649 research outputs found

    Novel analysis of global DNA methylation in the limbic system of the bovine brain

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    Citation: Cantrell, B. A., McKay, S. D., Weaber, R. L., Funston, R. N., & Lachance, H. (2016). Novel analysis of global DNA methylation in the limbic system of the bovine brain. Journal of Animal Science, 94, 43-43. doi:10.2134/jas2016.94supplement443xThere has been limited research focusing on the genetic-environmental interactions in bovine brains. Global DNA methylation has been measured in brains of several species, but has yet to be examined in bovine. The objective of this study was to characterize global DNA methylation in 9 regions of the limbic system in the bovine brain: amygdala, bed nucleus of the stria terminalis, cingulate gyrus, dorsal raphe, hippocampus, hypothalamus, nucleus accumbens, periaqueductal gray, and prefrontal cortex. DNA was extracted from brain and blood samples of 6 Red Angus × Simmental steers (less than 20 mo of age), using the DNA Extraction Kit from Agilent Technologies (Santa Clara, CA) and a phenol chloroform extraction. Percent of global DNA methylation was determined using the MethylFlash Methylated DNA Quantification Kit (Colormetric) from Epigentek (Farmingdale, NY). Varying amounts of global DNA methylation were observed among the 9 functionally distinct regions of the bovine limbic system. Amygdala, bed nucleus of the stria terminalis, cingulate gyrus, dorsal raphe, periaqueductal gray, prefrontal cortex, and nucleus accumbens are all significantly different (P < 0.05) from 1 or more brain tissue type, using a paired t test in SPSS (IBM, Armonk, NY). Conversely, global DNA methylation of blood was not significantly different (P < 0.05) from any brain tissue type. This study shows significant differences in global DNA methylation among different tissue types in the limbic system of the bovine brain. Understanding the differences in global DNA methylation within different tissues in the brain will facilitate future research involving the effects of differential methylation with regard to economically important traits

    Effect of Supplementation during the Breeding Season on a May-calving Herd in the Nebraska Sandhills

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    Females in their first and second breeding season received either a 32% crude protein (DM) supplement or no supplement throughout the breeding season. Supplementation did not affect heifer BW, BCS, and pregnancy rate at pregnancy diagnosis. Supplementation impacted primiparous cow BW and BCS at pregnancy diagnosis, but did not affect pregnancy rates. Calf birth weight and dystocia rates were unaffected by supplementation for both heifers and primiparous cow. Calves nursing supplemented dams were heavier at weaning. Greater supplementation may be needed to affect pregnancy rate

    Plasmonic nanoparticle monomers and dimers: From nano-antennas to chiral metamaterials

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    We review the basic physics behind light interaction with plasmonic nanoparticles. The theoretical foundations of light scattering on one metallic particle (a plasmonic monomer) and two interacting particles (a plasmonic dimer) are systematically investigated. Expressions for effective particle susceptibility (polarizability) are derived, and applications of these results to plasmonic nanoantennas are outlined. In the long-wavelength limit, the effective macroscopic parameters of an array of plasmonic dimers are calculated. These parameters are attributable to an effective medium corresponding to a dilute arrangement of nanoparticles, i.e., a metamaterial where plasmonic monomers or dimers have the function of "meta-atoms". It is shown that planar dimers consisting of rod-like particles generally possess elliptical dichroism and function as atoms for planar chiral metamaterials. The fabricational simplicity of the proposed rod-dimer geometry can be used in the design of more cost-effective chiral metamaterials in the optical domain.Comment: submitted to Appl. Phys.

    Effects of Maternal Late Gestation Nutrition on May-Born Heifer Progeny

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    May-calving dams in late gestation grazed either sub-irrigated meadow with or without supplement or upland range with or without supplement. Supplementation was 1 lb/d of a 33% CP (DM) supplement. Heifer progeny from these dams were followed through their first and second breeding seasons. Both dam grazing and supplement treatment affected heifer progeny BW and BCS. Heifers born to dams who grazed meadow in late gestation attained a greater percentage of mature BW at the start of their first breeding season and increased pregnancy rates as primiparous cows. Grazing of meadow by May-calving dams in late gestation may increase stayability of heifer progeny. Although supplementing the dam during late gestation tended to increase heifer progeny BW at first breeding, the increased risk of dystocia at heifer’s first parturition may negate the benefit

    Impact of Cow Size on Cow-Calf and Subsequent Steer Feedlot Performance

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    This study retrospectively evaluated the effect of cow size on cow-calf performance and post-weaning steer feedlot performance of cows at the Gudmundsen Sandhills Laboratory, Whitman. Cows were categorized at small, medium, or moderate within cow age from 13 years of data. Small cows had decreased reproductive performance, weaned smaller calves, and produced steer progeny with smaller carcass weights. In this dataset and under the environmental and management conditions at Gudmundsen Sandhills Laboratory, overall productivity of the cowherd decreased as cow size decreased with 1,150 to 1,200 lb cow being the most productive cow size

    The Effect of Cow Udder Score on Subsequent Calf Performance in the Nebraska Sandhills

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    Cow records were evaluated over a 5-yr period to investigate how cow udder score affected calf growth and carcass performance. Cows from 2 calving herds, March and May, were classified as bad or good based on udder scores recorded at calving. Calves suckling dams with bad udders performed similarly during the pre-weaning period to good udder counterparts, with no differences in overall steer feedlot performance between udder groups. However, steers suckling good udder cows had heavier carcass weights and greater back fat thickness

    Field Evaluations of Insecticide Modes of Action Classes for Control of Horn Flies in Nebraska

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    Insecticides of different Mode of Action (MoA) classes were tested for their ability to reduce horn fly populations on cattle in Nebraska pastures between 2009 and 2016. Macrocyclic lactone products were the most efficacious, reducing horn fly numbers by an average of 93% over ten location years of testing. Organophosphate and pyrethroid MoA products, tested in 7 and 12 location years, reduced fly numbers by 75% and 73%. Classes tested only once were METI (88% reduction) and a combination of organophosphate + pyrethroid (64%)

    Multihospital Outbreak of Clostridium difficile Ribotype 027 Infection: Epidemiology and Analysis of Control Measures

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    Objective. To report a large outbreak of Clostridium difficile infection (CDI; ribotype 027) between June 2007 and August 2008, describe infection control measures, and evaluate the impact of restricting the use of fluoroquinolones in controlling the outbreak. Design. Outbreak investigation in 3 acute care hospitals of the Northern Health and Social Care Trust in Northern Ireland. Interventions. Implementation of a series of CDI control measures that targeted high-risk antibiotic agents (ie, restriction of fluoroquinolones), infection control practices, and environmental hygiene. Results. A total of 318 cases of CDI were identified during the outbreak, which was the result of the interaction between C. difficile ribotype 027 being introduced into the affected hospitals for the first time and other predisposing risk factors (ranging from host factors to suboptimal compliance with antibiotic guidelines and infection control policies). The 30-day all-cause mortality rate was 24.5%; however, CDI was the attributable cause of death for only 2.5% of the infected patients. Time series analysis showed that restricting the use of fluoroquinolones was associated with a significant reduction in the incidence of CDI (coefficient, —0.054; lag time, 4 months; P = .003). Conclusion. These findings provide additional evidence to support the value of antimicrobial stewardship as an essential element of multifaceted interventions to control CDI outbreaks. The present CDI outbreak was ended following the implementation of an action plan improving communication, antibiotic stewardship, infection control practices, environmental hygiene, and surveillanc

    Book Review

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    A. Funston, M. Gil &amp; G. Gilmore (Eds). (2014). Strong starts, supportedtransitions and student success. UK: Cambridge Scholars Publishing.Reviewed by Birgit Schreiber

    Atomic-scale confinement of optical fields

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    In the presence of matter there is no fundamental limit preventing confinement of visible light even down to atomic scales. Achieving such confinement and the corresponding intensity enhancement inevitably requires simultaneous control over atomic-scale details of material structures and over the optical modes that such structures support. By means of self-assembly we have obtained side-by-side aligned gold nanorod dimers with robust atomically-defined gaps reaching below 0.5 nm. The existence of atomically-confined light fields in these gaps is demonstrated by observing extreme Coulomb splitting of corresponding symmetric and anti-symmetric dimer eigenmodes of more than 800 meV in white-light scattering experiments. Our results open new perspectives for atomically-resolved spectroscopic imaging, deeply nonlinear optics, ultra-sensing, cavity optomechanics as well as for the realization of novel quantum-optical devices
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