615 research outputs found
Genome-wide association study for milk production and conformation traits in Canadian Alpine and Saanen dairy goats.
Increasing the productivity of Canadian dairy goats is critical to the competitiveness of the sector; however, little is known about the underlying genetic architecture of economically important traits in these populations. Consequently, the objectives of this study were as follows: (1) to perform a single-step GWAS for milk production traits (milk, protein, and fat yields, and protein and fat percentages in first and later lactations) and conformation traits (body capacity, dairy character, feet and legs, fore udder, general appearance, rear udder, suspensory ligament, and teats) in the Canadian Alpine and Saanen breeds; and (2) to identify positional and functional candidate genes related to these traits. The data available for analysis included 305-d milk production records for 6,409 Alpine and 3,434 Saanen does in first lactation and 5,827 Alpine and 2,632 Saanen does in later lactations; as well as linear type conformation records for 5,158 Alpine and 2,342 Saanen does. Genotypes were available for 833 Alpine and 874 Saanen animals. Both single-breed and multiple-breed GWAS were performed using single-trait animal models. Positional and functional candidate genes were then identified in downstream analyses. The GWAS identified 189 unique SNP that were significant at the chromosomal level, corresponding to 271 unique positional candidate genes within 50 kb up- and downstream, across breeds and traits. This study provides evidence for the economic importance of several candidate genes (e.g., CSN1S1, CSN2, CSN1S2, CSN3, DGAT1, and ZNF16) in the Canadian Alpine and Saanen populations that have been previously reported in other dairy goat populations. Moreover, several novel positional and functional candidate genes (e.g., RPL8, DCK, and MOB1B) were also identified. Overall, the results of this study have provided greater insight into the genetic architecture of milk production and conformation traits in the Canadian Alpine and Saanen populations. Greater understanding of these traits will help to improve dairy goat breeding programs
Single- and multiple-breed genomic evaluations for conformation traits in Canadian Alpine and Saanen dairy goats.
Conformation traits are functional traits known to affect longevity, production efficiency, and profitability of dairy goats. However, genetic progress for these traits is expected to be slower than for milk production traits due to the limited number of herds participating in type classification programs, and often lower heritability estimates. Genomic selection substantially accelerates the rate of genetic progress in many species and industries, especially for lowly heritable, difficult, or expensive to measure traits. Therefore, the main objectives of this study were (1) to evaluate the potential benefits of the implementation of single-step genomic evaluations for conformation traits in Canadian Alpine and Saanen dairy goats, and (2) to investigate the effect of the use of single- and multiple-breed training populations. The phenotypes used in this study were linear conformation scores, on a 1-to-9 scale, for 8 traits (i.e., body capacity, dairy character, fore udder, feet and legs, general appearance, rear udder, medial suspensory ligament, and teats) of 5,158 Alpine and 2,342 Saanen does. Genotypes were available for 833 Alpine and 874 Saanen animals. Averaged across all traits, the use of multiple-breed analyses increased validation accuracy for Saanen, and reduced bias of genomically enhanced breeding values (GEBV) for both Alpine and Saanen compared with single-breed analyses. Little benefit was observed from the use of GEBV relative to pedigree-based EBV in terms of validation accuracy and bias, possibly due to limitations in the validation design, but substantial gains of 0.14 to 0.21 (32-50%) were observed in the theoretical accuracy of validation animals when averaged across traits for single- and multiple-breed analyses. Across the whole genotyped population, average gains in theoretical accuracy for GEBV compared with EBV across all traits ranged from 0.15 to 0.17 (32-37%) for Alpine and 0.17 to 0.19 (40-41%) for Saanen, depending on the model used. The largest gains were observed for does without classification records (0.19-0.22 or 50-55%) and bucks without daughter classification records (0.20-0.27 or 57-82%), which have the least information contributing to their traditional EBV. The use of multiple-breed rather than single-breed models was most beneficial for the Saanen breed, which had fewer phenotypic records available for the analyses. These results suggest that the implementation of genomic selection could increase the accuracy of breeding values for conformation traits in Canadian dairy goats
Bose glass and Mott glass of quasiparticles in a doped quantum magnet
The low-temperature states of bosonic fluids exhibit fundamental quantum
effects at the macroscopic scale: the best-known examples are Bose-Einstein
condensation (BEC) and superfluidity, which have been tested experimentally in
a variety of different systems. When bosons are interacting, disorder can
destroy condensation leading to a so-called Bose glass. This phase has been
very elusive to experiments due to the absence of any broken symmetry and of a
finite energy gap in the spectrum. Here we report the observation of a Bose
glass of field-induced magnetic quasiparticles in a doped quantum magnet
(Br-doped dichloro-tetrakis-thiourea-Nickel, DTN). The physics of DTN in a
magnetic field is equivalent to that of a lattice gas of bosons in the
grand-canonical ensemble; Br-doping introduces disorder in the hoppings and
interaction strengths, leading to localization of the bosons into a Bose glass
down to zero field, where it acquires the nature of an incompressible Mott
glass. The transition from the Bose glass (corresponding to a gapless spin
liquid) to the BEC (corresponding to a magnetically ordered phase) is marked by
a novel, universal exponent governing the scaling on the critical temperature
with the applied field, in excellent agreement with theoretical predictions.
Our study represents the first, quantitative account of the universal features
of disordered bosons in the grand-canonical ensemble.Comment: 13+6 pages, 5+6 figures; v2: Fig. 5 update
Is Mitigation Translocation an Effective Strategy for Conserving Common Chuckwallas?
Mitigation translocation remains a popular conservation tool despite ongoing debate regarding its utility for population conservation. To add to the understanding of the effectiveness of mitigation translocation, in 2017 and 2018 we monitored a population of protected common chuckwallas (Sauromalus ater) following translocation away from the area of construction of a new highway near the South Mountains, Phoenix, Arizona, USA. We removed chuckwallas from the construction right-of-way, paint-marked and pit-tagged them, and then released them in a nearby municipal preserve. We deployed very high frequency radio-telemetry transmitters on a sub-sample of 15 translocated adult chuckwallas. We monitored the radio-marked chuckwallas once a day at 1- to 3-day intervals for up to 46 days to document survival, body mass, and post-release movements. The average distance moved following translocation was 359 ± 53 m. Using minimum convex polygons, the average home range size of translocated lizards was 0.9 ± 0.3 ha, which was 18–45 times larger than expected for the species. Following translocations, we surveyed the translocation sites 1 month later and again 1 year later to determine the presence of translocated chuckwallas. Translocated individuals were rarely observed a second time: in 2017, only 11 of 160 translocated chuckwallas were seen again, and in 2018, only 11 of 192 translocated chuckwallas were detected. In the light of low recapture rate, consistent loss of body mass, and large movements of marked lizards, we conclude that survival of translocated chuckwallas was low over a single year. In the future, efficacy of mitigation translocation could be better evaluated by assessing the spatial ecology of both resident and translocated individuals simultaneously using radio-telemetry
Metering Best Practices, A Guide to Achieving Utility Resource Efficiency, Release 2.0
This release is an update and expansion of the information provided in Release 1.0 of the Metering Best Practice Guide that was issued in October 2007. This release, as was the previous release, was developed under the direction of the U.S. Department of Energy's Federal Energy Management Program (FEMP). The mission of FEMP is to facilitate the Federal Government's implementation of sound cost-effective energy management and investment practices to enhance the nation's energy security and environmental stewardship. Each of these activities is directly related to achieving requirements set forth in the Energy Policy Acts of 1992 and 2005, the Energy Independence and Security Act (EISA) of 2007, and the goals that have been established in Executive Orders 13423 and 13514 - and also those practices that are inherent in sound management of Federal financial and personnel resources
Methane Emissions from Process Equipment at Natural Gas Production Sites in the United States: Liquid Unloadings
Methane emissions from liquid unloadings were measured at 107 wells in natural gas production regions throughout the United States. Liquid unloadings clear wells of accumulated liquids to increase production, employing a variety of liquid lifting mechanisms. In this work, wells with and without plunger lifts were sampled. Most wells without plunger lifts unload less than 10 times per year with emissions averaging 21 000–35 000 scf methane (0.4–0.7 Mg) per event (95% confidence limits of 10 000–50 000 scf/event). For wells with plunger lifts, emissions averaged 1000–10 000 scf methane (0.02–0.2 Mg) per event (95% confidence limits of 500–12 000 scf/event). Some wells with plunger lifts are automatically triggered and unload thousands of times per year and these wells account for the majority of the emissions from all wells with liquid unloadings. If the data collected in this work are assumed to be representative of national populations, the data suggest that the central estimate of emissions from unloadings (270 Gg/yr, 95% confidence range of 190–400 Gg) are within a few percent of the emissions estimated in the EPA 2012 Greenhouse Gas National Emission Inventory (released in 2014), with emissions dominated by wells with high frequencies of unloadings
Estimated Exposure to Arsenic in Breastfed and Formula-Fed Infants in a United States Cohort
Background: Previous studies indicate that concentrations of arsenic in breast milk are relatively low even in areas with high drinking-water arsenic. However, it is uncertain whether breastfeeding leads to reduced infant exposure to arsenic in regions with lower arsenic concentrations.
Objective: We estimated the relative contributions of breast milk and formula to arsenic exposure during early infancy in a U.S. population.
Methods: We measured arsenic in home tap water (n = 874), urine from 6-week-old infants (n = 72), and breast milk from mothers (n = 9) enrolled in the New Hampshire Birth Cohort Study (NHBCS) using inductively coupled plasma mass spectrometry. Using data from a 3-day food diary, we compared urinary arsenic across infant feeding types and developed predictive exposure models to estimate daily arsenic intake from breast milk and formula.
Results: Urinary arsenic concentrations were generally low (median, 0.17 μg/L; maximum, 2.9 μg/L) but 7.5 times higher for infants fed exclusively with formula than for infants fed exclusively with breast milk (β = 2.02; 95% CI: 1.21, 2.83; p \u3c 0.0001, adjusted for specific gravity). Similarly, the median estimated daily arsenic intake by NHBCS infants was 5.5 times higher for formula-fed infants (0.22 μg/kg/day) than for breastfed infants (0.04 μg/kg/day). Given median arsenic concentrations measured in NHBCS tap water and previously published for formula powder, formula powder was estimated to account for ~ 70% of median exposure among formula-fed NHBCS infants.
Conclusions: Our findings suggest that breastfed infants have lower arsenic exposure than formula-fed infants, and that both formula powder and drinking water can be sources of exposure for U.S. infants
Quantitative measures of estrogen receptor expression in relation to breast cancer-specific mortality risk among white women and black women
Abstract
Introduction
The association of breast cancer patients’ mortality with estrogen receptor (ER) status (ER + versus ER-) has been well studied. However, little attention has been paid to the relationship between the quantitative measures of ER expression and mortality.
Methods
We evaluated the association between semi-quantitative, immunohistochemical staining of ER in formalin-fixed paraffin-embedded breast carcinomas and breast cancer-specific mortality risk in an observational cohort of invasive breast cancer in 681 white women and 523 black women ages 35-64 years at first diagnosis of invasive breast cancer, who were followed for a median of 10 years. The quantitative measures of ER examined here included the percentage of tumor cell nuclei positively stained for ER, ER Histo (H)-score, and a score based on an adaptation of an equation presented by Cuzick and colleagues, which combines weighted values of ER H-score, percentage of tumor cell nuclei positively stained for the progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) results. This is referred to as the ER/PR/HER2 score.
Results
After controlling for age at diagnosis, race, study site, tumor stage, and histologic grade in multivariable Cox proportional hazards regression models, both percentage of tumor cell nuclei positively stained for ER (P trend = 0.0003) and the ER H-score (P trend = 0.0004) were inversely associated with breast cancer-specific mortality risk. The ER/PR/HER2 score was positively associated with breast cancer-specific mortality risk in women with ER + tumor (P trend = 0.001). Analyses by race revealed that ER positivity was associated with reduced risk of breast cancer-specific mortality in white women and black women. The two quantitative measures for ER alone provided additional discrimination in breast cancer-specific mortality risk only among white women with ER + tumors (both P trend ≤ 0.01) while the ER/PR/HER2 score provided additional discrimination for both white women (P trend = 0.01) and black women (P trend = 0.03) with ER + tumors.
Conclusions
Our data support quantitative immunohistochemical measures of ER, especially the ER/PR/HER2 score, as a more precise predictor for breast cancer-specific mortality risk than a simple determination of ER positivity
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