Forest growth dynamics of managed forests in the Southwestern Brazilian Amazon.

The objective of this work was to present the growth forest dynamics results obtained in two sites located in Acre and Amazonas states in the southwestern Brazilian Amazon.Abstracts of the XXV IUFRO World Congress

El agronegocio del cultivo de tartago em el mundo.

bitstream/CNPA/18351/1/CIRTEC101.pd

A Point Mutation in the Transcriptional Repressor PerR Results in a Constitutive Oxidative Stress Response in Clostridioides difficile 630(delta)Derm

The human pathogen Clostridioides difficile has evolved into the leading cause of nosocomial diarrhea. The bacterium is capable of spore formation, which even allows survival of antibiotic treatment. Although C. difficile features an anaerobic lifestyle, we determined a remarkably high oxygen tolerance of the laboratory reference strain 630Δerm. A mutation of a single nucleotide (single nucleotide polymorphism [SNP]) in the DNA sequence (A to G) of the gene encoding the regulatory protein PerR results in an amino acid substitution (Thr to Ala) in one of the helices of the helix-turn-helix DNA binding domain of this transcriptional repressor in C. difficile 630Δerm. PerR is a sensor protein for hydrogen peroxide and controls the expression of genes involved in the oxidative stress response. We show that PerR of C. difficile 630Δerm has lost its ability to bind the promoter region of PerR-controlled genes. This results in a constitutive derepression of genes encoding oxidative stress proteins such as a rubrerythrin (rbr1) whose mRNA abundance under anaerobic conditions was increased by a factor of about 7 compared to its parental strain C. difficile 630. Rubrerythrin repression in strain 630Δerm could be restored by the introduction of PerR from strain 630. The permanent oxidative stress response of C. difficile 630Δerm observed here should be considered in physiological and pathophysiological investigations based on this widely used model strain

Preliminary report on cross-species microsatellite amplification for bumblebee biodiversity and conservation studies

The Iberian Peninsula holds a high diversity of bumblebees but there is a general lack of information about their biodiversity in this area. To overcome this and facilitate conservation studies, we present two novel multiplex assays for the amplification of six and five microsatellite loci respectively. Both assays successfully amplified for most of the studied species in the Iberian populations. Sibling workers and population genetic parameters were analysed in the managed species B. terrestris and in the wild species B. monticola and B. mesomelas, demonstrating the capability of these multiplex assays for biodiversity studies of both managed and wild bumblebee species

Enhanced synthesis of medium-chain-length poly(3-hydroxyalkanoates) by inactivating the tricarboxylate transport system of Pseudomonas putida KT2440 and process development using waste vegetable oil

Indexación: Scopus.The use of waste materials as feedstock for biosynthesis of valuable compounds has been an intensive area of research aiming at diminishing the consumption of non-renewable materials. In this study, P. putida KT2440 was employed as a cell factory for the bioconversion of waste vegetable oil into medium-chain-length Polyhydroxyalkanoates. In the presence of the waste oil this environmental strain is capable of secreting enzymes with lipase activities that enhance the bioavailability of this hydrophobic carbon substrate. It was also found that the oxygen transfer coefficient is directly correlated with high PHA levels in KT2440 cells when metabolizing the waste frying oil. By knocking out the tctA gene, encoding for an enzyme of the tripartite carboxylate transport system, an enhanced intracellular level of mcl-PHA was found in the engineered strain when grown on fatty acids. Batch bioreactors showed that the KT2440 strain produced 1.01 (g⋅L −1 ) of PHA whereas the engineered ΔtctA P. putida strain synthesized 1.91 (g⋅L −1 ) after 72 h cultivation on 20 (g⋅L −1 ) of waste oil, resulting in a nearly 2-fold increment in the PHA volumetric productivity. Taken together, this work contributes to accelerate the pace of development for efficient bioconversion of waste vegetable oils into sustainable biopolymers. © 2018 Elsevier Ltd.https://www.sciencedirect.com/science/article/pii/S135951131831451X?via%3Dihu

Possible Conservation of the K -Quantum Number in Excited Rotating Nuclei

The \ensuremath{\gamma} cascades feeding into low-K and high-K bands in ${}^{163}$Er are investigated analyzing variances and covariance of the spectrum fluctuations. From a large data set of 1${0}^{9}$ triple coincidences, \ensuremath{\gamma}-\ensuremath{\gamma} coincidence spectra gated by resolved low-lying rotational bands are analyzed. Low-K bands are found to be fed by a much larger effective number of cascades than high-K bands. The covariance between pairs of gated spectra shows that the cascades feeding low-K bands are different from those feeding the high-K bands. The persistence of the K-selection rules for the excited rotational bands within the angular momentum region 30\ensuremath{\Elzxh}\ensuremath{\le}I\ensuremath{\le}40\ensuremath{\Elzxh} is suggested as explanation

Análise ecointegradora do manejo florestal sustentável de estoques madeireiros na Amazônia sul ocidental - Brasil.

O presente trabalho propõe uma modelagem de interpretação transdisciplinar, sob a visão da economia ecológica e do enfoque ecointegrador proposto por Naredo (1987), aplicado nos resultados dos limites físicos dos monitoramentos florestais efetuados pela EMBRAPA do Estado do Acre, em estoques madeireiros de uma área de Floresta Ombrófila Aberta com presença de espécies de Guadua spp. na Amazônia Sul Ocidental do Brasil. O método aplicado oferece maiores opções de compreensão para a gestão florestal na Amazônia, através de uma visão financeira da evolução das taxas efetivas dos estoques ao longo do tempo. A determinação do ponto de equilíbrio monetário (PEM) e das análises dos índices de mercado da atividade permitem o entendimento bioeconômico e financeiro, isento da arbitragem de taxas de desconto futuras em cenários incertos e utilizando somente variáveis ecológicas e econômicas conhecidas. O modelo pode ser aplicado a qualquer momento, entre os ciclos de corte da operação florestal e confirma a necessidade da prática do monitoramento de florestas tropicais para acompanhar os efeitos antrópicos da exploração, efeitos dos fenômenos extremos provocados pelas mudanças climáticas e a evolução dos estoques do capital natural

Dinâmica e estrutura florestal em área explorada sob regime de manejo florestal sustentável na Amazônia Sul Ocidental, Brasil.

O capítulo demonstra ferramentas de apoio e pesquisa ao MFS na Amazônia que sejam úteis para avaliar as medidas silviculturais adotadas, ou a efetuar, o planejamento estratégico, operacional e tático, e prever ciclos de corte. Esta estratégia atende ao princípio da sustentabilidade florestal na exploração de madeira tropical em toras na Amazônia.bitstream/item/209200/1/26955.pdfVersão impressa publicada em 2020