5,618 research outputs found
A cohort study of the associations between udder conformation, milk somatic cell count, and lamb weight in suckler ewes
A cohort study of 67 suckler ewes from 1 farm was carried out from January to May 2010 to investigate associations between udder conformation, udder half milk somatic cell count (SCC), and lamb weight. Ewes and lambs were observed at lambing. Ewe health and teat condition and lamb health and weight were recorded on 4 to 5 further occasions at 14-d intervals. At each observation, a milk sample was collected from each udder half for somatic cell counting. Two weeks after lambing, ewe udder conformation and teat placement were scored. Low lamb weight was associated with ewe SCC >400,000 cells/mL (−0.73kg), a new teat lesion 14 d previously (−0.91kg), suboptimal teat position (−1.38kg), rearing in a multiple litter (−1.45kg), presence of diarrhea at the examination (−1.19kg), and rearing by a 9-yr-old ewe compared with a 6-yr-old ewe (−2.36kg). High lamb weight was associated with increasing lamb age (0.21kg/d), increasing birth weight (1.65kg/kg at birth), and increasing number of days the ewe was given supplementary feed before lambing (0.06kg/d). High udder half SCC was associated with pendulous udders (9.6% increase in SCC/cm of drop) and greater total cross-sectional area of the teats (7.2% increase of SCC/cm2). Low SCC were associated with a heavier mean litter weight (6.7% decrease in SCC/kg). Linear, quadratic, and cubic terms for days in lactation were also significant. We conclude that poor udder and teat conformation are associated with high levels of intramammary infection, as indicated by increased SCC and that both physical attributes of the udder and SCC are linked to lamb growth, suggesting that selection of suckler ewes with better udder and teat conformation would reduce intramammary infection and increase lamb growth rate
Species-dependent role of crossmodal connectivity among the primary sensory cortices
When a major sense is lost, crossmodal plasticity substitutes functional processing from the remaining, intact senses. Recent studies of deafness-induced crossmodal plasticity in different subregions of auditory cortex indicate that the phenomenon is largely based on the “unmasking” of existing inputs. However, there is not yet a consensus on the sources or effects of crossmodal inputs to primary sensory cortical areas. In the present review, a rigorous re-examination of the experimental literature indicates that connections between different primary sensory cortices consistently occur in rodents, while primary-to-primary projections are absent/inconsistent in non-rodents such as cats and monkeys. These observations suggest that crossmodal plasticity that involves primary sensory areas are likely to exhibit species-specific distinctions
Ferric iron reduction by bacteria associated with the roots of freshwater and marine macrophytes
In vitro assays of washed, excised roots revealed maximum potential ferric iron reduction rates of \u3e100 μmol g (dry weight)-1 day-1 for three freshwater macrophytes and rates between 15 and 83 μmol (dry weight)-1 day-1 for two marine species. The rates varied with root morphology but not consistently (fine root activity exceeded smooth root activity in some but not all cases). Sodium molybdate added at final concentrations of 0.2 to 20 mM did not inhibit iron reduction by roots of marine macrophytes (Spartina alterniflora and Zostera marina). Roots of a freshwater macrophyte, Sparganium eurycarpum, that were incubated with an analog of humic acid precursors, anthroquinone disulfate (AQDS), reduced freshly precipitated iron oxyhydroxide contained in dialysis bags that excluded solutes with molecular weights of \u3e 1,000; no reduction occurred in the absence of AQDS. Bacterial enrichment cultures and isolates from freshwater and marine roots used a variety of carbon and energy sources (e.g., acetate, ethanol, succinate, toluene, and yeast extract) and ferric oxyhydroxide, ferric citrate, uranate, and AQDS as terminal electron acceptors. The temperature optima for a freshwater isolate and a marine isolate were equivalent (approximately 32°C). However, iron reduction by the freshwater isolate decreased with increasing salinity, while reduction by the marine isolate displayed a relatively broad optimum salinity between 20 and 35 ppt. Our results suggest that by participating in an active iron cycle and perhaps by reducing humic acids, iron reducers in the rhizoplane of aquatic macrophytes limit organic availability to other heterotrophs (including methanogens) in the rhizosphere and bulk sediments
A Quantum Yield Map for Synthetic Eumelanin
The quantum yield of synthetic eumelanin is known to be extremely low and it
has recently been reported to be dependent on excitation wavelength. In this
paper, we present quantum yield as a function of excitation wavelength between
250 and 500 nm, showing it to be a factor of 4 higher at 250 nm than at 500 nm.
In addition, we present a definitive map of the steady-state fluorescence as a
function of excitation and emission wavelengths, and significantly, a
three-dimensional map of the specific quantum yield: the fraction of photons
absorbed at each wavelength that are subsequently radiated at each emission
wavelength. This map contains clear features, which we attribute to certain
structural models, and shows that radiative emission and specific quantum yield
are negligible at emission wavelengths outside the range of 585 and 385 nm (2.2
and 3.2 eV), regardless of excitation wavelength. This information is important
in the context of understanding melanin biofunctionality, and the quantum
molecular biophysics therein.Comment: 10 pages, 6 figure
Acoustic characterization of crack damage evolution in sandstone deformed under conventional and true triaxial loading
We thank the Associate Editor, Michelle Cooke, and the reviewers, Ze'ev Reches and Yves Guéguen, for useful comments which helped to improve the manuscript. We thank J.G. Van Munster for providing access to the true triaxial apparatus at KSEPL and for technical support during the experimental program. We thank R. Pricci for assistance with technical drawings of the apparatus. This work was partly funded by NERC award NE/N002938/1 and by a NERC Doctoral Studentship, which we gratefully acknowledge. Supporting data are included in a supporting information file; any additional data may be obtained from J.B. (e-mail: [email protected]).Peer reviewedPublisher PD
Fifty Shades of Leather and Misogyny: An Investigation of Anti-Woman Perspectives among Leathermen
The Fifty Shades books and films shed light on a sexual and leather-clad subculture predominantly kept in the dark: bondage, discipline, submission, and sadomasochism (BDSM). Such new interest in this community also generated widespread misconceptions about the sexual practices that take place in these circles, especially in regard to the treatment of women. In the current study, we investigate how a BDSM or “leather” identity is related to attitudes toward women. We use a nationally representative sample of U.S. adult men aged 18–64 stratified by U.S. Census categories of age, race/ethnicity, and census region (N = 1474) and a subsample of leathermen (n = 65; 58% hetero-leather identified and 42% nonhetero- leather identified). Specifically, we explore leather identity as it relates to the support of laws/policies helping women, non-feminist identity, patriarchal gender norms, and the stigmatization of lesbian, bisexual, transgender, and queer (LBTQ) women among both hetero and non-hetero leathermen. Overall, our findings indicate a robust relationship between these anti-woman perspectives and leatherman identity that is especially pronounced among hetero leathermen and demonstrate the importance of continuing to consider how leather identity shapes misogyny among leathermen
Male Ballet Dancers and Their Performances of Heteromasculinity
Although previous research has investigated men in feminized sports, we took a different approach in this study and examined men in ballet. Because ballet is one of the most highly gender-codified sports, male ballet dancers must negotiate their identities as men while performing a dance form that is highly stigmatized as effeminate. We investigated how five self-identified heterosexual male college dance majors perceive and perform heteromasculinity within male ballet culture using qualitative data gathered from structured interviews. Results provide three unique contributions to the literature. First, we found that these men develop and contextualize their heteromasculinity in the context of a male ballet culture. Second, the results demonstrate three unique stigma-management techniques within male ballet culture. Third, men described a hegemonic heteromasculinity and the roles of masculinity and emotionality in male ballet performance as parts of male ballet culture. We hope this study will stimulate future research that can help personnel and faculty to better understand how college ballet programs can be informed by the ways masculinity may be institutionalized and reproduced within the context of dance programs, as well as the ways male ballet dancers can challenge heteromasculine hegemony in the sports world
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