144 research outputs found

    Whooping crane (Grus americana) demography and environmental factors in a population growth simulation model

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    The Whooping Crane (Grus americana) is among North AmericaÂs most charismatic species. Between 1938 and 2004, the population that migrates between Aransas National Wildlife Refuge (ANWR) and Wood Buffalo National Park (WBNP), grew from 18 to 217 individuals. The recovery plan objective for this endangered species is to downlist the population in 2035, but this requires interpretive assessment of population responses to environmental factors over the long term. I analyzed 27 years of banding data, 37 years of nest monitoring data, and 20 years of winter reports to estimate age-specific mortality and fecundity rates. The resulting life table yielded an intrinsic rate of increase (r) of 0.14/y, a net reproductive rate (Ro) of 6.4/y, and a mean length of a generation (G) of 13y. Path analysis of environmental factors, demographic variables (natality and mortality), and the finite rate of population increase (lambda) showed that annual mortality, temperatures from the ANWR, WBNP and at a migration stop-over in Nebraska, and pond water depth were good predictors of lambda variability. However, other environmental factors were significantly correlated: at ANWR, October- March temperature (extreme minimum and maximum), December temperature (mean and extreme minimum), November-January precipitation, and September-March freshwater inflow; at WBNP, March-September precipitation, March-May temperature, and temperatures during the September - October fall migration. The Pacific Decadal Oscillation (PDO) affected lambda indirectly through environmental factors in Nebraska and ANWR. I graphically analyzed relevant data trends from 1967 to 2004 to identify the relation between phases of PDO and environmental and demographic variables. During PDO cold phases, a synchronization of Âextreme environmental values was observed from the different regions; during warm phases extreme environmental values were scattered. Most periods of Whooping Crane population decline happened during cold phases. I developed a compartment model to represent Whooping Crane population dynamics utilizing the new data on survivorship and fecundity from banded birds. The model was capable of simulating historical population trends with adjustments in brood success and egg mortality. The model will allow future studies to test population responses to various environmental scenarios at the WBNP, during fall and spring migrations, and at the ANWR

    Dismantling the Beania magellanica (Busk, 1852) species complex (Bryozoa, Cheilostomata): two new species from European waters

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    New research on bryozoans has determined that formerly widespread species are in many cases complexes of similar, but distinct, species with more restricted distributions. Notwithstanding, the limits of distribution are still unresolved for many taxa, and occasionally a wide distribution is confirmed. Beania magellanica has been considered a widespread species, distributed throughout the Southern Hemisphere, parts of northern Pacific and Atlantic Oceans and the Mediterranean Sea. This study examines the Magellanic-type material, together with other historic samples and new specimens collected in the western Mediterranean and Adriatic, and for the first time, presents specimens from the European North Atlantic. Morphological comparisons and biometric analysis show the existence of three different species among the specimens studied. A redescription of B. magellanica based on the type specimen is presented, and two new species are described: B. serrata sp. nov. from the Northeast Atlantic and B. mediterranea sp. nov. from the Mediterranean Sea. These results indicate that B. magellanica s.l. is a large complex of species and that most specimens from different parts of the world must be revisedThis research was conducted thanks to the funds granted by the Austrian Science Fund (FWF, project number AP28954-B29). The work of Karine Nascimento and Leandro M. Vieira was supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, project numbers 142058/2015-7 and 422563/2016-1) and by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, project number 88881.135517/2016-01). Part of the revision of the samples was supported by the project “Fauna Ibérica: Briozoos II (Familia Cribrilinidae–Familia Watersiporidae)” (CGL2010-22267-C07-02), co-financed by the Ministerio de Economía y Competitividad (Spanish government) and FEDERS

    As consequĂŞncias da pandemia do Covid-19 em gestantes

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    A síndrome respiratória aguda provocada pelo vírus SARS-CoV-2, chamada de COVID-19, começou em Wuhan, na China, e foi dada como uma pandemia em 2020, essa infecção provoca consequências em grávidas devido às alterações fisiológicas que essas sofrem no período gestacional. Diante disso, o presente estudo teve como objetivo analisar em forma de revisão de literatura artigos dos últimos cinco anos que mostrassem a relação da COVID-19 com as grávidas. Para isso, foram utilizados descritores como “gestantes”, “pandemia da COVID-19”, “SARS-CoV-2”, “pregnant women and the COVID-19 pandemic” nas bases de dados Biblioteca Virtual de Saúde (BVS), Scientific Eletronic Library Online (SciELO), National Library of Medicine (PubMed) e EbscHost. Foram encontrados 23 artigos que abordassem o necessário para a realização desse artigo. Nesse sentido, encontramos os sintomas mais comuns em gestantes, por exemplo, dispneia, diarreia, coriza, congestão nasal e até complicações mais graves como a síndrome respiratória aguda grave (SARS), além de problemas no nascimento ou durante a gestação como partos prematuros, aumento da possibilidade de aborto e de mortalidade materna e pré-eclâmpsia. Ademais, foram notadas ainda complicações neonatais, por exemplo o baixo peso ao nascer e a prematuridade. A transmissão vertical não foi confirmada, com isso, não houve contraindicação de parto natural e recomendou-se que a amamentação fosse feita de maneira normal desde que a história clínica permitisse e fossem seguidas as medidas higiênicas. Portanto, concluímos a importância desse estudo para os profissionais de saúde saberem a maneira correta de lidar com as gestantes em um cenário de pandemia ou epidemia, principalmente se alguma dessas acometer o sistema respiratório, além de ser extremamente importante para o autocuidado das grávidas em alguma situação semelhante

    Exhaustive analysis of BH4 and dopamine biosynthesis genes in patients with Dopa-responsive dystonia

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    Dopa-responsive dystonia is a childhood-onset dystonic disorder, characterized by a dramatic response to low dose of l-Dopa. Dopa-responsive dystonia is mostly caused by autosomal dominant mutations in the GCH1 gene (GTP cyclohydrolase1) and more rarely by autosomal recessive mutations in the TH (tyrosine hydroxylase) or SPR (sepiapterin reductase) genes. In addition, mutations in the PARK2 gene (parkin) which causes autosomal recessive juvenile parkinsonism may present as Dopa-responsive dystonia. In order to evaluate the relative frequency of the mutations in these genes, but also in the genes involved in the biosynthesis and recycling of BH4, and to evaluate the associated clinical spectrum, we have studied a large series of index patients (n = 64) with Dopa-responsive dystonia, in whom dystonia improved by at least 50% after l-Dopa treatment. Fifty seven of these patients were classified as pure Dopa-responsive dystonia and seven as Dopa-responsive dystonia-plus syndromes. All patients were screened for point mutations and large rearrangements in the GCH1 gene, followed by sequencing of the TH and SPR genes, then PTS (pyruvoyl tetrahydropterin synthase), PCBD (pterin-4a-carbinolamine dehydratase), QDPR (dihydropteridin reductase) and PARK2 (parkin) genes. We identified 34 different heterozygous point mutations in 40 patients, and six different large deletions in seven patients in the GCH1 gene. Except for one patient with mental retardation and a large deletion of 2.3 Mb encompassing 10 genes, all patients had stereotyped clinical features, characterized by pure Dopa-responsive dystonia with onset in the lower limbs and an excellent response to low doses of l-Dopa. Dystonia started in the first decade of life in 40 patients (85%) and before the age of 1 year in one patient (2.2%). Three of the 17 negative GCH1 patients had mutations in the TH gene, two in the SPR gene and one in the PARK2 gene. No mutations in the three genes involved in the biosynthesis and recycling of BH4 were identified. The clinical presentations of patients with mutations in TH and SPR genes were strikingly more complex, characterized by mental retardation, oculogyric crises and parkinsonism and they were all classified as Dopa-responsive dystonia-plus syndromes. Patient with mutation in the PARK2 gene had Dopa-responsive dystonia with a good improvement with l-Dopa, similar to Dopa-responsive dystonia secondary to GCH1 mutations. Although the yield of mutations exceeds 80% in pure Dopa-responsive dystonia and Dopa-responsive dystonia-plus syndromes groups, the genes involved are clearly different: GCH1 in the former and TH and SPR in the late

    Prevalence of amyloid PET positivity in dementia syndromes: a meta-analysis

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    IMPORTANCE: Amyloid-β positron emission tomography (PET) imaging allows in vivo detection of fibrillar plaques, a core neuropathological feature of Alzheimer disease (AD). Its diagnostic utility is still unclear because amyloid plaques also occur in patients with non-AD dementia. OBJECTIVE: To use individual participant data meta-analysis to estimate the prevalence of amyloid positivity on PET in a wide variety of dementia syndromes. DATA SOURCES: The MEDLINE and Web of Science databases were searched from January 2004 to April 2015 for amyloid PET studies. STUDY SELECTION: Case reports and studies on neurological or psychiatric diseases other than dementia were excluded. Corresponding authors of eligible cohorts were invited to provide individual participant data. DATA EXTRACTION AND SYNTHESIS: Data were provided for 1359 participants with clinically diagnosed AD and 538 participants with non-AD dementia. The reference groups were 1849 healthy control participants (based on amyloid PET) and an independent sample of 1369 AD participants (based on autopsy). MAIN OUTCOMES AND MEASURES: Estimated prevalence of positive amyloid PET scans according to diagnosis, age, and apolipoprotein E (APOE) ε4 status, using the generalized estimating equations method. RESULTS: The likelihood of amyloid positivity was associated with age and APOE ε4 status. In AD dementia, the prevalence of amyloid positivity decreased from age 50 to 90 years in APOE ε4 noncarriers (86% [95% CI, 73%-94%] at 50 years to 68% [95% CI, 57%-77%] at 90 years; n = 377) and to a lesser degree in APOE ε4 carriers (97% [95% CI, 92%-99%] at 50 years to 90% [95% CI, 83%-94%] at 90 years; n = 593; P < .01). Similar associations of age and APOE ε4 with amyloid positivity were observed in participants with AD dementia at autopsy. In most non-AD dementias, amyloid positivity increased with both age (from 60 to 80 years) and APOE ε4 carriership (dementia with Lewy bodies: carriers [n = 16], 63% [95% CI, 48%-80%] at 60 years to 83% [95% CI, 67%-92%] at 80 years; noncarriers [n = 18], 29% [95% CI, 15%-50%] at 60 years to 54% [95% CI, 30%-77%] at 80 years; frontotemporal dementia: carriers [n = 48], 19% [95% CI, 12%-28%] at 60 years to 43% [95% CI, 35%-50%] at 80 years; noncarriers [n = 160], 5% [95% CI, 3%-8%] at 60 years to 14% [95% CI, 11%-18%] at 80 years; vascular dementia: carriers [n = 30], 25% [95% CI, 9%-52%] at 60 years to 64% [95% CI, 49%-77%] at 80 years; noncarriers [n = 77], 7% [95% CI, 3%-18%] at 60 years to 29% [95% CI, 17%-43%] at 80 years. CONCLUSIONS AND RELEVANCE: Among participants with dementia, the prevalence of amyloid positivity was associated with clinical diagnosis, age, and APOE genotype. These findings indicate the potential clinical utility of amyloid imaging for differential diagnosis in early-onset dementia and to support the clinical diagnosis of participants with AD dementia and noncarrier APOE ε4 status who are older than 70 years

    The GRAVITY+ Project: Towards All-sky, Faint-Science, High-Contrast Near-Infrared Interferometry at the VLTI

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    The GRAVITY instrument has been revolutionary for near-infrared interferometry by pushing sensitivity and precision to previously unknown limits. With the upgrade of GRAVITY and the Very Large Telescope Interferometer (VLTI) in GRAVITY+, these limits will be pushed even further, with vastly improved sky coverage, as well as faint-science and high-contrast capabilities. This upgrade includes the implementation of wide-field off-axis fringe-tracking, new adaptive optics systems on all Unit Telescopes, and laser guide stars in an upgraded facility. GRAVITY+ will open up the sky to the measurement of black hole masses across cosmic time in hundreds of active galactic nuclei, use the faint stars in the Galactic centre to probe General Relativity, and enable the characterisation of dozens of young exoplanets to study their formation, bearing the promise of another scientific revolution to come at the VLTI.Comment: Published in the ESO Messenge
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