2,114 research outputs found

    Success of several programed AI-breeding protocols including ovsynch

    Get PDF
    In Experiment 1, four programmed AIbreeding treatments were tested. The so-called OvSynch program, which requires no heat detection before a fixed-time insemination, decreased conception rates compared with a similar treatment in which inseminations occurred after detected estrus (30 vs 51%). The traditional two-injection prostaglandin program produced greater conception rate for cattle inseminated after a detected estrus (53%) than after one fixed-time insemination was given in the absence of estrus (31%). A similar protocol of two prostaglandin injections plus an injection of gonadotropin-releasing hormone (GnRH or Cystorelin®) before one fixed-time insemination produced lower conception rates (33%) than when cattle were inseminated after detected estrus (53%). In Experiment 2, the OvSynch program was retested with the interval between the PGF and the second GnRH 2a injection being 48 hr (36 hr in Experiment 1). Conception in 27 cows on the OvSynch48 program with timed insemination (37%) was comparable with 43% in 21 cows on a similar program without the second GnRH injection but inseminated at estrus

    P17. P3b event-related potentials show changes in varsity football players due to accumulated sub-concussive head impacts

    Get PDF
    BACKGROUND: Concussion has been a focus in football at all levels of participation. However, there is a growing appreciation that repetitive sub-concussive impacts may have more significant effects on overall neurological health than the isolated diagnosed concussions that have been the focus of recent research. The purpose of this study was to evaluate the relationship between the number of head impacts that players experience throughout the season and their P300 evoked potential. METHODS: Canadian university football players (n=45) were separated into three groups based on player mass and position/skill (small-skilled, big-skilled and big-unskilled). Groups were separated into low and high levels of impact exposure based on the total number of head impacts experienced in-season. Players completed baseline, midseason, postseason, and follow-up neurophysiological tests to measure P300 evoked potentials. Statistically significant differences between high versus low impact subgroups for each player group were assessed using independent-samples t-tests. RESULTS: Small-skilled and big-skilled players showed statistically significant decreases in P300 amplitude at midseason and postseason for high impact players compared to low impact players. Follow-up measures revealed that all groups were not significantly different compared to baseline measures. DISCUSSION & CONCLUSION: Players that experience a large number of head impacts in varsity football demonstrate significant decreases in specific EEG measures of cognitive function and information processing. INTERDISCIPLINARY REFLECTION: The combination of biomechanical head impact exposure with neurophysiological outcomes yields insight into the processes behind head impacts and their effects on the human brain

    The test case of HD26965: difficulties disentangling weak Doppler signals from stellar activity

    Full text link
    We report the discovery of a radial velocity signal that can be interpreted as a planetary-mass candidate orbiting the K dwarf HD26965, with an orbital period of 42.364±\pm0.015 days, or alternatively, as the presence of residual, uncorrected rotational activity in the data. Observations include data from HIRES, PFS, CHIRON, and HARPS, where 1,111 measurements were made over 16 years. Our best solution for HD26965 bb is consistent with a super-Earth that has a minimum mass of 6.92±\pm0.79 M_{\oplus} orbiting at a distance of 0.215±\pm0.008 AU from its host star. We have analyzed the correlation between spectral activity indicators and the radial velocities from each instrument, showing moderate correlations that we include in our model. From this analysis, we recover a \sim38 day signal, which matches some literature values of the stellar rotation period. However, from independent Mt. Wilson HK data for this star, we find evidence for a significant 42 day signal after subtraction of longer period magnetic cycles, casting doubt on the planetary hypothesis for this period. Although our statistical model strongly suggests that the 42-day signal is Doppler in origin, we conclude that the residual effects of stellar rotation are difficult to fully model and remove from this dataset, highlighting the difficulties to disentangle small planetary signals and photospheric noise, particularly when the orbital periods are close to the rotation period of the star. This study serves as an excellent test case for future works that aim to detect small planets orbiting `Sun-like' stars using radial velocity measurements.Comment: 16 pages, 10 figures, 13 tables, accepted for publication in A

    Cell-specific discrimination of desmosterol and desmosterol mimetics confers selective regulation of LXR and SREBP in macrophages.

    Get PDF
    Activation of liver X receptors (LXRs) with synthetic agonists promotes reverse cholesterol transport and protects against atherosclerosis in mouse models. Most synthetic LXR agonists also cause marked hypertriglyceridemia by inducing the expression of sterol regulatory element-binding protein (SREBP)1c and downstream genes that drive fatty acid biosynthesis. Recent studies demonstrated that desmosterol, an intermediate in the cholesterol biosynthetic pathway that suppresses SREBP processing by binding to SCAP, also binds and activates LXRs and is the most abundant LXR ligand in macrophage foam cells. Here we explore the potential of increasing endogenous desmosterol production or mimicking its activity as a means of inducing LXR activity while simultaneously suppressing SREBP1c-induced hypertriglyceridemia. Unexpectedly, while desmosterol strongly activated LXR target genes and suppressed SREBP pathways in mouse and human macrophages, it had almost no activity in mouse or human hepatocytes in vitro. We further demonstrate that sterol-based selective modulators of LXRs have biochemical and transcriptional properties predicted of desmosterol mimetics and selectively regulate LXR function in macrophages in vitro and in vivo. These studies thereby reveal cell-specific discrimination of endogenous and synthetic regulators of LXRs and SREBPs, providing a molecular basis for dissociation of LXR functions in macrophages from those in the liver that lead to hypertriglyceridemia

    Addressing student models of energy loss in quantum tunnelling

    Full text link
    We report on a multi-year, multi-institution study to investigate student reasoning about energy in the context of quantum tunnelling. We use ungraded surveys, graded examination questions, individual clinical interviews, and multiple-choice exams to build a picture of the types of responses that students typically give. We find that two descriptions of tunnelling through a square barrier are particularly common. Students often state that tunnelling particles lose energy while tunnelling. When sketching wave functions, students also show a shift in the axis of oscillation, as if the height of the axis of oscillation indicated the energy of the particle. We find inconsistencies between students' conceptual, mathematical, and graphical models of quantum tunnelling. As part of a curriculum in quantum physics, we have developed instructional materials to help students develop a more robust and less inconsistent picture of tunnelling, and present data suggesting that we have succeeded in doing so.Comment: Originally submitted to the European Journal of Physics on 2005 Feb 10. Pages: 14. References: 11. Figures: 9. Tables: 1. Resubmitted May 18 with revisions that include an appendix with the curriculum materials discussed in the paper (4 page small group UW-style tutorial

    Planning, implementation and scientific goals of the Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) field mission

    Get PDF
    The Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) field mission based at Ellington Field, Texas, during August and September 2013 employed the most comprehensive airborne payload to date to investigate atmospheric composition over North America. The NASA ER-2, DC-8, and SPEC Inc. Learjet flew 57 science flights from the surface to 20 km. The ER-2 employed seven remote sensing instruments as a satellite surrogate and eight in situ instruments. The DC-8 employed 23 in situ and five remote sensing instruments for radiation, chemistry, and microphysics. The Learjet used 11 instruments to explore cloud microphysics. SEAC4RS launched numerous balloons, augmented AErosol RObotic NETwork, and collaborated with many existing ground measurement sites. Flights investigating convection included close coordination of all three aircraft. Coordinated DC-8 and ER-2 flights investigated the optical properties of aerosols, the influence of aerosols on clouds, and the performance of new instruments for satellite measurements of clouds and aerosols. ER-2 sorties sampled stratospheric injections of water vapor and other chemicals by local and distant convection. DC-8 flights studied seasonally evolving chemistry in the Southeastern U.S., atmospheric chemistry with lower emissions of NOx and SO2 than in previous decades, isoprene chemistry under high and low NOx conditions at different locations, organic aerosols, air pollution near Houston and in petroleum fields, smoke from wildfires in western forests and from agricultural fires in the Mississippi Valley, and the ways in which the chemistry in the boundary layer and the upper troposphere were influenced by vertical transport in convective clouds

    Treatment with ETC-1002 alone and in combination with ezetimibe lowers LDL cholesterol in hypercholesterolemic patients with or without statin intolerance

    Get PDF
    BackgroundETC-1002 is an oral, once-daily, first-in-class medication being developed to treat hypercholesterolemia.ObjectivesTo compare 2 doses of ETC-1002, alone or combined with ezetimibe 10 mg (EZE), vs EZE monotherapy for lowering low-density lipoprotein cholesterol (LDL-C).MethodsThis phase 2b, multicenter, double-blind trial-evaluated hypercholesterolemic patients (LDL-C, 130 to 220 mg/dL) with (n = 177) or without (n = 171) muscle-related intolerance to ≥2 statins; 1 at lowest approved dose. Subjects were randomized to 12-week treatment with ETC-1002 120 mg or ETC-1002 180 mg alone, EZE alone, ETC-1002 120 mg plus EZE, or ETC-1002 180 mg plus EZE.ResultsEZE alone lowered LDL-C by 21%, whereas ETC-1002 monotherapy with 120 mg or 180 mg reduced LDL-C by 27% (P = .0008 vs EZE) and 30% (P < .0001 vs EZE), respectively. The combination of ETC-1002, 120 mg or 180 mg plus EZE reduced LDL-C by 43% and 48%, respectively (both P < .0001 vs EZE). ETC-1002 alone or combined with EZE also reduced non–high-density lipoprotein cholesterol, total cholesterol, apolipoprotein B, LDL particle number, and high-sensitivity C-reactive protein compared with EZE alone. Across all treatment groups, statin-intolerant patients reported more muscle-related adverse events than did statin-tolerant patients. ETC-1002 was safe and well tolerated, and rates of muscle-related adverse events were similar in all treatment groups.ConclusionsIn patients with and without statin intolerance, daily treatment with ETC-1002 120 mg and 180 mg alone or with EZE reduced LDL-C more than EZE alone and had a similar tolerability profile (NCT01941836)
    corecore