Effects of Bull Exposure and Gonadotropin Releasing Hormone on Postpartum Interval and Fertility in Beef Cowsa

Spring calving beef cows were utilized in a study to determine the effects of bull exposure (BE) and Gonadotropin Releasing Hormone (GnRH) administration on return to estrus and reproductive efficiency. Cows were either exposed to an epididectomized bull soon after calving until the breeding season or not exposed to bulls (NE). All cows were synchronized with Synchro-Mate B (SMB). One-half of the BE and NE cows were implanted with GnRH at SMB implant removal in 1987 or given an injection of GnRH at breeding in 1988. Each year, 20 cows were bled hourly for 80 consecutive hours after SMB removal. There was no difference (P\u3e.05) in days from calving to first estrus, calving date, number of cows cycling before breeding or conception rate to the synchronized estrus between BE or NE cow groups. In 1987 GnRH implants reduced (P\u3c.05) the time from SMB removal to the pre-ovulatory LH peak by 23.5 hours. However, there was no difference (P\u3e.05) in LH peak levels, duration of Luteinizing Hormone (LH) peak or conception rate. Bull exposure and GnRH implants had little effect on the interval from calving to first estrus or reproductive performance

Effects of Bull Exposure on Post-partum Interval and Reproductive Performance in Beef Cows

Spring calving beef cows were utilized to study the effect of bull exposure early postpartum on return to estrus and fertility. In the spring of 1985 and 1986, cows were randomly exposed to epididectomized bulls 3 to 7 days after calving until beginning of the breeding season or not exposed to bulls. Cows were observed for estrus twice daily beginning approximately 4 weeks after the start of calving until synchronization. I n 1986, blood samples were collected weekly by jugular venipuncture during heat detection and serum progesterone concentrations were determined. ALL cows were synchronized with Synchro-Mate B and inseminated 48 hours after implant removal. Calves were removed for 48 hours following implant removal. Each year a group of cows was selected from the two treatment groups and cannulated at estrus following Synchro-Mate B implant removal. Blood samples were collected at 15-minute intervals for 2 hours and every 2 hours for 46 hours for determination of luteinizing hormone concentration. Bull exposed cows had a shorter (Pa.09) interval to first estrus in 1985 and there was no difference (P\u3e.05) in 1986. The percentage exhibiting estrus prior to synchronization was greater (P\u3e.01) for bull exposed than nonexposed in 1985 and there was no difference (P\u3e.05) in 1986. There was no difference (P\u3e.05) in conception rates to the timed insemination in 1985 and 1986 and the total percentage pregnant did not differ (P\u3e.05) in either year. Bull exposure may reduce the interval from calving to first estrus and increase the percentage cycling prior to breeding, but conception rates are not influenced

The Bailey Point Region and Other Muskox Refugia in the Canadian Arctic: A Short Review

The muskox (Ovibos moschatus) is widely distributed over much of arctic Canada but only at a few locations do their densities remain high and populations relatively stable. These refugia constitute the most favourable muskox ranges in the Canadian Arctic Archipelago .... Refugia for muskoxen in the High Arctic include lowlands on eastern Axel Heiberg Island in the Mokka Fiord region, the lowlands of northeastern Devon Island, and the Bailey Point region of Melville Island .... All of those regions historically have supported high densities of muskoxen from time to time but the Bailey Point region must be considered the best habitat for muskoxen in the Canadian High Arctic. ..

Precision Primordial 4^4He Measurement with CMB Experiments

Big bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) are two major pillars of cosmology. Standard BBN accurately predicts the primordial light element abundances ($^4$He, D, $^3$He and $^7$Li), depending on one parameter, the baryon density. Light element observations are used as a baryometers. The CMB anisotropies also contain information about the content of the universe which allows an important consistency check on the Big Bang model. In addition CMB observations now have sufficient accuracy to not only determine the total baryon density, but also resolve its principal constituents, H and $^4$He. We present a global analysis of all recent CMB data, with special emphasis on the concordance with BBN theory and light element observations. We find $\Omega_{B}h^{2}=0.025+0.0019-0.0026$ and $Y_{p}=0.250+0.010-0.014$ (fraction of baryon mass as $^4$He) using CMB data alone, in agreement with $^4$He abundance observations. With this concordance established we show that the inclusion of BBN theory priors significantly reduces the volume of parameter space. In this case, we find $\Omega_{B}h^2=0.0244+0.00137-0.00284$ and $Y_p = 0.2493+0.0006-0.001$. We also find that the inclusion of deuterium abundance observations reduces the $Y_p$ and $\Omega_{B}h^2$ ranges by a factor of $\sim$2. Further light element observations and CMB anisotropy experiments will refine this concordance and sharpen BBN and the CMB as tools for precision cosmology.Comment: 7 pages, 3 color figures made minor changes to bring inline with journal versio

Towards a formalism for mapping the spacetimes of massive compact objects: Bumpy black holes and their orbits

Observations have established that extremely compact, massive objects are common in the universe. It is generally accepted that these objects are black holes. As observations improve, it becomes possible to test this hypothesis in ever greater detail. In particular, it is or will be possible to measure the properties of orbits deep in the strong field of a black hole candidate (using x-ray timing or with gravitational-waves) and to test whether they have the characteristics of black hole orbits in general relativity. Such measurements can be used to map the spacetime of a massive compact object, testing whether the object's multipoles satisfy the strict constraints of the black hole hypothesis. Such a test requires that we compare against objects with the ``wrong'' multipole structure. In this paper, we present tools for constructing bumpy black holes: objects that are almost black holes, but that have some multipoles with the wrong value. The spacetimes which we present are good deep into the strong field of the object -- we do not use a large r expansion, except to make contact with weak field intuition. Also, our spacetimes reduce to the black hole spacetimes of general relativity when the ``bumpiness'' is set to zero. We propose bumpy black holes as the foundation for a null experiment: if black hole candidates are the black holes of general relativity, their bumpiness should be zero. By comparing orbits in a bumpy spacetime with those of an astrophysical source, observations should be able to test this hypothesis, stringently testing whether they are the black holes of general relativity. (Abridged)Comment: 16 pages + 2 appendices + 3 figures. Submitted to PR

Effects of Bull Exposure on Postpartum Intervals and Reproductive Performance in Beef Cows: A progress Report

The effects of bull exposure on time from calving until estrus, conception rates and calving interval were studied for mature beef cows. In the spring of I985 and 1986, cows were randomly allotted to one of two treatment groups. Cows were exposed to vasectomized bulls after calving until breeding or no bull exposure. Cows were heat detected twice daily and blood samples were collected weekly to determine progesterone levels. Heat detection data and progesterone levels indicated onset of estrous cycles occurred earlier in bull exposed cows than non-exposed cows. Conception rates to a timed insemination were not different between the two groups. Bull exposed cows tended t o calve earlier

Effectiveness of Albendazole Against Parasites and Cow and Calf Performance

Albendazole was utilized in drench and feed additive form to determine its effectiveness against parasite control, cow weight and conception rate and calf weaning weights. Fecal oocyte number was decreased by administration of Albendazole. Calf weaning weights from treated cows were heavier the first two years (14.5 lb for heifers and 10.5 lb for bulls) but decreased the third year (13 lb and 6 lb for heifers and bulls, respectively). Conception rates were similar between the two groups, with the only difference occurring the third year when control cows had a higher conception rate from the second AI than treated cows

A Proposed Test of Charge Symmetry in Σ\Sigma Decay

The semi-leptonic decays of $\Sigma^\pm$ offer a vehicle for observing charge symmetry-breaking. The effect is expected to be about 6\%, enhanced due to the replacement of two u quarks by d quarks. We propose that present experimental data be improved to search for this effect.Comment: 6 pages, submitted to Physical Review D, Brief Reports, Report # DOE/ER/40427-14-N9

Nonlocal Effects and Shrinkage of the Vortex Core Radius in YNi2B2C Probed by muSR

The magnetic field distribution in the vortex state of YNi2B2C has been probed by muon spin rotation (muSR). The analysis based on the London model with nonlocal corrections shows that the vortex lattice has changed from hexagonal to square with increasing magnetic field H. At low fields the vortex core radius, rho_v(H), decreases with increasing H much steeper than what is expected from the sqrt(H) behavior of the Sommerfeld constant gamma(H), strongly suggesting that the anomaly in gamma(H) primarily arises from the quasiparticle excitations outside the vortex cores.Comment: 4 pages, 4 figures, submitted to Phys. Rev.