Extending Grazing In Heifer Development Systems Decreases Cost Without Compromising Production

Three experiments compared heifer development systems. In Exp. 1, 299 heifers (253 ± 2 kg) from 3 yr were used to compare dry lot (DL) to grazing corn residue (CR) post weaning. Heifers in the DL consumed a common diet after weaning for 187 d until breeding. The CR heifers grazed for 145 d with a supplement (0.45 kg/d; 28% CP) and were then fed in the DL until breeding. In Exp. 2, 270 heifers (225 ± 2 kg) in 3 yr grazed Sandhills winter range (WR) or CR with a supplement (0.45 kg/d; 28% CP) post weaning. In Exp. 3, 180 heifers (262 ± 3 kg) in 2 yr grazed Eastern Nebraska WR or CR with a supplement (0.45 – 0.90 kg/d; 29% CP) post weaning. The CR heifers had lower (P \u3c 0.001) ADG before breeding compared to DL or WR heifers in Exp. 1 and 2, but WR and CR were similar (P = 0.66) in Exp. 3. The DL and WR heifers were heavier (P \u3c 0.003) than CR at breeding and pregnancy diagnosis in Exp. 1 and 2, but similar (P = 0.62) in Exp. 3. The percentage of heifers pubertal at breeding was greater (P \u3c 0.001) for DL than CR in Exp. 1, for WR than CR in yr 1 and 2 of Exp. 2 (P \u3c 0.01), but similar (P = 0.36) in Exp. 3. Pregnancy rate to AI was lower (P = 0.08) for CR than DL heifers in Exp. 1, but not different (P = 0.89) in Exp. 3. Final pregnancy rate was not affected (P ≥ 0.27) in Exp. 1, 2 or 3. In Exp. 2,, yr 2, CR heifers required (P = 0.01) more calving assistance than WR. Milk production of WR heifers was greater (P = 0.04) than CR in Exp. 3. Calf weaning BW, two-year old AI (Exp. 1 and 3) and final pregnancy rates (Exp. 1, 2 and 3) were not different (P \u3e 0.10). Development grazing CR reduced cost by $45/pregnancy compared to DL, but cost of WR was similar to CR. Development grazing CR reduces ADG before breeding without sacrificing final pregnancy rate. Development grazing WR increases milk production, but does not increase weaning BW. Grazing CR during heifer development reduces cost compared to DL. Grazing CR or WR is suitable for heifer development at similar cost

Suspension by regular and groupy waves over bedforms in a large wave flume (SISTEX99)

Suspended sand concentrations and bedforms under waves were measured in the controlled environment of a large wave flume. Three suspension conditions are discussed here; those occurring with regular (monochromatic) waves of height 0.55m over anorbital ripples, regular waves 1.0m high over orbital bedforms, and repeating wave groups (with a significant wave height of 0.6m) also over orbital-scale features. In all cases the wave-to-wave variability in suspended load was high (∼30%). Patterns of suspension were dependent on the bedform type and on instrument location relative to the bedform. Regular waves suspended an order of magnitude more sediment than groupy waves with a similar significant wave height illustrating,the importance of sequences of high waves in pumping-up sediment concentration into the water column

Renal pericytes: regulators of medullary blood flow

Regulation of medullary blood flow (MBF) is essential in maintaining normal kidney function. Blood flow to the medulla is supplied by the descending vasa recta (DVR), which arise from the efferent arterioles of juxtamedullary glomeruli. DVR are composed of a continuous endothelium, intercalated with smooth muscle-like cells called pericytes. Pericytes have been shown to alter the diameter of isolated and in situ DVR in response to vasoactive stimuli that are transmitted via a network of autocrine and paracrine signalling pathways. Vasoactive stimuli can be released by neighbouring tubular epithelial, endothelial, red blood cells and neuronal cells in response to changes in NaCl transport and oxygen tension. The experimentally described sensitivity of pericytes to these stimuli strongly suggests their leading role in the phenomenon of MBF autoregulation. Because the debate on autoregulation of MBF fervently continues, we discuss the evidence favouring a physiological role for pericytes in the regulation of MBF and describe their potential role in tubulo-vascular cross-talk in this region of the kidney. Our review also considers current methods used to explore pericyte activity and function in the renal medulla

Calculation of magnetic anisotropy energy in SmCo5

SmCo5 is an important hard magnetic material, due to its large magnetic anisotropy energy (MAE). We have studied the magnetic properties of SmCo5 using density functional theory (DFT) calculations where the Sm f-bands, which are difficult to include in DFT calculations, have been treated within the LDA+U formalism. The large MAE comes mostly from the Sm f-shell anisotropy, stemming from an interplay between the crystal field and the spin-orbit coupling. We found that both are of similar strengths, unlike some other Sm compounds, leading to a partial quenching of the orbital moment (f-states cannot be described as either pure lattice harmonics or pure complex harmonics), an optimal situation for enhanced MAE. A smaller portion of the MAE can be associated with the Co-d band anisotropy, related to the peak in the density of states at the Fermi energy. Our result for the MAE of SmCo5, 21.6 meV/f.u., agrees reasonably with the experimental value of 13-16 meV/f.u., and the calculated magnetic moment (including the orbital component) of 9.4 mu_B agrees with the experimental value of 8.9 mu_B.Comment: Submitted to Phys. Rev.

Finite temperature phase diagram of spin-1/2 bosons in two-dimensional optical lattice

We study a two-species bosonic Hubbard model on a two-dimensional square lattice by means of quantum Monte Carlo simulations and focus on finite temperature effects. We show in two different cases, ferro- and antiferromagnetic spin-spin interactions, that the phase diagram is composed of solid Mott phases, liquid phases and superfluid phases. In the antiferromagnetic case, the superfluid (SF) is polarized while the Mott insulator (MI) and normal Bose liquid (NBL) phases are not. On the other hand, in the ferromagnetic case, none of the phases is polarized. The superfluid-liquid transition is of the Berezinsky-Kosterlitz-Thouless type whereas the solid-liquid passage is a crossover.Comment: 9 pages, 13 figure

Revealing Nanoscale Chemical Heterogeneities in Polycrystalline Mo-BiVO4 Thin Films

Indexación: Scopus.The activity of polycrystalline thin film photoelectrodes is impacted by local variations of the material properties due to the exposure of different crystal facets and the presence of grain/domain boundaries. Here a multi-modal approach is applied to correlate nanoscale heterogeneities in chemical composition and electronic structure with nanoscale morphology in polycrystalline Mo-BiVO4. By using scanning transmission X-ray microscopy, the characteristic structure of polycrystalline film is used to disentangle the different X-ray absorption spectra corresponding to grain centers and grain boundaries. Comparing both spectra reveals phase segregation of V2O5 at grain boundaries of Mo-BiVO4 thin films, which is further supported by X-ray photoelectron spectroscopy and many-body density functional theory calculations. Theoretical calculations also enable to predict the X-ray absorption spectral fingerprint of polarons in Mo-BiVO4. After photo-electrochemical operation, the degraded Mo-BiVO4 films show similar grain center and grain boundary spectra indicating V2O5 dissolution in the course of the reaction. Overall, these findings provide valuable insights into the degradation mechanism and the impact of material heterogeneities on the material performance and stability of polycrystalline photoelectrodes. © 2020 The Authors. Published by Wiley-VCH GmbHhttps://onlinelibrary-wiley-com.recursosbiblioteca.unab.cl/doi/10.1002/smll.20200160

Integrated analysis of germline and somatic variants in ovarian cancer

We report the first large-scale exome-wide analysis of the combined germline-somatic landscape in ovarian cancer. Here we analyze germline and somatic alterations in 429 ovarian carcinoma cases and 557 controls. We identify 3,635 high confidence, rare truncation and 22,953 missense variants with predicted functional impact. We find germline truncation variants and large deletions across Fanconi pathway genes in 20% of cases. Enrichment of rare truncations is shown in BRCA1, BRCA2, and PALB2. Additionally, we observe germline truncation variants in genes not previously associated with ovarian cancer susceptibility (NF1, MAP3K4, CDKN2B, and MLL3). Evidence for loss of heterozygosity was found in 100% and 76% of cases with germline BRCA1 and BRCA2 truncations respectively. Germline-somatic interaction analysis combined with extensive bioinformatics annotation identifies 237 candidate functional germline truncation and missense variants, including 2 pathogenic BRCA1 and 1 TP53 deleterious variants. Finally, integrated analyses of germline and somatic variants identify significantly altered pathways, including the Fanconi, MAPK, and MLL pathways

The Similarity Hypothesis in General Relativity

Self-similar models are important in general relativity and other fundamental theories. In this paper we shall discuss the ``similarity hypothesis'', which asserts that under a variety of physical circumstances solutions of these theories will naturally evolve to a self-similar form. We will find there is good evidence for this in the context of both spatially homogenous and inhomogeneous cosmological models, although in some cases the self-similar model is only an intermediate attractor. There are also a wide variety of situations, including critical pheneomena, in which spherically symmetric models tend towards self-similarity. However, this does not happen in all cases and it is it is important to understand the prerequisites for the conjecture.Comment: to be submitted to Gen. Rel. Gra

Ground state phase diagram of spin-1/2 bosons in a two-dimensional optical lattice

We study a two-species bosonic Hubbard model on a two-dimensional square lattice by means of quantum Monte Carlo simulations. In addition to the usual contact repulsive interactions between the particles, the Hamiltonian has an interconversion term which allows the transformation of two particles from one species to the other. The phases are characterized by their solid or superfluid properties and by their polarization, i.e. the difference in the populations. When inter-species interactions are smaller than the intra-species ones, the system is unpolarized, whereas in the opposite case the system is unpolarized in even Mott insulator lobes and polarized in odd Mott lobes and also in the superfluid phase. We show that in the latter case the transition between the Mott insulator of total density two and the superfluid can be either of second or first order depending on the relative values of the interactions, whereas the transitions are continuous in all other cases.Comment: 10 pages, 17 figure