nilsson, Sven G., and Franzén, Markus
- Subjects
BUTTERFLIES ,METAPOPULATION (Ecology) ,GRASSLANDS ,COLONIZATION (Ecology) - Abstract
Copyright of Ecoscience (Ecoscience) is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2011
- Full Text
- View/download PDF
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