Importância de Fatores Ecológicos, Filogenéticos e Alométricos na Variação da Forma do Crânio Roedores

Rodentia é a ordem de mamíferos mais diversa em todo o Mundo, padrão que é observado principalmente nos Neotrópicos, incluso o Brasil, conforme as listas de espécies a nível regional e nacional. Possui distribuição cosmopolita com grande diversidade de dietas e hábitos locomotores. Suas sinapomorfias-chave são características cranianas e dentais, portanto neste trabalho o crânio foi utilizado como objeto de estudo, analisando sua interação com fatores alométricos, dieta, sexo e parentesco. As 32 espécies estudadas ocorrem no Espírito Santo e são pertencentes a 7 famílias da ordem. A ferramenta utilizada nessa investigação foi a morfometria geométrica, utilizando nas análises dos dados testes estatísticos multivariados, análises discriminantes, regressões e análise das variáveis canônicas. Não foi verificado dimorfismo sexual quando todas as espécies são analisadas, porém há diferenciação na forma e tamanho do crânio. A comparação entre os herbívoros e insetívoros mostrou que há diferenças morfológicas entre as espécies com dietas diferentes, mesmo quando elas possuem parentesco filogenético. Ainda assim as árvores quando reconstruídas, com base nos caracteres cranianos, tiveram o mesmo resultado em todas as vistas avaliadas, tanto do crânio quanto mandíbula, conseguindo manter praticamente todas as relações de parentesco entre as famílias corretamente (exceto Sciuridae e Dasyproctidae). A alometria, entretanto, não é um fator de variação no crânio de roedores, alcançando valores desprezíveis de regressão, porém esse trabalho mostrou ser possível diferenciar diferentes tipos de dieta e relações de parentesco pela morfometria geométrica do crânio de roedores

Ghost Condensates and Dynamical Breaking of SL(2,R) in Yang-Mills in the Maximal Abelian Gauge

Ghost condensates of dimension two in SU(N) Yang-Mills theory quantized in the Maximal Abelian Gauge are discussed. These condensates turn out to be related to the dynamical breaking of the SL(2,R) symmetry present in this gaugeComment: 16 pages, LaTeX2e, final version to appear in J. Phys.

Estimates of ikaite export from sea ice to the underlying seawater in a sea ice-seawater mesocosm

The precipitation of ikaite and its fate within sea ice is still poorly understood.We quantify temporal inorganic carbon dynamics in sea ice from initial formation to its melt in a sea ice.seawater mesocosm pool from 11 to 29 January 2013. Based on measurements of total alkalinity (TA) and total dissolved inorganic carbon (TCO2), the main processes affecting inorganic carbon dynamics within sea ice were ikaite precipitation and CO2 exchange with the atmosphere. In the underlying seawater, the dissolution of ikaite was the main process affecting inorganic carbon dynamics. Sea ice acted as an active layer, releasing CO2 to the atmosphere during the growth phase, taking up CO2 as it melted and exporting both ikaite and TCO2 into the underlying seawater during the whole experiment. Ikaite precipitation of up to 167 μmolkg-1 within sea ice was estimated, while its export and dissolution into the underlying seawater was responsible for a TA increase of 64.66 μmolkg-1 in the water column. The export of TCO2 from sea ice to the water column increased the underlying seawater TCO2 by 43.5 μmolkg-1, suggesting that almost all of the TCO2 that left the sea ice was exported to the underlying seawater. The export of ikaite from the ice to the underlying seawater was associated with brine rejection during sea ice growth, increased vertical connectivity in sea ice due to the upward percolation of seawater and meltwater flushing during sea ice melt. Based on the change in TA in the water column around the onset of sea ice melt, more than half of the total ikaite precipitated in the ice during sea ice growth was still contained in the ice when the sea ice began to melt. Ikaite crystal dissolution in the water column kept the seawater pCO2 undersaturated with respect to the atmosphere in spite of increased salinity, TA and TCO2 associated with sea ice growth. Results indicate that ikaite export from sea ice and its dissolution in the underlying seawater can potentially hamper the effect of oceanic acidification on the aragonite saturation state (ωaragonite) in fall and in winter in ice-covered areas, at the time when ωaragonite is smallest

Indução de resistência de genótipos de soja a meloidogyne Javanica.

Nematóides parasitas de plantas estão amplamente distribuídos no Brasil, sendo M. javanica a espécie que vem causando os danos mais severos à cultura da soja. Essa praga é difícil de controlar, sendo a resistência de plantas a principal estratégia de controle. A indução de compostos de defesa pela aplicação de cis-jasmone foi analisada em extratos de raízes de plântulas dos genótipos BRS 133 (suscetível) e PI 595099 (resistente). As plantas foram tratadas com pulverização foliar e os extratos foram analisados em cromatógrafo líquido de alta eficiência (HPLC) para quantificação de compostos fenólicos e atividade da PAL (fenilalanina amônia-liase). A pulverização foliar com cis-jasmone induziu sistemicamente nas raízes das plantas a atividade da PAL, após 120h da aplicação, e a síntese de daidzeína, genisteína e coumestrol, após 144h, sendo essa indução mais acentuada no genótipo resistente. Estes resultados sugerem que a indução de forma sistêmica da fitoalexina coumestrol, nas raízes de soja, por cis-jasmone, pode estar relacionada à resistência de genótipos de soja à M. javanica

Compostos de defesa em genótipos de soja utilizados como fontes de resistência à mosca-branca, Bemisia tabaci biótipo B.

Durante todo seu ciclo, a soja é atacada por diversos insetos e patógenos. Recentemente, altas infestações da mosca-branca Bemisia tabaci biótipo B vem sendo relatadas, causando danos a essa cultura. O uso de cultivares resistentes é o método ideal de controle, tendo sido identificadas cultivares com nível moderado de resistência a esse inseto. Assim, objetivou-se com este trabalho levantar e caracterizar quimicamente os compostos secundários envolvidos na resistência a essa praga. Folhas dos diferentes genótipos foram coletadas e maceradas em N2 líquido, adicionando-se MeOH-80% para extração dos compostos de defesa constitutivos e/ou induzidos. Os extratos preparados foram submetidos à cromatografia líquida de alta eficiência (HPLC) para identificação dos compostos de defesa. A rutina foi a principal substância encontrada nos genótipos resistentes á mosca-branca. O genótipo Barreiras apresentou as maiores concentrações das substâncias relacionadas à defesa de plantas, como rutina, genistina e genisteína. Em geral, as concentrações dos metabolitos secundários glicosilados (rutina, genistina, e malonil genistina) aumentaram no final do estádio vegetativos (V7 e V8) e a aglicona (genisteina) atingiu sua maior concentração no estádio V4

Temporal dynamics of ikaite in experimental sea ice

Ikaite (CaCO3 · 6H2O) is a metastable phase of calcium carbonate that normally forms in a cold environment and/or under high pressure. Recently, ikaite crystals have been found in sea ice, and it has been suggested that their precipitation may play an important role in air-sea CO 2 exchange in ice-covered seas. Little is known, however, of the spatial and temporal dynamics of ikaite in sea ice. Here we present evidence for highly dynamic ikaite precipitation and dissolution in sea ice grown at an outdoor pool of the Sea-ice Environmental Research Facility (SERF) in Manitoba, Canada. During the experiment, ikaite precipitated in sea ice when temperatures were below -4 °C, creating three distinct zones of ikaite concentrations: (1) a millimeter-to-centimeter-thin surface layer containing frost flowers and brine skim with bulk ikaite concentrations of >2000 μmol kg-1, (2) an internal layer with ikaite concentrations of 200-400 μmol kg -1, and (3) a bottom layer with ikaite concentrations of <100 μmol kg-1. Snowfall events caused the sea ice to warm and ikaite crystals to dissolve. Manual removal of the snow cover allowed the sea ice to cool and brine salinities to increase, resulting in rapid ikaite precipitation. The observed ikaite concentrations were on the same order of magnitude as modeled by FREZCHEM, which further supports the notion that ikaite concentration in sea ice increases with decreasing temperature. Thus, varying snow conditions may play a key role in ikaite precipitation and dissolution in sea ice. This could have a major implication for CO2 exchange with the atmosphere and ocean that has not been accounted for previously

ADME studies and preliminary safety pharmacology of LDT5, a lead compound for the treatment of benign prostatic hyperplasia

This study aimed to estimate the absorption, distribution, metabolism and excretion (ADME) properties and safety of LDT5, a lead compound for oral treatment of benign prostatic hyperplasia that has previously been characterized as a multi-target antagonist of α1A-, α1D-adrenoceptors and 5-HT1A receptors. The preclinical characterization of this compound comprised the evaluation of its in vitro properties, including plasma, microsomal and hepatocytes stability, cytochrome P450 metabolism and inhibition, plasma protein binding, and permeability using MDCK-MDR1 cells. De-risking and preliminary safety pharmacology assays were performed through screening of 44 off-target receptors and in vivo tests in mice (rota-rod and single dose toxicity). LDT5 is stable in rat and human plasma, human liver microsomes and hepatocytes, but unstable in rat liver microsomes and hepatocytes (half-life of 11 min). LDT5 is highly permeable across the MDCK-MDR1 monolayer (Papp ∼32×10-6 cm/s), indicating good intestinal absorption and putative brain penetration. LDT5 is not extensively protein-bound and is a substrate of human CYP2D6 and CYP2C19 but not of CYP3A4 (half-life >60 min), and did not significantly influence the activities of any of the human cytochrome P450 isoforms screened. LDT5 was considered safe albeit new studies are necessary to rule out putative central adverse effects through D2, 5-HT1A and 5-HT2B receptors, after chronic use. This work highlights the drug-likeness properties of LDT5 and supports its further preclinical development

Greenhouse gas balance and mitigation of pasture-based dairy production systems in the Brazilian Atlantic Forest Biome.

Brazilian cattle production is mostly carried out in pastures, and the need to mitigate the livestock's greenhouse gas (GHG) emissions and its environmental footprint has become an important requirement. The adoption of well-suited breeds and the intensification of pasture-based livestock production systems are alternatives to optimize the sector's land use. However, further research on tropical systems is necessary. The objective of this research was to evaluate the effect of Holstein (HO) and Jersey?Holstein (JE x HO) crossbred cows in different levels of pasture intensification (continuous grazing system with low stocking rate?CLS; irrigated rotational grazing system with high stocking rate?RHS), and the interaction between these two factors on GHG mitigation. Twenty-four HO and 24 JE x HO crossbred dairy cows were used to evaluate the effect of two grazing systems on milk production and composition, soil GHG emissions, methane (CH4) emission, and soil carbon accumulation (0?100 cm). These variables were used to calculate carbon balance (CB), GHG emission intensity, the number of trees required to mitigate GHG emission, and the land-saving effect. The number of trees necessary to mitigate GHG emission was calculated, considering the C balance within the farm gate. The mitigation of GHG emissions comes from the annual growth rate and accumulation of C in eucalyptus trees' trunks. The CB of all systems and genotypes presented a deficit in carbon (C); there was no difference for genotypes, but RHS was more deficient than CLS (-4.99 to CLS and ?28.72 to RHS ton CO2e..ha?1.year?1). The deficit of C on GHG emission intensity was similar between genotypes and higher for RHS (?0.480 to RHS and ?0.299 to CLS kg CO2e..kg FCPCmilk?1). Lower GHG removals (0.14 to CLS higher than 0.02 to RHS kg CO2e..kg FCPCmilk?1) had the greatest influence on the GHG emission intensity of milk production. The deficit number of trees to abatement emissions was higher to HO (?46.06 to HO and ?38.37 trees/cow to JE x HO) and to RHS (?51.9 to RHS and ?33.05 trees/cow to CLS). However, when the results are expressed per ton of FCPCmilk, there was a difference only between pasture management, requiring ?6.34 tree. ton FCPCmilk?1 for the RHS and ?3.99 tree. ton FCPCmilk?1 for the CLS system. The intensification of pastures resulted in higher milk production and land-saving effect of 2.7 ha. Due to the reservation of the pasture-based dairy systems in increasing soil C sequestration to offset the GHG emissions, especially enteric CH4, planting trees can be used as a mitigation strategy. Also, the land-save effect of intensification can contribute to the issue, since the area spared through the intensification in pasture management becomes available for reforestation with commercial trees

ADME studies and preliminary safety pharmacology of LDT5, a lead compound for the treatment of benign prostatic hyperplasia

This study aimed to estimate the absorption, distribution, metabolism and excretion (ADME) properties and safety of LDT5, a lead compound for oral treatment of benign prostatic hyperplasia that has previously been characterized as a multi-target antagonist of α1A-, α1D-adrenoceptors and 5-HT1A receptors. The preclinical characterization of this compound comprised the evaluation of its in vitro properties, including plasma, microsomal and hepatocytes stability, cytochrome P450 metabolism and inhibition, plasma protein binding, and permeability using MDCK-MDR1 cells. De-risking and preliminary safety pharmacology assays were performed through screening of 44 off-target receptors and in vivo tests in mice (rota-rod and single dose toxicity). LDT5 is stable in rat and human plasma, human liver microsomes and hepatocytes, but unstable in rat liver microsomes and hepatocytes (half-life of 11 min). LDT5 is highly permeable across the MDCK-MDR1 monolayer (Papp ∼32×10-6 cm/s), indicating good intestinal absorption and putative brain penetration. LDT5 is not extensively protein-bound and is a substrate of human CYP2D6 and CYP2C19 but not of CYP3A4 (half-life >60 min), and did not significantly influence the activities of any of the human cytochrome P450 isoforms screened. LDT5 was considered safe albeit new studies are necessary to rule out putative central adverse effects through D2, 5-HT1A and 5-HT2B receptors, after chronic use. This work highlights the drug-likeness properties of LDT5 and supports its further preclinical development