492 research outputs found
Administration of human chorionic gonadotropin at embryo transfer induced ovulation of a first-wave dominant follicle and increased progesterone and transfer pregnancy rates
Beef Cattle Research, 2011 is known as Cattlemen’s Day, 2011Embryo transfer (ET) has become more widespread in recent years as a way to improve
cattle genetics. According to the annual statistical survey of the American Embryo
Transfer Association, more than 200,000 fresh and frozen bovine embryos were
transferred in 2008. But despite advancements in reproductive technologies that have
occurred since ET was commercialized in the 1970s, industrywide pregnancy rates are
only 62.4 and 56.9% for fresh and frozen-thawed ET, respectively. Using ET helps
avoid problems from failed fertilization; however, fertilization failure has been characterized
as a relatively unimportant factor of pregnancy loss. Approximately 10% of pregnancy
failures resulted from fertilization failure and another 10% from failed embryo
development. Approximately 20 to 25% of the pregnancy loss in an ET program could
be characterized as early embryonic loss
Structure of Spinning Particle Suggested by Gravity, Supergravity and Low Energy String Theory
The structure of spinning particle suggested by the rotating Kerr-Newman
(black hole) solution, super-Kerr-Newman solution and the Kerr-Sen solution to
low energy string theory is considered. Main peculiarities of the Kerr spinning
particle are discussed: a vortex of twisting principal null congruence,
singular ring and the Kerr source representing a rotating relativistic disk of
the Compton size. A few stringy structures can be found in the real and complex
Kerr geometry.
Low-energy string theory predicts the existence of a heterotic string placed
on the sharp boundary of this disk. The obtained recently supergeneralization
of the Kerr-Newman solution suggests the existence of extra axial singular line
and fermionic traveling waves concentrating near these singularities.
We discuss briefly a possibility of experimental test of these predictions.Comment: Latex, 8 pages, talk at the International Workshop Spin'99, Prague,
5-11 September, 199
Complex Kerr Geometry and Nonstationary Kerr Solutions
In the frame of the Kerr-Schild approach, we consider the complex structure
of Kerr geometry which is determined by a complex world line of a complex
source. The real Kerr geometry is represented as a real slice of this complex
structure. The Kerr geometry is generalized to the nonstationary case when the
current geometry is determined by a retarded time and is defined by a
retarded-time construction via a given complex world line of source. A general
exact solution corresponding to arbitrary motion of a spinning source is
obtained. The acceleration of the source is accompanied by a lightlike
radiation along the principal null congruence. It generalizes to the rotating
case the known Kinnersley class of "photon rocket" solutions.Comment: v.3, revtex, 16 pages, one eps-figure, final version (to appear in
PRD), added the relation to twistors and algorithm of numerical computations,
English is correcte
Recent results from a folded waveguide ICRF Antenna development project
Preliminary high power tests have been performed on a folded waveguide (FWG) ICRF launcher with a curved coupling faceplate installed. Two alternative faceplate configurations have been built and tested at low power and will be tested at high power in the near future. The new designs include a dipole plate which provides a 0-<font face="symbol">p</font> launch spectrum and a more transparent, flexible monopole face plate configuration. This FWG design is a 12 vane, 57 MHz design with a 0.31 m square cross section. The FWG can be installed with either fast wave or ion-Bernstein wave polarization and can also be retracted behind a vacuum isolation valve. A 1 x 4 FWG array optimized for fast wave current drive on DIII-D has been conceptualized
Phase-shift analysis of low-energy elastic-scattering data
Using electromagnetic corrections previously calculated by means of a
potential model, we have made a phase-shift analysis of the
elastic-scattering data up to a pion laboratory kinetic energy of 100 MeV. The
hadronic interaction was assumed to be isospin invariant. We found that it was
possible to obtain self-consistent databases by removing very few measurements.
A pion-nucleon model was fitted to the elastic-scattering database obtained
after the removal of the outliers. The model-parameter values showed an
impressive stability when the database was subjected to different criteria for
the rejection of experiments. Our result for the pseudovector
coupling constant (in the standard form) is . The six
hadronic phase shifts up to 100 MeV are given in tabulated form. We also give
the values of the s-wave scattering lengths and the p-wave scattering volumes.
Big differences in the s-wave part of the interaction were observed when
comparing our hadronic phase shifts with those of the current GWU solution. We
demonstrate that the hadronic phase shifts obtained from the analysis of the
elastic-scattering data cannot reproduce the measurements of the
charge-exchange reaction, thus corroborating past evidence that the hadronic
interaction violates isospin invariance. Assuming the validity of the result
obtained within the framework of chiral perturbation theory, that the mass
difference between the - and the -quark has only a very small effect on
the isospin invariance of the purely hadronic interaction, the
isospin-invariance violation revealed by the data must arise from the fact that
we are dealing with a hadronic interaction which still contains residual
effects of electromagnetic origin.Comment: 43 pages, 6 figure
The health of adolescents in detention : a global scoping review
Adolescents detained within the criminal justice system are affected by complex health problems, health-risk behaviours, and high rates of premature death. We did a global synthesis of the evidence regarding the health of this population. We searched Embase, PsycINFO, Education Resources Information Center, PubMed, Web of Science, CINCH, Global Health, the Cochrane Database of Systematic Reviews, the Campbell Library, the National Criminal Justice Reference System Abstract Database, and Google Scholar for peer-reviewed journal articles, including reviews, that reported the prevalence of at least one health outcome (physical, mental, sexual, infectious, and neurocognitive) in adolescents (aged <20 years) in detention, and were published between Jan 1, 1980, and June 30, 2018. The reference lists of published review articles were scrutinised for additional relevant publications. Two reviewers independently screened titles and abstracts, and three reviewed full texts of relevant articles. The protocol for this Review was registered with PROSPERO (CRD42016041392). 245 articles (204 primary research articles and 41 reviews) were included, with most primary research (183 [90%]) done in high-income countries. A high lifetime prevalence of health problems, risks, and conditions was reported in detained adolescents, including mental disorders (0–95%), substance use disorders (22–96%), self-harm (12–65%), neurodevelopmental disabilities (2–47%), infectious diseases (0–34%), and sexual and reproductive conditions (pregnant by age 19 years 20–37%; abnormal cervical screening test result 16%). Various physical and mental health problems and health-risk behaviours are more common among adolescents in detention than among their peers who have not been detained. As the social and structural drivers of poor health overlap somewhat with factors associated with exposure to the criminal justice system, strategies to address these factors could help to reduce both rates of adolescent detention and adolescent health inequalities. Improving the detection of mental and physical disorders, providing appropriate interventions during detention, and optimising transitional health care after release from detention could improve the health outcomes of these vulnerable young people
Magnetic Anisotropy in the Molecular Complex V15
We apply degenerate perturbation theory to investigate the effects of
magnetic anisotropy in the magnetic molecule V15. Magnetic anisotropy is
introduced via Dzyaloshinskii-Moriya (DM) interaction in the full Hilbert space
of the system. Our model provides an explanation for the rounding of
transitions in the magnetization as a function of applied field at low
temperature, from which an estimate for the DM interaction is found. We find
that the calculated energy differences of the lowest energy states are
consistent with the available data. Our model also offers a novel explanation
for the hysteretic nature of the time-dependent magnetization data.Comment: Final versio
Global Warming: Forecasts by Scientists versus Scientific Forecasts
In 2007, the Intergovernmental Panel on Climate Change’s Working Group One, a panel of experts established by the World Meteorological Organization and the United Nations Environment Programme, issued its Fourth Assessment Report. The Report included predictions of dramatic increases in average world temperatures over the next 92 years and serious harm resulting from the predicted temperature increases. Using forecasting principles as our guide we asked: Are these forecasts a good basis for developing public policy? Our answer is “no”. To provide forecasts of climate change that are useful for policy-making, one would need to forecast (1) global temperature, (2) the effects of any temperature changes, and (3) the effects of feasible alternative policies. Proper forecasts of all three are necessary for rational policy making. The IPCC WG1 Report was regarded as providing the most credible long-term forecasts of global average temperatures by 31 of the 51 scientists and others involved in forecasting climate change who responded to our survey. We found no references in the 1056-page Report to the primary sources of information on forecasting methods despite the fact these are conveniently available in books, articles, and websites. We audited the forecasting processes described in Chapter 8 of the IPCC’s WG1 Report to assess the extent to which they complied with forecasting principles. We found enough information to make judgments on 89 out of a total of 140 forecasting principles. The forecasting procedures that were described violated 72 principles. Many of the violations were, by themselves, critical. The forecasts in the Report were not the outcome of scientific procedures. In effect, they were the opinions of scientists transformed by mathematics and obscured by complex writing. Research on forecasting has shown that experts’ predictions are not useful in situations involving uncertainly and complexity. We have been unable to identify any scientific forecasts of global warming. Claims that the Earth will get warmer have no more credence than saying that it will get colder
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