2,308 research outputs found

    Estimates of Genetic Parameters for Calving Performance from Designed Selection Studies

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    A multiple trait animal model was implemented to study the direct genetic and maternal genetic relationship among four traits, dystocia (DYS), perinatal mortality (PM), birth weight (BW) and gestation length(GL), expressed at the birth of a calf. The sign and magnitude of genetic correlations among calving traits demonstrates the need to use multi-trait animal models for genetic evaluation of animals for calving performance. Adequate information exists to begin developing a calving performance index. This index will enable breeders of dairy cattle to optimize the health and well-being of replacement animals and reduce the incidence of dystocia and perinatal mortality

    Overview of Dairy Cattle Breeding

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    The overall objectives of dairy cattle breeding research are to generate new knowledge and to provide this information to breeders in Iowa and the nation. We are attempting to accomplish this by developing new knowledge that will be of value in the future and also have information that can be provided to the breeding industry to answer present-day problems. Because more than 70% of the dairy cattle in the United States are bred artificially, our work will have more impact if it can eventually be applied through the artificial insemination (AI) industry and breed associations. A great deal of research and groundwork needs to be done before research can be applied on an industry-wide basis

    Perinatal Mortality in Holsteins

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    A comprehensive analysis of perinatal mortality for Holsteins in the upper Midwest was recently completed. Results showed that the incidence of perinatal mortality or calf losses near birth has been increasing since 1985; from 9.5% in 1985 to 13.2% in 1996 for virgin heifers; 5.3 to 6.6% in multiparous cows over the same time period. Replacement value of calves lost to perinatal mortality in the United States is about $125.3 million per year. Sufficient data exist to permit identification of those sires whose daughters have a higher than average incidence for perinatal mortality with the birth of their calves. Further research is in progress to more completely establish the mode of inheritance for perinatal mortality. Other quantitative traits associated with early calfhood diseases, e.g., gestation length, dystocia, and incidence of twins are being examined

    Heterogeneity in Short Gamma-ray Bursts

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    We analyze the Swift/BAT sample of short gamma-ray bursts, using an objective Bayesian Block procedure to extract temporal descriptors of the bursts' initial pulse complexes (IPCs). The sample comprises 12 and 41 bursts with and without extended emission (EE) components, respectively. IPCs of non-EE bursts are dominated by single pulse structures, while EE bursts tend to have two or more pulse structures. The medians of characteristic timescales - durations, pulse structure widths, and peak intervals - for EE bursts are factors of ~ 2-3 longer than for non-EE bursts. A trend previously reported by Hakkila and colleagues unifying long and short bursts - the anti-correlation of pulse intensity and width - continues in the two short burst groups, with non-EE bursts extending to more intense, narrower pulses. In addition we find that preceding and succeeding pulse intensities are anti-correlated with pulse interval. We also examine the short burst X-ray afterglows as observed by the Swift/XRT. The median flux of the initial XRT detections for EE bursts (~ 6 x 10^-10 erg cm^-2 s^-1) is ~> 20 x brighter than for non-EE bursts, and the median X-ray afterglow duration for EE bursts (~ 60,000 s) is ~ 30 x longer than for non-EE bursts. The tendency for EE bursts toward longer prompt-emission timescales and higher initial X-ray afterglow fluxes implies larger energy injections powering the afterglows. The longer-lasting X-ray afterglows of EE bursts may suggest that a significant fraction explode into more dense environments than non-EE bursts, or that the sometimes-dominant EE component efficiently powers the afterglow. Combined, these results favor different progenitors for EE and non-EE short bursts.Comment: 30 pages, 11 figures, 3 tables; accepted to The Astrophysical Journa

    Ultrasound imaging of the sciatic nerve division in the popliteal fossa: A volunteer study

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    Background and Objectives: A sciatic nerve block at the level of the popliteal fossa is frequently administered for post-operative analgesia for surgery below the knee. While ultrasound continues to gain popularity as the technique of choice for guiding needle positioning during peripheral nerve blocks, practitioners can begin to utilize ultrasound to look for patterns of anatomical significance. Recognizing anatomical variations among different demographic populations can help practitioners improve in performing nerve blocks. We aim to determine if predictable variability exists in sciatic nerve bifurcation location and depth at the level of the popliteal fossa. Methods: After IRB approval, eligible subjects were screened for ASA I or II status and demographic data was collected. Fifty subjects were enrolled. The SonoSite MicroMaxx® with 38-mm broadband linear array, 13-6 MHz probe with color Doppler and image capturing capabilities was used for ultrasound measurements. With subject lying prone, the location of the sciatic nerve in relation to the popliteal crease and skin-to-nerve distance were assessed via ultrasound. Two independent investigators confirmed nerve location for measurements. Analyses were performed with SAS version 9.1 using Pearson Correlation Coefficients and regression analysis. Results: Gender stratification revealed that, while males were both taller and heavier, skin-nerve measurements for depth were consistently deeper in females (p-value 0.02). Independent of the right or left leg, male gender and increased height decreases the skin-nerve distance, while increased weight increases the distance. There was no correlation between patient characteristics and crease-nerve distance. In some subjects, variability of crease-nerve distance even existed between their right and left leg. Conclusion: We show that significant variability exists for actual sciatic nerve bifurcation location, or target injection site, with consistently deeper skin depth values for female patients when compared to male patients, accounting for height and weight. These findings suggest visualization techniques such as ultrasound may lead to better localization of ideal injection sites

    Highly-ordered graphene for two dimensional electronics

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    With expanding interest in graphene-based electronics, it is crucial that high quality graphene films be grown. Sublimation of Si from the 4H-SiC(0001) Si-terminated) surface in ultrahigh vacuum is a demonstrated method to produce epitaxial graphene sheets on a semiconductor. In this paper we show that graphene grown from the SiC(0001ˉ)(000\bar{1}) (C-terminated) surface are of higher quality than those previously grown on SiC(0001). Graphene grown on the C-face can have structural domain sizes more than three times larger than those grown on the Si-face while at the same time reducing SiC substrate disorder from sublimation by an order of magnitude.Comment: Submitted to Appl. Phys. Let

    International clinical rotations during U.S. residency training: Creating an accreditation council for graduate medical education-approved rotation

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    Healthcare professionals increasingly report interest in global health and participation in international healthcare delivery. Growth opportunities exist for trainees to improve knowledge, skills and attitudes through international experiences. Professional development via international medicine may have lasting effects on patient care and practice patterns following training. In 2010, the first resident took part in an international, exchange elective between The George Washington University’s Department of Anesthesiology in Washington, DC and La Universidad de San Francisco’s Department of Anesthesiology in Quito, Ecuador. This resident elective rotation resulted from a strategic partnership, initiated in 2008, between two training institutions with an established track record of medical student educational exchange programs. The goal of any resident elective rotation should be to enhance an educational experience, to improve upon a perceived training deficiency, or to create a unique offering that takes advantage of local assets and connections. International electives, if properly conceived, can accomplish all three goals. This guide for program leadership addresses the rationale and challenges, from concept to Accreditation Council for Graduate Medical Education approval, of creating an international clinical rotation for residents

    The crucial role of bilateral infraclavicular nerve blocks in the anesthetic management of a trauma patient

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    Bilateral brachial plexus blocks and regional anesthesia in trauma patients are rarely performed due to potential complications when using these techniques. We illustrate a case in which bilateral infraclavicular nerve blocks were placed as part of a multimodal approach to pain management in a trauma patient. We discuss potential hazards, important considerations, and rationale for attempting this procedure. Ultimately, performing bilateral brachial plexus nerve blocks in trauma patients is a viable option when choosing pain management techniques

    Physical activity counseling in overweight and obese primary care patients: Outcomes of the VA-STRIDE randomized controlled trial.

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    The purpose of this 2-arm randomized clinical trial was to evaluate the effectiveness of a 12-month, expert system-based, print-delivered physical activity intervention in a primary care Veteran population in Pittsburgh, Pennsylvania. Participants were not excluded for many health conditions that typically are exclusionary criteria in physical activity trials. The primary outcome measures were physical activity reported using the Community Healthy Activities Model Program for Seniors (CHAMPS) questionnaire and an accelerometer-based activity assessment at baseline, 6, and 12 months. Of the 232 Veterans enrolled in the study, 208 (89.7%) were retained at the 6-month follow-up and 203 (87.5%) were retained at 12 months. Compared to the attention control, intervention participants had significantly increased odds of meeting the U.S. recommended guideline of ≥ 150 min/week of at least moderate-intensity physical activity at 12 months for the modified CHAMPS (odds ratio [OR] = 2.86; 95% CI: 1.03-7.96; p = 0.04) but not at 6 months (OR = 1.54; 95% CI: 0.56-4.23; p = 0.40). Based on accelerometer data, intervention participants had significantly increased odds of meeting ≥ 150 min/week of moderate-equivalent physical activity at 6 months (OR = 6.26; 95% CI: 1.26-31.22; p = 0.03) and borderline significantly increased odds at 12 months (OR = 4.73; 95% CI: 0.98-22.76; p = 0.053). An expert system physical activity counseling intervention can increase or sustain the proportion of Veterans in primary care meeting current recommendations for moderate-intensity physical activity. Trial Registration Clinical trials.gov identifier: NCT00731094 URL: http://www.clinicaltrials.gov/ct2/show/NCT00731094

    Low-density lipoprotein aggregation predicts adverse cardiovascular events in peripheral artery disease

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    Background and aims: Peripheral artery disease (PAD) is a systemic manifestation of atherosclerosis that is associated with a high risk of major adverse cardiovascular events (MACE). LDL aggregation contributes to atherosclerotic plaque progression and may contribute to plaque instability. We aimed to determine if LDL aggregation is associated with MACE in patients with PAD undergoing lower extremity revascularization (LER). Methods: Two hundred thirty-nine patients with PAD undergoing LER had blood collected at baseline and were followed prospectively for MACE (myocardial infarction, stroke, cardiovascular death) for one year. Nineteen age, sex and LDL-C-matched control subjects without cardiovascular disease also had blood drawn. Subject LDL was exposed to sphingomyelinase and LDL aggregate size measured via dynamic light scattering. Results: Mean age was 72.3 10.9 years, 32.6% were female, and LDL-cholesterol was 68 +/- 25 mg/dL. LDL aggregation was inversely associated with triglycerides, but not associated with demographics, LDL-cholesterol or other risk factors. Maximal LDL aggregation occurred significantly earlier in subjects with PAD than in control subjects. 15.9% of subjects experienced MACE over one year. The 1st tertile (shortest time to maximal aggregation) exhibited significantly higher MACE (25% vs. 12.5% in tertile 2 and 10.1% in tertile 3, p = 0.012). After multivariable adjustment for demographics and CVD risk factors, the hazard ratio for MACE in the 1st tertile was 4.57 (95% CI 1.60-13.01; p = 0.004) compared to tertile 3. Inclusion of LDL aggregation in the Framingham Heart Study risk calculator for recurrent coronary heart disease events improved the c-index from 0.57 to 0.63 (p = 0.01). Conclusions: We show that in the setting of very well controlled LDL-cholesterol, patients with PAD with the most rapid LDL aggregation had a significantly elevated MACE risk following LER even after multivariable adjustment. This measure further improved the classification specificity of an established risk prediction tool. Our findings support broader investigation of this assay for risk stratification in patients with atherosclerotic CVD.Peer reviewe
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