519 research outputs found

    Relationship of postpartum interval to estrus, body condition score, milk yield and blood biochemical parameters in Surti buffaloes (Bubalus bubalis)

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    The aim of the present investigation was to find out the relationship among postpartum interval to estrus, body condition score, milk yield and blood biochemical parameters of Surti buffaloes (Bubalus bubalis). The study was conducted on sixteen clinically healthy Surti buffaloes (parity 1-7) with normal parturition. These animals were divided into two groups on the basis of their postpartum interval to estrus (PPIE). Group 1 animals had PPIE ? 50 days whereas group 2 had PPIE > 50 days. Body condition score (BCS), milk yield and Blood samples were collected by jugular venipuncture on days starting from 6th day after calving thereafter at fortnight interval till 90th day postpartum. Blood serum parameters such as glucose, total protein, blood urea, creatinine, cholesterol, triglyceride, progesterone and estrogen were measured. Perusal of data revealed that animals having higher BCS on the day of estrus had significantly (P?0.05) shorter PPIE. There was non-significant effect of daily and cumulative 100 days milk yield on PPIE. Serum concentration of glucose and creatinine was significantly (P?0.05) higher for group 1 animals at most of the stages. There was non-significant difference between serum concentration of total protein, blood urea nitrogen and cholesterol between both the groups. Progesterone and Estradiol-17 ? concentrations were significantly (P?0.05) higher in group 1 animals than group 2 animals at different stages of this study

    Engineering Cold Stress Tolerance in Crop Plants

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    Plants respond with changes in their pattern of gene expression and protein products when exposed to low temperatures. Thus ability to adapt has an impact on the distribution and survival of the plant, and on crop yields. Many species of tropical or subtropical origin are injured or killed by non-freezing low temperatures, and exhibit various symptoms of chilling injury such as chlorosis, necrosis, or growth retardation. In contrast, chilling tolerant species are able to grow at such cold temperatures. Conventional breeding methods have met with limited success in improving the cold tolerance of important crop plants involving inter-specific or inter-generic hybridization. Recent studies involving full genome profiling/ sequencing, mutational and transgenic plant analyses, have provided a deep insight of the complex transcriptional mechanism that operates under cold stress. The alterations in expression of genes in response to cold temperatures are followed by increases in the levels of hundreds of metabolites, some of which are known to have protective effects against the damaging effects of cold stress. Various low temperature inducible genes have been isolated from plants. Most appear to be involved in tolerance to cold stress and the expression of some of them is regulated by C-repeat binding factor/ dehydration-responsive element binding (CBF/DREB1) transcription factors. Numerous physiological and molecular changes occur during cold acclimation which reveals that the cold resistance is more complex than perceived and involves more than one pathway. The findings summarized in this review have shown potential practical applications for breeding cold tolerance in crop and horticultural plants suitable to temperate geographical locations

    Asymmetric Fluid Criticality II: Finite-Size Scaling for Simulations

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    The vapor-liquid critical behavior of intrinsically asymmetric fluids is studied in finite systems of linear dimensions, LL, focusing on periodic boundary conditions, as appropriate for simulations. The recently propounded ``complete'' thermodynamic (L)(L\to\infty) scaling theory incorporating pressure mixing in the scaling fields as well as corrections to scaling [arXiv:condmat/0212145]{[arXiv:cond-mat/0212145]}, is extended to finite LL, initially in a grand canonical representation. The theory allows for a Yang-Yang anomaly in which, when LL\to\infty, the second temperature derivative, (d2μσ/dT2)(d^{2}\mu_{\sigma}/dT^{2}), of the chemical potential along the phase boundary, μσ(T)\mu_{\sigma}(T), diverges when T\to\Tc -. The finite-size behavior of various special {\em critical loci} in the temperature-density or (T,ρ)(T,\rho) plane, in particular, the kk-inflection susceptibility loci and the QQ-maximal loci -- derived from QL(T,L)L2/<m4>LQ_{L}(T,_{L}) \equiv ^{2}_{L}/< m^{4}>_{L} where mρLm \equiv \rho - _{L} -- is carefully elucidated and shown to be of value in estimating \Tc and \rhoc. Concrete illustrations are presented for the hard-core square-well fluid and for the restricted primitive model electrolyte including an estimate of the correlation exponent ν\nu that confirms Ising-type character. The treatment is extended to the canonical representation where further complications appear.Comment: 23 pages in the two-column format (including 13 figures) This is Part II of the previous paper [arXiv:cond-mat/0212145

    Beta-decay in odd-A and even-even proton-rich Kr isotopes

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    Beta-decay properties of proton-rich odd-A and even-even Krypton isotopes are studied in the framework of a deformed selfconsistent Hartree-Fock calculation with density-dependent Skyrme forces, including pairing correlations between like nucleons in BCS approximation. Residual spin-isospin interactions are consistently included in the particle-hole and particle-particle channels and treated in Quasiparticle Random Phase Approximation. The similarities and differences in the treatment of even-even and odd-A nuclei are stressed. Comparison to available experimental information is done for Gamow-Teller strength distributions, summed strengths, and half-lives. The dependence of these observables on deformation is particularly emphasized in a search for signatures of the shape of the parent nucleus.Comment: 29 pages, 16 figure

    High-Order Coupled Cluster Method (CCM) Calculations for Quantum Magnets with Valence-Bond Ground States

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    In this article, we prove that exact representations of dimer and plaquette valence-bond ket ground states for quantum Heisenberg antiferromagnets may be formed via the usual coupled cluster method (CCM) from independent-spin product (e.g. N\'eel) model states. We show that we are able to provide good results for both the ground-state energy and the sublattice magnetization for dimer and plaquette valence-bond phases within the CCM. As a first example, we investigate the spin-half J1J_1--J2J_2 model for the linear chain, and we show that we are able to reproduce exactly the dimerized ground (ket) state at J2/J1=0.5J_2/J_1=0.5. The dimerized phase is stable over a range of values for J2/J1J_2/J_1 around 0.5. We present evidence of symmetry breaking by considering the ket- and bra-state correlation coefficients as a function of J2/J1J_2/J_1. We then consider the Shastry-Sutherland model and demonstrate that the CCM can span the correct ground states in both the N\'eel and the dimerized phases. Finally, we consider a spin-half system with nearest-neighbor bonds for an underlying lattice corresponding to the magnetic material CaV4_4O9_9 (CAVO). We show that we are able to provide excellent results for the ground-state energy in each of the plaquette-ordered, N\'eel-ordered, and dimerized regimes of this model. The exact plaquette and dimer ground states are reproduced by the CCM ket state in their relevant limits.Comment: 34 pages, 13 figures, 2 table

    Dipolar origin of the gas-liquid coexistence of the hard-core 1:1 electrolyte model

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    We present a systematic study of the effect of the ion pairing on the gas-liquid phase transition of hard-core 1:1 electrolyte models. We study a class of dipolar dimer models that depend on a parameter R_c, the maximum separation between the ions that compose the dimer. This parameter can vary from sigma_{+/-} that corresponds to the tightly tethered dipolar dimer model, to R_c --> infinity, that corresponds to the Stillinger-Lovett description of the free ion system. The coexistence curve and critical point parameters are obtained as a function of R_c by grand canonical Monte Carlo techniques. Our results show that this dependence is smooth but non-monotonic and converges asymptotically towards the free ion case for relatively small values of R_c. This fact allows us to describe the gas-liquid transition in the free ion model as a transition between two dimerized fluid phases. The role of the unpaired ions can be considered as a perturbation of this picture.Comment: 16 pages, 13 figures, submitted to Physical Review

    Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events

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    The B0B^0-Bˉ0\bar B^0 oscillation frequency has been measured with a sample of 23 million \B\bar B pairs collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we select events in which both B mesons decay semileptonically and use the charge of the leptons to identify the flavor of each B meson. A simultaneous fit to the decay time difference distributions for opposite- and same-sign dilepton events gives Δmd=0.493±0.012(stat)±0.009(syst)\Delta m_d = 0.493 \pm 0.012{(stat)}\pm 0.009{(syst)} ps1^{-1}.Comment: 7 pages, 1 figure, submitted to Physical Review Letter

    Evidence for Shock Acceleration and Intergalactic Magnetic Fields in a Large-Scale Filament of Galaxies ZwCl 2341.1+0000

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    We report the discovery of large-scale diffuse radio emission from what appears to be a large-scale filamentary network of galaxies in the region of cluster ZwCl 2341.1+0000, and stretching over an area of at least 6h5016 h^{-1}_{50} Mpc in diameter. Multicolour CCD observations yield photometric redshifts indicating that a significant fraction of the optical galaxies in this region is at a redshift of z=0.3. This is supported by spectroscopic measurements of 4 galaxies in the SDSS survey at a mean z=0.27. We present VLA images at 20 cm (NVSS) and 90 cm wavelengths, showing the detailed radio structure of the filaments. Comparison with the VLA high resolution FIRST radio survey shows that the diffuse emission is not due to known individual point sources. The diffuse radio-emission has a spectral index α0.5\alpha \lesssim -0.5, and is most likely synchrotron emission from relativistic charged particles in an inter-galactic magnetic field. Furthermore, this optical/radio structure is detected in X-rays by the ROSAT all-sky survey. It has a 0.1--2.4 keV luminosity of about 104410^{44} erg s1^{-1} and shows an extended highly non-relaxed morphology. These observations suggest that ZwCl 2341.1+0000 is possibly a proto-cluster of galaxies in which we are witnessing the process of structure formation. We show (both analytically and by numerical simulations) that the energetics of accretion shocks generated in forming large-scale structures are sufficient to produce enough high energy cosmic-ray (CR) electrons required to explain the observed radio emission, provided a magnetic field of strength of about 1 micro Gauss is present there.Thus it is the first evidence of cosmic-ray particle acceleration and magnetic fields occuring on a super-cluster scale. (Abridged)Comment: Replaced with the published version. The published paper can be accessed from http://www.elsevier.com/gej-ng/10/33/29/71/56/53/article.htm
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