85 research outputs found

    Climate and landscape changes enhance the global spread of a bloom-forming dinoflagellate related to fish kills and water quality deterioration

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    Global inland water biodiversity is under mounting stress facing future scenarios of climate change, biological invasions, pollution, diversion, damming of rivers, and increase of water abstractions. Apart from having isolated effects, all these stressors threats act synergistically and thus pose additional emerging threats to biodiversity and ecosystem services. Native to Northern Europe, the nuisance and potential toxic dinoflagellate Ceratium furcoides (Levander) Langhans 1925 is a silent invader that blooms in freshwater systems; it has one of the most rapid spread rates globally. We propose a framework to determine the worldwide most vulnerable areas for the invasion by C. furcoides shortly (2041-2060) by combining future scenarios of climate change (a proxy for invasiveness) derived from ecological niche models with future dam construction data (a proxy for invasibility). The nine models applied in four future scenarios of greenhouse gas emission from Coupled Model Intercomparison Project Phase 6 showed a general increase in areas suitable for the invasion success of C. furcoides. High susceptibility overlapped with areas densely occupied by large and medium-size dams and future dam construction projects. Considering that C. furcoides can reproduce from a single cell, produces resistant stages, and has several strategies to cope with local environmental constraints, early detection protocols, and mitigation actions are urgently needed to avoid biodiversity declines related to this invader.Peer reviewe

    Estimating the causal effects of modifiable, non-genetic factors on Huntington Disease progression using propensity score weighting

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    Introduction Despite being genetically inherited, it is unclear how non-genetic factors (e.g., substance use, employment) might contribute to the progression and severity of Huntington's disease (HD). Methods We used propensity score (PS) weighting in a large (n = 2914) longitudinal dataset (Enroll-HD) to examine the impact of education, employment status, and use of tobacco, alcohol, and recreational and therapeutic drugs on HD progression. Each factor was investigated in isolation while controlling for 19 other factors to ensure that groups were balanced at baseline on potential confounders using PS weights. Outcomes were compared several years later using doubly robust models. Results Our results highlighted cases where modifiable (non-genetic) factors - namely light and moderate alcohol use and employment - would have been associated with HD progression in models that did not use PS weights to control for baseline imbalances. These associations did not hold once we applied PS weights to balance baseline groups. We also found potential evidence of a protective effect of substance use (primarily marijuana use), and that those who needed antidepressant treatment were likely to progress faster than non-users. Conclusions Our study is the first to examine the effect of non-genetic factors on HD using a novel application of PS weighting. We show that previously-reported associated factors – including light and moderate alcohol use – are reduced and no longer significantly linked to HD progression after PS weighting. This indicates the potential value of PS weighting in examining non-genetic factors contributing to HD as well as in addressing the known biases that occur with observational data

    Influence of sweeteners in the biodistribution of radiopharmaceutical and laboratory tests in rats

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    This study aimed to evaluate the effect of supplementation of sucralose and fructose on the metabolism of adolescent rats. Eighteen male Wistar rats were divided into 3 groups: control group (GC), fructose group (GF) treated with 50 mg/kg of fructose, and sucralose group (GS) receiving 50 mg/kg of sucralose for 24 days. The weight and feed intake were measured weekly. At the end of the experiment, some biochemical parameters, histopathology of the liver and biodistribution of the radiotracer 99mTc-sodium phytate in liver and blood were analyzed. The GF showed higher body weight only in the first week compared with GS and GC (p<0.05). Histopathology and % ATI/g radiotracer 99mTc-sodium phytate in liver and blood were not different between the groups. The GF showed higher values of aspartate aminotransferase activity, bilirubin, alkaline phosphatase activity and gamma glutamyl transferase activity, compared with the other groups (GC and GS) (p<0.05). Activity of alanine aminotransferase and albumin level of GF were higher than GS (p<0.05). For other parameters, no statistical difference was observed. It was concluded that the use of fructose during the experiment was able to alter hepatic enzymes, but on the other hands, the use of sucralose caused no change.Keywords: Sucralose, fructose, adolescent rats, radiopharmaceutica

    Wild dogs at stake: deforestation threatens the only Amazon endemic canid, the short-eared dog (Atelocynus microtis)

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    The persistent high deforestation rate and fragmentation of the Amazon forests are the main threats to their biodiversity. To anticipate and mitigate these threats, it is important to understand and predict how species respond to the rapidly changing landscape. The short-eared dog Atelocynus microtis is the only Amazon-endemic canid and one of the most understudied wild dogs worldwide. We investigated short-eared dog habitat associations on two spatial scales. First, we used the largest record database ever compiled for short-eared dogs in combination with species distribution models to map species habitat suitability, estimate its distribution range and predict shifts in species distribution in response to predicted deforestation across the entire Amazon (regional scale). Second, we used systematic camera trap surveys and occupancy models to investigate how forest cover and forest fragmentation affect the space use of this species in the Southern Brazilian Amazon (local scale). Species distribution models suggested that the short-eared dog potentially occurs over an extensive and continuous area, through most of the Amazon region south of the Amazon River. However, approximately 30% of the short-eared dog's current distribution is expected to be lost or suffer sharp declines in habitat suitability by 2027 (within three generations) due to forest loss. This proportion might reach 40% of the species distribution in unprotected areas and exceed 60% in some interfluves (i.e. portions of land separated by large rivers) of the Amazon basin. Our local-scale analysis indicated that the presence of forest positively affected short-eared dog space use, while the density of forest edges had a negative effect. Beyond shedding light on the ecology of the short-eared dog and refining its distribution range, our results stress that forest loss poses a serious threat to the conservation of the species in a short time frame. Hence, we propose a re-assessment of the short-eared dog's current IUCN Red List status (Near Threatened) based on findings presented here. Our study exemplifies how data can be integrated across sources and modelling procedures to improve our knowledge of relatively understudied species

    Tibouchina sellowiana (Cham.) Cogn.: enraizamento, anatomia e análises bioquímicas nas quatro estações do ano.

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    The present work tried to verify the effects of application of different concentration of indolebutyric acid (IBA) in talc in solution, in the rooting of cutting of Tibouchina sellowiana (Cham.) Cogn.  collected in the four seasons, as well as its anatomical and biochemical variation. The semiharwood cuttings were treated with 0, 1500 and 3000 mg L-1 indolebutyric acid (IBA), in powder and alchoolic solutions. After 65 days in a greenhouse, rooting percentage, length and number of roots, cutting with callus percentage and survival, were evaluated. The use of the IBA was efficient in the induction radicial, being indifferent the form in which it was applied. The most promising stations in the formation of the system radicial were the spring (78,75%) with 3000 mg L-1 or mg kg-1 IBA and the summer (63,12 %)  with 1500 mg L-1 or mg kg-1 IBA.  (82,50%) with 3000 mg kg-1 IBA. Considering the cutting in the base of the stakes, in the moment of the cutting, no possible anatomical barrier or structural difference were detected so that it should promoted variations in the answers of the rooting uring the four seasons. Biochemical analyses done from the cuttings collected in the four seasons revealed that the largest concentrations of total sugars were obtained in the winter (83,21 mg g-1) and in the autumn (72,79 mg g-1). The same stations also presented the largest protein concentrations (4,69 and 3,95 mg g-1 respectively).O presente trabalho buscou verificar os efeitos da aplicação de diferentes concentrações do ácido indolbutírico (AIB), em talco e em solução, no enraizamento de estacas caulinares de Tibouchina sellowiana (Cham.) Cogn. coletadas nas quatro estações do ano, bem como suas variações anatômicas e bioquímicas. Estacas semilenhosas foram tratadas com 0, 1500 e 3000 mg L-1 de ácido indolbutírico (AIB), em talco e solução 50% alcoólica. Após 65 dias em casa-de-vegetação, foram avaliados a porcentagem de estacas enraizadas, o número e o comprimento das raízes, a porcentagem de estacas com calos e a sobrevivência. O uso do AIB mostrou-se eficiente na indução radicial, sendo indiferente a forma em que foi aplicado. As estações mais promissoras foram a primavera (78,75%) com 3.000 mg L-1 ou mg kg-1 de AIB e o verão (63,12%) com 1.500 mg L-1 ou mg kg-1 de AIB. Das secções feitas na base das estacas, no momento da estaquia, não foi detectada nenhuma possível barreira anatômica ou diferença estrutural que promovesse variações no enraizamento. Análises bioquímicas feitas das estacas revelaram que as maiores concentrações de açúcares totais foram obtidas no inverno (83,21 mg g-1 de tecido) e no outono (72,79 mg g-1), as estações que também apresentaram as maiores concentrações de proteínas (4,69 e 3,95 mg g-1 respectivamente)

    ADHERENCE TO CARDIOVASCULAR REHABILITATION WITH THE USE OF EXERGAMING: A SYSTEMATIC REVIEW

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    Introdução: Estudos mostram que há uma baixa adesão à reabilitação cardiovascular (RCV) implicando em limitações quanto aos benefícios esperados. É importante investigar se a diversificação de intervenções já aplicadas na RCV, como a adoção do exergaming, pode proporcionar maior adesão à esse tratamento. Objetivo: Revisar estudos que investigaram a adesão intragrupo à RCV de pacientes em uso do exergaming e comparar, intergrupos, com pacientes submetidos a RCV convencional. Métodos: Trata-se de uma revisão sistemática que incluiu estudos de intervenção originais, indexados em bases de dados e publicados até abril de 2021, sem restrições de idioma. A busca foi realizada no PubMed/Medline, Web of Science, Scopus, Cochrane e PEDro, em abril de 2021. Resultados: Foram incluídos 8 estudos. Em 3 deles, a média de adesão às sessões de RCV com exergaming foi de 77%. Em outro estudo, cerca de 60% dos participantes estavam mais de 80% aderentes ao tempo de jogo recomendado. No quinto estudo, o tempo médio de uso do exergaming foi de 28 ± 13 minutos/dia, superior ao recomendado de 20 minutos/dia. No sexto estudo, a mediana de atendimento individual foi de 96%. No sétimo, houve 100% de adesão às sessões de RCV. Já no oitavo estudo, houve aumento significativo na adesão em 12 semanas de RCV com exergaming (72,87% para 82,80%) e redução quando exergaming foi descontinuado (82,80% para 65,48%, p < 0,05). Conclusão: A melhor evidência disponível demonstra um efeito positivo do exergaming na adesão do paciente à RCV.Introduction: Studies show that there is a low adherence to cardiovascular rehabilitation (CVR) implying limitations as to expected benefits. It is important to investigate whether the diversification of interventions already applied in CVR, such as the adoption of exergaming, can provide greater adherence to this treatment. Objective: To review studies that investigated the intragroup adherence to CVR of patients using exergaming and comparing, intergroup, with patients undergoing conventional CVR. Methods: This was a systematic review that included original intervention studies indexed in databases and published up to April 2021, without language restrictions. The search was performed in PubMed/Medline, Web of Science, Scopus, Cochrane, and PEDro, in April 2021. Results: A total of 8 studies were included. In 3 of them, the average adherence to CVR sessions with exergaming was 77%. In another study, about 60% of the participants were more than 80% adherent to the recommended playing time. In the fifth study, the average time of exergaming use was 28 ± 13 minutes/day, which is higher than the recommended 20 minutes/day. In the sixth study, the median of individual attendance was 96%. In the seventh, there was 100% adherence to the CVR sessions. And in the eighth study, there was a significant increase in adherence at 12 weeks of CVR with exergaming (72.87% vs. 82.80%) and a reduction when exergaming was discontinued (82.80% to 65.48%, p < 0.05). Conclusion: The best available evidence demonstrates a positive effect of exergaming on CVR patient adherence

    A Deviation from the Bipolar-Tetrapolar Mating Paradigm in an Early Diverged Basidiomycete

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    In fungi, sexual identity is determined by specialized genomic regions called MAT loci which are the equivalent to sex chromosomes in some animals and plants. Usually, only two sexes or mating types exist, which are determined by two alternate sets of genes (or alleles) at the MAT locus (bipolar system). However, in the phylum Basidiomycota, a unique tetrapolar system emerged in which four different mating types are generated per meiosis. This occurs because two functionally distinct molecular recognition systems, each encoded by one MAT region, constrain the selection of sexual partners. Heterozygosity at both MAT regions is a pre-requisite for mating in both bipolar and tetrapolar basidiomycetes. Tetrapolar mating behaviour results from the absence of genetic linkage between the two regions bringing forth up to thousands of mating types. The subphylum Pucciniomycotina, an early diverged lineage of basidiomycetes encompassing important plant pathogens such as the rusts and saprobes like Rhodosporidium and Sporidiobolus, has been so far poorly explored concerning the content and organization of MAT loci. Here we show that the red yeast Sporidiobolus salmonicolor has a mating system unlike any previously described because occasional disruptions of the genetic cohesion of the bipolar MAT locus originate new mating types. We confirmed that mating is normally bipolar and that heterozygosity at both MAT regions is required for mating. However, a laboratory cross showed that meiotic recombination may occur within the bipolar MAT locus, explaining tetrapolar features like increased allele number and evolution rates of some MAT genes. This pseudo-bipolar system deviates from the classical bipolar–tetrapolar paradigm and, to our knowledge, has never been observed before. We propose a model for MAT evolution in the Basidiomycota in which the pseudo-bipolar system may represent a hitherto unforeseen gradual form of transition from an ancestral tetrapolar system to bipolarity

    European Organization for Caries Research Workshop: Methodology for Determination of Potentially Available Fluoride in Toothpastes

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    Toothpastes are the most universally accepted form of fluoride delivery for caries prevention. To provide anti-caries benefits, they must be able to release fluoride during the time of tooth brushing or post brushing into the oral cavity. However, there is no standard accepted procedure to measure how much fluoride in a toothpaste may be (bio) available for release. The European Organization for Caries Research proposed and supported a workshop with experts in fluoride analysis in toothpastes and representatives from industry. The objective of the workshop was to discuss issues surrounding fluoride analysis in toothpaste and reach consensus on terminology and best practices, wherever the available evidence allowed it. Participants received a background paper and heard presentations followed by structured discussion to define the problem. The group also reviewed evidence on the validity, reliability and feasibility of each technique (namely chromatography and fluoride electroanalysis) and discussed their strengths and limitations. Participants were able to reach a consensus on terminology and were also able to identify and summarize the advantages and disadvantages of each technique. However, they agreed that most currently available methods were developed for regulatory agencies several decades ago, utilizing the best available data from clinical trials then, but require to be updated. They also agreed that although significant advances to our understanding of the mechanism of action of fluoride in toothpaste have been achieved over the past 4 decades, this clearly is an extraordinarily complex subject and more work remains to be done
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