ABSTRACT
The MiniBooNE-DM Collaboration searched for vector-boson mediated production of dark matter using the Fermilab 8-GeV Booster proton beam in a dedicated run with 1.86×10^{20} protons delivered to a steel beam dump. The MiniBooNE detector, 490 m downstream, is sensitive to dark matter via elastic scattering with nucleons in the detector mineral oil. Analysis methods developed for previous MiniBooNE scattering results were employed, and several constraining data sets were simultaneously analyzed to minimize systematic errors from neutrino flux and interaction rates. No excess of events over background was observed, leading to a 90% confidence limit on the dark matter cross section parameter, Y=ε^{2}α_{D}(m_{χ}/m_{V})^{4}â²10^{-8}, for α_{D}=0.5 and for dark matter masses of 0.01
ABSTRACT
Reproductive technologies to synchronize estrus and ovulation in cattle have enhanced the ability to practically utilize artificial insemination to increase both genetic merit and reproductive management of beef and dairy herds. The ability to successfully synchronize a follicular wave and ovulation, in heifers and cows, has improved substantially in recent years. Consequently, pregnancy rates to a single fixed-time artificial insemination (FTAI) can approximate that of insemination following spontaneous estrus. Despite these advances, a subset of heifers and cows often has a physiologically immature dominant follicle at the time of GnRH-induced ovulation. These animals will exhibit reduced pregnancy rates and decreased embryonic survival if a pregnancy happens to become established. The physiological mechanisms underlying the preceding decreased fertility have been a focus of our laboratories and may include an effect of the follicular microenvironment on both oocyte competence and the maternal environment. Oocytes must have adequate opportunity to complete cytoplasmic and molecular maturation during the final stages of oocyte maturation that occur within the preovulatory follicle. Follicular status, during the proestrus period, must be such that adequate circulating concentrations of estradiol are present before FTAI to increase oviductal transport of gametes and enhance both the luteinizing capacity of granulosa cells and progesterone receptor population in the post-ovulatory uterus. Following ovulation, the follicles transformation to a functional corpus luteum to secrete adequate amounts of progesterone is essential for the establishment of pregnancy. The physiological status of the preovulatory follicle, prior to FTAI, greatly affects the concepts discussed above and has an important impact on pregnancy establishment and maintenance in cattle.(AU)
Subject(s)
Animals , Female , Pregnancy , Cattle , Cattle/embryology , Ovarian Follicle/embryology , Oocytes/classification , Reproductive TechniquesABSTRACT
Pregnancy detection has evolved over the last few decades and the importance of early pregnancy detection is critical to minimize the amount of time a cow spends not pregnant. Embryonic mortality (EM) is generally considered to be the primary factor limiting pregnancy rates in cattle and occurs early (Subject(s)
Female
, Animals
, Pregnancy
, Cattle
, Cattle/embryology
, Embryonic Development
, MicroRNAs/analysis
, Pregnancy Tests
, Pregnancy Tests/veterinary
, Mortality
ABSTRACT
Reproductive technologies to synchronize estrus and ovulation in cattle have enhanced the ability to practically utilize artificial insemination to increase both genetic merit and reproductive management of beef and dairy herds. The ability to successfully synchronize a follicular wave and ovulation, in heifers and cows, has improved substantially in recent years. Consequently, pregnancy rates to a single fixed-time artificial insemination (FTAI) can approximate that of insemination following spontaneous estrus. Despite these advances, a subset of heifers and cows often has a physiologically immature dominant follicle at the time of GnRH-induced ovulation. These animals will exhibit reduced pregnancy rates and decreased embryonic survival if a pregnancy happens to become established. The physiological mechanisms underlying the preceding decreased fertility have been a focus of our laboratories and may include an effect of the follicular microenvironment on both oocyte competence and the maternal environment. Oocytes must have adequate opportunity to complete cytoplasmic and molecular maturation during the final stages of oocyte maturation that occur within the preovulatory follicle. Follicular status, during the proestrus period, must be such that adequate circulating concentrations of estradiol are present before FTAI to increase oviductal transport of gametes and enhance both the luteinizing capacity of granulosa cells and progesterone receptor population in the post-ovulatory uterus. Following ovulation, the follicles transformation to a functional corpus luteum to secrete adequate amounts of progesterone is essential for the establishment of pregnancy. The physiological status of the preovulatory follicle, prior to FTAI, greatly affects the concepts discussed above and has an important impact on pregnancy establishment and maintenance in cattle.
Subject(s)
Female , Animals , Pregnancy , Cattle , Cattle/embryology , Ovarian Follicle/embryology , Oocytes/classification , Reproductive TechniquesABSTRACT
The MiniBooNE Collaboration reports a search for nu_{micro} and nu[over]_{micro} disappearance in the Deltam;{2} region of 0.5-40 eV;{2}. These measurements are important for constraining models with extra types of neutrinos, extra dimensions, and CPT violation. Fits to the shape of the nu_{micro} and nu[over]_{micro} energy spectra reveal no evidence for disappearance at the 90% confidence level (C.L.) in either mode. The test of nu[over]_{micro} disappearance probes a region below Deltam;{2} = 40 eV;{2} never explored before.
ABSTRACT
We compared three preschool tests as predictors of school problems at the end of first grade. A stratified sample of 113 4 1/2- to 5 1/2-year-old children, oversampling those at risk for developmental difficulties, was administered the Denver Developmental Screening Test (DDST), the Stanford-Binet IQ test (SB), and a two-stage shortened form of the DDST in the spring before school entry. Data from achievement tests, special class placement, and grade retention were obtained for 106 of the children at the end of first grade. Eighty-four percent of children with abnormal DDST scores had school difficulties by the end of first grade, compared with 47% of children with scores in the questionable range and only 15% of children in the normal range. Prediction from the SB was not as accurate; 72% of the children who scored less than 68 and 42% of those who scored between 68 and 84 on the preschool SB had school problems. Prediction for those children who had abnormal or questionable scores on the two-stage DDST was as good as prediction from the full DDST. However, far fewer of the total number of school problems were identified by the two-stage DDST. It appears that the DDST can be used on an individual basis for prediction of school problems.