Padrão de pastejo de fêmeas de corte em campo nativo no Sul do Brasil.

JAI

A Pipeline to Determine RT-QPCR Control Genes for Evolutionary Studies: Application to Primate Gene Expression across Multiple Tissues

Because many species-specific phenotypic differences are assumed to be caused by differential regulation of gene expression, many recent investigations have focused on measuring transcript abundance. Despite the availability of high-throughput platforms, quantitative real-time polymerase chain reaction (RT-QPCR) is often the method of choice because of its low cost and wider dynamic range. However, the accuracy of this technique heavily relies on the use of multiple valid control genes for normalization. We created a pipeline for choosing genes potentially useful as RT-QPCR control genes for measuring expression between human and chimpanzee samples across multiple tissues, using published microarrays and a measure of tissue-specificity. We identified 13 genes from the pipeline and from commonly used control genes: ACTB, USP49, ARGHGEF2, GSK3A, TBP, SDHA, EIF2B2, GPDH, YWHAZ, HPTR1, RPL13A, HMBS, and EEF2. We then tested these candidate genes and validated their expression stability across species. We established the rank order of the most preferable set of genes for single and combined tissues. Our results suggest that for at least three tissues (cerebral cortex, liver, and skeletal muscle), EIF2B2, EEF2, HMBS, and SDHA are useful genes for normalizing human and chimpanzee expression using RT-QPCR. Interestingly, other commonly used control genes, including TBP, GAPDH, and, especially ACTB do not perform as well. This pipeline could be easily adapted to other species for which expression data exist, providing taxonomically appropriate control genes for comparisons of gene expression among species

Optical response of small silver clusters

The time-dependent local density approximation is applied to the optical response of the silver clusters, Ag_2, Ag_3, Ag_8 and Ag_9^+. The calculation includes all the electrons beyond the closed-shell Ag^{+11} ionic core, thus including for the first time explicitly the filled d-shell in the response. The excitation energy of the strong surface plasmon near 4 eV agrees well with experiment. The theoretical transition strength is quenched by a factor of 4 with respect to the pure s-electron sum rule in Ag_8 due to the d-electrons. A comparable amount of strength lies in complex states below 6 eV excitation. The total below 6 eV, about 50% of the s sum rule, is consistent with published experiments.Comment: 13 pages RevTex and 9 Postscript figure

Autopsy in adults with congenital heart disease (ACHD).

The adult congenital heart diseases (ACHD) population is exceeding the pediatric congenital heart diseases (CHD) population and is progressively expanding each year, representing more than 90% of patients with CHD. Of these, about 75% have undergone surgical and/or percutaneous intervention for palliation or correction. Autopsy can be a very challenging procedure in ACHD patients. The approach and protocol to be used may vary depending on whether the pathologists are facing native disease without surgical or percutaneous interventions, but with various degrees of cardiac remodeling, or previously palliated or corrected CHD. Moreover, interventions for the same condition have evolved over the last decades, as has perioperative myocardial preservations and postoperative care, with different long-term sequelae depending on the era in which patients were operated on. Careful clinicopathological correlation is, thus, required to assist the pathologist in performing the autopsy and reaching a diagnosis regarding the cause of death. Due to the heterogeneity of the structural abnormalities, and the wide variety of surgical and interventional procedures, there are no standard methods for dissecting the heart at autopsy. In this paper, we describe the most common types of CHDs that a pathologist could encounter at autopsy, including the various types of surgical and percutaneous procedures and major pathological manifestations. We also propose a practical systematic approach to the autopsy of ACHD patients

Radial elasticity of multi-walled carbon nanotubes

We report an experimental and a theoretical study of the radial elasticity of multi-walled carbon nanotubes as a function of external radius. We use atomic force microscopy and apply small indentation amplitudes in order to stay in the linear elasticity regime. The number of layers for a given tube radius is inferred from transmission electron microscopy, revealing constant ratios of external to internal radii. This enables a comparison with molecular dynamics results, which also shed some light onto the applicability of Hertz theory in this context. Using this theory, we find a radial Young modulus strongly decreasing with increasing radius and reaching an asymptotic value of 30 +/- 10 GPa.Comment: 5 pages, 3 figure

Atributos microbianos do solo sob pastagens naturais com diferentes intensidades de pastejo

The soil microbial biomass is the living fraction of organic matter, being responsible for several biological and biochemical processes of the soil and influenced by the conditions imposed by the environment. To evaluate the effect of grazing on changes in soil microbial attributes we studied four grazing intensities based on natural grassland of Pampa Biome: 4, 8, 12 and 16 kg of dry matter per day per 100 kg of animal live weight, compared to an area without grazing. We used randomized block design with two replications. Samples were taken on 11/23/2011 and analyzed to determine the levels of soil organic matter (SOM), microbial biomass, nitrogen, respiration and metabolic quotient. The results showed that at intermediate grazing intensities, such as 12%, minor disturbances occur in soil microbial biomass compared to other intensities, emit less CO2 into the atmosphere for each animal unit produced. The levels of organic matter and soil microbial biomass systems are lower in grazed than in areas excluded from grazing for a long period.A biomassa microbiana do solo constitui a fração viva da matéria orgânica, sendo responsável por diversos processos biológicos e bioquímicos do solo e influenciada pelas condições impostas pelo meio. Visando avaliar o efeito do pastejo nas alterações dos atributos microbianos do solo, foram estudados 4 intensidades de pastejo baseados em pastagem natural do Bioma Pampa: 4, 8, 12 e 16% de oferta de forragem (kg de peso vivo em MS), comparados com uma área sem pastejo. Foi utilizado o delineamento em blocos casualizados com duas repetições. As amostras foram tomadas no dia 23/11/2011, sendo avaliados os teores de matéria orgânica do solo (MOS), biomassa microbiana, nitrogênio, respiração e quociente metabólico. Os resultados apontaram que em intensidades de pastejo intermediárias, como 12%, ocorrem menores distúrbios na biomassa microbiana do solo quando comparados às demais ofertas, emitindo menor quantidade de CO2 para a atmosfera para cada unidade animal produzida. Os teores de matéria orgânica e biomassa microbiana do solo em sistemas pastejados são inferiores àqueles de áreas excluídas do pastejo por um longo período

Synergism and phenolic bioaccessibility during in vitro co-digestion of cooked cowpea with orange juice.

Foods are susceptible to matrix interferences during the gastrointestinal transit that can affect bioactive molecules. We proposed in vitro co-digestion of cowpea beans and orange juice to assess polyphenols bioaccessibility and synergisms. We performed astrointestinal simulation combining beans and a fruit beverage, to mimic a common meal in a more realistic set-up than the usual single-food models