88 research outputs found
Tamanho de amostra para avaliar a densidade populacional de lagartas em lavouras de soja
A amostragem de pragas é uma das bases para a tomada de decisão no manejo de pragas em lavouras de soja. Assim, determinar o plano amostral mais adequado consiste em definir a unidade amostral, o método de amostragem e o tamanho de amostra para a quantificação da entomofauna. O objetivo foi estimar o tamanho de amostra para medir a densidade populacional de espécies de lagartas, variando métodos de coleta, altitude e cultivares de soja. Foram amostradas 100 lavouras de soja, distribuídas em nove municípios da região central do Rio Grande do Sul, em três safras agrícolas (2010/2011, 2011/2012, 2012/2013). Em cada lavoura foram demarcados 30 pontos distanciados 20 metros entre si. Em cada ponto foram coletadas lagartas das espécies Chrysodeixis includens, Anticarsia gemmatalis e Rachiplusia nu, por meio dos métodos pano-de-batida largo e rede entomológica, totalizando 6.000 coletas. Para cada lavoura, método de coleta e espécie de lagarta foi estimado a média da densidade populacional e o tamanho de amostra por meio de reamostragem. Usando o pano-de-batida largo para a coleta de lagartas em soja, para um erro de estimação (amplitude do intervalo de confiança) igual a dois lagartas e densidade populacional na classe > 2 lagartas. m-2, o tamanho de amostra é 47, 78 e 18, respectivamente, para as espécies C. includens, A. gemmatalis e R. nu e para rede o tamanho de amostra é 19 e 43, respectivamente, para as espécies C. includens e A. gemmatalis. Os resultados indicam que o tamanho de amostra (número de pontos) para determinar a densidade populacional de lagartas varia com o método de coleta, altitude, cultivar e a densidade populacional
Mitral valve repair by Double Teflon technique: cardiac remodeling analysis by tridimensional echocardiography
INTRODUÇÃO: A plastia valvar mitral é o tratamento de escolha para a insuficiência mitral, porém a literatura é escassa em relação ao comportamento do átrio e ventrículo esquerdos após a plastia mitral sem utilização de anéis protéticos. OBJETIVO: Analisar a morfologia e a função cardíaca de indivíduos submetidos à plastia valvar mitral pela técnica de Duplo Teflon, por meio da ecocardiografia tridimensional. MÉTODOS: Foram incluídos 14 pacientes com insuficiência mitral mixomatosa, submetidos à plastia mitral pela técnica de Duplo Teflon. Treze pacientes encontravam-se em classe III/IV. Os pacientes foram avaliados nos períodos pré-operatório, pós-operatório imediato (POI), 6 meses e 1 ano após a plastia mitral. Foi utilizado teste de análise de variância de medidas repetidas para o estudo estatístico, sendo considerado estatisticamente significante P<0,05. RESULTADOS: A análise dos volumes sistólicos, atrial e ventricular demonstrou redução volumétrica significativa entre POI e 1 ano (P=0,028 e P=0,020, respectivamente). Entre o pré-operatório e 1 ano, houve redução média de 19,9% e 15,4% nos volumes atrial e ventricular, respectivamente. Os volumes diastólicos atrial e ventricular apresentaram redução significativa no POI (P<0,001 e P=0,024, respectivamente), permanecendo estáveis ao longo do estudo. Houve aumento na fração de ejeção do átrio esquerdo após 6 meses (P<0,001), porém não houve variação na função ventricular esquerda. CONCLUSÕES: Os pacientes submetidos à plastia valvar mitral por meio da técnica de Duplo Teflon apresentaram remodelamento reverso do átrio esquerdo e do ventrículo esquerdo. Esta redução nos volumes cavitários esteve associada à melhora da função atrial esquerda durante o estudo.INTRODUCTION: Mitral valve repair is the treatment of choice to correct mitral insufficiency. Although the literature related to left atrial and ventricular behavior after mitral repair without use of prosthetic rings is scarce. OBJECTIVE: To analyze cardiac morphology and function using real time tridimensional echocardiography in individuals submitted to mitral valve repair with Double Teflon technique. METHODS: Were included 14 patients with mixomatous mitral valve insufficiency that were submitted to mitral valve repair with the Double Teflon technique. Of them, 13 patients were in class III/IV. Patients were evaluated in preoperative period, immediate postoperative period, 6 months and 1 year after mitral repair. Statistic analysis was made by repeated measures ANOVA test and was considered statistically significant P < 0.05. RESULTS: The analysis of systolic volumes, atrial and ventricular, demonstrated a significant volumetric reduction between immediate postoperative period and 1 year (P=0.028 and P=0.020, respectively). Between preoperative period and 1 year, there was a mean reduction in atrial and ventricle volumes of 19.9% and 15.4%, respectively. Atrial and ventricle diastolic volumes presented a significant reduction in immediate postoperative period (P <0.001 and P =0.024, respectively), remaining stable during the study. There was an increase in left atrial ejection fraction after 6 months (P<0.001), although there was no significant variation in left ventricle ejection fraction. CONCLUSIONS: Patients submitted to mitral valve repair by the Double Teflon technique demonstrated a left atrial and ventricle reverse remodeling. These reductions were associated with an improvement in left atrial function during the study.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
Anti-viral effects of medicinal plants in the management of dengue: a systematic review
Background: Dengue is considered as an important arboviral disease. Safe, low-cost, and effective drugs that possess inhibitory activity against dengue virus (DENV) are mostly needed to try to combat the dengue infection worldwide. Medicinal plants have been considered as an important alternative to manage several diseases, such as dengue. As authors have demonstrated the antiviral effect of medicinal plants against DENV, the aim of this study was to review systematically the published research concerning the use of medicinal plants in the management of dengue using the PubMed database.Materials and Methods: Search and selection of publications were made using the PubMed database following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA statement).Results: Six publications met the inclusion criteria and were included in the final selection after thorough analysis.Conclusion: It is suggested that medicinal plants’ products could be used as potential anti-DENV agents.Keywords: Dengue, arbovirus, medicinal plants, PubMe
Evaluation of the diagnostic value of the tourniquet test in predicting severe dengue cases in a population from Belo Horizonte, State of Minas Gerais, Brazil
EFFECT OF MECHANICAL VIBRATION GENERATED IN OSCILLATING/VIBRATORY PLATFORM ON THE CONCENTRATION OF PLASMA BIOMARKERS AND ON THE WEIGHT IN RATS.
Background: Whole body vibration (WBV) exercise has been used in health sciences. Authors have reported that
changes on the concentration of plasma biomarkers could be associated with the WBV effects. The aim of this
investigation is to assess the consequences of exposition of 25 Hz mechanical vibration generated in
oscillating/vibratory platform (OVP) on the concentration of some plasma biomarkers and on the weight of rats.
Materials and Methods: Wistar rats were divided into two groups. The animals of the Experimental Group (EG) were
submitted to vibration (25 Hz) generated in an OVP with four bouts of 30 seconds with rest time of 60 seconds between
the bouts. This procedure was performed daily for 12 days. The animals of the control group (CG) were not exposed to
vibration.
Results: Our findings show that the WBV exercise at 25 Hz was not capable to alter significantly (
Geography and ecology shape the phylogenetic composition of Amazonian tree communities
Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types.
Location: Amazonia.
Taxon: Angiosperms (Magnoliids; Monocots; Eudicots).
Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran\u27s eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny.
Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R = 28%). A greater number of lineages were significant indicators of geographic regions than forest types.
Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4
While the increasing availability of global databases on ecological communities has advanced our knowledge
of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In
the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of
Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 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 or ganism 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 ne glected 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 lostinfo:eu-repo/semantics/publishedVersio
Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates
Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis).
Time period: Tree-inventory plots established between 1934 and 2019.
Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm.
Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield.
Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes.
Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests.
Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types
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