2,155 research outputs found
Effect of immunocastration and caponization on fatty acid composition of male chicken meat
Research Areas: AgricultureAiticle in International JournalABSTRACT - Recently, immunocastration with Improvac (ImmC). has been tested in broilers and a considerable reduction in serum testosterone concentration (reduced by 79% compared to roosters) was observed. The aim of this study was to evaluate the effect of immunocastration on meat fatty acid (FA) composition and its comparison with caponized and intact males (roosters). The study was conducted with 3 experimental groups: control group (roosters), the group of birds submitted to surgical caponization (SurgC), and the group of birds submitted to immunocastration with Improvac. The comparison of breast meat partial FA sums of castrated (SurgC and ImmC) with control birds (roosters) revealed that castrated birds showed significantly higher content of n-3 polyunsaturated fatty acids (n-3 PUFA) than control birds (1.76 vs. 1.46 g/100 g of total FA; superiority of 20.2%), which has contributed to the occurrence of significant differences on both the n-6/n-3 ratio and the atherogenicity index (AI). In contrast, on leg meat portion, castrated birds displayed higher contents of both total saturated and monounsaturated fatty acids (SFA and MUFA, with 2.2 and 4.1% more, respectively) and lower total n-6 PUFA content (8.3% less) than was observed in control birds, which contributed to significant differences in the AI index. On the other hand, the comparison of breast meat portion from SurgC with ImmC showed that immunocastration contributed to lower total SFA and higher total n-6 PUFA, which have contributed to significant differences on both Polyunsaturated/Saturated (P/S) and n-6/n-3 ratios. Whereas, on leg meat portion no significant differences were observed on partial sums and a single difference was observed on the thrombogenicity index. Immunocastration of broilers has contributed to minor changes in the FA profile, but has improved the overall lipid quality indexes in both breast and leg meat portions. Therefore, immunocastration could be applied as an alternative method to caponization without negative consequences in meat FA profile.info:eu-repo/semantics/publishedVersio
Nutritional value of meat lipid fraction from red-legged partridge (Alectoris rufa) obtained from wild and farmed specimens
Research Areas; Agriculture, Dairy & Animal ScienceArticle in International JournalABSTRACT - The red-legged partridge (Alectoris rufa) is a feathered game species of great socioeconomic importance in its native range and also in the UK. The aim of this study was to present a detailed comparison of meat's lipid fraction obtained from wild and farm-raised specimens and simultaneously compare the breast and leg meat portions.
Meat from wild specimens had a significant (P < 0.05) lower proportion of saturated fatty acid (less 5.1%) and presented better P/S and n-6/n-3 ratios, and atherogenicity index than farm-raised counterparts. The wild specimens presented significant (P < 0.001) higher contents of total vitamin E (8.8 vs. 2.2 mu g/g of fresh meat), is for that reason less prone to lipid peroxidation than farm-raised specimens.
Meat portions differed significantly (P < 0.05) on total lipid and total cholesterol contents and in all partial sums of fatty acids. The breast was leaner (0.86 vs. 1.47 g/100 g of meat), with lower total cholesterol (37.5 vs. 54.7 mg/100 g of meat), lower saturated fatty acid, monounsaturated fatty acid, polyunsaturated fatty acid, and n-6 polyunsaturated fatty acid (less 0.27, 0.28, 0.10, and 0.11 g/100 g of fresh meat, correspondingly). Regarding the fatty acid ratios and lipid quality indexes, breast meat presents better n-6/n-3 ratio and atherogenicity and thrombogenicity indexes.CIISAinfo:eu-repo/semantics/publishedVersio
Detailed dimethylacetal and fatty acid composition of rumen content from lambs fed lucerne or concentrate supplemented with soybean oil
Articles in International JournalsLipid metabolism in the rumen is responsible for the complex fatty acid profile of rumen outflow compared with the dietary
fatty acid composition, contributing to the lipid profile of ruminant products. A method for the detailed dimethylacetal and
fatty acid analysis of rumen contents was developed and applied to rumen content collected from lambs fed lucerne or
concentrate based diets supplemented with soybean oil. The methodological approach developed consisted on a basic/
acid direct transesterification followed by thin-layer chromatography to isolate fatty acid methyl esters from dimethylacetal,
oxo- fatty acid and fatty acid dimethylesters. The dimethylacetal composition was quite similar to the fatty acid
composition, presenting even-, odd- and branched-chain structures. Total and individual odd- and branched-chain
dimethylacetals were mostly affected by basal diet. The presence of 18:1 dimethylacetals indicates that biohydrogenation
intermediates might be incorporated in structural microbial lipids. Moreover, medium-chain fatty acid dimethylesters were
identified for the first time in the rumen content despite their concentration being relatively low. The fatty acids containing
18 carbon-chain lengths comprise the majority of the fatty acids present in the rumen content, most of them being
biohydrogenation intermediates of 18:2n26 and 18:3n23. Additionally, three oxo- fatty acids were identified in rumen
samples, and 16-O-18:0 might be produced during biohydrogenation of the 18:3n23
General Neutralino NLSPs at the Early LHC
Gauge mediated supersymmetry breaking (GMSB) is a theoretically
well-motivated framework with rich and varied collider phenomenology. In this
paper, we study the Tevatron limits and LHC discovery potential for a wide
class of GMSB scenarios in which the next-to-lightest superpartner (NLSP) is a
promptly-decaying neutralino. These scenarios give rise to signatures involving
hard photons, 's, 's, jets and/or higgses, plus missing energy. In order
to characterize these signatures, we define a small number of minimal spectra,
in the context of General Gauge Mediation, which are parameterized by the mass
of the NLSP and the gluino. Using these minimal spectra, we determine the most
promising discovery channels for general neutralino NLSPs. We find that the
2010 dataset can already cover new ground with strong production for all NLSP
types. With the upcoming 2011-2012 dataset, we find that the LHC will also have
sensitivity to direct electroweak production of neutralino NLSPs.Comment: 26 page
Environmental Costs of Government-Sponsored Agrarian Settlements in Brazilian Amazonia
Brazil has presided over the most comprehensive agrarian reform frontier colonization program on Earth, in which ~1.2 million settlers have been translocated by successive governments since the 1970's, mostly into forested hinterlands of Brazilian Amazonia. These settlements encompass 5.3% of this ~5 million km2 region, but have contributed with 13.5% of all land conversion into agropastoral land uses. The Brazilian Federal Agrarian Agency (INCRA) has repeatedly claimed that deforestation in these areas largely predates the sanctioned arrival of new settlers. Here, we quantify rates of natural vegetation conversion across 1911 agrarian settlements allocated to 568 Amazonian counties and compare fire incidence and deforestation rates before and after the official occupation of settlements by migrant farmers. The timing and spatial distribution of deforestation and fires in our analysis provides irrefutable chronological and spatially explicit evidence of agropastoral conversion both inside and immediately outside agrarian settlements over the last decade. Deforestation rates are strongly related to local human population density and road access to regional markets. Agrarian settlements consistently accelerated rates of deforestation and fires, compared to neighboring areas outside settlements, but within the same counties. Relocated smallholders allocated to forest areas undoubtedly operate as pivotal agents of deforestation, and most of the forest clearance occurs in the aftermath of government-induced migration
Reserve size, dispersal and population viability of wide ranging carnivores: the case of jaguars in Emas National Park, Brazil
Protected areas may be important refuges for large carnivores, but many are not large enough to sustain viable populations. Without sufficient dispersal between protected areas, large carnivore populations inside them are at risk of becoming genetically isolated and demographically vulnerable. In this study, we use the jaguar population in and around Emas National Park in the Brazilian Cerrado as a case study to evaluate the demographic sustainability of a large carnivore population within a small and potentially isolated protected area. We used camera trapping data and spatially explicit capture-recapture models to estimate density and corresponding population size of jaguars in Emas National Park. We then used a matrix-based age and sex structured stochastic population model to evaluate the demographic viability of jaguar populations across a range of population sizes, including those estimated for Emas. We detected 10 individual jaguars during our survey with a total of 74 detections. Our density estimation became unbiased using a buffer width of 30 km and produced a density of 0.17 jaguars per 100 km2. The estimated population sizes of 10 to 60 animals suffered extinction risks of 70-90% without net immigration. However, only a low number of immigrants were required to suppress extinction risk towards zero. Our density estimate for jaguars was lower than in previous studies, and our simulations suggested that this population may have a substantial extinction risk. Ensuring dispersal and connectivity outside of protected areas, through the implementation of habitat corridors, can greatly reduce this extinction risk, and we suggest that this scenario is potentially applicable to many other large carnivore populations
Evidence for distinct coastal and offshore communities of bottlenose dolphins in the north east Atlantic.
Bottlenose dolphin stock structure in the northeast Atlantic remains poorly understood. However, fine scale photo-id data have shown that populations can comprise multiple overlapping social communities. These social communities form structural elements of bottlenose dolphin (Tursiops truncatus) [corrected] populations, reflecting specific ecological and behavioural adaptations to local habitats. We investigated the social structure of bottlenose dolphins in the waters of northwest Ireland and present evidence for distinct inshore and offshore social communities. Individuals of the inshore community had a coastal distribution restricted to waters within 3 km from shore. These animals exhibited a cohesive, fission-fusion social organisation, with repeated resightings within the research area, within a larger coastal home range. The offshore community comprised one or more distinct groups, found significantly further offshore (>4 km) than the inshore animals. In addition, dorsal fin scarring patterns differed significantly between inshore and offshore communities with individuals of the offshore community having more distinctly marked dorsal fins. Specifically, almost half of the individuals in the offshore community (48%) had characteristic stereotyped damage to the tip of the dorsal fin, rarely recorded in the inshore community (7%). We propose that this characteristic is likely due to interactions with pelagic fisheries. Social segregation and scarring differences found here indicate that the distinct communities are likely to be spatially and behaviourally segregated. Together with recent genetic evidence of distinct offshore and coastal population structures, this provides evidence for bottlenose dolphin inshore/offshore community differentiation in the northeast Atlantic. We recommend that social communities should be considered as fundamental units for the management and conservation of bottlenose dolphins and their habitat specialisations
LHC Coverage of RPV MSSM with Light Stops
We examine the sensitivity of recent LHC searches to signatures of
supersymmetry with R-parity violation (RPV). Motivated by naturalness of the
Higgs potential, which would favor light third-generation squarks, and the
stringent LHC bounds on spectra in which the gluino or first and second
generation squarks are light, we focus on scenarios dominated by the pair
production of light stops. We consider the various possible direct and cascade
decays of the stop that involve the trilinear RPV operators. We find that in
many cases, the existing searches exclude stops in the natural mass range and
beyond. However, typically there is little or no sensitivity to cases dominated
by UDD operators or LQD operators involving taus. We propose several ideas for
searches which could address the existing gaps in experimental coverage of
these signals.Comment: 41 pages, 12 figures; v2: included new searches (see footnote 10),
minor corrections and improvement
MFV Reductions of MSSM Parameter Space
The 100+ free parameters of the minimal supersymmetric standard model (MSSM)
make it computationally difficult to compare systematically with data,
motivating the study of specific parameter reductions such as the cMSSM and
pMSSM. Here we instead study the reductions of parameter space implied by using
minimal flavour violation (MFV) to organise the R-parity conserving MSSM, with
a view towards systematically building in constraints on flavour-violating
physics. Within this framework the space of parameters is reduced by expanding
soft supersymmetry-breaking terms in powers of the Cabibbo angle, leading to a
24-, 30- or 42-parameter framework (which we call MSSM-24, MSSM-30, and MSSM-42
respectively), depending on the order kept in the expansion. We provide a
Bayesian global fit to data of the MSSM-30 parameter set to show that this is
manageable with current tools. We compare the MFV reductions to the
19-parameter pMSSM choice and show that the pMSSM is not contained as a subset.
The MSSM-30 analysis favours a relatively lighter TeV-scale pseudoscalar Higgs
boson and with multi-TeV sparticles.Comment: 2nd version, minor comments and references added, accepted for
publication in JHE
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