432 research outputs found
Digestible threonine and its effects on growth performance, gut morphology and carcass characteristics in broiler Japanese quails (Coturnix coturnix japonica)
Threonine is the third limiting amino acid in corn-soy-based poultry diets and has an important role in body and intestinal development of chicken. Although work on threonine (Thr) in chicken is well established, information about the effects of digestible threonine (dThr) on quail performance is limited. Therefore, the current study was designed to determine the impact of increasing levels of dThr on growth performance, feed conversion ratio (FCR), gut health and carcass characteristics in meat-type quails. A total of 324 mixed-sex day-old quail were randomly allocated to three treatments with six replicates per treatment and 18 birds per replicate. There were three dietary treatments, namely control (C) with recommended levels of dThr according to the Brazilian Tables guidelines for Japanese quails: 10% dThr (C diet supplemented with 10% more dThr) and 20%dThr (C diet supplemented with 20% more dThr). At day 35 of the experiment, three birds from each pen were slaughtered. A duodenal sample was collected and preserved to evaluate gut health. The carcass characteristics were determined from the slaughtered birds. Total feed intake and average daily feed intake were higher in the C treatment than in 10% dThr. Final bodyweight (BW), weight gain and average daily gain (ADG) increased linearly. The birds fed diets supplemented with 20% extra dThr had the highest final weight and bodyweight gain (BWG) compared with those birds that were fed on C and 10% dThr supplemented diets. Feed conversion ratio was improved in 10% dThr compared with the C birds. Villus height (VH) was similar among treatments. The highest crypt depth (CD) was observed in C, followed by 10% dThr and 20% dThr. The birds fed 20% dThr had higher VH:CD than 10% dThr. The birds in the C treatment had lowest VH:CD. Carcass weights with and without giblets were higher in the 20% dThr than in the 10% dThr and C treatments. Breast mass yield (BMY) was greatest in 20% dThr compared with C and 10% dThr. It may be concluded that supplementation of Thr higher than the requirements referred to in Brazilian Tables improves growth performance and gut health of meat-type quail.Keywords: Crypt depth, mucin, performance, quail, villus heigh
Gauges and Cosmological Backreaction
We present a formalism for spatial averaging in cosmology applicable to
general spacetimes and coordinates, and allowing the easy incorporation of a
wide variety of matter sources. We apply this formalism to a
Friedmann-LeMaitre-Robertson-Walker universe perturbed to second-order and
present the corrections to the background in an unfixed gauge. We then present
the corrections that arise in uniform curvature and conformal Newtonian gauges.Comment: 13 pages. Updated: reference added, typos corrected, exposition
clarified. Version 3: Replaced with version published by JCA
Averaging Robertson-Walker Cosmologies
The cosmological backreaction arises when one directly averages the Einstein
equations to recover an effective Robertson-Walker cosmology, rather than
assuming a background a priori. While usually discussed in the context of dark
energy, strictly speaking any cosmological model should be recovered from such
a procedure. We apply the Buchert averaging formalism to linear
Robertson-Walker universes containing matter, radiation and dark energy and
evaluate numerically the discrepancies between the assumed and the averaged
behaviour, finding the largest deviations for an Einstein-de Sitter universe,
increasing rapidly with Hubble rate to a 0.01% effect for h=0.701. For the LCDM
concordance model, the backreaction is of the order of Omega_eff~4x10^-6, with
those for dark energy models being within a factor of two or three. The impacts
at recombination are of the order of 10^-8 and those in deep radiation
domination asymptote to a constant value. While the effective equations of
state of the backreactions in Einstein-de Sitter, concordance and quintessence
models are generally dust-like, a backreaction with an equation of state
w_eff<-1/3 can be found for strongly phantom models.Comment: 18 pages, 11 figures, ReVTeX. Updated to version accepted by JCA
Early-onset progressive retinal atrophy associated with an IQCB1 variant in African black-footed cats (Felis nigripes)
African black-footed cats (Felis nigripes) are endangered wild felids. One male and full-sibling female African black-footed cat developed vision deficits and mydriasis as early as 3 months of age. The diagnosis of early-onset progressive retinal atrophy (PRA) was supported by reduced direct and consensual pupillary light reflexes, phenotypic presence of retinal degeneration, and a non-recordable electroretinogram with negligible amplitudes in both eyes. Whole genome sequencing, conducted on two unaffected parents and one affected offspring was compared to a variant database from 51 domestic cats and a Pallas cat, revealed 50 candidate variants that segregated concordantly with the PRA phenotype. Testing in additional affected cats confirmed that cats homozygous for a 2 base pair (bp) deletion within IQ calmodulin-binding motif-containing protein-1 (IQCB1), the gene that encodes for nephrocystin-5 (NPHP5), had vision loss. The variant segregated concordantly in other related individuals within the pedigree supporting the identification of a recessively inherited early-onset feline PRA. Analysis of the black-footed cat studbook suggests additional captive cats are at risk. Genetic testing for IQCB1 and avoidance of matings between carriers should be added to the species survival plan for captive management
Body appreciation around the world: Measurement invariance of the Body Appreciation Scale-2 (BAS-2) across 65 nations, 40 languages, gender identities, and age.
The Body Appreciation Scale-2 (BAS-2) is a widely used measure of a core facet of the positive body image construct. However, extant research concerning measurement invariance of the BAS-2 across a large number of nations remains limited. Here, we utilised the Body Image in Nature (BINS) dataset - with data collected between 2020 and 2022 - to assess measurement invariance of the BAS-2 across 65 nations, 40 languages, gender identities, and age groups. Multi-group confirmatory factor analysis indicated that full scalar invariance was upheld across all nations, languages, gender identities, and age groups, suggesting that the unidimensional BAS-2 model has widespread applicability. There were large differences across nations and languages in latent body appreciation, while differences across gender identities and age groups were negligible-to-small. Additionally, greater body appreciation was significantly associated with higher life satisfaction, being single (versus being married or in a committed relationship), and greater rurality (versus urbanicity). Across a subset of nations where nation-level data were available, greater body appreciation was also significantly associated with greater cultural distance from the United States and greater relative income inequality. These findings suggest that the BAS-2 likely captures a near-universal conceptualisation of the body appreciation construct, which should facilitate further cross-cultural research. [Abstract copyright: Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.
Molecular Features of Cancers Exhibiting Exceptional Responses to Treatment
A small fraction of cancer patients with advanced disease survive significantly longer than patients with clinically comparable tumors. Molecular mechanisms for exceptional responses to therapy have been identified by genomic analysis of tumor biopsies from individual patients. Here, we analyzed tumor biopsies from an unbiased cohort of 111 exceptional responder patients using multiple platforms to profile genetic and epigenetic aberrations as well as the tumor microenvironment. Integrative analysis uncovered plausible mechanisms for the therapeutic response in nearly a quarter of the patients. The mechanisms were assigned to four broad categories—DNA damage response, intracellular signaling, immune engagement, and genetic alterations characteristic of favorable prognosis—with many tumors falling into multiple categories. These analyses revealed synthetic lethal relationships that may be exploited therapeutically and rare genetic lesions that favor therapeutic success, while also providing a wealth of testable hypotheses regarding oncogenic mechanisms that may influence the response to cancer therapy. Profiling multi-platform genomics of 110 cancer patients with an exceptional therapeutic response, Wheeler et al. identify putative molecular mechanisms explaining this survival phenotype in ∼23% of cases. Therapeutic success is related to rare molecular features of responding tumors, exploiting synthetic lethality and oncogene addiction
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