126 research outputs found

    The Evolutionary Dynamics of the Lion Panthera leo Revealed by Host and Viral Population Genomics

    Get PDF
    The lion Panthera leo is one of the world's most charismatic carnivores and is one of Africa's key predators. Here, we used a large dataset from 357 lions comprehending 1.13 megabases of sequence data and genotypes from 22 microsatellite loci to characterize its recent evolutionary history. Patterns of molecular genetic variation in multiple maternal (mtDNA), paternal (Y-chromosome), and biparental nuclear (nDNA) genetic markers were compared with patterns of sequence and subtype variation of the lion feline immunodeficiency virus (FIVPle), a lentivirus analogous to human immunodeficiency virus (HIV). In spite of the ability of lions to disperse long distances, patterns of lion genetic diversity suggest substantial population subdivision (mtDNA ΊST = 0.92; nDNA FST = 0.18), and reduced gene flow, which, along with large differences in sero-prevalence of six distinct FIVPle subtypes among lion populations, refute the hypothesis that African lions consist of a single panmictic population. Our results suggest that extant lion populations derive from several Pleistocene refugia in East and Southern Africa (∌324,000–169,000 years ago), which expanded during the Late Pleistocene (∌100,000 years ago) into Central and North Africa and into Asia. During the Pleistocene/Holocene transition (∌14,000–7,000 years), another expansion occurred from southern refugia northwards towards East Africa, causing population interbreeding. In particular, lion and FIVPle variation affirms that the large, well-studied lion population occupying the greater Serengeti Ecosystem is derived from three distinct populations that admixed recently

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

    Get PDF
    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    The US Program in Ground-Based Gravitational Wave Science: Contribution from the LIGO Laboratory

    Get PDF
    Recent gravitational-wave observations from the LIGO and Virgo observatories have brought a sense of great excitement to scientists and citizens the world over. Since September 2015,10 binary black hole coalescences and one binary neutron star coalescence have been observed. They have provided remarkable, revolutionary insight into the "gravitational Universe" and have greatly extended the field of multi-messenger astronomy. At present, Advanced LIGO can see binary black hole coalescences out to redshift 0.6 and binary neutron star coalescences to redshift 0.05. This probes only a very small fraction of the volume of the observable Universe. However, current technologies can be extended to construct "3rd Generation" (3G) gravitational-wave observatories that would extend our reach to the very edge of the observable Universe. The event rates over such a large volume would be in the hundreds of thousands per year (i.e. tens per hour). Such 3G detectors would have a 10-fold improvement in strain sensitivity over the current generation of instruments, yielding signal-to-noise ratios of 1000 for events like those already seen. Several concepts are being studied for which engineering studies and reliable cost estimates will be developed in the next 5 years

    Relevé tridimensionnel du site de Preuilly :premiÚre phase

    No full text
    info:eu-repo/semantics/publishe

    Direct dating of brittle extensional deformation contemporaneous of Neogene exhumation of the internal zones of the Rif Chain

    No full text
    International audienceThe brittle deformation of internal zones of the Rif chain, corresponding to the southern margin of the West Alboran Basin, is not or poorly dated because of the lack of stratigraphic constraints. We provide for the first time a direct dating of brittle deformation of internal zones of the Rif chain, in the Ceuta peninsula located in the westernmost part of the Gibraltar arc. 40Ar/39Ar illite ages from fault gouges in the footwall and hanging wall of the Ceuta Shear Zone range from 11.9 ± 2.5 Ma to 15.7 ± 1.7 Ma and from 14.7 ± 0.1 Ma to 18.9 ± 0.8 Ma, respectively. In addition, (Usingle bondTh)/He apatite ages from both units have been measured. They are younger in the hangingwall (~20–21 Ma) than in the footwall (14–19 Ma), which highlights slightly different cooling histories. Thus, we interpret the illite ages to date growth of authigenic illite (1M polytype) during exhumation through the top few kilometers of the earth's surface.This study of brittle deformation within the internal zones of the Rif chain reveals that an E-W directed extension occurred between ~18–15 Ma during the low temperature exhumation of Sebtide-AlpujĂĄrride units. From 15 to 11 Ma, the direction of extension shifted to NNW-SSE and only minor steep normal faults occurred. Brittle normal faulting occurred during a stage of slow cooling (~1–2 °C/myr) starting at ~19 Ma and coeval with exhumation processes within the uppermost levels of the continental crust. These new data emphasize a continuum of extensional deformation during the Burdigalian–Serravalian interval with an early E-W directed phase and then a NNW-SSE directed phase that match well the main subsidence pulses identified offshore in the neighboring West Alboran Basin

    Fear of COVID-19 Scale (FCV-19S) across countries : Measurement invariance issues

    No full text
    Aim: The threats of novel coronavirus disease 2019 (COVID-19) have caused fears worldwide. The Fear of COVID-19 Scale (FCV-19S) was recently developed to assess the fear of COVID-19. Although many studies found that the FCV-19S is psychometrically sound, it is unclear whether the FCV-19S is invariant across countries. The present study aimed to examine the measurement invariance of the FCV-19S across eleven countries. Design: Cross-sectional study. Methods: Using data collected from prior research on Bangladesh (N = 8,550), United Kingdom (N = 344), Brazil (N = 1,843), Taiwan (N = 539), Italy (N = 249), New Zealand (N = 317), Iran (N = 717), Cuba (N = 772), Pakistan (N = 937), Japan (N = 1,079) and France (N = 316), comprising a total 15,663 participants, the present study used the multigroup confirmatory factor analysis (CFA) and Rasch differential item functioning (DIF) to examine the measurement invariance of the FCV-19S across country, gender and age (children aged below 18 years, young to middle-aged adults aged between 18 and 60 years, and older people aged above 60 years). Results: The unidimensional structure of the FCV-19S was confirmed. Multigroup CFA showed that FCV-19S was partially invariant across country and fully invariant across gender and age. DIF findings were consistent with the findings from multigroup CFA. Many DIF items were displayed for country, few DIF items were displayed for age, and no DIF items were displayed for gender. Conclusion: Based on the results of the present study, the FCV-19S is a good psychometric instrument to assess fear of COVID-19 during the pandemic period. Moreover, the use of FCV-19S is supported in at least ten countries with satisfactory psychometric properties

    Lack of acclimation in Ophionotus victoriae: brittle stars are not fish

    No full text
    Acclimation is possibly the most important criterion deciding an animal's ability to survive change. Species with poor abilities to acclimate to small environmental change are likely to be the most vulnerable in future warming scenarios. Two separate assemblages of Ophionotus victoriae were slowly acclimated from 0A degrees C to either +2 or +3A degrees C and then held at these higher temperatures over a prolonged timescale. None of the animals were able to acclimate; with failure occurring from day 19 at +3A degrees C and day 24 at +2A degrees C, indicating that this species is very sensitive to small long-term seawater temperature increases. These data indicate that O. victoriae has probably the poorest ability to acclimate to elevated temperatures of any species studied to date. Given previous data showing some Antarctic fish can acclimate to +4A degrees C, the predicted effects of increased seawater temperatures on the Antarctic food web and ecology must be assessed at the individual species level and interpreted with care
    • 

    corecore