35 research outputs found
Produtividade Da Crotalaria Juncea Sob Podas E Densidades De Semeadura Nos Tabuleiros Costeiros Do PiauĂ
The northern region of Piauà state is an important center of irrigated organic fruit farming, wherein sandy soils with low organic matter content are predominant, besides climate with high temperatures, long periods of water deficit and constant wind. Given this situation, it becomes necessary to investigate alternative management options able to meet the challenges of agricultural productivity. In this context, green manuring becomes an important practice, mainly when using fast-growing species and with great potential for biomass production. Thus, a study was carried out at Embrapa Meio-Norte to measure Crotalaria juncea biomass yield after thinning and at various sowing densities. The evaluated parameters were plant height, stem diameter, number of branches per plant, fresh and dry weight of shoots and roots. The results showed that sowing density had no influence on plant height; however, unthinned plants reached greater heights, which might have been due to reduced competition for light. Thinning had no effect on diameters of plant stem base; on the other hand, lower planting densities promoted larger diameters also due to less competition. Likewise, the number of branches per plant was not affected by thinning, being greater at lower planting densities on account of less competition. Thinned plants achieved higher averages of fresh shoot weight. Nevertheless, shoot dry biomass was greater at higher planting densities. Furthermore, both fresh and dry weight of roots were not influenced by any of the adopted treatments. © 2016, Universidade Federal Rural do Semi-Arid. All rights reserved.29487888
Consequences of Giant Impacts on Early Uranus for Rotation, Internal Structure, Debris, and Atmospheric Erosion
We perform a suite of smoothed particle hydrodynamics simulations to investigate in detail the results of a giant impact on the young Uranus. We study the internal structure, rotation rate, and atmospheric retention of the post-impact planet, as well as the composition of material ejected into orbit. Most of the material from the impactor's rocky core falls in to the core of the target. However, for higher angular momentum impacts, significant amounts become embedded anisotropically as lumps in the ice layer. Furthermore, most of the impactor's ice and energy is deposited in a hot, high-entropy shell at a radius of ~3 R â. This could explain Uranus' observed lack of heat flow from the interior and be relevant for understanding its asymmetric magnetic field. We verify the results from the single previous study of lower resolution simulations that an impactor with a mass of at least 2 M â can produce sufficiently rapid rotation in the post-impact Uranus for a range of angular momenta. At least 90% of the atmosphere remains bound to the final planet after the collision, but over half can be ejected beyond the Roche radius by a 2 or 3 M â impactor. This atmospheric erosion peaks for intermediate impactor angular momenta (~3 Ă 1036 kg m2 sâ1). Rock is more efficiently placed into orbit and made available for satellite formation by 2 M â impactors than 3 M â ones, because it requires tidal disruption that is suppressed by the more massive impactors
Structure of Anopheles (Diptera: Culicidae) population in areas with different degrees of human settlement: CantĂĄ - Roraima - Brazil
EficiĂȘncias Reprodutiva e Produtiva em Vacas das Raças Gir, HolandĂȘs e Cruzadas HolandĂȘs x Zebu
Comprehensive analysis of epigenetic clocks reveals associations between disproportionate biological ageing and hippocampal volume
The concept of age acceleration, the difference between biological age and chronological age, is of growing interest, particularly with respect to age-related disorders, such as Alzheimerâs Disease (AD). Whilst studies have reported associations with AD risk and related phenotypes, there remains a lack of consensus on these associations. Here we aimed to comprehensively investigate the relationship between five recognised measures of age acceleration, based on DNA methylation patterns (DNAm age), and cross-sectional and longitudinal cognition and AD-related neuroimaging phenotypes (volumetric MRI and Amyloid-ÎČ PET) in the Australian Imaging, Biomarkers and Lifestyle (AIBL) and the Alzheimerâs Disease Neuroimaging Initiative (ADNI). Significant associations were observed between age acceleration using the Hannum epigenetic clock and cross-sectional hippocampal volume in AIBL and replicated in ADNI. In AIBL, several other findings were observed cross-sectionally, including a significant association between hippocampal volume and the Hannum and Phenoage epigenetic clocks. Further, significant associations were also observed between hippocampal volume and the Zhang and Phenoage epigenetic clocks within Amyloid-ÎČ positive individuals. However, these were not validated within the ADNI cohort. No associations between age acceleration and other Alzheimerâs disease-related phenotypes, including measures of cognition or brain Amyloid-ÎČ burden, were observed, and there was no association with longitudinal change in any phenotype. This study presents a link between age acceleration, as determined using DNA methylation, and hippocampal volume that was statistically significant across two highly characterised cohorts. The results presented in this study contribute to a growing literature that supports the role of epigenetic modifications in ageing and AD-related phenotypes
Studies on entomological monitoring: mosquito species frequency in riverine habitats of the Igarapava Dam, Southern Region, Brazil
Respostas correlacionadas em caracterĂsticas reprodutivas no programa de melhoramento do ecĂłtipo Mantiqueira para produção de leite
Uncovering the heterogeneity and temporal complexity of neurodegenerative diseases with Subtype and Stage Inference
The heterogeneity of neurodegenerative diseases is a key confound to disease understanding and treatment development, as study cohorts typically include multiple phenotypes on distinct disease trajectories. Here we introduce a machine-learning technique\u2014Subtype and Stage Inference (SuStaIn)\u2014able to uncover data-driven disease phenotypes with distinct temporal progression patterns, from widely available cross-sectional patient studies. Results from imaging studies in two neurodegenerative diseases reveal subgroups and their distinct trajectories of regional neurodegeneration. In genetic frontotemporal dementia, SuStaIn identifies genotypes from imaging alone, validating its ability to identify subtypes; further the technique reveals within-genotype heterogeneity. In Alzheimer\u2019s disease, SuStaIn uncovers three subtypes, uniquely characterising their temporal complexity. SuStaIn provides fine-grained patient stratification, which substantially enhances the ability to predict conversion between diagnostic categories over standard models that ignore subtype (p = 7.18
7 10 124 ) or temporal stage (p = 3.96
7 10 125 ). SuStaIn offers new promise for enabling disease subtype discovery and precision medicine
Aplicação da tĂ©cnica de PCR na detecção de Yersinia enterocolitica em suĂnos abatidos sem inspeção PCR technique application in Yersinia enterocolitica detection in non-inspected swine
Avaliou-se a contaminação de carcaças e tonsilas de suĂnos por Y. enterocolitica em estabelecimentos de abate nĂŁo inspecionados, comparando a pesquisa microbiolĂłgica convencional com a tĂ©cnica da reação em cadeia de polimerase (PCR) e o tipo de amostra analisada (de tonsila ou de carcaça), como subsĂdio ao monitoramento microbiano em sistemas de anĂĄlise de perigos e pontos crĂticos de controle. Calcularam-se os custos dos dois testes. NĂŁo se detectou Y. enterocolitica pela tĂ©cnica microbiolĂłgica convencional, mas, pela tĂ©cnica de PCR foi possĂvel detectar a bactĂ©ria em 40% das carcaças e em 43% das tonsilas, incluindo cepas patogĂȘnicas nas tonsilas. NĂŁo houve diferença entre os resultados positivos para as amostras de tonsilas e esfregaços de superfĂcie das carcaças. A PCR apresentou-se como uma alternativa na detecção do agente e uma tĂ©cnica aparentemente mais eficaz, econĂŽmica e rĂĄpida. Os resultados indicam a PCR como um importante recurso para o controle de qualidade da carne suĂna.The contamination of swine carcasses and tonsils by Yersinia enterocolitica in slaughterhouses without inspection was evaluated. The conventional microbiological analysis was compared with the PCR technique of carcass or tonsil swabs, as a subsidy to the microbiological evaluation in the HACCP system. The costs of the two techniques were also calculated. Y. enterocolitica was not detected by the conventional microbiological analysis. Using the PCR, it was possible to detect this bacterium in carcass (40%) and tonsil (43%) samples. There was no difference between the positive results for the carcass and tonsil samples. The PCR showed to be a more effective, fast and economic alternative for the Y. enterocolitica detection, as compared to the conventional microbiological analysis