Directed Random Markets: Connectivity determines Money

Boltzmann-Gibbs distribution arises as the statistical equilibrium probability distribution of money among the agents of a closed economic system where random and undirected exchanges are allowed. When considering a model with uniform savings in the exchanges, the final distribution is close to the gamma family. In this work, we implement these exchange rules on networks and we find that these stationary probability distributions are robust and they are not affected by the topology of the underlying network. We introduce a new family of interactions: random but directed ones. In this case, it is found the topology to be determinant and the mean money per economic agent is related to the degree of the node representing the agent in the network. The relation between the mean money per economic agent and its degree is shown to be linear.Comment: 14 pages, 6 figure

Infusão de antibiótico via veia digital palmar em cavalos da raça Puro-Sangue-Inglês

O artigo não apresenta resumo

Abordagem etiológica da trombose venosa profunda: relato de um caso

Este relato clínico tem o intuito de ressaltar a importância do diagnóstico etiológico da trombose venosa profunda (TVP), pois esta conduta pode propiciar o diagnóstico precoce de uma doença grave em sua fase assintomática e direcionar o tratamento de outras possíveis causas. Trata-se de um relato de caso de uma mulher de 39 anos sem fatores de risco aparentes para a condição clínica apresentada. Após detalhamento da história clínica da paciente, bem como condutas adotadas, discutiu-se o tema através de artigos publicados em meio eletrônico. Conclui-se que o fenômeno de TVP não deve ser considerado apenas como intercorrente, sendo ponto primordial na conduta clínica o esclarecimento etiológico para uma abordagem terapêutica adequada e diagnóstico precoce de uma possível neoplasia

Optimizing hydropower dam location and removal in the São Francisco River basin, Brazil to balance hydropower and river biodiversity tradeoffs

To support eco-friendly hydropower planning in developing regions, we propose a spatial optimization model for locating dams to balance tradeoffs between hydropower generation and migratory fish species richness. Our model incorporates two special features. First, it is tailored to the dispersal of tropical migratory fishes, which require long, unimpeded river stretches to complete their life-cycle. To model fish with this type of dispersal pattern, we introduce the concept of a river pathway, which represents a novel way to describe river connectivity. Second, it combines decisions about dam placement and removal, thus facilitating opportunities for hydropower offsetting. We apply our model to the São Francisco River basin, Brazil, an area of hydropower-freshwater biodiversity conflict. We find that dams have reduced weighted migratory fish richness 51% compared to a pre-dam baseline. We also find that even limited dam removal has the potential to significantly enhance fish biodiversity. Offsetting the removal of a single dam by the optimal siting of new dams could increase fish richness by 25% above the current average. Moving forward, optimizing new dam sites to increase hydropower by 20%, rather than selecting the fewest number of dams, could reduce fish species losses by 89%. If decisions about locating new dams are combined with dam removal, then a win-win can even be achieved with 20% greater hydropower and 19% higher species richness. Regardless of hydropower targets and dam removal options, a key observation is that optimal sites for dams are mostly located in the upper reaches of the basin rather than along the main stem of the São Francisco River or its main tributaries

Copy number variation arising from gene conversion on the human Y chromosome

We describe the variation in copy number of a ~ 10 kb region overlapping the long intergenic noncoding RNA (lincRNA) gene, TTTY22, within the IR3 inverted repeat on the short arm of the human Y chromosome, leading to individuals with 0–3 copies of this region in the general population. Variation of this CNV is common, with 266 individuals having 0 copies, 943 (including the reference sequence) having 1, 23 having 2 copies, and two having 3 copies, and was validated by breakpoint PCR, fbre-FISH, and 10× Genomics Chromium linked-read sequencing in subsets of 1234 individuals from the 1000 Genomes Project. Mapping the changes in copy number to the phylogeny of these Y chromosomes previously established by the Project identifed at least 20 mutational events, and investigation of fanking paralogous sequence variants showed that the mutations involved fanking sequences in 18 of these, and could extend over > 30 kb of DNA. While either gene conversion or double crossover between misaligned sister chromatids could formally explain the 0–2 copy events, gene conversion is the more likely mechanism, and these events include the longest non-allelic gene conversion reported thus far. Chromosomes with three copies of this CNV have arisen just once in our data set via another mechanism: duplication of 420 kb that places the third copy 230 kb proximal to the existing proximal copy. Our results establish gene conversion as a previously under-appreciated mechanism of generating copy number changes in humans and reveal the exceptionally large size of the conversion events that can occur