Stochastic blockmodel approximation of a graphon: Theory and consistent estimation

Non-parametric approaches for analyzing network data based on exchangeable graph models (ExGM) have recently gained interest. The key object that defines an ExGM is often referred to as a graphon. This non-parametric perspective on network modeling poses challenging questions on how to make inference on the graphon underlying observed network data. In this paper, we propose a computationally efficient procedure to estimate a graphon from a set of observed networks generated from it. This procedure is based on a stochastic blockmodel approximation (SBA) of the graphon. We show that, by approximating the graphon with a stochastic block model, the graphon can be consistently estimated, that is, the estimation error vanishes as the size of the graph approaches infinity.Comment: 20 pages, 4 figures, 2 algorithms. Neural Information Processing Systems (NIPS), 201

Understanding Drought Dynamics during Dry Season in Eastern Northeast Brazil

Eastern Northeast Brazil (ENEB) generally experiences a high variability in precipitation in the dry season, with amplitudes that can overcome 500mm. The understanding of this variability can help in mitigating the socio-economic issues related to the planning and management of water resources this region, which is highly vulnerable to drought. This work aims to assess spatio-temporal variability of precipitation during the dry season and investigate the relationships between climate phenomena and drought events in the ENEB, using univariate (Spearman correlation) and multivariate statistical techniques, such as Principal Component Analysis, Cluster Analysis, and Maximum Covariance Analysis. The results indicate that the variability of precipitation in the dry season can be explained mainly (62%) by local physical conditions and climate conditions have a secondary contribution. Further analysis of the larger anomalous events suggests that the state of Atlantic and Pacific oceans can govern the occurrence of those events, and the conditions of Atlantic Ocean can be considered a potential modulator of anomalous phenomena of precipitation in ENEB

Phenology and Seasonal Ecosystem Productivity in an Amazonian Floodplain Forest

everal studies have explored the linkages between phenology and ecosystem productivity across the Amazon basin. However, few studies have focused on flooded forests, which correspond to c.a. 14% of the basin. In this study, we assessed the seasonality of ecosystem productivity (gross primary productivity, GPP) from eddy covariance measurements, environmental drivers and phenological patterns obtained from the field (leaf litter mass) and satellite measurements (enhanced vegetation index (EVI) from the Moderate Resolution Imaging Spectroradiometer/multi-angle implementation correction (MODIS/MAIAC)) in an Amazonian floodplain forest. We found that ecosystem productivity is limited by soil moisture in two different ways. During the flooded period, the excess of water limits GPP (Spearman’s correlation; rho = −0.22), while during non-flooded months, GPP is positively associated with soil moisture (rho = 0.34). However, GPP is maximized when cumulative water deficit (CWD) increases (rho = 0.81), indicating that GPP is dependent on the amount of water available. EVI was positively associated with leaf litter mass (Pearson’s correlation; r = 0.55) and with GPP (r = 0.50), suggesting a coupling between new leaf production and the phenology of photosynthetic capacity, decreasing both at the peak of the flooded period and at the end of the dry season. EVI was able to describe the inter-annual variations on forest responses to environmental drivers, which have changed during an observed El Niño-Southern Oscillation (ENSO) year (2015/2016)

Study Bioprospecting of Medicinal Plant Extracts of the Semiarid Northeast: Contribution to the Control of Oral Microorganisms

Dental pathologies can be caused by plaque-forming bacteria and yeast, which reside in the oral cavity. The bacteria growing in dental plaque, a naturally occurring biofilm, display increased resistance to antimicrobial agents. The objective was the evaluation of a preclinical assay of medicinal plants of the semiarid region from the northeast against oral pathogenic microorganism, aiming at bioprospecting a new product. The selection of plant material for this study was based on the ethnobotanical data on the traditional use of plants from the semiarid region. The thirty extracts were subjected to the determination of antibiofilm activity against gram-positive, gram-negative bacteria and yeast. The hydroalcoholic extract which showed positive antibiofilm activity against most of the microorganisms tested in agar diffusion assay was further tested for the determination of minimum inhibitory concentration (MIC) and Bioassay with Artemia salina. Plant samples tested in this study exhibited good antibiofilm activity for the treatment of oral problems. The Schinopsis brasiliensis showed greater activity for Pseudomonas aeruginosa and Staphylococcus aureus, but toxicity against Artemia salina

Genomic evolution and complexity of the Anaphase-promoting Complex (APC) in land plants

<p>Abstract</p> <p>Background</p> <p>The orderly progression through mitosis is regulated by the Anaphase-Promoting Complex (APC), a large multiprotein E₃ubiquitin ligase that targets key cell-cycle regulators for destruction by the 26 S proteasome. The APC is composed of at least 11 subunits and associates with additional regulatory activators during mitosis and interphase cycles. Despite extensive research on APC and activator functions in the cell cycle, only a few components have been functionally characterized in plants.</p> <p>Results</p> <p>Here, we describe an in-depth search for APC subunits and activator genes in the Arabidopsis, rice and poplar genomes. Also, searches in other genomes that are not completely sequenced were performed. Phylogenetic analyses indicate that some APC subunits and activator genes have experienced gene duplication events in plants, in contrast to animals. Expression patterns of paralog subunits and activators in rice could indicate that this duplication, rather than complete redundancy, could reflect initial specialization steps. The absence of subunit APC7 from the genome of some green algae species and as well as from early metazoan lineages, could mean that APC7 is not required for APC function in unicellular organisms and it may be a result of duplication of another tetratricopeptide (TPR) subunit. Analyses of TPR evolution suggest that duplications of subunits started from the central domains.</p> <p>Conclusions</p> <p>The increased complexity of the APC gene structure, tied to the diversification of expression paths, suggests that land plants developed sophisticated mechanisms of APC regulation to cope with the sedentary life style and its associated environmental exposures.</p

Investigação sorológica de espécies de Ehrlichia em cães, equinos e humanos de um assentamento rural do sul do Brasil

Objetivou-se determinar a soroprevalência de Ehrlichia spp. e os fatores de risco associados a exposição em uma população restrita de cães, cavalos e humanos altamente expostos a picadas de carrapatos em um assentamento rural brasileiro utilizando um teste comercial de ELISA rápido e dois testes de imunofluorescência indireta (IFI) com antígenos brutos de E. canis e E. chaffeensis. Amostras de soro de 132 cães, 16 cavalos e 100 humanos foram utilizadas. Cinquenta e seis/132 (42,4%) cães foram soropositivos para E. canis. Cães &gt; um ano apresentaram mais chance de serem soropositivos para E. canis do que cães ≤ um ano (p =0,0051). Dez/16 (62,5%) e 8/16 (50%) cavalos foram soropositivos pelo ELISA comercial e IFI, respectivamente. Cinco/100 (5%) humanos foramsoropositivos para E. canis e E. chaffeensis. Rhipicephalus sanguineus (n= 291, 97,98%) nos cães e A. cajennense (n = 25, 96,15%) nos cavalos foram os carrapatos mais encontrados. Concluindo, anticorpos anti-Ehrlichia spp. foram encontrados em cavalos; entretanto, a ausência de uma caracterização molecular impede qualquer conclusão sobre agente envolvido. Além disso, a alta soroprevalência de E. canis em cães e a evidência de anticorpos anti-Ehrlichia sp. em humanos, sugere que os casos de erliquiose humana no Brasil possam ser causados por E. canis ou outra espécie intimamente relacionada.The aims of this study were to determine the seroprevalence of Ehrlichia spp. and risk factors for exposure in a restricted population of dogs, horses, and humans highly exposed to tick bites in a Brazilian rural settlement using a commercial ELISA rapid test and two indirect immunofluorescent assays (IFA) with E. canis and E. chaffeensis crude antigens. Serum samples from 132 dogs, 16 horses and 100 humans were used. Fifty-six out of 132 (42.4%) dogs were seropositive for E. canis. Dogs &gt; one year were more likely to be seropositive for E. canis than dogs ≤ one year (p = 0.0051). Ten/16 (62.5%) and 8/16 (50%) horses were seropositive by the commercial ELISA and IFA, respectively. Five out of 100 (5%) humans were seropositive for E. canis and E. chaffeensis. Rhipicephalus sanguineus (n = 291, 97.98%) on dogs and Amblyomma cajennense (n = 25, 96.15%) on horses were the most common ticks found. In conclusion, anti-Ehrlichia spp. antibodies were found in horses; however, the lack of a molecular characterization precludes any conclusion regarding the agent involved. Additionally, the higher seroprevalence of E. canis in dogs and the evidence of anti-Ehrlichia spp. antibodies in humans suggest that human cases of ehrlichiosis in Brazil might be caused by E. canis, or other closely related species

Estratégia de Controle Cooperativo em Unidades de Geração Distribuídas Integrada a Sistemas de Armazenamento de Energia Elétrica / Cooperative Control Strategy in Distributed Generation Units Distributed Generation Units Integrated with Power Storage Systems

O aumento do nível de penetração de fontes re[1]nováveis conectadas a rede elétrica através de conversores de potência, pode provocar instabilidades em microrredes CA devido à natureza não-despachável em potência desses sistemas. A integração de sistemas de armazenamento de energia elétrica ao inversor do gerador distribuído pode suavizar a injeção de potência no ponto de acoplamento comum (PAC), contribuindo para a estabilidade de tensão e de frequência do sistema de potência. Neste trabalho, propõe-se uma estratégia de controle cooperativo para regular a tensão do barramento CC integrada a uma estrutura de armazenamento de um sistema de geração distribuída para minimizar eventuais flutuações de tensão e de frequência no PAC. Comparações com métodos tradicionais de controle são realizados para avaliar a efetividade do método proposto. A validação da estratégia de controle é realizada por meio de resultados experimentais

Ticks from the Brazilian Amazon: Species, Distribution and Host-Relations

Ticks are important ectoparasites and can transmit a wide variety of pathogens to animals and humans worldwide. These ectoparasites are the most important vectors of diseases causing pathogens in domestic and wild animals, and the second for man. In Brazil, Spotted Fever is the only disease transmitted to humans by ticks, while for animals we can highlight babesiosis, ehrlichiosis and anaplasmosis. Although ticks are found in all of Brazil’s biomes, little is known about its diversity and host-relations in the Amazon biome. The existing gaps and the lack of research indicate that the diversity of ticks and their possible pathogens are underestimated in the Brazilian Amazon. Therefore, in order to guide the next studies in the Amazon biome, we present in this chapter a compilation of the records of hard ticks and soft ticks parasitizing wild and domestic animals, and humans. We present the general list of ticks for this biome, their distribution, hosts and importance for public health and veterinary. Finally, the ixodofauna found in the Brazilian Amazon and presented here does not match the vertebrate diversity of this biome, which is one of the largest on the planet. Therefore, more acarologists and epidemiologists are needed in this region

Harvest of endangered marine invertebrates in a priority area for conservation in Brazil

The harvesting of marine organisms for aquarium and ornamental art crafts is a very common and widespread activity, threatening a number of coral reef species. The goal of this manuscript is to report the intensive harvesting of two marine invertebrate species, the starfish Oreaster reticulatus and the gorgonian Phyllogorgia dilatata, in reef environments of a national priority area for the creation of a Marine Protected Area (MPA) in the Espírito Santo State, central coast of Brazil. These species were present on the 2003 Brazilian Red List of Endangered species as threatened of extinction, but P. dilatata was removed from the most recent 2014 Brazilian Red List, while O. reticulatus is currently considered vulnerable. Neither species have been assessed by IUCN. The harvest of these invertebrates was registered in 17% of the 51 days of monitoring (ten expeditions between March 2005 and February 2006), with catches of up to 24 starfishes and 1000 gorgonians in a single day. Starfishes used to be sold to local traders for US$0.50 each, and each gorgonian for US$ 0.15. This starfish is already in decline on a regional scale, and the actual harvesting rate of the gorgonian could lead to the extinction of the local population in about 17 years of exploitation. Due to the ecological importance of these two endangered species, their harvest threatens the entire local rocky reef ecosystem. Further ecological and fisheries studies on these species should be conducted, and the definition and creation of the MPA could help to manage all the unsustainable activities conducted and expected in the region

Expanding the knowledge on lignocellulolytic and redox enzymes of worker and soldier castes from the lower termite coptotermes gestroi

Termites are considered one of the most efficient decomposers of lignocelluloses on Earth due to their ability to produce, along with its microbial symbionts, a repertoire of carbohydrate-active enzymes (CAZymes). Recently, a set of Pro-oxidant, Antioxidant, and Detoxification enzymes (PAD) were also correlated with the metabolism of carbohydrates and lignin in termites. The lower termite Coptotermes gestroi is considered the main urban pest in Brazil, causing damage to wood constructions. Recently, analysis of the enzymatic repertoire of C. gestroi unveiled the presence of different CAZymes. Because the gene profile of CAZy/PAD enzymes endogenously synthesized by C. gestroi and also by their symbiotic protists remains unclear, the aim of this study was to explore the eukaryotic repertoire of these enzymes in worker and soldier castes of C. gestroi. Our findings showed that worker and soldier castes present similar repertoires of CAZy/PAD enzymes, and also confirmed that endo-glucanases (GH9) and beta-glucosidases (GH1) were the most important glycoside hydrolase families related to lignocellulose degradation in both castes. Classical cellulases such as exo-glucanases (GH7) and endo-glucanases (GH5 and GH45), as well as classical xylanases (GH10 and GH11), were found in both castes only taxonomically related to protists, highlighting the importance of symbiosis in C. gestroi. Moreover, our analysis revealed the presence of Auxiliary Activity enzyme families (AAs), which could be related to lignin modifications in termite digestomes. In conclusion, this report expanded the knowledge on genes and proteins related to CAZy/PAD enzymes from worker and soldier castes of lower termites, revealing new potential enzyme candidates for second-generation biofuel processes7CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP140796/2013-4; 310186/2014-5; 442333/2014-511/20977-3; 15/06971-3; 12/19040-0; 14/10351-8; 06/59086-8; 14/20576- 7; 13/03061-0; 10/11469-1; 08/58037-9; 14/50371-8; 08/50114-