7,782 research outputs found
Experimentation with accumulation
We study signal-dependent experimentation in the presence of accumulation
and show that the passive-learner’s action surprisingly coincides with
the experimentor’s when the unknown term is the one determining the decay
rate of the stock, while they differ when the parameter being learned is
the one measuring the accumulation rate. These results highlight the importance
of the dynamic structure of the problem in signal-dependent experimentation.
Moreover, they have important consequences for the pollution-accumulation
debate currently in progress
GRASS UTILIZATION IN GROWING FINISHING BÍSARO PIGS (85-107 KG). PERFORMANCE AND CARCASS COMPOSITION
The use of different quantities of vegetables, forages or fresh grass as fodder for growing-finishing pigs is an important factor of the northern Portugal traditional system. The increasing development of swine production in outdoor systems, extensive and organic production, turns to upcoming natural diets, in which grass performs a significant part. With regard to this, some investigation has been made concerning the use of fibre-rich feed ingredients in pig nutrition. Metabolic effects of its ingestion are analysed concerning different sights (economical, social, environmental and physiological ones).
The aim of this work was to study the effects of grass utilization in the diets on performances of finishing Bísaro pigs. A total of 22 pigs (16 castrated males and 6 females) was housed outdoor and fed ad libitum (37 – 85 kg live weight) with a growing diet and then transferred to an indoor system (with free access to an outdoor area) for 49 days, according to 3 different treatments: 100% concentrate (C), 75% concentrate + ad libitum grass (CE75), 50% concentrate + ad libitum grass (CE50). The grass was supplied and its intake registered on a daily basis. Every 14 days, the pigs were weighted and their back fat (P2 in vivo) measured. After slaughter (average weight of 107 kg LW), yield and ½ left carcass characteristics were controlled. During the outdoor growing phase, the ADG was 513 g/day. During the indoor finishing phase, the increase grass intake was proportional to the reduction of concentrate in the diet. The ADG (g) and the fat deposition (P2 cm) were significantly different (P<0,05) in the 3 treatments (ADG: C=641, CE75=467, CE50=356 and: C=11,4, CE75=+9,5, CE50=+6,2). The empty body weight (kg) was also proportional to the intake of concentrate (C=116,2; CE75=107,7; CE50=102,2). Comparatively to the weight of the body parts, pigs that had higher intake of grass and lower of concentrate showed a higher % of shoulder (P<0,05; C=20,4, CE75=21,7, CE50=22,2) and the pH45min of CE carcasses was significantly higher (P<0,05). As a conclusion, concentrate substitution for grass showed a slower growing rate, thinner carcasses and a high technological quality.
Neverthelles variability (CV %) of the productive parameters at the end of this study were higher in the treatments that included grass: live weight (C= 10,5%; C75=10,7%; C50=14,3%), finishing ADG (C=24%; C75=37%, C50=42%), and final fat (C=37%; C75=32%, C50=52%). These values suggest that the utilization of fibrous feeds in growing-finishing swine may be one of the possible explanations of the more heterogeneous products and carcasses found in the traditional or extensive systems, common users of fibrous feeds in the carcass finishing phase
History, synthesis, properties, applications and regulatory issues of prebiotic oligosaccharides
In this chapter, the health promoting effects of carbohydrate prebiotics are addressed. A brief description of their synthesis, thermo-physical properties,
mechanisms of action, technological applications and current regulatory issues are presented
An Empirical Bayesian Approach to Quantify Multi-Scale Spatial Structural Diversity in Remote Sensing Data
Landscape structure is as much a driver as a product of environmental and biological interactions and it manifests as scale-specific, but also as multi-scale patterns. Multi-scale structure affects processes on smaller and larger scales and its detection requires information from different scales to be combined. Herein, we propose a novel method to quantify multi-scale spatial structural diversity in continuous remote sensing data. We combined information from different extents with an empirical Bayesian model and we applied a new entropy metric and a value co-occurrence approach to capture heterogeneity. We tested this method on Normalized Difference Vegetation Index data in northern Eurasia and on simulated data and we also tested the effect of coarser pixel resolution. We find that multi-scale structural diversity can reveal itself as patches and linear landscape features, which persist or become apparent across spatial scales. Multi-scale line features reveal the transition zones between spatial regimes and multi-scale patches reveal those areas within transition zones where values are most different from each other. Additionally, spatial regimes themselves can be distinguished. We also find the choice of scale need not be informed by typical length-scales, which makes the method easy to implement. The proposed multi-scale approach can be applied to other contexts, following the roadmap we pave out in this study and using the tools available in the accompanying R package StrucDiv
A combined approach for comparative exoproteome analysis of Corynebacterium pseudotuberculosis
Background: Bacterial exported proteins represent key components of the host-pathogen interplay. Hence, we
sought to implement a combined approach for characterizing the entire exoproteome of the pathogenic
bacterium Corynebacterium pseudotuberculosis, the etiological agent of caseous lymphadenitis (CLA) in sheep and
goats.
Results: An optimized protocol of three-phase partitioning (TPP) was used to obtain the C. pseudotuberculosis
exoproteins, and a newly introduced method of data-independent MS acquisition (LC-MSE) was employed for
protein identification and label-free quantification. Additionally, the recently developed tool SurfG+ was used for in
silico prediction of sub-cellular localization of the identified proteins. In total, 93 different extracellular proteins of
C. pseudotuberculosis were identified with high confidence by this strategy; 44 proteins were commonly identified
in two different strains, isolated from distinct hosts, then composing a core C. pseudotuberculosis exoproteome.
Analysis with the SurfG+ tool showed that more than 75% (70/93) of the identified proteins could be predicted as
containing signals for active exportation. Moreover, evidence could be found for probable non-classical export of
most of the remaining proteins.
Conclusions: Comparative analyses of the exoproteomes of two C. pseudotuberculosis strains, in addition to
comparison with other experimentally determined corynebacterial exoproteomes, were helpful to gain novel
insights into the contribution of the exported proteins in the virulence of this bacterium. The results presented
here compose the most comprehensive coverage of the exoproteome of a corynebacterial species so far
Prediction of friction degradation in highways with linear mixed models
The development of a linear mixed model to describe the degradation of friction on flexible road pavements to be included in pavement management systems is the aim of this study. It also aims at showing that, at the network level, factors such as temperature, rainfall, hypsometry, type of layer, and geometric alignment features may influence the degradation of friction throughout time. A dataset from six districts of Portugal with 7204 sections was made available by the Ascendi Concession highway network. Linear mixed models with random effects in the intercept were developed for the two-level and three-level datasets involving time, section and district. While the three-level models are region-specific, the two-level models offer the possibility to be adopted to other areas. For both levels, two approaches were made: One integrating into the model only the variables inherent to traffic and climate conditions and the other including also the factors intrinsic to the highway characteristics. The prediction accuracy of the model was improved when the variables hypsometry, geometrical features, and type of layer were considered. Therefore, accurate predictions for friction evolution throughout time are available to assist the network manager to optimize the overall level of road safety.This research was funded by FCT—Fundação para a Ciência e Tecnologia (Foundation for Science and Technology), Grants No. UIDB/04029/2020 and UIDB/00319/2020
Aplastic anemia after pediatric liver transplantation
A aplasia de medula é uma das mais raras (<1%) e sérias complicações após o transplante hepático por insuficiência hepática aguda grave viral não A, não B e não C. Esta condição clínica, que acomete simultaneamente o tecido hepático e o hematopoético, foi descrita pela primeira vez em 1987, por Stock, e a fisiopatologia relacionada é uma condição imunomediada, provavelmente secundária à infecção viral desconhecida, e associada a grave prognóstico. A recuperação espontânea da aplasia medular adquirida habitualmente é muito rara e 50%-70% dos pacientes respondem ao tratamento imunossupressor com ciclosporina A (CsA) e glubulina antitimocítica (ATG), mesmo após o transplante hepático. Além do tratamento imunossupressor, outra opção é o transplante de medula óssea (TMO). Apresentamos o caso de uma criança com aplasia medular grave após transplante hepático, por insuficiência hepática aguda grave, que recebeu tratamento imunossupressor com CsA e ATG e evoluiu com recuperação completa das três séries do hemograma.Aplastic anemia (AA) is one of the rarest (<1%) and most serious complications of liver transplantation for fulminant non-A, non-B and non-C hepatitis. It was first described in 1987 by Stock; the mechanism involved is an immunologically mediated condition secondary to an unknown viral infection. The disease is associated with a dismal prognosis. Spontaneous recovery from acquired AA is very rare however some patients (50-70%) recover after immunosuppressive therapy, such as Cyclosporin A (CsA) and Antithymocyte globulin (ATG), even after liver transplantation. Another treatment option is bone marrow transplantation. We report on a child who developed AA following liver transplantation for fulminant viral hepatitis that was treated with intensive immunosuppression including CsA and ATG and achieved complete recovery
Evaluation Model of Virtual Learning Environments: A Pilot Study
Virtual learning environments (VLE) have frequently been used in educational practices, and the evaluation of their effectiveness as instruments to support learning gains must consider several dimensions. This paper presents an evaluation model for VLE, called MA-AVA (Model for the Evaluation of VLE), built after a review of the literature and focused on verifying students\u27 learning gains. The MA-AVA evaluation model was applied in a pilot study to an undergraduate engineering class, using a VLE, Educ-MAS-GA, in the discipline of Analytical Geometry. The results indicate that, although students\u27 perception of learning in VLE is relevant, the knowledge acquired is more subtle and difficult to assess. Therefore, a VLE learning evaluation model should include different dimensions of learning, such as the students’ perceptions and their measures of learning gain
- …