Vitamin K treatment of sweet clover poisoning in calves

Dicumarol poisoning was reproduced by feeding naturally spoiled, sweet clover hay, which contained a minimum of 90 ppm dicumarol. Vitamin K1 administered IM was effective in treating the disease at dosages of 1.1, 2.2, and 3.3 mg/kg of body weight. Vitamin K3 treatment by various routes and dosages was ineffective.     

Oxygen Concentration and Cysteamine Supplementation During In vitro Production of Buffalo (Bubalus bubalis) Embryos Affect mRNA Expression of BCL‐2, BCL‐XL,MCL‐1, BAX and BID

This study examined the effects of O₂ concentration (5% vs 20%) during in vitro maturation (IVM), fertilization (IVF) and culture (IVC) or supplementation of IVM and IVC media with cysteamine (50 and 100 μm , respectively; IVM, IVF and IVC carried out in 20% O₂), on blastocyst rate and relative mRNA abundance of some apoptosis‐related genes measured by real‐time qPCR in immature and in vitro‐matured buffalo oocytes and in embryos at 2‐, 4‐, 8‐ to 16‐cell, morula and blastocyst stages. The blastocyst rate was significantly higher (p < 0.05) while the percentage of TUNEL‐positive cells was significantly lower (p < 0.05) under 5% O₂ than that under 20% O₂. The mRNA expression of anti‐apoptotic genes BCL‐2 and MCL‐1 was significantly higher (p < 0.05) and that of pro‐apoptotic genes BAX and BID was lower (p < 0.05) under 5% O₂ than that under 20% O₂ concentration at many embryonic stages. Following cysteamine supplementation, the blastocyst rate and the relative mRNA abundance of BCL‐XL and MCL‐1 was significantly higher (p < 0.05) and that of BAX but not BID was lower (p < 0.05) at many stages of embryonic development, although it did not affect the percentage of TUNEL positive cells in the blastocysts significantly. The mRNA expression pattern of these genes during embryonic development was different in 5% vs 20% O₂ groups and in cysteamine supplemented vs controls. At the 8‐ to 16‐cell stage, where developmental block occurs in buffalo, the relative mRNA abundance of BCL‐2 and MCL‐1 was highest under 5% O₂ concentration and that of BAX and BID was highest (p < 0.05) under 20% O₂ concentration. These results suggest that one of the mechanisms through which beneficial effects of low O₂ concentration and cysteamine supplementation are mediated during in vitro embryo production is through an increase in the expression of anti‐apoptotic and a decrease in the expression of pro‐apoptotic genes.     

Dimensionality-driven insulator-to-metal transition in the bechgaard salts

Optical experiments were conducted on a series of organic linear chain conductors with different values of the interchain single-electron transfer integral tb, which quantifies the degree of anisotropy. Electron-electron interactions together with Umklapp scattering resulted in a correlation gap and an insulating state for small tb. An insulator-to-metal transition was observed when tb exceeded a critical value, on the order of the correlation gap Egap. The absence of a plasma edge on the insulator side of the transition for polarization perpendicular to the chains suggests that the electrons are confined to the chains. The optical features of the metallic state, when contrasted with the magnetic properties, are suggestive of spin-charge separation.     

Amplification of Bovine Viral Diarrhoea Virus Introduced into an In Vitro Embryo Production System Via Oocytes from Persistently Infected Cattle

The purpose of this study was to determine whether or not embryos derived from in vitro fertilization of oocytes from persistently infected (PI) cattle would contain infectious virus. Three in vitro embryo production treatment groups were assessed: 1) oocytes and uterine tubal cells (UTC) free of bovine viral diarrhoea virus (BVDV) (negative control), 2) oocytes free of BVDV fertilized and cultured in media containing UTC obtained from PI heifers, and 3) oocytes from PI heifers fertilized and cultured in media containing UTC free of BVDV. The developmental media, UTC and embryos (individual or groups of five) were assayed for virus. Virus was not isolated from any samples in treatment group 1. As shown in previous studies, a proportion of embryo samples were positive for BVDV in treatment group 2. In treatment group 3, the virus associated with the oocytes contaminated the developmental media and infected susceptible co-culture cells used during fertilization and culture. In addition, 65% (11/17) of the degenerated ova from treatment group 3 had infectious virus associated with them. While none of the ova developed into transferable embryos, the study did confirm that use of oocytes from PI cows could lead to amplification of BVDV and cross contamination during in vitro embryo production.     

Comparison of G-banded chromosomes from clinically normal lambs and lambs affected with ovine hereditary chondrodysplasia (spider syndrome)

Lymphocytes from 5 clinically normal lambs and 5 lambs affected with ovine hereditary chondrodysplasia (spider syndrome) were cultured, G-banded, and karyotyped. Fifty metaphase karyotypes and one heterogram were evaluated for chromosome number and morphologic features. All lambs had normal diploid (2n) chromosome numbers of 54,XX or 54,XY, and there were no apparent differences in the morphologic features of the chromosomes.     

Current speed and filtration rate link caddisfly phylogeny and distributional patterns on a stream gradient

Patterns of body size and net construction suggest that current speed and food-particle concentration (not size) influence the distribution of suspension-feeding caddisflies on a downstream gradient. Large ancestral taxa with high filtration rates occur in resource-poor upstream habitats; more derived members of the phylogeny enter successively in downstream reaches with slower current and greater concentrations of particulate food.