25 research outputs found

    Synthesis of the land carbon fluxes of the Amazon region between 2010 and 2020

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    The Amazon is the largest continuous tropical forest in the world and plays a key role in the global carbon cycle. Human-induced disturbances and climate change have impacted the Amazon carbon balance. Here we conduct a comprehensive synthesis of existing state-of-the-art estimates of the contemporary land carbon fluxes in the Amazon using a set of bottom-up methods (i.e., dynamic vegetation models and bookkeeping models) and a top-down inversion (atmospheric inversion model) over the Brazilian Amazon and the whole Biogeographical Amazon domain. Over the whole biogeographical Amazon region bottom-up methodologies suggest a small average carbon sink over 2010-2020, in contrast to a small carbon source simulated by top-down inversion (2010-2018). However, these estimates are not significantly different from one another when accounting for their large individual uncertainties, highlighting remaining knowledge gaps, and the urgent need to reduce such uncertainties. Nevertheless, both methodologies agreed that the Brazilian Amazon has been a net carbon source during recent climate extremes and that the south-eastern Amazon was a net land carbon source over the whole study period (2010-2020). Overall, our results point to increasing human-induced disturbances (deforestation and forest degradation by wildfires) and reduction in the old-growth forest sink during drought

    Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

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    Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

    Evaluation of the mortality rate caused by different periods of selective portal vein occlusion in rats Avaliação da mortalidade causada por diferentes períodos de oclusão seletiva da veia porta em ratos

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    Mortality from acute selective portal vein occlusion (SPVO) is a matter of concern for surgeons during the management of traumatic portal vein injury. However, mortality rates related to different periods of SPVO remains undetermined. PURPOSE: To determine the mortality rates resulting from different periods of acute SPVO in rats. METHODS: Wistar male rats were randomized into 8 experimental, and 8 control groups. Experimental animals underwent SPVO during 15 to 75 minutes, and control groups underwent sham procedures. All surviving animals were followed up to 14 days for assessment of mortality rate. RESULTS: Death rates varied from 0% in the 15 min SPVO group, to 100% with 65 and 75 minutes of SPVO. A strongly positive correlation was observed between mortality rates and SPVO periods (p<0.001) with either linear or quadratic regression analysis tests. All deaths in the 20min and 25min SPVO groups occurred after 75 min from the moment of clamping (or after 60 min from unclamping); death from 30 or more min SPVO occurred predominantly within 75 min from clamping moment (or within 60 min from unclamping). (Exact Fisher test, p=0.009). CONCLUSIONS: The mortality from SPVO in rats increases with longer duration of SPVO; with deaths occurring later for short periods (< 25 min) of SPVO and earlier for longer periods (> 30 min) of SPVO.<br>A mortalidade da oclusão seletiva da veia porta (OSVP) preocupa os cirurgiões durante o tratamento de lesão traumática da veia porta. Entretanto, as taxas de mortalidade decorrentes de diferentes períodos de OSVP não estão determinadas. OBJETIVO: Determinar a mortalidade Decorrente de diferentes períodos de oclusão seletiva da veia porta (OSVP) em ratos. MÉTODOS: Ratos Wistar machos foram randomizados em 8 grupos experimentais e 8 controles. Os experimentais foram submetidos a OSVP por períodos de 15 a 75 minutos, seguidos de observação até o óbito, e os sobreviventes até 14 dias. Os grupos controles receberam idênticos procedimentos, exceto a OSVP. RESULTADOS: A mortalidade, a partir do momento da oclusão, aumentou progressivamente, de 0% no grupo de 15min, atingindo 100% nos grupos de 65min e 75min de OSVP. Houve alta correlação positiva entre mortalidade e duração da OSVP (p<0.001; tanto em teste de Regressão linear quanto quadrática). Os óbitos decorrentes de 20 e 25 min de OSVP ocorreram após 75min do clampeamento (ou após 60 min do desclampeamento); os decorrentes de 30min ou mais ocorreram predominantemente antes de decorridos 75 min do clampeamento (ou 60 min do desclampeamento). (Teste exato de Fisher, p<0.05). CONCLUSÕES: A mortalidade da OSVP em ratos aumenta com a maior duração da oclusão; os óbitos ocorrem mais tardiamente após oclusões breves (< 25 min), e mais precocemente nas oclusões mais prolongadas (> 30 minutos)

    Oral Administration of Probiotics (Bacillus subtilis and Lactobacillus plantarum) in Nile Tilapia (Oreochromis niloticus) Vaccinated and Challenged with Streptococcus agalactiae

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    Streptococcus agalactiae is an important bacterial pathogen in intensive Nile tilapia production, causing high mortality rates and great economic losses. This work aimed to evaluate the Nile tilapia vaccination against S. agalactiae and fed with ration containing probiotic AQUA PHOTO&reg; composed of Bacillus subtilis and Lactobacillus plantarum, on the immune response action and gut microbiota. The experimental design was completely randomized with five treatments (CON = control; ADJ = adjuvant; PRO = probiotic; VAC = vaccine; PRO + VAC = probiotic + vaccine) and five replicates. The vaccine (bacterin + adjuvant) was injected after 21 days (21d) of probiotic feeding and the vaccine was booster 14 days post-vaccination (35d). After 14 days of the booster (49d), the fish were challenged with S. agalactiae and observed for more than 14 days, completing 63 days. The immunized group showed a better survival rate (CON 40%; ADJ 57%; PRO 67%; VAC 87%; PRO + VAC 97%). The treatments VAC and PRO + VAC, after booster produced higher levels of IgM antibodies compared with the control from the same time. The combination of probiotic and vaccination provided better protection against S. agalactiae infection, directly affecting the gut microbiological profile. These results indicated the contribution of probiotic to the adaptive immune response through the modulation of the intestinal microbiota, improving the effect of the vaccination. In conclusion, AQUA PHOTO&reg;, composed of B. subtilis and L. plantarum, orally administered to Nile tilapia vaccinated against and challenged with S. agalactiae increases protection from infection and modifies the intestinal microbiota profile of the host, promoting the microbiota balance and improving adaptive immune response

    Micropropagação de Cabralea canjerana Micropropagation of Cabralea canjerana

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    A Cabralea canjerana (Vell.) Mart. (Meliaceae) (canjarana) é uma espécie arbórea nativa brasileira importante para fornecimento de madeira de boa qualidade. As sementes desta espécie não podem ser armazenadas por muito tempo e, por tanto, existe a necessidade do desenvolvimento de técnicas alternativas de propagação como a micropropagação. Neste trabalho, foram realizados experimentos de multiplicação utilizando segmentos nodais, retirados de plantas germinadas in vitro. Os segmentos foram inoculados em meio de cultura MS ou WPM, adicionado de 6-benzilaminopurina (BAP) e, ou, 2-isopenteniladenina (2-iP) nas concentrações de 2,5 ou 5 &micro;M. Microestacas de rebrotas foram colocadas em meio de cultura MS/2, com a metade da concentração dos sais do meio MS, adicionado de ácido indol 3-butírico (AIB) (0, 2,5 e 5 &micro;M). Após sete dias, foram transferidas para meio MS/2 sem auxina e na luz. Na fase de multiplicação, o meio de cultura MS foi mais adequado que o meio WPM. O segmento nodal, em presença de 2,5 &micro;M de BAP, propiciou um dos melhores resultados, com uma taxa de multiplicação de 1,77 por mês, em meio de cultura MS. O enraizamento das microestacas oriundas de rebrotas foi de 87,5% em presença de 5 &micro;M de AIB durante sete dias. A aclimatização foi realizada em casa de vegetação e proporcionou 90% de sobrevivência das mudas após 30 dias. A micropropagação da canjarana a partir de segmentos nodais de mudas cultivadas in vitro é viável para a multiplicação dessa espécie.<br>Cabralea canjerana (Vell.) Mart. (Meliaceae) ("canjarana") is a native tree of economic importance in Brazil. The storage of seeds is of short duration and it is therefore necessary to establish a protocol for micropropagation of this species. In this work, multiplication experiments were carried out using nodal segments, excised from in vitro germinated plants. The segments were inoculated in MS or WPM culture medium, supplemented with 6-benzylaminopurine (BAP) and/or 2-isopentenyladenine (2-iP) at 2.5 or 5 &micro;M. Micro-cuttings were taken from new shoots developed from the seeds and used in a rooting experiment using a culture medium with half-strength MS medium (MS/2) supplemented with indolbutyric acid (IBA) (0, 2.5 and 5 &micro;M). After 7 days in this medium, they were transferred to MS/2 medium without auxin under light. During the multiplication phase, the MS culture medium was more suitable for the multiplication of C. canjerana than WPM medium. The nodal segments cultured in the presence of 2.5 &micro;M BAP showed the best result, with a multiplication rate of 1.77 per month on MS medium. The rooting of the microcuttings was 87.5% when they were kept in the presence of 5 &micro;M IBA for 7 days. An acclimatization rate of 90% was achieved after 30 days in the greenhouse. In conclusion, the micropropagation of C. canjerana from nodal segments of plantlets is possible for this species
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