Consorciação de gramíneas e leguminosas forrageiras no Acre.

As consorciações entre sete gramíneas e seis leguminosas forrageiras foram avaliadas no campo experimental do Projeto de Melhoramento de Pastagens da Amazônia Legal - PROPASTO, localizado no município de Senador Guiomard - Acre, em área de floresta tropical úmida. A importância do trabalho está relacionada ao fato das leguminosas constituirem o meio natural e, possivelmente, o mais importante método de incorporar nitrogênio do sistema solo/planta, além de contribuir para aumentar a qualidade da forragem. Foram efetuadas avaliações qualitativas e quantitativas das consorciações no período de fevereiro/77 a fevereiro/80 a intervalos de 45 a 56 dias no período chuvoso e seco, respectivamente. A consorciação de Quicuio da Amazônia (Brachiaria humidícula) com Puerária (Pueraria phaseoloides) apresentou a melhor persistência de produção e composição botânica no período seco e chuvoso. A utilização da Puerária em consorciação com gramíneas aumentou o valor nutritivo da pastagem, permitindo aumentar a performance animal e, consequentemente, a rentabilidade do empreendimento.bitstream/item/161391/1/1018.pd

Longitudinal effects of ketamine on cell proliferation and death in the CNS of zebrafish

Funding Information: This work was funded by FEDER funds through the Operational Competitiveness Programme – COMPETE and by National Funds through FCT – Portuguese Foundation for Science and Technology under the project FCOMP-01-0124-FEDER-028683 (PTDC/CVT-WEL/4672/2012). Publisher Copyright: © 2023 The AuthorsZebrafish is known for its widespread neurogenesis and regenerative capacity, as well as several biological advantages, which turned it into a relevant animal model in several areas of research, namely in toxicological studies. Ketamine is a well-known anesthetic used both in human as well as veterinary medicine, due to its safety, short duration and unique mode of action. However, ketamine administration is associated with neurotoxic effects and neuronal death, which renders its use on pediatric medicine problematic. Thus, the evaluation of ketamine effects administration at early stages of neurogenesis is of pivotal importance. The 1‐41–4 somites stage of zebrafish embryo development corresponds to the beginning of segmentation and formation of neural tube. In this species, as well as in other vertebrates, longitudinal studies are scarce, and the evaluation of ketamine long-term effects in adults is poorly understood. This study aimed to assess the effects of ketamine administration at the 1–4 somites stage, both in subanesthetic and anesthetic concentrations, in brain cellular proliferation, pluripotency and death mechanisms in place during early and adult neurogenesis. For that purpose, embryos at the 1–4 somites stage (10.5 h post fertilization - hpf) were distributed into study groups and exposed for 20 min to ketamine concentrations at 0.2/0.8 mg/mL. Animals were grown until defined check points, namely 50 hpf, 144 hpf and 7 months adults. The assessment of the expression and distribution patterns of proliferating cell nuclear antigen (PCNA), of sex-determining region Y-box 2 (Sox 2), apoptosis-inducing factor (AIF) and microtubule-associated protein 1 light chain 3 (LC3) was performed by Western-blot and immunohistochemistry. The results evidenced the main alterations in 144 hpf larvae, namely in autophagy and in cellular proliferation at the highest concentration of ketamine (0.8 mg/mL). Nonetheless, in adults no significant alterations were seen, pointing to a return to a homeostatic stage. This study allowed clarifying some of the aspects pertaining the longitudinal effects of ketamine administration regarding the CNS capacity to proliferate and activate the appropriate cell death and repair mechanisms leading to homeostasis in zebrafish. Moreover, the results indicate that ketamine administration at 1–4 somites stage in the subanesthetic and anesthetic concentrations despite some transitory detrimental effects at 144 hpf, is long-term safe for CNS, which are newly and promising results in this research field.publishersversionpublishe

Reconciling cattle ranching and environmental conservation in the Legal Brazilian Amazon.

The Legal Brazilian Amazon is a region with growing economic, social and environmental relevance in the national and international scenarios. With a cattle heard above 70 million heads and an area of native and cultivated pastures above 61 million hectares cattle ranching has been one of the main focus of the debate regarding the sustainable development of the Region In the last 30 years, gains in productivity avoided need for incorporation of 147.5 million hectares of the biomes Cerrado and Amazon to the cattle production systems in the Legal Amazon to meet the current world demand for meat. Studies conducted at farm level in the State of Acre show that improved mixed grass-legume pastures with grass species of the genera Braquiaria or Panicum and the legumes Pueraria phaseoloides or Arachis pintoi managed correctly can allow farmers to sustainably maintain stocking rates of 2.5-2.7 animal units/hectare (1 animal unit is equivalent to 450 kg of live weight), with no need of nitrogen fertilizer, the most limiting and expensive nutrient to agricultural production in the tropics. .bitstream/item/198160/1/26798.pd

Viabilidade de sementes de Arachis pintoi pelo teste de tetrazólio.

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Dynamical large deviations for a boundary driven stochastic lattice gas model with many conserved quantities

We prove the dynamical large deviations for a particle system in which particles may have different velocities. We assume that we have two infinite reservoirs of particles at the boundary: this is the so-called boundary driven process. The dynamics we considered consists of a weakly asymmetric simple exclusion process with collision among particles having different velocities

Efeito do sombreamento natural na produtividade e na composição química de capim elefante no Acre.

No estado do Acre, a cobertura vegetal predominante é a floresta tropical úmida, com elevada diversidade de espécies por hectare. Neste áreas, a principal atividade econômica, no último século, tem sido o extrativismo do látex da seringueira (Hevea brasiliense) e a coleta da castanha-do-brasil (Bertholletia excelsa). Entretanto, nos últimos 30 anos, a desestruturação do sistema extrativo da borracha nos seringais nativos, a criação de projetos de colonização e a implantação e expansão da atividade pecuária transformaram a economia do setor primário do Acre. Este trabalho objetivou avaliar a produtividade e composição química da forragem de capim elefante associado às leguminosas arbóreas nativas bordão-de-velho (Samanea sp.) e timbaúba (Enterolobium maximum), espécies que se regeneram naturalmente nas pastagens.bitstream/CPAF-AC/3646/1/comunicado116.pd