Search

Wildfire pressure involves today to implement silvicultural practices that provide a good compromise between reducing fire risk and maintaining ecological functioning. Thinning reduces tree density and low branches, but results in the deposition of a considerable biomass of woody debris on the ground (up to 4800 g m 2 in this study). They can be eliminated by prescribed burning, but this raises questions about the fire intensity that can be generated and the impact on soil fauna. We undertook the monitoring of a thinning and prescribed burning operation, separated and combined, in November 2020, in a Pinus laricio stand prone to fire risk, located in Bavella, Corsica. Fuel load was determined, and temperature measurements in the soil were performed using K-type thermocouples. Soil arthropod populations were monitored using pitfall traps, in particular Collembola, Acari, Aranae, and Coleoptera. The combination of thinning and burning resulted in a fire intensity of 75.8 versus 8.4 kW m -1 for burning alone. Maximum temperature rise measured at -2 cm below the surface was less than 5°C for both treatments. The combination of thinning and burning did not result in higher fire intensity at ground level than burning alone, and the soil showed high insulation capacity. Most of the woody debris that burned was small-diameter, and large-diameter debris remained unconsumed. This burning, performed during a period of low biological activity, had no effect on soil arthropods, and the presence of large debris may have provided refuge areas. Collembola group was the faster to recover, and were followed by cohorts of predators in summer, especially Acari. Our results suggest that a combination of burning and thinning in autumn may be beneficial for fire prevention. However, the decomposition of woody debris in relation to fire risk, and the occurrence of pests after these treatments need to be monitored., Competing Interests: The authors declare that they have no conflict of interest., (© 2024 The Author(s). Ecology and Evolution published by John Wiley & Sons Ltd.)

Objective: We sought to determine whether the type 1 diabetes genetic risk score-2 (T1D-GRS2) and single nucleotide polymorphisms (SNPs) are associated with C-peptide preservation before type 1 diabetes diagnosis., Methods: We conducted a retrospective analysis of 713 autoantibody-positive participants who developed type 1 diabetes in the TrialNet Pathway to Prevention Study who had T1DExomeChip data. We evaluated the relationships of 16 known SNPs and T1D-GRS2 with area under the curve (AUC) C-peptide levels during oral glucose tolerance tests conducted in the 9 months before diagnosis., Results: Higher T1D-GRS2 was associated with lower C-peptide AUC in the 9 months before diagnosis in univariate (β=-0.06, P<0.0001) and multivariate (β=-0.03, P=0.005) analyses. Participants with the JAZF1 rs864745 T allele had lower C-peptide AUC in both univariate (β=-0.11, P=0.002) and multivariate (β=-0.06, P=0.018) analyses., Conclusions: The type 2 diabetes-associated JAZF1 rs864745 T allele and higher T1D-GRS2 are associated with lower C-peptide AUC prior to diagnosis of type 1 diabetes, with implications for the design of prevention trials., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Optic neuritis (ON) is associated with numerous immune-mediated inflammatory diseases, but 50% patients are ultimately diagnosed with multiple sclerosis (MS). Differentiating MS-ON from non-MS-ON acutely is challenging but important; non-MS ON often requires urgent immunosuppression to preserve vision. Using data from the United Kingdom Biobank we showed that combining an MS-genetic risk score (GRS) with demographic risk factors (age, sex) significantly improved MS prediction in undifferentiated ON; one standard deviation of MS-GRS increased the Hazard of MS 1.3-fold (95% confidence interval 1.07-1.55, P < 0.01). Participants stratified into quartiles of predicted risk developed incident MS at rates varying from 4% (95%CI 0.5-7%, lowest risk quartile) to 41% (95%CI 33-49%, highest risk quartile). The model replicated across two cohorts (Geisinger, USA, and FinnGen, Finland). This study indicates that a combined model might enhance individual MS risk stratification, paving the way for precision-based ON treatment and earlier MS disease-modifying therapy., (© 2024. The Author(s).)

Objective: Genetic risk scores (GRS) aid classification of diabetes type in White European adult populations. We aimed to assess the utility of GRS in the classification of diabetes type among racially/ethnically diverse youth in the U.S., Research Design and Methods: We generated type 1 diabetes (T1D)- and type 2 diabetes (T2D)-specific GRS in 2,045 individuals from the SEARCH for Diabetes in Youth study. We assessed the distribution of genetic risk stratified by diabetes autoantibody positive or negative (DAA+/-) and insulin sensitivity (IS) or insulin resistance (IR) and self-reported race/ethnicity (White, Black, Hispanic, and other)., Results: T1D and T2D GRS were strong independent predictors of etiologic type. The T1D GRS was highest in the DAA+/IS group and lowest in the DAA-/IR group, with the inverse relationship observed with the T2D GRS. Discrimination was similar across all racial/ethnic groups but showed differences in score distribution. Clustering by combined genetic risk showed DAA+/IR and DAA-/IS individuals had a greater probability of T1D than T2D. In DAA- individuals, genetic probability of T1D identified individuals most likely to progress to absolute insulin deficiency., Conclusions: Diabetes type-specific GRS are consistent predictors of diabetes type across racial/ethnic groups in a U.S. youth cohort, but future work needs to account for differences in GRS distribution by ancestry. T1D and T2D GRS may have particular utility for classification of DAA- children., (© 2022 by the American Diabetes Association.)

Forest management can benefit from decision support tools, including GIS-based multicriteria decision-aiding approach. In the Mediterranean region, Pinus pinaster forests play a very important role in biodiversity conservation and offer many socioeconomic benefits. However, the conservation of this species is affected by the increase in forest fires and the expansion of Matsucoccus feytaudi. This paper proposes a methodology based on commonly available data for assessing the values and risks of P. pinaster forests and to generating maps to aid in decisions pertaining to fire and phytosanitary risk management. The criteria for assessing the values (land cover type, legislative tools for biodiversity conservation, environmental tourist sites and access routes, and timber yield) and the risks (fire and phytosanitation) of P. pinaster forests were obtained directly or by considering specific indicators, and they were subsequently aggregated by means of GIS-based multicriteria analysis. This approach was tested on the island of Corsica (France), and maps to aid in decisions pertaining to fire risk and phytosanitary risk (M. feytaudi) were obtained for P. pinaster forest management. Study results are used by the technical offices of the local administration-Corsican Agricultural and Rural Development Agency (ODARC)-for planning the conservation of P. pinaster forests with regard to fire prevention and safety and phytosanitary risks. The decision maker took part in the evaluation criteria study (weight, normalization, and classification of the values). Most suitable locations are given to target the public intervention. The methodology presented in this paper could be applied to other species and in other Mediterranean regions.

Fire is a dominant ecological factor in Mediterranean-type ecosystems. Forest management includes many preventive tools, in particular for fire prevention, such as mechanical treatments and prescribed burning. Prescribed burning is a commonly used method for treating fuel loads, but fuel reduction targets for reducing wildfire hazards must be balanced against fuel retention targets in order to maintain habitat and other forest functions. This approach was used on Pinus nigra ssp laricio var. Corsicana, a pine endemic to Corsica of great ecological and economic importance. Many studies of plant phenolic compounds have been carried out concerning responses to various stresses. The aim of this study was to understand i) the effects of prescribed burning 1 to 16 months later and ii) the effects of the seasonality of burning, spring or fall, on the production of phenolic compounds in Pinus laricio. After prescribed burning conducted in spring, Pinus laricio increases the synthesis of total phenolic compounds for a period of 7 months. The increase is greater after spring-burning than fall-burning. With regard to simple phenols, only dihydroferulic acid responds about 1 year after both types of prescribed burning. The causes of these increases are discussed in this paper. Total phenolic compounds could be used as a bioindicator for the short-term response of Pinus laricio needles to prescribed burning. Simple phenols may be useful for revealing the medium-term effects of prescribed burning. The results of this study include recommending forest managers to use prescribed burning in the fall rather than spring to reduce fuel loads and have less impact on the trees.

Fire is a dominant ecological factor in Mediterranean-type ecosystems. Management strategies include prescribed (controlled) burning, which has been used in the management of several species, such as Pinus nigra ssp laricio var. Corsicana, a pine endemic to Corsica of great ecological and economic importance. The effects of prescribed burning on Pinus laricio have been little studied. The first aim of this study was to characterize total and simple phenolic compounds in Pinus laricio. The second aim was to understand: i) the short term (one to three months) and medium term (three years) effects of prescribed burning, and ii) the effects of periodic prescribed burning on the production of phenolic compounds in Pinus laricio. The first result of this study is the presence of total and simple phenolic compounds in the needles of Pinus laricio. 3-Vanillyl propanol is the major compound. After a prescribed burning, the synthesis of total phenolic compounds increases in Pinus laricio for a period of three months. Total phenolic compounds could be used as bioindicators for the short-term response of Pinus laricio needles to prescribed burning. Simple phenolic compounds do not seem to be good indicators of the impact of prescribed burning because prescribed burnings are low in intensity.

In recent times, more and more studies have focused on flavonoids as biomarkers of environmental quality in aquatic plants, in particular, Posidonia oceanica (Linnaeus) Delile. It is therefore of interest to determine how different prehandling methods can affect flavonoid concentrations. The methods tested were (1) immediate extraction of fresh samples, (2) extraction after 48 hr chilling, (3) freeze-drying, and (4) oven drying. Chilling and freeze-drying considerably altered the quantity of flavonoids measured, but not their profile. The effect of oven drying was not significant. Chilling led to a loss of 57% of total (pro)anthocyanidins, 39% of total flavonols, and 48% of all simple flavonols (myricetin, quercetin, isorhamnetin, and kaempferol). Freeze-drying caused a loss of 71% of total (pro)anthocyanidins, 87% of total flavonols, and 95% of all simple flavonols.

Integrated Coastal Zone Management (ICZM) contributes towards maximizing the benefits provided by the coastal zone and minimizing conflicts and the harmful effects of activities upon each other. The coastal zone includes highly productive and biologically diverse ecosystems, but ecological data (including structure and processes) seem to be neglected. The purpose of this article is to present a case study of Posidonia oceanica meadows (seagrass beds) along the Corsican coastline (Mediterranean Sea) in order to exemplify the usefulness of ecological data to Integrated Costal Management programs. We will try to determine how the use of organisms could be enhanced. These investigations show the undoubted success of the Corsican Posidonia oceanica protection program, with a detailed description of the ICZM that precisely presents each component (e.g., mapping, assessment of water quality, implementation of a system to aid decision-making concerning the installation of new aquaculture units). This experience on the Corsican coasts could be used as an example in order to transfer to other locations in the Mediterranean Sea and/or to other target species.

This work is a first approach to flavonoid responses (total proanthocyanidins and total and simple flavonols) in Posidonia oceanica in function of nutrient enrichment (aquaculture activities - fish farming), in the western Mediterranean Sea (Calvi-Corsica-France). The first result is the presence of total and simple flavonoids in P. oceanica. The second result shows an increase in total proanthocyanidin and total flavonol concentrations near cages, which would be linked to the high grazing pressure induced by meadow enrichment. Concerning simple flavonols, only quercetin shows a response to fish farming, which could be due to its strong antioxidant capacity. The presence of fish farming, which causes variations in environmental parameters, could affect the functioning of P. oceanica meadows. Flavonoid concentrations in P. oceanica seem to be a possible bioindicator of nutrient enrichment for the management of the littoral environment.

Despite their registration on the list of the Ramsar convention sites, the Mediterranean lagoons rarely beneficiate of an effective protection, and are particularly sensitive to environmental quality. A control of these wetlands needs the creation of an inventory of knowledge for the concerned environment. In this perspective, the seagrass beds were followed up in the coastal lagoon of Urbino (Corse, France) since 1990. A cartographic study was carried out by remote sensing of aerial photography. Temporal evolution of the seagrass beds (Cymodocea nodosa principally) allows to determine the vitality of these structures. A comparison of the surface areas occupied by Cymodocea nodosa, between 1990 and 1999, did not allow seeing any significant evolution. However, some variations appear like biotopes all more fragile and coveted as the Mediterranean coastal fringe is straight and is the privileged site of appear in the localization of the beds, due to the modification of environmental conditions in the lagoon.

Mercury concentrations, non-protein thiol levels and the enzyme activities of glutathione-S-transferase (GST) were measured in the blades and sheaths of the marine phanerogam Posidonia oceanica. The seagrass was collected in January and June and at three sites: the Bay of Rosignano (Italy) known for its mercury contamination, the north of the Lérins islands (Bay of Cannes, France), the Bay of Tonnara (Corsica, France). The two latter sites are considered as free of any known industrial inputs. Mercury concentrations and GST activities in both tissues were always higher in samples from Rosignano, particularly in June. Non-protein thiol levels were significantly higher in the blades than in the sheaths of P. oceanica from Tonnara and Lérins. In contrast, at Rosignano, the sheaths presented a significantly higher non-protein thiol concentration than the blades, particularly in June. Levels in the sheaths appeared to increase with the degree of pollution. Western Blot performed on sheaths of P. oceanica collected in June at Rosignano and Lérins revealed a characteristic band of GSTs at 31 kDa, proving the presence of the GST enzyme in this tissue. Mercury seemed to exert an influence upon non-protein thiol metabolism, including GST induction, in P. oceanica collected from the NW Mediterranean.

The aim of this study was to examine the experimental uptake of mercury and the enzymatic response, i.e., glutathione S-transferase (GST) activity, to this metal introduced into the medium under organic (methylmercury chloride) and nonorganic (mercury chloride) forms. Shoots of Posidonia oceanica were collected in a nonpolluted area in the northwestern Mediterranean Sea and were treated in aquaria with increasing mercury concentrations/exposure times (48, 96, and 144 h). Compared with the controls, a significant uptake was noted in the blades contaminated by HgCl2, whereas in the sheaths, a significant decrease of total mercury was noted. The blades exposed to CH3HgCl exhibited higher mercury concentrations than the controls; after 144 h exposure to organic mercury, the levels found in the blades were approximately sevenfold the values of the controls. The uptake noted in the sheaths treated with organic mercury followed the same pattern as with HgCl2 (decreased value compared with the controls) except after 144 h, where a slight increase in mercury was found in this tissue. The percentage of organic mercury in controls and treated blades and sheaths (treatment with both forms of mercury) represented always more than 50% of the total mercury in the plant. Glutathione S-transferase activities were significantly increased in the blades and sheaths of P. oceanica exposed to mercury chloride, whereas exposure to methylmercury was not significant. The presence of a GST isoform of 31 kDa was demonstrated by immunochemical methods (Western blotting) in the sheaths but not in the blades of the phanerogam.