AI-driven remote sensing enhances Mediterranean seagrass monitoring and conservation to combat climate change and anthropogenic impacts.

Seagrasses are undergoing widespread loss due to anthropogenic pressure and climate change. Since 1960, the Mediterranean seascape lost 13-50% of the areal extent of its dominant and endemic seagrass-Posidonia oceanica, which regulates its ecosystem. Many conservation and restoration projects failed due to poor site selection and lack of long-term monitoring.

Live-Imaging Analysis of Epithelial Zippering During Mouse Neural Tube Closure.

Zippering is a phenomenon of tissue morphogenesis whereby fusion between opposing epithelia progresses unidirectionally over significant distances, similar to the travel of a zip fastener, to ultimately ensure closure of an opening. A comparable process can be observed during Drosophila dorsal closure and mammalian wound healing, while zippering is employed by numerous organs such as the optic fissure, palatal shelves, tracheoesophageal foregut, and presumptive genitalia to mediate tissue sealing during normal embryonic development. Particularly striking is zippering propagation during neural tube morphogenesis, where the fusion point travels extensively along the embryonic axis to ensure closure of the neural tube.

Hypogonadism: a neglected comorbidity in young and middle-aged HIV-positive men on effective combination antiretroviral therapy.

Objective: Male hypogonadism is poorly characterized in young-to-middle-aged people with HIV (PWH). We used a reliable free testosterone assay to assess the prevalence and predictive factors for male hypogonadism in PWH on effective combined antiretroviral therapy (cART).

Design: A French cross-sectional study from January 2013 to June 2016.

Vangl2-environment interaction causes severe neural tube defects, without abnormal neuroepithelial convergent extension.

Planar cell polarity (PCP) signalling is vital for initiation of mouse neurulation, with diminished convergent extension (CE) cell movements leading to craniorachischisis, a severe neural tube defect (NTD). Some humans with NTDs also have PCP gene mutations but these are heterozygous, not homozygous as in mice. Other genetic or environmental factors may interact with partial loss of PCP function in human NTDs.

Human embryo polarization requires PLC signaling to mediate trophectoderm specification.

Apico-basal polarization of cells within the embryo is critical for the segregation of distinct lineages during mammalian development. Polarized cells become the trophectoderm (TE), which forms the placenta, and apolar cells become the inner cell mass (ICM), the founding population of the fetus. The cellular and molecular mechanisms leading to polarization of the human embryo and its timing during embryogenesis have remained unknown.

Modelling the impact of decidual senescence on embryo implantation in human endometrial assembloids.

Decidual remodelling of midluteal endometrium leads to a short implantation window after which the uterine mucosa either breaks down or is transformed into a robust matrix that accommodates the placenta throughout pregnancy. To gain insights into the underlying mechanisms, we established and characterized endometrial assembloids, consisting of gland-like organoids and primary stromal cells. Single-cell transcriptomics revealed that decidualized assembloids closely resemble midluteal endometrium, harbouring differentiated and senescent subpopulations in both glands and stroma.

Rethinking Human Embryo Research Policies.

It now seems technically feasible to culture human embryos beyond the "fourteen-day limit," which has the potential to increase scientific understanding of human development and perhaps improve infertility treatments. The fourteen-day limit was adopted as a compromise but subsequently has been considered an ethical line. Does it remain relevant in light of technological advances permitting embryo maturation beyond it? Should it be changed and, if so, how and why? What justifications would be necessary to expand the limit, particularly given that doing so would violate some people's moral commitments regarding human embryos? Robust stakeholder engagement preceded adoption of the fourteen-day limit and should arguably be part of efforts to reassess it.

Partial migration in savanna elephant populations distributed across southern Africa.

Migration is an important, but threatened ecological process. Conserving migration requires the maintenance of functional connectivity across sufficiently large areas. Therefore, we need to know if, where and why species migrate.

Savanna elephants maintain homeothermy under African heat.

To conserve body water, mammals may reduce evaporative water loss by storing heat, allowing core body temperature to rise more than usual during the day, and to fall more than usual during the cooler night, so demonstrating heterothermy. It has been proposed that elephants are heterothermic, but body temperature never has been measured in elephants over 24 h at environmental temperatures higher than body temperature, where elephants would have to rely on evaporative cooling to maintain homeothermy. We used ingested temperature data loggers to record core temperature of four partly free-ranging savanna elephants exposed to high solar radiation and environmental temperatures that exceeded core temperature (> 36 °C) in their natural habitat.

Vangl2 disruption alters the biomechanics of late spinal neurulation leading to spina bifida in mouse embryos.

Human mutations in the planar cell polarity component VANGL2 are associated with the neural tube defect spina bifida. Homozygous Vangl2 mutation in mice prevents initiation of neural tube closure, precluding analysis of its subsequent roles in neurulation. Spinal neurulation involves rostral-to-caudal 'zippering' until completion of closure is imminent, when a caudal-to-rostral closure point, 'Closure 5', arises at the caudal-most extremity of the posterior neuropore (PNP).

Biomechanical coupling facilitates spinal neural tube closure in mouse embryos.

Neural tube (NT) formation in the spinal region of the mammalian embryo involves a wave of "zippering" that passes down the elongating spinal axis, uniting the neural fold tips in the dorsal midline. Failure of this closure process leads to open spina bifida, a common cause of severe neurologic disability in humans. Here, we combined a tissue-level strain-mapping workflow with laser ablation of live-imaged mouse embryos to investigate the biomechanics of mammalian spinal closure.

Coping with heat: behavioural and physiological responses of savanna elephants in their natural habitat.

Most of southern Africa's elephants inhabit environments where environmental temperatures exceed body temperature, but we do not know how elephants respond to such environments. We evaluated the relationships between apparent thermoregulatory behaviour and environmental, skin and core temperatures for tame savanna elephants () that were free-ranging in the hot parts of the day, in their natural environment. Environmental temperature dictated elephant behaviour within a day, with potential consequences for fine-scale habitat selection, space use and foraging.

Regulation of cell protrusions by small GTPases during fusion of the neural folds.

Epithelial fusion is a crucial process in embryonic development, and its failure underlies several clinically important birth defects. For example, failure of neural fold fusion during neurulation leads to open neural tube defects including spina bifida. Using mouse embryos, we show that cell protrusions emanating from the apposed neural fold tips, at the interface between the neuroepithelium and the surface ectoderm, are required for completion of neural tube closure.

Cellular basis of neuroepithelial bending during mouse spinal neural tube closure.

Bending of the neural plate at paired dorsolateral hinge points (DLHPs) is required for neural tube closure in the spinal region of the mouse embryo. As a step towards understanding the morphogenetic mechanism of DLHP development, we examined variations in neural plate cellular architecture and proliferation during closure. Neuroepithelial cells within the median hinge point (MHP) contain nuclei that are mainly basally located and undergo relatively slow proliferation, with a 7 h cell cycle length.

Claudin-1 gene variants and susceptibility to hepatitis C infection in HIV-1 infected intravenous drug users (an ANRS case-control study).

Hepatitis C virus (HCV) seroprevalence is highly diverse among human immunodeficiency virus-1 (HIV-1) infected patients, ranging between 10% of HIV-1 infected homo-bisexuel men, to >92% in patients infected with HIV-1 who acquired HIV-1 through intravenous drug use. Thus, being HCV-free while having acquired HIV-1 via intravenous drug use is a rare situation. Claudin-1 is a protein involved in intracellular tight-junctions and has been identified as a major cellular co-receptor for HCV infection.

[Risk factors for incident cervical intraepithelial neoplasia (CIN) among HIV-infected women: a prospective study].

Objectives: To study risk factors for incident cervical intraepithelial neoplasia (CIN) among HIV-infected women.

Patients And Methods: Prospective study of a population of 97 HIV-infected women with normal Pap smear at inclusion.

Results: Fourteen CIN (diagnosed by colposcopy and confirmed with biopsy) were observed within a median follow-up of 38 months (13 CIN 1, one CIN 2).

Cyclo-oxygenase-2 expression in Barrett's oesophageal carcinogenesis: an immunohistochemical study.

Background: The incidence of Barrett's oesophageal adenocarcinoma is increasing more rapidly than any other malignancy in industrialized countries. Cyclo-oxygenase-2 appears to play an important role in gastrointestinal carcinogenesis. Previous studies on cyclo-oxygenase-2 expression in Barrett's oesophageal carcinogenesis have utilized tissue samples obtained from different patients.

Dibromoacetic acid, a prevalent by-product of drinking water disinfection, compromises the synthesis of specific seminiferous tubule proteins following both in vivo and in vitro exposures.

Dibromoacetic acid (DBA) is a by-product of drinking water disinfection that alters spermatogenesis in adult male rats. To identify a mechanism by which DBA alters spermatogenesis, seminiferous tubules representing specific groups of spermatogenic stages were exposed either in vivo or in vitro, and structural and functional consequences were evaluated. Seminiferous tubules representing stages I-V, VI-VIII, and IX-XIV were isolated from testes of adult rats and cultured overnight in conditions of reduced oxygen and temperature.

Toward a biologically based dose-response model for developmental toxicity of 5-fluorouracil in the rat: a mathematical construct.

Biologically based dose-response (BBDR) models comprise one way to incorporate mechanistic information into a dose-response assessment to be used for risk assessments. The chemotherapeutic drug 5-fluorouracil (5-FU) has been used as a prototypic compound for the construction of a BBDR model for developmental toxicity. Previous work has provided data and a general mechanistic framework for the developmental toxicity of 5-FU when it was administered to pregnant rats subcutaneously on gestation day 14.

Toward a biologically based dose-response model for developmental toxicity of 5-fluorouracil in the rat: acquisition of experimental data.

Biologically based dose-response (BBDR) models represent an emerging approach to improving the current practice of human health-risk assessment. The concept of BBDR modeling is to incorporate mechanistic information about a chemical that is relevant to the expression of its toxicity into descriptive mathematical terms, thereby providing a quantitative model that will enhance the ability for low-dose and cross-species extrapolation. Construction of a BBDR model for developmental toxicity is particularly complicated by the multitude of possible mechanisms.

Influence of the drinking water disinfection by-product dibromoacetic acid on rat estrous cyclicity and ovarian follicular steroid release in vitro.

The drinking water disinfection by-product, dibromoacetic acid (DBA) has been reported to affect gonadal functions in the male rat. However, there is little information regarding the influence of DBA on female reproductive activity. Consequently, the present study investigated the effects of DBA on estrous cyclicity and the impact in vitro of DBA on ovarian follicular steroid secretion.