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Background: Estuaries are complex ecosystems linking river and marine environments, where microorganisms play a key role in maintaining ecosystem functions. In the present study, we investigated monthly 8 sites at two depth layers and over a one-year period the bacterial and eukaryotic community dynamics along the Seine macrotidal estuary (Normandy, France). To date, the taxonomy of the microbial diversity present in this anthropized estuary remains elusive and the drivers of the microbial community structure are still unknown., Results: The metabarcoding analysis of 147 samples revealed both a high bacterial and eukaryotic diversity, dominated by Proteobacteria, Bacteriodota, Actinobacteriota and Bacillariophyta, Spirotrichea, Dinophyceae, respectively. Along the estuary we only detected significant spatial patterns in the bacterial and eukaryotic community compositions for three and two months out of twelve, respectively. However, we found a clear seasonal effect on the diversity of both microbial communities driven by physical and chemical variables that were fluctuating over the year (temperature, irradiance, river flow). Biotic associations were also significant drivers of both alpha and beta diversity. Throughout the year, we identified a diverse and abundant core microbiota composed of 74 bacterial and 41 eukaryotic OTUs. These regionally abundant species include habitat generalists encompassing heterotrophs, phototrophs and consumers. Yet, many of these core OTUs remain taxonomically and functionally poorly assigned., Conclusions: This molecular survey represents a milestone in the understanding of macrotidal estuary dynamics and the Seine ecosystem, through the identification of putative markers of ecosystem functioning. It also identifies seasons and biotic associations as main drivers of the Seine estuary microbiota and reveals the importance of a core microbiota throughout the year., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Background: When indicated, ureteroceles and ectopic ureters in duplicated collecting systems can be managed via upper or lower urinary tract surgical approaches, or a combination of both. Open ureteroureterostomy (UU) has been described to address these conditions in the absence of lower pole (LP) vesicoureteral reflux (VUR). We report outcomes from multiple centers worldwide with mid-term follow-up., Methods: Our study consists of a retrospective review of records and imaging of children who underwent open distal UU via inguinal incision for duplicated collecting system without lower pole VUR in institutions from North America, South America, and the Caribbean. Descriptive statistics and univariate analysis were utilized., Results: The records of 127 patients who underwent open distal UU for double collecting system between 2009 and 2022 were reviewed. Of those, 65% were female (n = 82), with a mean age at operation of 18 months (range 3-180). Main presentation at surgery included prenatal hydronephrosis (64%, n = 81), followed by febrile urinary tract infections (28%, n = 36), and urinary incontinence or other (8%, n = 10). The patients with antenatal or incidental diagnosis of hydronephrosis were classified as preoperative Society for Fetal Urology (SFU) grade 3 (n = 64) and 4 (n = 54) (96%). Those who were classified with SFU grade 0-2 (4%) had symptomatic clinical presentations including febrile urinary tract infections (UTIs) (n = 3), urinary incontinence (n = 3), and a 12-year-old patient with recurrent abdominal pain (n = 1). Mean operative time from skin incision to skin closure was 86 min (range 45-240). Mean hospital stay was estimated at 1.1 days (range 0.5-4). In our cohort of 127 patients, 3 (2%) developed Clavien-Dindo grade I (2 with ureteral stent displacement and 1 with a urine leak/managed conservatively), 6 (5%) with grade II (3 febrile and 3 non-febrile UTIs managed with oral antibiotics), and 2 (2%) with grade IIIb complications (urine leaks requiring surgical management), which were appropriately treated. None presented grade IV or V complications. A double J stent was used in 56 patients (44%), and a Penrose drain was left in 10 (8%). A total of 125 children (98%, n = 125/127) showed sonographic improvement of hydronephrosis, or resolution of symptoms with stable ultrasound findings. Successful outcome was similar for both ureterocele and ectopic ureter subgroups: 49/49 patients with ureterocele showed 100% improvement, 76/78 children with ectopic ureter showed improvement in 97% of the cases. On univariate analysis, outcomes were similar regardless of the use of ureteral stents (p = 0.11). Mean follow-up was 28.2 months (range 12-85)., Conclusions: Open distal UU is a good alternative for the definitive surgical management of ectopic ureters and ureteroceles without LP VUR. This multicentric and mid-term follow-up study demonstrates that open distal UU offers high success rates, low morbidity, short operative times and hospital stays, and satisfactory aesthetic outcomes. Additionally, the surgery is performed extra-peritoneally and may not require the use of stents or drains, depending on surgeon preference. Further investigations are being conducted to determine the role of UU in the settings of double collecting systems associated with ipsilateral LP VUR., Competing Interests: Conflict of interest None., (Copyright © 2024 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)

Brown seaweeds are keystone species of coastal ecosystems, often forming extensive underwater forests, and are under considerable threat from climate change. In this study, analysis of multiple genomes has provided insights across the entire evolutionary history of this lineage, from initial emergence, through later diversification of the brown algal orders, down to microevolutionary events at the genus level. Emergence of the brown algal lineage was associated with a marked gain of new orthologous gene families, enhanced protein domain rearrangement, increased horizontal gene transfer events, and the acquisition of novel signaling molecules and key metabolic pathways, the latter notably related to biosynthesis of the alginate-based extracellular matrix, and halogen and phlorotannin biosynthesis. We show that brown algal genome diversification is tightly linked to phenotypic divergence, including changes in life cycle strategy and zoid flagellar structure. The study also showed that integration of large viral genomes has had a significant impact on brown algal genome content throughout the emergence of the lineage., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Mussels and tubeworms have evolved similar adhesive systems to cope with the hydrodynamics of intertidal environments. Both secrete adhesive proteins rich in DOPA, a post-translationally modified amino acid playing essential roles in their permanent adhesion. DOPA is produced by the hydroxylation of tyrosine residues by tyrosinase enzymes, which can also oxidize it further into dopaquinone. We have compiled a catalog of the tyrosinases potentially involved in the adhesive systems of Mytilus edulis and Sabellaria alveolata . Some were shown to be expressed in the adhesive glands, with a high gland specificity in mussels but not in tubeworms. The diversity of tyrosinases identified in the two species suggests the coexistence of different enzymatic activities and substrate specificities. However, the exact role of the different enzymes needs to be further investigated. Phylogenetic analyses support the hypothesis of independent expansions and parallel evolution of tyrosinases involved in DOPA-based adhesion in both lineages., Competing Interests: The authors declare no competing interests., (© 2024 The Authors.)

Background: In the marine environment, knowledge of biodiversity remains incomplete for many taxa, requiring assessments to understand and monitor biodiversity loss. Environmental DNA (eDNA) metabarcoding is a powerful tool for monitoring marine biodiversity, as it enables several taxa to be characterised simultaneously in a single sample. However, the data generated by environmental DNA metabarcoding are often not easily reusable. Implementing FAIR principles and standards for eDNA-derived data can facilitate data-sharing within the scientific community., New Information: This study focuses on the detection of marine vertebrate biodiversity using eDNA metabarcoding on the leeward coast of Guadeloupe, a known hotspot for marine biodiversity in the French West Indies. Occurrences and DNA-derived data are shared here using DarwinCore standards combined with MIMARKS standards., (Rachel Haderlé, Laurent Bouveret, Jordane Chazal, Justine Girardet, Samuel Iglésias, Pascal-Jean Lopez, Cédric Millon, Alice Valentini, Visotheary Ung, Jean-Luc Jung.)

Land use change and anthropogenic forcing can drastically alter the rates and patterns of sediment transport and modify biodiversity and ecosystem functions in coastal transition zones, such as the coastal ecosystems. Molecular studies of sediment extracted DNAs provide information on currently living organisms within the upper layers or buried from various periods of time, but might also provide knowledge on species dynamics, replacement and turnover. In this study, we evaluated the eukaryotic communities of a marine core that present a shift in soil erosion that was linked to glyphosate usage and correlated to chlordecone resurgence since 2000. We show differences in community composition between samples from the second half of the last century and those from the last two decades. Temporal analyses of the relative abundance, alpha diversity, and beta diversity for the two periods demonstrated different temporal dynamics depending on the considered taxonomic group. In particular, Ascomycetes showed a decrease in abundance over the most recent period associated with changes in community membership but not community structure. Two photosynthetic groups, Bacillariophyceae and Prasinophytes clade VII, showed a different pattern with an increase in abundance since the beginning of the 21st century with a decrease in diversity and evenness to form more heterogeneous communities dominated by a few abundant OTUs. Altogether, our data reveal that agricultural usages such as pesticide use can have long-term and species-dependent implications for microeukaryotic coastal communities on a tropical island., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier B.V.)

Purpose: The Anderson-Hynes technique has been the treatment of choice for primary ureteropelvic junction obstruction in children. Laparoscopic approach has shown similar outcomes to open, with advantages of shorter hospital stay and less pain. We reviewed the experience of 11 geographically diverse, tertiary pediatric urology institutions focusing on the outcomes and complications of laparoscopic pyeloplasty., Materials and Methods: A descriptive, retrospective study was conducted evaluating patients undergoing Anderson-Hynes dismembered laparoscopic pyeloplasty. Centers from four different continents participated. Demographic data, perioperative management, results, and complications are described., Results: Over a 9-year period, 744 laparoscopic pyeloplasties were performed in 743 patients. Mean follow-up was 31 months (6-120m). Mean age at surgery was 82 months (1 w-19 y). Median operative time was 177 min. An internal stent was placed in 648 patients (87%). A catheter was placed for bladder drainage in 702 patients (94%). Conversion to open pyeloplasty was necessary in seven patients. Average length of hospital stay was 2.8 days. Mean time of analgesic requirement was 3.2 days. Complications, according to Clavien-Dindo classification, were observed in 56 patients (7.5%); 10 (1%) were Clavien-Dindo IIIb. Treatment failure occurred in 35 cases with 30 requiring redo pyeloplasty (4%) and 5 cases requiring nephrectomy (0.6%)., Conclusion: We have described the laparoscopic pyeloplasty experience of institutions with diverse cultural and economic backgrounds. They had very similar outcomes, in agreement with previously published data. Based on these findings, we conclude that laparoscopic pyeloplasty is safe and successful in diverse geographics areas of the world., Competing Interests: Conflicts of interest None., (Copyright © 2022 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)

Purpose: This multi-institutional study aimed to assess the outcomes of laparoscopic ureterocalicostomy (LUC) and robot-assisted laparoscopic ureterocalicostomy (RALUC) and compare them with laparoscopic pyeloplasty (LP) and robot-assisted laparoscopic pyeloplasty (RALP) in children with pelvi-ureteric junction obstruction (PUJO)., Methods: The data of 130 patients (80 boys), with median age 7.6 years and median weight 33.8 kg, receiving minimally invasive treatment of PUJO over a 6-year period, were retrospectively analyzed. Patients were grouped according to the operative approach: G1 included 15 patients, receiving LUC (n = 9) and RALUC (n = 6), and G2 included 115 patients, receiving LP (n = 30) and RALP (n = 85). Patient characteristics and operative outcomes were compared in both groups., Results: The median patient age and weight were significantly higher in G1 than in G2 [p = 0.001]. The median operative time was similar in both groups (157.6 vs 150.1 min) [p = 0.66] whereas the median anastomotic time was shorter in G1 than in G2 (59.5 vs 83.1 min) [p = 0.03]. The surgical success rate was similar in both groups (100% vs 97.4%) [p = 0.33]. Post-operative complications rate was higher in G1 than in G2 (20% vs 6.1%) but all G1 complications were Clavien 2 and did not require re-intervention., Conclusion: LUC/RALUC can be considered safe and effective alternative approaches to LP/RALP for PUJO repair and reported excellent outcomes as primary and salvage procedures. Robot-assisted technique was the preferred option to treat most patients with recurrent PUJO in both groups., (© 2022. The Author(s).)

Background: Since the development of minimally invasive surgery (MIS), laparoscopic and robotic approaches have been widely adopted. However, little has been published detailing the learning curve of MIS, especially in infants., Objective: To quantify the learning curve of laparoscopic (LP) and robot-assisted laparoscopic pyeloplasty (RAL-P) for treatment of uretero-pelvic junction obstruction (UPJO) in infants evidenced by number of cases, operative time, success and complications., Patients and Methods: Between 2009 and 2017, we retrospectively reviewed pyeloplasty cases for treatment of UPJO in infants at three academic institutions. The primary outcome was success. Secondary outcomes were UPJO recurrence, complications, and operative time as a surrogate of skill acquisition. Continuous variables were analyzed by t test, Welch-test, and one-way ANOVA. Non-continuous variables were analyzed by Chi-squared test or Fisher's exact test. Learning curves (LC) were studied by r-to-z transformation and CUSUM., Results: Thirty-nine OP, 26 LP, and 39 RAL-P had mean operative times (OT) of 106, 121, and 151 min, respectively. LCs showed plateau in OT after 18 and 13 cases for LP and RAL-P, respectively. RAL-P showed a second phase of further improvements after 37 cases. At 16 months follow-up, there were similar rates of success and complications between the three groups., Conclusions: Despite different duration of learning phases, proficiency was achieved in both LP and RAL-P as evidenced by stabilization of operative time and similar success rates and complications to OP. Before and after achievement of proficiency, LP and RAL-P can be safely learned and implemented for treatment of UPJO in infants., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Massive Sargassum sp. beachings have been occurring on Caribbean shores since 2011. The sargassum involved in such events are S. fluitans and S. natans, two drifting species whose proliferation has been observed in the southern North Atlantic Ocean. Both for reasons of environmental and sanitary assessment and repurposing, Sargassum sp. that is ashore piled up on beaches and decaying must be studied. Studies are required because of the concerning content of pelagic arsenic reported in the literature. They are also needed owing to Sargassum sp. contamination subsequent to historical pollution in the French West Indies by chlordecone, an insecticide used against the banana weevil Cosmopolites sordidus. The present study aims to describe the contamination and decontamination toxicokinetics of arsenic and chlordecone for Sargassum sp. stranding on shores and shallows in the Caribbean, in order to support the decision-making of the authorities involved. In situ and in mesocosm experiments performed in the present study show that Sargassum sp. contamination by chlordecone is mainly done after 2 h of exposition and reaches equilibrium after a day of exposure in polluted water, but BCF study suggests that the phenomenon is not actively supported (passive soption only). Arsenic transudation is intense in the case of immerged algae both. Half of the arsenic content is transudated after 13 h at sea and will transudate until vestigial arsenic concentration. Sargassum sp. contamination by arsenic, due to phytoaccumulation offshore, is broadly homogeneous before decay, and then leaks lead rapidly to a decrease in concentration in Sargassum sp. necromass, questioning the subsequent contamination of the coastal environment., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.)

Rafts of drifting pelagic Sargassum that are circulating across the Atlantic Ocean are complex ecosystems composed of a large number of associated species. Upon massive stranding, they lead to various socio-environmental issues including the inflow of contaminants and human health concerns. In this study, we used metabarcoding approaches to examine the differences in both the eukaryotic- and prokaryotic-associated communities from Sargassum present in two islands of the Lesser Antilles, namely Guadeloupe and Martinique. We detected significant differences in microbial community structure and composition between landing Sargassum , the surrounding seawater, and Sargassum from inland storage sites. In total we identified 22,214 prokaryotic and 17,679 eukaryotic OTUs. Among them, functional prediction analyses revealed a number of prokaryotes that might contribute to organic matter decomposition, nitrogen cycling and gas production, including sulfate-reducing bacteria at coastal landing sites, and methanogenic archaea at inland storage sites. We also found that Metazoan was the most abundant group in Sargassum samples, with nematode clades that presented exclusive or specific richness and abundance patterns depending on their Sargassum substrate. Together, these molecular inventories of the micro- and meiofauna communities provide baseline information for further characterization of trophic interactions, algal organic matter decomposition and nutrient transfers at coastal and inland storage sites., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Hervé, Lambourdière, René-Trouillefou, Devault and Lopez.)

This multi-authored contribution explores what the COVID-19 pandemic demands of critical inquiry with a focus on the more-than-human. We show how COVID-19 is a complex series of multispecies encounters shaped by humans, non-human animals, and of course viruses. Central to these encounters is a politics of difference in which certain human lives are protected and helped to flourish while others, both human and animal, are forgotten if not sacrificed. Such difference encompasses practices of racialisation and racism, healthcare austerity, the circulation of capital, border-making, intervention into non-human nature, wildlife trade bans, anthropocentrism, and the exploitation of animal test subjects. The contributions highlight how COVID-19 provides a needed opportunity to unite new materialist and anti-racist, anti-colonial scholarship as well as reimagine more radically sustainable multispecies futures. This requires embracing anti-colonial humility, confronting debts owed to lab animal frontline workers, and rethinking economic systems that helped unleash COVID-19 and ensured it became a disaster., (© 2021 The Author. Antipode © 2021 Antipode Foundation Ltd.)

Background: In the French West Indies, more than 20 species of cetaceans have been observed over the last decades. The recognition of this hotspot of biodiversity of marine mammals, observed in the French Exclusive Economic Zone of the West Indies, motivated the French government to create in 2010 a marine protected area (MPA) dedicated to the conservation of marine mammals: the Agoa Sanctuary. Threats that cetacean populations face are multiple, but well-documented. Cetacean conservation can only be achieved if relevant and reliable data are available, starting by occurrence data. In the Guadeloupe Archipelago and in addition to some data collected by the Agoa Sanctuary, occurrence data are mainly available through the contribution of citizen science and of local stakeholders (i.e. non-profit organisations (NPO) and whale-watchers). However, no observation network has been coordinated and no standards exist for cetacean presence data collection and management., New Information: In recent years, several whale watchers and NPOs regularly collected cetacean observation data around the Guadeloupe Archipelago. Our objective was to gather datasets from three Guadeloupean whale watchers, two NPOs and the Agoa Sanctuary, that agreed to share their data. These heterogeneous data went through a careful process of curation and standardisation in order to create a new extended database, using a newly-designed metadata set. This aggregated dataset contains a total of 4,704 records of 21 species collected in the Guadeloupe Archipelago from 2000 to 2019. The database was called Kakila ("who is there?" in Guadeloupean Creole). The Kakila database was developed following the FAIR principles with the ultimate objective of ensuring sustainability. All these data were transferred into the PNDB repository (Pöle National de Données de Biodiversité, Biodiversity French Data Hub, https://www.pndb.fr).In the Agoa Sanctuary and surrounding waters, marine mammals have to interact with increasing anthropogenic pressure from growing human activities. In this context, the Kakila database fulfils the need for an organised system to structure marine mammal occurrences collected by multiple local stakeholders with a common objective: contribute to the knowledge and conservation of cetaceans living in the French Antilles waters. Much needed data analysis will enable us to identify high cetacean presence areas, to document the presence of rarer species and to determine areas of possible negative interactions with anthropogenic activities., (Lorraine Coché, Elie Arnaud, Laurent Bouveret, Romain David, Eric Foulquier, Nadège Gandilhon, Etienne Jeannesson, Yvan Le Bras, Emilie Lerigoleur, Pascal Jean Lopez, Bénédicte Madon, Julien Sananikone, Maxime Sèbe, Iwan Le Berre, Jean-Luc Jung.)

Introduction: Aim: to determine the relationship between perceived loneliness, happiness, and health, and quality of diet, observing the moderator role of weight status in elementary school children during the state of alarm decreed for COVID-19. Methods: a descriptive, cross-sectional study in a sample of 116 Spanish schoolchildren. The perception of loneliness, happiness, and health was assessed using three items of the Health Behavior in School-aged Children questionnaire. The quality of their Mediterranean diet was assessed using the Mediterranean Diet Quality Index quetsionnaire for children and adolescents. Anthropometric variables were collected through a self-reported questionnaire, and for the calculation of body mass index the Quetelet index (kg/m2) was used. Results: the descriptive analysis showed no differences in the perception of loneliness, happiness, or health, quality of diet, or anthropometric variables (p > 0.005), except for weight (p < 0.005), according to sex. The inferential analysis showed that higher values in quality of diet are correlated with higher scores in perceived happiness and health (p < 0.005). In turn, the linear regression test showed an association between quality of diet and perception of happiness after the model was adjusted for normal weight (R2 = 0.382; p < 0.005). Likewise, it showed a significant association between quality of diet and perception of health after the model was adjusted for overweight schoolchildren (R2 = 0.455; p < 0.005). Conclusion: the association between perceived health and happiness with quality of diet seems to be moderated by weight status.

Objective: To collect baseline information on the ultrasonographic reporting preferences. Method: A 13-multiple choice questionnaire was designed and distributed worldwide among pediatric urologists, pediatric surgeons, and urologists. The statistical analysis of the survey data consisted of 3 steps: a univariate analysis, a bivariate and a multivariate analysis. Results: Three hundred eighty participants responded from all the continents. The bivariate analysis showed the significant differences in the geographical area, the years of experience and the volume of cases. Most of the physicians prefer the SFU and APD systems because of familiarity and simplicity (37 and 34%, respectively). Respondents noted that their imaging providers most often report findings utilizing the mild-moderate-severe system or the APD measurements (28 and 39%, respectively) except for North America (SFU in 50%). Multivariate analysis did not provide significant differences. Conclusion: Our study evaluates the opinions regarding the various pediatric hydronephrosis classification systems from a large number of specialists and demonstrates that there is no single preferred grading system. The greatest reported shortcoming of all the systems was the lack of universal utilization. The observations taken from this study may serve as basis for the construction of a common worldwide system. As APD and SFU are the preferred systems and the UTD a newer combination of both, it is possible that with time, UTD may become the universal language for reporting hydronephrosis. This time, based on the result of this survey, seems not arrived yet., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Vallasciani, Bujons Tur, Gatti, Machado, Cooper, Farrugia, Zhou, El Anbari and Lopez.)

2020 in the United States was marked by two converging crises-the COVID-19 pandemic and the large-scale uprisings in support of Black lives. These crises were met with both a counterproductive and inadequate response from the federal government. We examine these converging crises at the individual, social, and political scales. The biological realities of COVID-19 impact different populations in widely varied ways-the poor, the elderly, Black, Indigenous, and people of color, and those living with comorbidities get sick and die at the highest rates. Social distancing guidelines shifted millions of people to work-from-home and millions more lost their jobs, even as care laborers, preponderantly women, Black, Indigenous, and people of color, were asked to put their and their loved ones' lives on the line for the continuation of all of our lives. These biological, social, and economic crises have been punctuated by civil unrest, as millions took to the streets for racial justice, noting the unequal impacts of the pandemic. These converging crises have laid bare decades of neoliberal and neoconservative policies and ideologies, undergirded as they have been by racial capitalism, for their fundamental uncaringness. In this paper, we argue that this pandemic not only made a wider population more acutely aware of the necessity and importance of the need to care and for caring labors, but also that we stand at the precipice of potentiality--of producing a more caring society. To frame our argument, we draw on Nancy Scheper-Hughes and Margaret Lock's (1987) framework of three bodies-individual, social, and political-to unpack the multi-scalar entanglements in the differential impacts of COVID-19, questions of care, and their articulation in the current political-economic context., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Chlordecone (CLD) levels measured in the rivers of the French West Indies were among the highest values detected worldwide in freshwater ecosystems, and its contamination is recognised as a severe health, environmental, agricultural, economic, and social issue. In these tropical volcanic islands, rivers show strong originalities as simplified food webs, or numerous amphidromous migrating species, making the bioindication of contaminations a difficult issue. The objective of this study was to search for biological responses to CLD pollution in a spatially fixed and long-lasting component of the rivers in the West Indies: the epilithic biofilm. Physical properties were investigated through complementary analyses: friction, viscosity as well as surface adhesion were analyzed and coupled with measures of biofilm carbon content and exopolymeric substance (EPS) production. Our results have pointed out a mesoscale chemical and physical reactivity of the biofilm that can be correlated with CLD contamination. We were able to demonstrate that epilithic biofilm physical properties can effectively be used to infer freshwater environmental quality of French Antilles rivers. The friction coefficient is reactive to contamination and well correlated to carbon content and EPS production. Monitoring biofilm physical properties could offer many advantages to potential users in terms of effectiveness and ease of use, rather than more complex or time-consuming analyses.

Streets are constantly crossed by billions of vehicles and pedestrians. Their gutters, which convey stormwater and contribute to waste management, and are important for human health and well-being, probably play a number of ecological roles. Street surfaces may also represent an important part of city surface areas. To better characterize the ecology of this yet poorly explored compartment, we used filtration and DNA metabarcoding to address microbial community composition and assembly across the city of Paris, France. Diverse bacterial and eukaryotic taxonomic groups were identified, including members involved in key biogeochemical processes, along with a number of parasites and putative pathogens of human, animals and plants. We showed that the beta diversity patterns between bacterial and eukaryotic communities were correlated, suggesting interdomain associations. Beta diversity analyses revealed the significance of biotic factors (cohesion metrics) in shaping gutter microbial community assembly and, to a lesser extent, the contribution of abiotic factors (pH and conductivity). Co-occurrences analysis confirmed contrasting non-random patterns both within and between domains of life, specifically when comparing diatoms and fungi. Our results highlight microbial coexistence patterns in streets and reinforce the need to further explore biodiversity in urban ground transportation infrastructures., (© 2020 Society for Applied Microbiology and John Wiley & Sons Ltd.)

The cuttlefish shell is an internal structure with a composition and general organization unique among molluscs. Its formation and the structure-function relation are explored during Sepia officinalis development, using computerized axial tomography scanning (CAT-scan) three-dimensional analyses coupled to physical measurements and modelling. In addition to the evolution of the overall form, modifications of the internal structure were identified from the last third embryonic stages to adult. Most of these changes can be correlated to life cycle stages and environmental constraints. Protected by the capsule during embryonic life, the first internal chambers are sustained by isolated pillars formed from the dorsal to the ventral septum. After hatching, the formation of pillars appears to be a progressive process from isolated points to interconnected pillars forming a wall-delineated labyrinthine structure. We analysed the interpillar space, the connectivity and the tortuosity of the labyrinth. The labyrinthine pillar network is complete just prior to the wintering migration, probably to sustain the need to adapt to high pressure and to allow buoyancy regulation. At that time, the connectivity in the pillar network is compensated by an increase in tortuosity, most probably to reduce liquid diffusion in the shell. Altogether these results suggest adjustment of internal calcified structure development to both external forces and physiological needs.

Purpose: This retrospective study aimed to report a multi-institutional experience with laparoscopic and robotic-assisted repair of retrocaval ureter in children and to compare outcome of minimally invasive surgery (MIS) with open repair., Methods: The records of all children, who underwent MIS and open repair of retrocaval ureters in six international pediatric urology units over a 5-year period, were retrospectively collected. Data were grouped according to the operative approach: a laparoscopic group (G1) included five patients, a robotic-assisted group (G2) included four patients, and an open group (G3) included three patients. The groups were compared in regard to operative and postoperative outcomes., Results: At follow-up, all patients (one G1 patient after redo-surgery) reported complete resolution of symptoms and radiologic improvement of hydronephrosis and obstruction. In regard to postoperative complications, one G1 patient developed stenosis of anastomosis and needed re-operation with no further recurrence (IIIb Clavien). G2 reported the lowest average operative time (135 min) compared to G1 (178.3 min) and G3 (210 min). MIS (G1-G2) reported a significantly better postoperative outcome compared to open repair (G3) in terms of analgesic requirements, hospitalization, and cosmetic results., Conclusions: The study outcomes suggest that MIS should be the first choice for retrocaval ureter because of the minimal invasiveness and the better cosmetic outcome compared to open surgery. Furthermore, our results showed that robotic-assisted reconstruction was technically easier, safer, and quicker compared to laparoscopic repair, and for these reasons, it should be preferentially adopted, when available.

Objectives: There is a lack of a standardised protocol for the investigation and non-operative management of paediatric multicystic dysplastic kidney (MCDK). Institutional protocols for non-operative management remain essentially ad hoc. The primary outcome of this systematic review is to establish the incidence of hypertension associated with an MCDK. The secondary outcome is to determine the malignancy risk associated with an MCDK. The tertiary outcome is to assess the rate of MCDK involution. Subsequent to these, an evidence-based algorithm for follow-up is described., Methodology: A systematic review of all relevant studies published between 1968 and April 2017 was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies were identified by specific inclusion and exclusion criteria, all of which included data relevant to the primary, secondary and tertiary outcomes. Hypertension was defined as systolic blood pressure greater than the 95th centile for gender, age and height centile. Subset analysis was performed for hypertension associated with an MCDK., Results: The primary outcome measure revealed a 3.2% (27/838) risk of developing hypertension associated with an MCDK. The secondary outcome measure noted a 0.07% malignancy risk (2/2820). The tertiary outcome measure established that 53.3% (1502/2820) had evidence of involution of the dysplastic kidney. A total of 44 cohort studies (2820 patients) were analysed., Conclusion: Given the low risk of hypertension and malignancy, which is similar to the general population, the current conservative non-operative pathway is an appropriate management strategy. An algorithm to help support clinicians with ongoing management is proposed., (Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.)

Tube-building sabellariid polychaetes are hermatypic organisms capable of forming vast reefs in highly turbulent marine habitats. Sabellariid worms assemble their tube by gluing together siliceous and calcareous clastic particles using a polyelectrolytic biocement. Here, we performed transcriptomic analyses to investigate the genes that are differentially expressed in the parathorax region, which contains the adhesive gland and tissues, from the rest of the body. We found a large number of candidate genes to be involved in the composition and formation of biocement in two species: Sabellaria alveolata and Phragmatopoma caudata. Our results indicate that the glue is likely to be composed by a large diversity of cement-related proteins, including Poly(S), GY-rich, H-repeat and miscellaneous categories. However, sequences divergence and differences in expression profiles between S. alveolata and P. caudata of cement-related proteins may reflect adaptation to the type of substratum used to build their tube, and/or to their habitat (temperate vs tropical, amplitude of pH, salinity …). Related to the L-DOPA metabolic pathways and linked with the genes that were differentially expressed in the parathorax region, we found that tyrosinase and peroxidase gene families may have undergone independent expansion in the two Sabellariidae species investigated. Our data also reinforce the importance of protein modifications in cement formation. Altogether these new genomic resources help to identify novel transcripts encoding for cement-related proteins, but also important enzymes putatively involved in the chemistry of the adhesion process, such as kinases, and may correspond to new targets to develop biomimetic approaches., Statements of Significance: The diversity of bioadhesives elaborated by marine invertebrates is a tremendous source of inspiration to develop biomimetic approaches for biomedical and technical applications. Recent studies on the adhesion system of mussel, barnacle and sea star had highlighted the usefulness of high-throughput RNA sequencing in accelerating the development of biomimetic adhesives. Adhesion in sandcastle worms, which involves catechol and phosphate chemistries, polyelectrolyte complexes, supramolecular architectures, and a coacervation process, is a useful model to develop multipurpose wet adhesives. Using transcriptomic tools, we have explored the diversity of genes encoding for structural and catalytic proteins involved in cement formation of two sandcastle worm species, Sabellaria alveolata and Phragmatopoma caudata. The important genomic resource generated should help to design novel "blue" adhesives., (Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Surgical training has changed radically in the last few decades. The traditional Halstedian model of time-bound apprenticeship has been replaced with competency-based training. Advanced understanding of mastery learning principles has vastly altered educational methodology in surgical training, in terms of instructional design, delivery of educational content, assessment of learning, and programmatic evaluation. As part of this educational revolution, fundamentals of simulation-based education have been adopted into all levels and aspects of surgical training, requiring an understanding of concepts of fidelity and realism and the impact they have on learning. There are many educational principles and theories that can help clinical teachers understand the way that their trainees learn. In the acquisition of surgical expertise, concepts of mastery learning, deliberate practice, and experiential learning are particularly important. Furthermore, surgical teachers need to understand the principles of effective feedback, which is essential to all forms of skills learning. This article, the first of two papers, presents an overview of relevant learning theory for the busy paediatric surgeon and urologist. Seeking to introduce the concepts underpinning current changes in surgical education and training, providing practical tips to optimise teaching endeavours., (Copyright © 2018 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)

Surgical training has changed radically in the last few decades. The traditional Halstedian model of time-bound apprenticeship has been replaced with competency-based training. In our previous article, we presented an overview of learning theory relevant to clinical teaching; a summary for the busy paediatric surgeon and urologist. We introduced the concepts underpinning current changes in surgical education and training. In this next article, we give an overview of the various modalities of surgical simulation, the educational principles that underlie them, and potential applications in clinical practice. These modalities include; open surgical models and trainers, laparoscopic bench trainers, virtual reality trainers, simulated patients and role-play, hybrid simulation, scenario-based simulation, distributed simulation, virtual reality, and online simulation. Specific examples of technology that may be used for these modalities are included but this is not a comprehensive review of all available products., (Copyright © 2018 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)

Objective: Appendicovesicostomy (APV) and Monti ileovesicostomy (Monti) are durable catheterizable channels. While subfascial revision rates vary by channel type, a channel implanted in the anterior (vs posterior) aspect of the bladder may have a lower subfascial revision risk, due to decreased channel mobility and better fascial fixation. The present study aimed to compare long-term durability of anteriorly compared to posteriorly implanted APV and Monti channels in a large international cohort., Materials and Methods: A retrospective cohort study was conducted on patients aged ≤21 years and who underwent APV or Monti surgery with an open technique at three high-volume centers (1990-2015). The following were noted: patient demographics, stomal and subfascial revisions, stomal location, channel placement (anterior/posterior), and channel type - APV, spiral Monti to umbilicus (SMU), other Monti channels. Survival analysis and Cox proportional hazards regression were used to separately examine the three channel groups., Results: Of the 675 patients who met inclusion criteria, 387 had an APV (71.3% anterior), 53 had an SMU (13.2% anterior) and 235 had other Monti channels (42.1% anterior). Median age at surgery was 8.8 years for APV (median follow-up: 5.5 years), 9.2 years for other Monti (follow-up: 6.6 years) and 7.9 years for SMU (follow-up: 9.0 years). Patients originated from the USA (67.9%), Argentina (26.4%) and Chile (5.8%). Overall, 76 stomal and 77 subfascial revisions occurred. Risk of stomal revision was 9.3-12.0% at 5 years of follow-up, and was similar between channel types or location (P = 0.57). Risk of subfascial revision at 5 years was 7.4% for APV, 12.7% for all other Monti channels and 25.9% for SMU (P = 0.001). On survival analysis, stomal and subfascial revision rates were similar between anterior and posterior channels for APV (P ≥ 0.16), other Monti channels (P ≥ 0.62) and SMU (P ≥ 0.43) (Summary Fig.). On multivariate regression, channel configuration was not associated with stomal or subfascial revision for APV (P ≥ 0.18) or other Monti channels (P ≥ 0.64). Sex, age, diagnosis, country and stomal location were not associated with revision risk (P ≥ 0.06)., Discussion: Contrary to the hypothesis, subfascial revision rates were no different between anterior and posterior channels. Given that many reported outcomes related to genitourinary reconstruction occur rarely and require prolonged follow-up, collaborative research in this area should be encouraged., Conclusions: The study demonstrated durable long-term results with the APV and Monti techniques in an international cohort. Risks of stomal and subfascial complications were not significantly different between anteriorly and posteriorly implanted channels. As previously reported, Monti channels, particularly SMU, were more prone to undergoing subfascial revisions., (Copyright © 2017 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)

In most cities, streets are designed for collecting and transporting dirt, litter, debris, storm water and other wastes as a municipal sanitation system. Microbial mats can develop on street surfaces and form microbial communities that have never been described. Here, we performed the first molecular inventory of the street gutter-associated eukaryotes across the entire French capital of Paris and the non-potable waters sources. We found that the 5782 OTUs (operational taxonomic units) present in the street gutters which are dominated by diatoms (photoautotrophs), fungi (heterotrophs), Alveolata and Rhizaria, includes parasites, consumers of phototrophs and epibionts that may regulate the dynamics of gutter mat microbial communities. Network analyses demonstrated that street microbiome present many species restricted to gutters, and an overlapping composition between the water sources used for street cleaning (for example, intra-urban aquatic networks and the associated rivers) and the gutters. We propose that street gutters, which can cover a significant surface area of cities worldwide, potentially have important ecological roles in the remediation of pollutants or downstream wastewater treatments, might also be a niche for growth and dissemination of putative parasite and pathogens.

In metazoans, there is a remarkable diversity of photosensitive structures; their shapes, physiology, optical properties, and development are different. To approach the evolution of photosensitive structures and visual function, cephalopods are particularly interesting organisms due to their most highly centralized nervous system and their camerular eyes which constitute a convergence with those of vertebrates. The eye morphogenesis in numerous metazoans is controlled mainly by a conserved Retinal Determination Gene Network (RDGN) including pax, six, eya , and dac playing also key developmental roles in non-retinal structures and tissues of vertebrates and Drosophila . Here we have identified and explored the role of Sof-dac, Sof-six1/2, Sof-eya in eye morphogenesis, and nervous structures controlling the visual function in Sepia officinalis . We compare that with the already shown expressions in eye development of Sof-otx and Sof-pax genes. Rhodopsin is the pigment responsible for light sensitivity in metazoan, which correlate to correlate visual function and eye development. We studied Sof-rhodopsin expression during retina differentiation. By in situ hybridization, we show that (1) all of the RDGN genes, including Sof-pax6 , are expressed in the eye area during the early developmental stages but they are not expressed in the retina, unlike Sof-otx , which could have a role in retina differentiation; (2) Sof-rhodopsin is expressed in the retina just before vision gets functional, from stage 23 to hatching. Our results evidence a role of Sof-six1/2, Sof-eya , and Sof-dac in eye development. However, the gene network involved in the retinal photoreceptor differentiation remains to be determined. Moreover, for the first time, Sof-rhodopsin expression is shown in the embryonic retina of cuttlefish suggesting the evolutionary conservation of the role of rhodopsin in visual phototransduction within metazoans. These findings are correlated with the physiological and behavioral observations suggesting that S. officinalis is able to react to light stimuli from stage 25 of organogenesis on, as soon as the first retinal pigments appear.

Salinity regimes in estuaries and coastal areas vary with river discharge patterns, seawater evaporation, the morphology of the coastal waterways and the dynamics of marine water mixing. Therefore, microalgae have to respond to salinity variations at time scales ranging from daily to annual cycles. Microalgae may also have to adapt to physical alterations that induce the loss of connectivity between habitats and the enclosure of bodies of water. Here, we integrated physiological assays and measurements of morphological plasticity with a functional genomics approach to examine the regulatory changes that occur during the acclimation to salinity in the estuarine diatom Thalassiosira weissflogii. We found that cells exposed to different salinity regimes for a short or long period presented adjustments in their carbon fractions, silicon pools, pigment concentrations and/or photosynthetic parameters. Salinity-induced alterations in frustule symmetry were observed only in the long-term (LT) cultures. Whole transcriptome analyses revealed a down-regulation of nuclear and plastid encoded genes during the LT response and identified only a few regulated genes that were in common between the ST and LT responses. We propose that in diatoms, one strategy for acclimating to salinity gradients and maintaining optimal cellular fitness could be a reduction in the cost of transcription., (© 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.)

Protein compounds constituting mollusk shells are known for their major roles in the biomineralization processes. These last years, a great diversity of shell proteins have been described in bivalves and gastropods allowing a better understanding of the calcification control by organic compounds and given promising applications in biotechnology. Here, we analyzed for the first time the organic matrix of the aragonitic Sepia officinalis shell, with an emphasis on protein composition of two different structures: the dorsal shield and the chambered part. Our results highlight an organic matrix mainly composed of polysaccharide, glycoprotein and protein compounds as previously described in other mollusk shells, with quantitative and qualitative differences between the dorsal shield and the chamber part. Proteomic analysis resulted in identification of only a few protein compounds underlining the lack of reference databases for Sepiidae. However, most of them contain domains previously characterized in matrix proteins of aragonitic shell-builder mollusks, suggesting ancient and conserved mechanisms of the aragonite biomineralization processes within mollusks., Biological Significance: The cuttlefish's inner shell, better known under the name "cuttlebone", is a complex mineral structure unique in mollusks and involved in tissue support and buoyancy regulation. Although it combines useful properties as high compressive strength, high porosity and high permeability, knowledge about organic compounds involved in its building remains limited. Moreover, several cuttlebone organic matrix studies reported data very different from each other or from other mollusk shells. Thus, this study provides 1) an overview of the organization of the main mineral structures found in the S. officinalis shell, 2) a reliable baseline about its organic composition, and 3) a first descriptive proteomic approach of organic matrices found in the two main parts of this shell. These data will contribute to the general knowledge about mollusk biomineralization as well as in the identification of protein compounds involved in the Sepiidae shell calcification., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Vesicoureteral reflux (VUR) is a disorder that has been studied since the early days of pediatric urology. From 1893, when it was first documented in humans by Pozzi, the research and clinical management of VUR has been marked by pendulum swings through the decades. Initially, the vesicoureteral junction was the main subject of study, whereas current practice takes into account the bladder and bowel dynamics. The primary objective, however, is unchanged: preservation of the kidney and its function. Management of the condition has included open surgery, minimally invasive surgery, endoscopic treatment, antibiotic prophylaxis, and watchful waiting. In this article, we will attempt to cover every angle of this complex pathology and its current management in children.

Purpose: Central venous catheters (CVC) are frequently used for haemodialysis (HD) in children. However, there is paucity of information on the outcomes of CVCs when used for HD in very young patients. Our objective is to report the success, safety and complication rates of CVCs used for HD in children weighing less than 15 kg., Materials and Methods: This is a single-center retrospective study of all patients with end-stage renal disease (ESRD) weighing <15kg, who underwent a tunneled CVC placement for HD, between July 2006 and June 2012 at our institution. Analysed data included clinical background, age and weight at initiation of HD, outcome of HD, CVC vein insertion site, reason for removal, and catheter survival (in days)., Results: Thirty-one CVC were placed in 11 patients weighing <15 kg, 8 males and 3 females. The main causes of ESRD were renal dysplasia and congenital nephrotic syndrome. At the beginning of HD, mean age was 27.5 (range 5-60) months and mean weight was 10.4 kg (4.5-13 kg). The preferred insertion site was the right internal jugular vein (90%). Mean duration of HD was 312 days. Mechanical factors were the main reason for catheter removal (39%). Mean catheter survival was 110 days/catheter., Conclusions: We believe our study provides relevant information and encouraging data to support the use of CVC for HD in this cohort of infants; however, further improvement in prevention of catheter thrombosis and management of infections needs to be achieved., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Objective: Balanitis xerotica obliterans (BXO) is a chronic inflammatory disease that is considered as male genital variant lichen sclerosis. The incidence varies greatly in different series; diagnosis is mostly clinical but histopathological confirmation is mandatory. Various treatments are described, but there is no consensus that one is the best., Materials and Methods: A literature review was made of BXO and lichen sclerosis in boys under 18 years of age, between 1995 and 2013, analyzing demographic dates, treatments and outcomes. In addition to that, we reviewed BXO cases treated in our centers in the last 10 years., Results: After literature review, only 13 articles matched the inclusion criteria. Analyzing those selected, the global incidence of BXO is nearly 35% among circumcised children. Described symptoms are diverse and the low index of clinical suspicion is highlighted. The main treatment is circumcision, with use of topical and intralesional steroids and immunosuppressive agents., Conclusion: BXO is a condition more common than we believe and we must be vigilant to find greater number of diagnoses to avoid future complications. The main treatment for BXO is circumcision, but as topical or intralesional treatments are now available with potentially good outcomes, they may be considered as coadjuvants., (Copyright © 2013. Published by Elsevier Ltd.)

Advanced frontal sinus disease non-responsive to conservative therapy has been treated with fat obliteration for decades. More recently, a wide variety of autogenous, allogenic or synthetic materials have also been used. In this study we present a treatment based on totally autogenous procedures and materials that was successfully implemented in 10 patients and followed up for a period of 6-10 years, to evaluate the feasibility of a new approach for the treatment of frontal sinus disease and other related cranial osseous derangements, based on regenerative medicine as an alternative to fat or other obliterating or grafting materials. Platelet-rich and -poor plasma (PRP, PPP) are set to clot with cortical shavings from the skull surface. After surgically stimulating the sinus to encourage cell chemotaxis, migration and homing, the bioactive scaffold is placed and covered with a PPP membrane and a periosteal flap. Ten patients with pathologies ranging from devastating infection to invasive tumours or trauma were treated with this regenerative procedure in a single-stage surgery. All patients had an uneventful recovery with bone formation and no complications or recurrences over the years. The application of modern principles in tissue regeneration and wound healing has resulted in a favourable outcome, with no complications or sequelae, in a series of 10 patients with advanced frontal sinus disease over a long period of time., (Copyright © 2012 John Wiley & Sons, Ltd.)

Red seaweeds are key components of coastal ecosystems and are economically important as food and as a source of gelling agents, but their genes and genomes have received little attention. Here we report the sequencing of the 105-Mbp genome of the florideophyte Chondrus crispus (Irish moss) and the annotation of the 9,606 genes. The genome features an unusual structure characterized by gene-dense regions surrounded by repeat-rich regions dominated by transposable elements. Despite its fairly large size, this genome shows features typical of compact genomes, e.g., on average only 0.3 introns per gene, short introns, low median distance between genes, small gene families, and no indication of large-scale genome duplication. The genome also gives insights into the metabolism of marine red algae and adaptations to the marine environment, including genes related to halogen metabolism, oxylipins, and multicellularity (microRNA processing and transcription factors). Particularly interesting are features related to carbohydrate metabolism, which include a minimalistic gene set for starch biosynthesis, the presence of cellulose synthases acquired before the primary endosymbiosis showing the polyphyly of cellulose synthesis in Archaeplastida, and cellulases absent in terrestrial plants as well as the occurrence of a mannosylglycerate synthase potentially originating from a marine bacterium. To explain the observations on genome structure and gene content, we propose an evolutionary scenario involving an ancestral red alga that was driven by early ecological forces to lose genes, introns, and intergenetic DNA; this loss was followed by an expansion of genome size as a consequence of activity of transposable elements.

Diatoms, the major contributors of the global biogenic silica cycle in modern oceans, account for about 40% of global marine primary productivity. They are an important component of the biological pump in the ocean, and their assemblage can be used as useful climate proxies; it is therefore critical to better understand the changes induced by environmental pH on their physiology, silicification capability and morphology. Here, we show that external pH influences cell growth of the ubiquitous diatom Thalassiosira weissflogii, and modifies intracellular silicic acid and biogenic silica contents per cell. Measurements at the single-cell level reveal that extracellular pH modifications lead to intracellular acidosis. To further understand how variations of the acid-base balance affect silicon metabolism and theca formation, we developed novel imaging techniques to measure the dynamics of valve formation. We demonstrate that the kinetics of valve morphogenesis, at least in the early stages, depends on pH. Analytical modeling results suggest that acidic conditions alter the dynamics of the expansion of the vesicles within which silica polymerization occurs, and probably its internal pH. Morphological analysis of valve patterns reveals that acidification also reduces the dimension of the nanometric pores present on the valves, and concurrently overall valve porosity. Variations in the valve silica network seem to be more correlated to the dynamics and the regulation of the morphogenesis process than the silicon incorporation rate. These multiparametric analyses from single-cell to cell-population levels demonstrate that several higher-level processes are sensitive to the acid-base balance in diatoms, and its regulation is a key factor for the control of pattern formation and silicon metabolism.

In this review we highlight recent advances in the understanding of biosilica production, biomodification of diatom frustules and their subsequent applications in bio/chemical sensors, and as a model membrane for filtration and separation.

Brown algae (Phaeophyceae) are complex photosynthetic organisms with a very different evolutionary history to green plants, to which they are only distantly related. These seaweeds are the dominant species in rocky coastal ecosystems and they exhibit many interesting adaptations to these, often harsh, environments. Brown algae are also one of only a small number of eukaryotic lineages that have evolved complex multicellularity (Fig. 1). We report the 214 million base pair (Mbp) genome sequence of the filamentous seaweed Ectocarpus siliculosus (Dillwyn) Lyngbye, a model organism for brown algae, closely related to the kelps (Fig. 1). Genome features such as the presence of an extended set of light-harvesting and pigment biosynthesis genes and new metabolic processes such as halide metabolism help explain the ability of this organism to cope with the highly variable tidal environment. The evolution of multicellularity in this lineage is correlated with the presence of a rich array of signal transduction genes. Of particular interest is the presence of a family of receptor kinases, as the independent evolution of related molecules has been linked with the emergence of multicellularity in both the animal and green plant lineages. The Ectocarpus genome sequence represents an important step towards developing this organism as a model species, providing the possibility to combine genomic and genetic approaches to explore these and other aspects of brown algal biology further.

Background: Diatoms represent the predominant group of eukaryotic phytoplankton in the oceans and are responsible for around 20% of global photosynthesis. Two whole genome sequences are now available. Notwithstanding, our knowledge of diatom biology remains limited because only around half of their genes can be ascribed a function based onhomology-based methods. High throughput tools are needed, therefore, to associate functions with diatom-specific genes., Results: We have performed a systematic analysis of 130,000 ESTs derived from Phaeodactylum tricornutum cells grown in 16 different conditions. These include different sources of nitrogen, different concentrations of carbon dioxide, silicate and iron, and abiotic stresses such as low temperature and low salinity. Based on unbiased statistical methods, we have catalogued transcripts with similar expression profiles and identified transcripts differentially expressed in response to specific treatments. Functional annotation of these transcripts provides insights into expression patterns of genes involved in various metabolic and regulatory pathways and into the roles of novel genes with unknown functions. Specific growth conditions could be associated with enhanced gene diversity, known gene product functions, and over-representation of novel transcripts. Comparative analysis of data from the other sequenced diatom, Thalassiosira pseudonana, helped identify several unique diatom genes that are specifically regulated under particular conditions, thus facilitating studies of gene function, genome annotation and the molecular basis of species diversity., Conclusions: The digital gene expression database represents a new resource for identifying candidate diatom-specific genes involved in processes of major ecological relevance.

Background: Diatoms are largely responsible for production of biogenic silica in the global ocean. However, in surface seawater, Si(OH)(4) can be a major limiting factor for diatom productivity. Analyzing at the global scale the genes networks involved in Si transport and metabolism is critical in order to elucidate Si biomineralization, and to understand diatoms contribution to biogeochemical cycles., Methodology/principal Findings: Using whole genome expression analyses we evaluated the transcriptional response to Si availability for the model species Phaeodactylum tricornutum. Among the differentially regulated genes we found genes involved in glutamine-nitrogen pathways, encoding putative extracellular matrix components, or involved in iron regulation. Some of these compounds may be good candidates for intracellular intermediates involved in silicic acid storage and/or intracellular transport, which are very important processes that remain mysterious in diatoms. Expression analyses and localization studies gave the first picture of the spatial distribution of a silicic acid transporter in a diatom model species, and support the existence of transcriptional and post-transcriptional regulations., Conclusions/significance: Our global analyses revealed that about one fourth of the differentially expressed genes are organized in clusters, underlying a possible evolution of P. tricornutum genome, and perhaps other pennate diatoms, toward a better optimization of its response to variable environmental stimuli. High fitness and adaptation of diatoms to various Si levels in marine environments might arise in part by global regulations from gene (expression level) to genomic (organization in clusters, dosage compensation by gene duplication), and by post-transcriptional regulation and spatial distribution of SIT proteins., Competing Interests: The authors have declared that no competing interests exist.

Doctor ties are often contaminated with bacteria, and it has been suggested that they should not be worn. We have compared bacterial counts from the ties and shirt pockets of 50 doctors. Counts were higher (P = .002) from ties that were rarely, if ever, cleaned than from shirts that were washed every 2 days or more frequently. The results support the need for further research on unwashable clothing of hospital staff.

Understanding the morphogenesis of mineralized structures found in shells, bones, teeth, spicules and plant cell walls is difficult because of the complexities underlying biomineralization, and the requirement of accurate models for pattern formation. Here, we investigated the spatial and temporal development of siliceous structures found in a model diatom species, Phaeodactylum tricornutum, for which the entire genome has been sequenced and transformation is routine. Analyses of pattern formation revealed that the process of silicification starts from a 'pi-like' structure that controls the spatial organization of a sternum upon which regular instabilities are initiated and developed. Detailed analyses also demonstrate that morphogenesis of silica is nonuniform. We also tested the sensitivity of pattern formation to perturbation of proton pumps, and found that selective inhibitors of H(+)-V-ATPases affect silica biomineralization both quantitatively and qualitatively. Morphometric analyses of valves purified from isogenic populations of cells show that the morphometric noise of several traits is under exquisite regulation, explaining why the overall valve pattern is reproducibly maintained. Altogether our analyses demonstrate that silica morphogenesis is a robust but nonuniform process, and allow us to propose a model for the dynamic growth of materials within a spatially controlled geometry.

Diatoms are photosynthetic secondary endosymbionts found throughout marine and freshwater environments, and are believed to be responsible for around one-fifth of the primary productivity on Earth. The genome sequence of the marine centric diatom Thalassiosira pseudonana was recently reported, revealing a wealth of information about diatom biology. Here we report the complete genome sequence of the pennate diatom Phaeodactylum tricornutum and compare it with that of T. pseudonana to clarify evolutionary origins, functional significance and ubiquity of these features throughout diatoms. In spite of the fact that the pennate and centric lineages have only been diverging for 90 million years, their genome structures are dramatically different and a substantial fraction of genes ( approximately 40%) are not shared by these representatives of the two lineages. Analysis of molecular divergence compared with yeasts and metazoans reveals rapid rates of gene diversification in diatoms. Contributing factors include selective gene family expansions, differential losses and gains of genes and introns, and differential mobilization of transposable elements. Most significantly, we document the presence of hundreds of genes from bacteria. More than 300 of these gene transfers are found in both diatoms, attesting to their ancient origins, and many are likely to provide novel possibilities for metabolite management and for perception of environmental signals. These findings go a long way towards explaining the incredible diversity and success of the diatoms in contemporary oceans.

RNA polymerases carry out the synthesis of an RNA copy from a DNA template. They move along DNA, incorporate nucleotide triphosphate (NTP) at the end of the growing RNA chain, and consume chemical energy. In a single-molecule assay using the T7 RNA polymerase, we study how a mechanical force opposing the forward motion of the enzyme along DNA affects the translocation rate. We also study the influence of nucleotide and magnesium concentration on this process. The experiment shows that the opposing mechanical force is a competitive inhibitor of nucleotide binding. Also, the single-molecule data suggest that magnesium ions are involved in a step that does not depend on the external load force. These kinetic results associated with known biochemical and mutagenic data, along with the static information obtained from crystallographic structures, shape a very coherent view of the catalytic cycle of the enzyme: translocation does not take place upon NTP binding nor upon NTP cleavage, but rather occurs after PPi release and before the next nucleotide binding event. Furthermore, the energetic bias associated with the forward motion of the enzyme is close to kT and represents only a small fraction of the free energy of nucleotide incorporation and pyrophosphate hydrolysis.