Publications by authors named "Renault L"

The warm Western Boundary Currents (WBCs) and their zonal extensions are persistent, deep, strong and narrow oceanic currents. They are known to anchor and energize the Extra-Tropical storm tracks by frontal thermal air-sea interactions. However, even in the latest generation of climate models, WBCs are characterized by large biases, and both the present storm-track activity and its recent intensification are poorly estimated.

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A key control on the magnitude of coastal eutrophication is the degree to which currents quickly transport nitrogen derived from human sources away from the coast to the open ocean before eutrophication develops. In the Southern California Bight (SCB), an upwelling-dominated eastern boundary current ecosystem, anthropogenic nitrogen inputs increase algal productivity and cause subsurface acidification and oxygen (O ) loss along the coast. However, the extent of anthropogenic influence on eutrophication beyond the coastal band, and the physical transport mechanisms and biogeochemical processes responsible for these effects are still poorly understood.

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Article Synopsis
  • Metabolomics is a new approach to identify biomarkers related to egg and embryo quality, which can help in understanding infertility issues.
  • Recent findings show that differences in metabolite concentrations in follicular fluid correlate with various infertility conditions, like endometriosis and polycystic ovary syndrome.
  • Larger studies and an international database are needed to validate these findings and potentially improve reproductive treatment outcomes by using biomarkers from follicular fluid.
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ExoY virulence factors are members of a family of bacterial nucleotidyl cyclases (NCs) that are activated by specific eukaryotic cofactors and overproduce cyclic purine and pyrimidine nucleotides in host cells. ExoYs act as actin-activated NC toxins. Here, we explore the Vibrio nigripulchritudo Multifunctional-Autoprocessing Repeats-in-ToXin (MARTX) ExoY effector domain (Vn-ExoY) as a model for ExoY-type members that interact with monomeric (G-actin) instead of filamentous (F-actin) actin.

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Objective: The essential role of ACTH on the growth and function of the human foetal adrenal (HFA) has long been recognized. In addition, many studies have suggested a role of the pituitary hormone prolactin (PRL) in the regulation of the HFA, but the effects of this hormone on steroidogenesis and gene expression are still unknown. Our objective was to investigate the effect of ACTH and PRL on the steroidogenic capacities of the HFA.

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Background: Steroidogenic factor 1 (SF-1), encoded by the nuclear receptor subfamily 5 group A member 1 () gene, is a transcriptional factor crucial for adrenal and gonadal organogenesis. Pathogenic variants of are responsible for a wide spectrum of phenotypes with autosomal dominant inheritance including disorders of sex development and oligospermia-azoospermia in 46,XY adults. Preservation of fertility remains challenging in these patients.

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Introduction: Diminished ovarian reserve remains a challenge in the reproductive medicine field. Treatment options for these patients are limited and there is no consensus to make any recommendations. Regarding adjuvant supplements, DHEA could play a role in follicular recruitment and, therefore, may increase spontaneous pregnancy rate.

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Internal waves contain a large amount of energy in the ocean and are an important source of turbulent mixing. Ocean mixing is relevant for climate because it drives vertical transport of water, heat, carbon and other tracers. Understanding the life cycle of internal waves, from generation to dissipation, is therefore important for improving the representation of ocean mixing in climate models.

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Context: Determination of steroid levels in the amniotic fluid gives some insight on fetal adrenal and gonadal functions.

Objective: Our objectives were to establish reference ranges of 12 steroid levels throughout pregnancy and to compare them with steroid levels from pregnancies with fetuses presenting with 21-hydroxylase deficiency (21OHD).

Methods: Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was applied to 145 "control" amniotic fluid samples from gynecology activity (12 + 6 to 32 + 4 gestational weeks, GW).

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Article Synopsis
  • The study investigates whether testicular sperm extraction (TESE) should be done after puberty or delayed until adulthood in patients with non-mosaic 47,XXY Klinefelter syndrome (KS).
  • Results show no significant difference in sperm retrieval rate (SRR) between younger patients (ages 15-22) and older patients (ages 23-43), with overall SRR at 45.4%.
  • Key hormonal factors like Anti-Müllerian hormone (AMH) and inhibin B were found to be higher in the younger group and in patients who successfully retrieved sperm.
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Many pathogens manipulate host cell cAMP signaling pathways to promote their survival and proliferation. Bacterial Exoenzyme Y (ExoY) toxins belong to a family of invasive, structurally-related bacterial nucleotidyl cyclases (NC). Inactive in bacteria, they use proteins that are uniquely and abundantly present in eukaryotic cells to become potent, unregulated NC enzymes in host cells.

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The speed and efficiency of data collection and image processing in cryo-electron microscopy have increased over the last decade. However, cryo specimen preparation techniques have lagged and faster, more reproducible specimen preparation devices are needed. Here, we present a vitrification device with highly automated sample handling, requiring only limited user interaction.

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Article Synopsis
  • * Research indicates that age is a significant factor in the success of TESE, with older patients (over 30) generally having lower sperm retrieval rates, while those younger than 20 show better outcomes similar to the 20-30 age range.
  • * There is still a need for more studies to explore new markers to predict sperm retrieval success, especially considering the effects of age and androgen therapy, which has shown no clear impact on retrieval outcomes.
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Background: pathogenic variants can cause congenital adrenal hypoplasia or primary adrenal insufficiency in early childhood usually associated with hypogonadotropic hypogonadism. is necessary for organogenesis of the adrenal cortex and to maintain normal spermatogenesis. In humans, restoration of fertility in patients carrying pathogenic variants is challenging.

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Cryo-electron microscopy has become an essential tool to understand structure and function of biological samples. Especially for pathogens, such as disease-causing bacteria and viruses, insights gained by cryo-EM can aid in developing cures. However, due to the biosafety restrictions of pathogens, samples are often treated by chemical fixation to render the pathogen inert, affecting the ultrastructure of the sample.

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ExoY is among the effectors that are injected by the type III secretion system (T3SS) of into host cells. Inside eukaryotic cells, ExoY interacts with F-actin, which stimulates its potent nucleotidyl cyclase activity to produce cyclic nucleotide monophosphates (cNMPs). ExoY has broad substrate specificity with GTP as a preferential substrate .

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Since its identification in 2003, grapevine Pinot gris virus (GPGV, ) has now been detected in most grape-growing countries. So far, little is known about the epidemiology of this newly emerging virus. In this work, we used datamining as a tool to monitor the sanitary status of three vineyards in Italy.

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Global change is leading to warming, acidification, and oxygen loss in the ocean. In the Southern California Bight, an eastern boundary upwelling system, these stressors are exacerbated by the localized discharge of anthropogenically enhanced nutrients from a coastal population of 23 million people. Here, we use simulations with a high-resolution, physical-biogeochemical model to quantify the link between terrestrial and atmospheric nutrients, organic matter, and carbon inputs and biogeochemical change in the coastal waters of the Southern California Bight.

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In this chapter, we present an overview of a standard protocol to achieve structure determination at high resolution by Single Particle Analysis cryogenic Electron Microscopy using apoferritin as a standard sample. The purified apoferritin is applied to a glow-discharged support and then flash frozen in liquid ethane. The prepared grids are loaded into the electron microscope and checked for particle spreading and ice thickness.

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Oxazepam, one of the most frequently prescribed anxiolytic drugs, is not completely removed from wastewater with conventional treatment processes. It can thus be found at trace levels in environmental water, with human urine constituting the major source of contamination. This study focused on the development and characterization of molecularly imprinted polymers (MIPs) for the selective solid-phase extraction of oxazepam at trace levels from environmental water and human urine samples.

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The trimeric spike (S) protein of SARS-CoV-2 is the primary focus of most vaccine design and development efforts. Due to intrinsic instability typical of class I fusion proteins, S tends to prematurely refold to the post-fusion conformation, compromising immunogenic properties and prefusion trimer yields. To support ongoing vaccine development efforts, we report the structure-based design of soluble S trimers with increased yields and stabilities, based on introduction of single point mutations and disulfide-bridges.

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Article Synopsis
  • The study investigates the coevolution between potato cyst nematodes and wild potatoes in Peru to understand local adaptation, focusing on how host root exudates influence cyst hatching.
  • Results revealed no strong local adaptation in nematodes, but combinations of local nematodes and wild potatoes improved cyst hatching, and hatching rates negatively correlated with geographical distance.
  • The origin of the root exudates significantly impacted hatching, with exudates from southern Peru being more effective, suggesting potential strategies for managing potato diseases.
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  • Climate change is expected to increase hypoxia in the California Current System (CCS), jeopardizing its marine biodiversity and productivity.
  • The study shows that the Metabolic Index (Φ), which measures how well the environment can support oxygen needs of various species, is highly variable in the CCS, indicating that local species face significant fluctuations in suitable living conditions.
  • By 2100, ocean warming and oxygen depletion could reduce Φ below critical levels for 30-50% of northern anchovy's range, threatening their survival and leading to potential loss of aerobic habitats, which will disrupt ecological relationships among different species in the region.
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