662 research outputs found
Genetic relationships between sex-specific traits in beef cattle: Mature weight, weight adjusted for body condition score, height and body condition score of cows, and carcass traits of their steer relatives
Data from the first four cycles of the Germplasm Evaluation Program at the U.S. Meat Animal Research Center (USMARC) were used to investigate genetic relationships between mature weight (MW, n = 37,710), mature weight adjusted for body condition score (AMW, n = 37,676), mature height (HT, n = 37,123), and BCS (n = 37,676) from 4- to 8-yr old cows (n = 1,800) and carcass traits (n = 4,027) measured on their crossbred paternal half-sib steers. Covariance components among traits were estimated using REML. Carcass traits were adjusted for age at slaughter. Estimates of heritability for hot carcass weight (HCWT); percentage of retail product; percentage of fat; percentage of bone; longissimus muscle area; fat thickness adjusted visually; estimated kidney, pelvic, and heart fat percentage; marbling score; Warner-Bratzler shear force; and taste panel tenderness measured on steers were moderate to high (0.26 to 0.65), suggesting that selection for carcass and meat traits could be effective. Estimates of heritability for taste panel flavor and taste panel juiciness were low and negligible (0.05 and 0.01, respectively). Estimates of heritability from cow data over all ages and seasons were high for MW, AMW, and HT (0.52, 0.57, 0.71; respectively) and relatively low for BCS (0.16). Pair-wise analyses for each female mature trait with each carcass trait were done with bivariate animal models. Estimates of genetic correlations between cow mature size and carcass composition or meat quality traits, with the exception of HCWT, were relatively low. Selection for cow mature size (weight and/or height) could be effective and would not be expected to result in much, if any, correlated changes in carcass and meat composition traits. However, genetic correlations of cow traits, with the possible exception of BCS, with HCWT may be too large to ignore. Selection for steers with greater HCWT would lead to larger cows
Comparison of Post-Detonation Combustion in Explosives Incorporating Aluminum Nanoparticles: Influence of the Passivation Layer
Aluminum nanoparticles and explosive formulations that incorporate them have been a subject of ongoing interest due to the potential of aluminum particles to dramatically increase energy content relative to conventional organic explosives. We have used time-resolved atomic and molecular emission spectroscopy to monitor the combustion of aluminum nanoparticles within the overall chemical dynamicsof post-detonation fireballs. We have studied the energy release dynamics of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) charges incorporating three types of aluminum nanoparticles: commercial oxide-passivated nanoparticles, oleic acid-capped aluminum nanoparticles (AlOA), and nanoparticles in which the oxide shell of the particle has been functionalized with an acrylic monomer and copolymerized into a fluorinated acrylic matrix (AlFA). The results indicate that the commercial nanoparticles and the AlFAnanoparticles are oxidized at a similar rate, while the AlOA nanoparticles combust more quickly. This is most likely due to the fact that the commercial nano-Al and the AlFA particles are both oxide-passivated, while the AlOA particles are protected by an organic shell that is more easily compromised than an oxide layer. The peak fireball temperatures for RDX charges containing 20 wt. % of commercial nano-Al, AlFA, or AlOA were ∼3900 K, ∼3400 K, and ∼4500 K, respectively
Benzyl 3-[(E,E)-3-phenylprop-2-enylidene]dithiocarbazate
The title compound, C17H16N2S2, a dithiocarbazate derivative, adopts an EE configuration with respect to the C=C and C=N double bonds of the propenylidine group. The 3-phenylprop-2-enylidene and dithiocarbazate fragments lie essentially in the same plane, with a maximum deviation from that plane of 0.074 (2) Å, while the dihedral angle between the 3-phenylprop-2-enylidene and the benzyl group is 77.78 (7)°. In the crystal structure, molecules are linked by an N—H⋯S hydrogen bond and a weak C—H⋯S interaction involving the terminal thione S atom, forming dimers that are arranged into sheets parallel to the bc plane. The crystal structure is also stabilized by C—H⋯π interactions
(E)-4-(Benzyloxy)benzaldehyde thiosemicarbazone
In the title compound, C15H15N3OS, the thiosemicarbazone group adopts an E configuration with respect to the C=N bond. The benzaldehyde thiosemicarbazone fragment is almost planar [maximum deviation = 0.012 (1) Å], while the dihedral angle between the benzyloxy and phenyl rings is 72.48 (5)°. In the crystal structure, molecules are interconnected by N—H⋯N and N—H⋯S hydrogen bonds, forming a two-dimensional network parallel to the bc plane and are further stacked along the a axis by π–π interactions [centroid–centroid separation 3.9043 (7) Å]. The crystal structure is also stabilized by C—H⋯π interactions
Role of the placenta in developmental programming: Observations from models using large animals
Developmental programming, which proposes that “insults” or “stressors” during intrauterine or postnatal development can have not only immediate but also long-term consequences for healthy and productivity, has emerged as a major biological principle, and based on studies in many animal species also seems to be a universal phenomenon. In eutherians, the placenta appears to be programmed during its development, which has consequences for fetal growth and development throughout pregnancy, and likewise has long-term consequences for postnatal development, leading to programming of organ function of the offspring even into adulthood. This review summarizes our current understanding of the placenta’s role in developmental programming, the mechanisms involved, and the challenges remaining
CHEMICAL TECHNOLOGY DIVISION, CHEMICAL DEVELOPMENT SECTION C PROGRESS REPORT FOR DECEMBER 1959 AND JANUARY 1960
The recovery of Th from Blind River ion exchange barrens with di(2- ethylhexyl)phosphoric acid was investigated. The recovery of Tc and Np from fluorination plant residues with tertiary amine was studied. The extraction of Np/sup 4+/ by quaternary ammonium nitrates is reported. A solvent recovery procedure involving successive use of Na/sub 2/CO/sub 3/washing and Al/sub 2/O/ sub 3/- adsorption was demonstrated in laboratory tests as a possible method for the purification and decontamaination of organophosphorus process solvents. The effect of nitrated fractions of Annsco 125-82 on Zr-Nb extractions by TBP was investigated. Treatnnent of TBPAmsco 125-82 solutions with 2 M HNO/sub 3/ at 60 ction prod- C for 1 to 48 hr showed that under these mild conditions the TBP degradation products were more important than those from Amsco as contributors to Zr-Nb extraction and as affecting efficiency of solvent clean-up. The interfacial tensions between benzene solutions of several amine salt and alkyl phosphate extractants and aqueous solutions were examined as functions of the solute concentrations. (For preceding period see CF-59-11-132.) (W.L.H.
Di-μ-methacrylato-κ4 O:O′-bis[aquabis(1,10-phenanthroline-κ2 N,N′)copper(II)] dinitrate dihydrate
The title complex, [Cu2(C4H5O2)2(C12H8N2)2(H2O)2](NO3)2·2H2O, contains a dimeric [Cu2(C4H5O2)2(C12H8N2)2(H2O)2]2+ dication with two five-coordinated CuII ions linked by two methacrylate ions in a syn–syn bridging arrangement. The dication possesses pseudo-twofold rotational symmetry. The pentacoordination of each CuII ion has a distorted square-pyramidal geometry, with two N donors from a phenanthroline ligand and two carboxylate O atoms occupying basal sites and the apical position being occupied by a water molecule. In the crystal packing, molecules are linked to form a three-dimensional framework by O—H⋯O and C—H⋯O hydrogen bonds and π–π interactions [centroid–centroid distances of 3.6039 (15), 3.5301 (15), 3.6015 (15), 3.6496 (15) and 3.6858 (15) Å]
A systematic review of strategies to recruit and retain primary care doctors
Background There is a workforce crisis in primary care. Previous research has looked at the reasons underlying recruitment and retention problems, but little research has looked at what works to improve recruitment and retention. The aim of this systematic review is to evaluate interventions and strategies used to recruit and retain primary care doctors internationally. Methods A systematic review was undertaken. MEDLINE, EMBASE, CENTRAL and grey literature were searched from inception to January 2015.Articles assessing interventions aimed at recruiting or retaining doctors in high income countries, applicable to primary care doctors were included. No restrictions on language or year of publication. The first author screened all titles and abstracts and a second author screened 20%. Data extraction was carried out by one author and checked by a second. Meta-analysis was not possible due to heterogeneity. Results 51 studies assessing 42 interventions were retrieved. Interventions were categorised into thirteen groups: financial incentives (n=11), recruiting rural students (n=6), international recruitment (n=4), rural or primary care focused undergraduate placements (n=3), rural or underserved postgraduate training (n=3), well-being or peer support initiatives (n=3), marketing (n=2), mixed interventions (n=5), support for professional development or research (n=5), retainer schemes (n=4), re-entry schemes (n=1), specialised recruiters or case managers (n=2) and delayed partnerships (n=2). Studies were of low methodological quality with no RCTs and only 15 studies with a comparison group. Weak evidence supported the use of postgraduate placements in underserved areas, undergraduate rural placements and recruiting students to medical school from rural areas. There was mixed evidence about financial incentives. A marketing campaign was associated with lower recruitment. Conclusions This is the first systematic review of interventions to improve recruitment and retention of primary care doctors. Although the evidence base for recruiting and care doctors is weak and more high quality research is needed, this review found evidence to support undergraduate and postgraduate placements in underserved areas, and selective recruitment of medical students. Other initiatives covered may have potential to improve recruitment and retention of primary care practitioners, but their effectiveness has not been established
Crystal structure of S-methyl ß-N-(methylacetyl)methylene-dithiocarbazate, C6H10N2OS2
CoH10N2OS2, monoclinic, P12(1)/n(1) (No. 14), a = 1.2699(1) Angstrom, b= 13.7534(2) Angstrom, c = 15.8'80(4) Angstrom, beta = 97.263(1)degrees, V = 922.1 Angstrom (3), 2 = 4, R(F) = 0.063, w(Ref)(F-2) = 0.173, T = 293 K
MSH3 polymorphisms and protein levels affect CAG repeat instability in huntington's disease mice
Expansions of trinucleotide CAG/CTG repeats in somatic tissues are thought to contribute to ongoing disease progression through an affected individual's life with Huntington's disease or myotonic dystrophy. Broad ranges of repeat instability arise between individuals with expanded repeats, suggesting the existence of modifiers of repeat instability. Mice with expanded CAG/CTG repeats show variable levels of instability depending upon mouse strain. However, to date the genetic modifiers underlying these differences have not been identified. We show that in liver and striatum the R6/1 Huntington's disease (HD) (CAG)~100 transgene, when present in a congenic C57BL/6J (B6) background, incurred expansion-biased repeat mutations, whereas the repeat was stable in a congenic BALB/cByJ (CBy) background. Reciprocal congenic mice revealed the Msh3 gene as the determinant for the differences in repeat instability. Expansion bias was observed in congenic mice homozygous for the B6 Msh3 gene on a CBy background, while the CAG tract was stabilized in congenics homozygous for the CBy Msh3 gene on a B6 background. The CAG stabilization was as dramatic as genetic deficiency of Msh2. The B6 and CBy Msh3 genes had identical promoters but differed in coding regions and showed strikingly different protein levels. B6 MSH3 variant protein is highly expressed and associated with CAG expansions, while the CBy MSH3 variant protein is expressed at barely detectable levels, associating with CAG stability. The DHFR protein, which is divergently transcribed from a promoter shared by the Msh3 gene, did not show varied levels between mouse strains. Thus, naturally occurring MSH3 protein polymorphisms are modifiers of CAG repeat instability, likely through variable MSH3 protein stability. Since evidence supports that somatic CAG instability is a modifier and predictor of disease, our data are consistent with the hypothesis that variable levels of CAG instability associated with polymorphisms of DNA repair genes may have prognostic implications for various repeat-associated diseases
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