Clorofila a e turbidez a partir de imagens MODIS : uma análise comparativa com 15 anos de dados in situ para a represa billings/sp

A Represa Billings é considerada a maior represa da Região Metropolitana de São Paulo (RMSP), sendo a grande responsável pelo seu abastecimento público. Como a qualidade da sua água é afetada pela expansão urbana e atividades econômicas, há a necessidade de monitoramento contínuo. Dentre as mais promissoras ferramentas de monitoramento, as técnicas de sensoriamento remoto possuem as vantagens de, terem um baixo custo operacional e possibilidade de monitoramento em larga escala. Neste trabalho, utilizamos dados do satélite MODIS a partir da plataforma Google Earth Engine, para explicar a variação em dados de clorofila-a e turbidez obtidos in situ pela CETESB ao longo de 15 anos (2002-2017), através de regressão múltipla e do método de inteligência artificial random forest. Para a clorofila, utilizando técnicas de seleção de modelos, encontramos que o modelo mais simples e com maior explicação inclui as bandas 1, 2, 3, 5 e 7, com um R²=0.18 (P<0.001). Com o método random forest, obtivemos um R²=0.32 com as mesmas bandas, indicando maior poder de explicação em relação aos modelos lineares. Para a turbidez, ambos os métodos explicaram menos de 5% da variação nos dados, indicando uma fraca relação. Apesar do menor poder explicativo em relação ao encontrado na literatura, possivelmente devido às limitações dos dados da CETESB (como a ausência de informações do horário e ponto exatos da coleta), os modelos foram significativos, reforçando o potencial das informações a partir de satélites como indicativos de qualidade da águaFil: Ruiz Haddad, Isadora . Universidade Federal de Sao Carlos (Brasil)Fil: Oswaldino da Silva, Letícia . Universidade Federal de Sao Carlos (Brasil)Fil: Santos Ricco, Milena . Universidade Federal de Sao Carlos (Brasil)Fil: Stoppa Espinossi, Nathalia . Universidade Federal de Sao Carlos (Brasil)Fil: Saito Satoru, Victor . Universidade Federal de Sao Carlos (Brasil

Subtropical streams harbour higher genus richness and lower abundance of insects compared to boreal streams, but scale matters

Aim: Biological diversity typically varies between climatically different regions, and regions closer to the equator often support higher numbers of taxa than those closer to the poles. However, these trends have been assessed for a few organism groups, and the existing studies have rarely been based on extensive identical surveys in different climatic regions. Location: We conducted standardized surveys of wadeable streams in a boreal (western Finland) and a subtropical (south-eastern Brazil) region, sampling insects identically from 100 streams in each region and measuring the same environmental variables in both regions. Taxon: Aquatic insects. Methods: Comparisons were made at the scales of local stream sites, drainage basins and entire regions. We standardized the spatial extent of the study areas by resampling regional richness based on subsets of sites with similar extents. We examined differences in genus richness and assemblage abundance patterns between the regions using graphical and statistical modelling approaches. Results: We found that while genus accumulation and rank-abundance curves were relatively similar at the regional scale between Finland and Brazil, regional genus richness was higher in the latter but regional abundance much higher in the former region. These regional patterns for richness and abundance were reproduced by basin and local genus richness that were higher in Brazil than in Finland, and assemblage abundance that was much higher in Finland than in Brazil. The magnitude of the difference in genus richness between Brazil and Finland tended to increase from local through basin to regional scales. Main conclusions: Our findings suggest that factors related to evolutionary diversification might explain differences in genus richness between these two climatically different regions, whereas higher nutrient concentrations of stream waters might explain the higher abundance of insects in Finland than in Brazil.Peer reviewe

Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples

Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts

Macroinvertebrados aquáticos em riachos de cerrado : abordagens ecológicas teórica e aplicada

The aquatic macroinvertebrates are widely used in ecological studies and recently applied for biomonitoring. The knowledge about composition and distribution patterns are essential to elaborate environmental biomonitoring programs. The Cerrado vegetation, considered hotspot of biodiversity, is one of the most threatened savanna in the world and due to this importance its biodiversity and natural resources needs their own methodology for monitoring. In view of the above this thesis was divided in two studies: 1) Study about the variation in faunal composition of the metacommunity and the importance of local variables and spatial variables. 2) Development of a regional multimetric index using metrics from the macroinvertebrates community. Both studies used the database of 21 streams from the central region of São Paulo State, being 14 impacted streams (seven of sugarcane monocultures and seven of pasture) and seven reference streams, inserted in conserved Cerrado areas. The results of the first paper showed a metacommunity influenced by local factors and little variation was explained by spatial factors. These results fits the studied metacommunity in the species sorting model, considered the ideal for bioindicator groups. In the second paper the filters tested the metrics for range, sensibility to anthropic impact, redundancy between metrics, correlation to natural variability of streams and simplicity. The following metrics passed all filters: of EPT richness to family level, Shannon s Diversity Index to family, percentage of Trichoptera, EPT/Chironomidae and Biological Monitoring Working Party adapted index. The 5 developed multimetric index use metrics of low taxonomic resolution and good response to environmental impact, showing a potential for application in biomonitoring programs in the studied region.Universidade Federal de Minas GeraisOs macroinvertebrados aquáticos são muito utilizados tanto em estudos de ecologia teórica quanto em estudos de ecologia aplicada. O conhecimento sobre a composição desta fauna e seus padrões de distribuição são essenciais para a elaboração de programas de biomonitoramento ambiental. O Cerrado, considerado hotspot de biodiversidade, é uma das savanas mais ameaçada do mundo e devido a essa importância a sua biodiversidade e recursos naturais necessitam de metodologia própria para o monitoramento. Diante disso esta dissertação foi dividida em dois trabalhos: 1) estudo sobre a variação na composição faunística da metacomunidade e a importância dos fatores abióticos locais e fatores regionais. 2) desenvolvimento de um índice multimétrico regional utilizando métricas da comunidade de macroinvertebrados aquáticos. Ambos os estudos utilizaram um banco de dados de 21 riachos da região central do Estado de São Paulo, sendo 14 riachos impactados (sete riachos de monocultura de cana-de-açúcar e sete de pastagem) e sete riachos de referência, inseridos em áreas conservadas de Cerrado. Os resultados do primeiro trabalho indicaram uma metacomunidade influenciada pelos fatores locais e pouca variação foi explicada pelo componente espacial. Esses resultados encaixam a metacomunidade estudada no modelo de sorteamento de espécies, considerada o modelo ideal para grupos bioindicadores. No segundo trabalho os filtros utilizados testaram as métricas quanto à amplitude, sensibilidade ao impacto antrópico, redundância entre as métricas, correlação à variabilidade natural dos riachos e simplicidade. As seguintes métricas passaram por todos os filtros: Riqueza de famílias de EPT, Índice de Diversidade Shannon para famílias, porcentagem de Trichoptera, razão EPT/Chironomidae e índice Biological Monitoring Working Party adaptado. O índice multimétrico desenvolvido utiliza métricas com baixa resolução taxonômica e boa resposta ao impacto ambiental, mostrando um elevado potencial de aplicação em programas de biomonitoramento na região estudada

Taxonomic composition and feeding habits of Chironomidae in Cerrado streams (Southeast Brazil): impacts of land use changes

The Chironomidae family is the most abundant and diverse member of the benthic community in streams, yet their identification is still neglected in many papers. It is considered a family tolerant to environmental impacts and with homogeneous feeding habit. AIM: To compare the richness, abundance and taxonomic composition of Chironomidae in Cerrado streams under different land uses as well as the feeding habit differences between genera of reference areas, sugar cane culture and pasture. METHODS: We selected seven streams in each land use and sampled six units using Surber sampler. The material was transported live for laboratory processing. RESULTS: Our results showed no significant differences in abundance and richness of Chironomidae among different land use, but we observed greater average values of abundance and richness in streams impacted by pasture. We found a distinct taxonomic composition between reference streams and impacted streams, both sugar cane and pasture. Stenochironomus was the most representative genus in reference areas, while Parametriocnemus was in sugar cane culture and Tanytarsus in pastures. The only statistically different feeding pattern found were between Cerrado streams and sugar cane for plant tissues, reflecting the greater abundance of Stenochironomus in Cerrado and among Cerrado streams and pasture for microalgae. CONCLUSIONS: We conclude that the conversion of natural areas in monocultures and pastures directly impact streams by modifying the taxonomic structure of Chironomidae. In contrast we did not observe a clear change in feeding patterns, because in all streams the diet pattern was mostly detritivorous

Square and rhombic lattices of magnetic skyrmions in a centrosymmetric binary compound

Magnetic skyrmions are topologically stable swirling spin textures with particle-like character, and have been intensively studied as a candidate of high-density information bit. While magnetic skyrmions were originally discovered in noncentrosymmetric systems with Dzyaloshinskii-Moriya interaction, recently a nanometric skyrmion lattice has also been reported for centrosymmetric rare-earth compounds, such as Gd2PdSi3 and GdRu2Si2. For the latter systems, a distinct skyrmion formation mechanism mediated by itinerant electrons has been proposed, and the search of a simpler model system allowing for a better understanding of their intricate magnetic phase diagram is highly demanded. Here, we report the discovery of square and rhombic lattices of nanometric skyrmions in a centrosymmetric binary compound EuAl4, by performing small-angle neutron and resonant elastic X-ray scattering experiments. Unlike previously reported centrosymmetric skyrmion-hosting materials, EuAl4 shows multiple-step reorientation of the fundamental magnetic modulation vector as a function of magnetic field, probably reflecting a delicate balance of associated itinerant-electron-mediated interactions. The present results demonstrate that a variety of distinctive skyrmion orders can be derived even in a simple centrosymmetric binary compound, which highlights rare-earth intermetallic systems as a promising platform to realize/control the competition of multiple topological magnetic phases in a single material. Typically, skyrmions appear in magnet systems which are non-centrosymmetric. Here, using neutron and X-ray scattering, Takagi et al show the emergence of a skyrmion phase in the centrosymmetric material EuAl4. This expands the range of materials potential hosting skyrmions

Sex differences in oncogenic mutational processes

Funder: Canadian Network for Research and Innovation in Machining Technology, Natural Sciences and Engineering Research Council of Canada (NSERC Canadian Network for Research and Innovation in Machining Technology); doi: https://doi.org/10.13039/501100002790Funder: Genome Canada (Génome Canada); doi: https://doi.org/10.13039/100008762Funder: Canada Foundation for Innovation (Fondation canadienne pour l'innovation); doi: https://doi.org/10.13039/501100000196Funder: Terry Fox Research Institute (Institut de Recherche Terry Fox); doi: https://doi.org/10.13039/501100004376Abstract: Sex differences have been observed in multiple facets of cancer epidemiology, treatment and biology, and in most cancers outside the sex organs. Efforts to link these clinical differences to specific molecular features have focused on somatic mutations within the coding regions of the genome. Here we report a pan-cancer analysis of sex differences in whole genomes of 1983 tumours of 28 subtypes as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium. We both confirm the results of exome studies, and also uncover previously undescribed sex differences. These include sex-biases in coding and non-coding cancer drivers, mutation prevalence and strikingly, in mutational signatures related to underlying mutational processes. These results underline the pervasiveness of molecular sex differences and strengthen the call for increased consideration of sex in molecular cancer research