12 research outputs found

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time, and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes, vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases. To worsen this situation, human-induced modifications may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge, it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    Measurement of vector boson production cross sections and their ratios using pp collisions at √s = 13.6 TeV with the ATLAS detector

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    Abstract available from publisher's website

    Beam-induced backgrounds measured in the ATLAS detector during local gas injection into the LHC beam vacuum

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    Inelastic beam-gas collisions at the Large Hadron Collider (LHC), within a few hundred metres of the ATLAS experiment, are known to give the dominant contribution to beam backgrounds. These are monitored by ATLAS with a dedicated Beam Conditions Monitor (BCM) and with the rate of fake jets in the calorimeters. These two methods are complementary since the BCM probes backgrounds just around the beam pipe while fake jets are observed at radii of up to several metres. In order to quantify the correlation between the residual gas density in the LHC beam vacuum and the experimental backgrounds recorded by ATLAS, several dedicated tests were performed during LHC Run 2. Local pressure bumps, with a gas density several orders of magnitude higher than during normal operation, were introduced at different locations. The changes of beam-related backgrounds, seen in ATLAS, are correlated with the local pressure variation. In addition the rates of beam-gas events are estimated from the pressure measurements and pressure bump profiles obtained from calculations. Using these rates, the efficiency of the ATLAS beam background monitors to detect beam-gas events is derived as a function of distance from the interaction point. These efficiencies and characteristic distributions of fake jets from the beam backgrounds are found to be in good agreement with results of beam-gas simulations performed with theFluka Monte Carlo programme

    Morfometria do aparelho genital e resposta superovulatória de coelhas suplementadas com geleia real

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    Avaliou-se o efeito da suplementação com geleia real sobre a morfometria do aparelho genital, resposta superovulatória e qualidade embrionária de coelhas. Trinta e seis fêmeas foram distribuídas em quatro grupos (G), sendo: G1 (n=9) formado por animais não suplementados com geleia real, e G2, G3 e G4 (n=9 em cada grupo) por animais suplementados com 10, 20 e 40mg/dia de geleia real. A superovulação consistiu na aplicação de 40UI de gonadotrofina coriônica equina, seguida por 40UI de gonadotrofina coriônica humana, via intramuscular, 48 horas após, e submetidas à cobrição natural. Os animais foram sacrificados, e os embriões coletados 72 horas após a cópula. Não houve diferença estatística entre tratamentos para as variáveis analisadas. O peso médio do aparelho genital foi de 10,88±0,38g; dos ovários - direito e esquerdo -, 0,28±0,02g; e o índice gonadossomático, 0,02±0,0g. O número médio de estruturas totais recuperadas foi de 9,2±1,4; de embriões viáveis, 8,7±1,4; e de degenerados, 0,5±0,2. Dos embriões viáveis, 5,6±0,8 foram classificados como grau I; 2,3±0,5, como grau II; e 0,8±0,2, como grau III. A suplementação com geleia real na dose de até 40mg/dia não apresentou efeito estimulador sobre o aparelho genital e a qualidade embrionária de coelhas

    Follicle-stimulating hormone to substitute equine chorionic gonadotropin in the synchronization of ovulation in Santa Inês ewes

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    The substitution of equine chorionic gonadotropin (eCG) by follicle-stimulating hormone (FSH) in protocols for synchronization of ovulation in Santa Inês ewes was assessed. Ten females were submitted to the insertion of intravaginal sponges containing 60 mg medroxyprogesterone acetate for 10 days; after this period sponges were withdrawn and the animals were randomly divided into two groups. Group 1 (n = 5): intramuscular injection of 0.5 mL d-cloprostenol and 300 UI eCG; Group 2 (n = 5): intramuscular injection of 0.5 mL d-cloprostenol and 20 mg FSH. Interval between sponge withdrawal and estrus beginning was 27.7 h and 35.9 h for eCG and FSH, respectively. Interval between sponge withdrawal and the end of estrus was 55.8 h for eCG treatment and 55.6 h for FSH treatment. Estrus length was 29.3 h and 19.6 h, for eCG and FSH treatments, respectively. The biggest follicle and the second in size measured 0.74 cm and 0.54 cm for eCG treatment, whereas for the FSH treatment they measured 0.73 and 0.50 cm. The interval between the beginning of estrus and ovulation was similar within all groups: 21.0 h for eCG treated ewes and 25.2 h for the ones treated with FSH. Ewes treated with eCG presented an interval of 47.5 h between sponge withdrawal and ovulation, while the ones treated with FSH presented a 61.1 h interval. Ovulation occurred 8.3 h before the end of estrus in the eCG group. On the other hand, ewes treated with FSH ovulated 5.5 h after the end of estrus. Estrus and ovulation were efficiently synchronized in Santa Inês ewes by using long-term progestogen protocol associated to the administration of 20 mg FSH, along with Prostaglandin F2α (PGF2α) at the moment of sponge withdrawal, thus substituting the use of eCG

    Plants and Phytocompounds Active Against Bothrops Venoms

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