1,629 research outputs found

    On the Chemistry of Hydrides of N Atoms and O+ Ions

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    Previous work by various authors has suggested that the detection by Herschel/HIFI of nitrogen hydrides along the low-density lines of sight toward G10.6-0.4 (W31C) cannot be accounted for by gas-phase chemical models. In this paper we investigate the role of surface reactions on dust grains in diffuse regions, and we find that formation of the hydrides by surface reactions on dust grains with efficiency comparable to that for H2 formation reconciles models with observations of nitrogen hydrides. However, similar surface reactions do not contribute significantly to the hydrides of O+ ions detected by Herschel/HIFI that are present along many sight lines in the Galaxy. The O+ hydrides can be accounted for by conventional gas-phase chemistry either in diffuse clouds of very low density with normal cosmic-ray fluxes or in somewhat denser diffuse clouds with high cosmic-ray fluxes. Hydride chemistry in dense dark clouds appears to be dominated by gas-phase ion–molecule reactions

    Comparative Morphological Studies on Lyssa in Carnivores and Camels with Special Reference to Its Surgical Resection

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    The lyssa is a morphologically supporting structure situated along the median plan on the ventral surface of the apex of the tongue in some animals. The present study aimed to describe the morphological differences of the lyssa in carnivores (dog and cat) and camel using conformist macroscopic and microscopic methods as well as evaluation of its surgical resection in the dog and cat. The lyssa is a rod-shaped in dog, strip like structure in cat and ridge-like structure in camel. It showed straight course in dog and helical appearance in cat. In the studied species, the lyssa was formed from adipose tissue intermingled with irregular connective tissue. However, dense striated muscles fibers were seen in the caudal half of the lyssa in dog. Besides, few bundles of longitudinally running muscle fibers were observed in cat and camel. In dog, the lyssa was defined by a coarse sheath of connective tissue, this capsule was ill-defined in cat and absent in camel. In cat, a pyramidal extension of the adipose tissue of the lyssa was attached to intrinsic striated muscle of the tongue. Full function of the tongue could be achieved after surgical resection of lyssa in dogs and cats

    Scale without Conformal Invariance at Three Loops

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    We carry out a three-loop computation that establishes the existence of scale without conformal invariance in dimensional regularization with the MS scheme in d=4-epsilon spacetime dimensions. We also comment on the effects of scheme changes in theories with many couplings, as well as in theories that live on non-conformal scale-invariant renormalization group trajectories. Stability properties of such trajectories are analyzed, revealing both attractive and repulsive directions in a specific example. We explain how our results are in accord with those of Jack & Osborn on a c-theorem in d=4 (and d=4-epsilon) dimensions. Finally, we point out that limit cycles with turning points are unlike limit cycles with continuous scale invariance.Comment: 21 pages, 3 figures, Erratum adde

    Effect of shackling, electrical stunning and halal slaughtering method on stress-linked hormones in broilers

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    The objective of this study was to evaluate the effect of shackling and halal slaughter with head-only electrical stunning (ES) using water bath or no stunning (NS) on plasma levels of adrenaline (AD), noradrenaline (NAD) and corticosterone (CORT) levels of broiler chickens. Male and female broiler chickens (Cobb 500) 38 days old from a commercial farm in Johore, Malaysia, were placed in plastic crates (0.80 × 0.60 × 0.31 m) at 10 birds per crate, and transported for 2.5 hours in an open truck. The ambient temperature during transportation was 25 to 27 °C. Upon arrival at a commercial processing plant, a total of 50 male broiler chickens (2.2 - 2.5 kg) were randomly selected from the flocks that were delivered, transferred to different five crates (10 birds per crate) and held in a lairage for 2 to 3 h. Blood samples were collected at various points, namely after lairaging (P1) (first sampling point for both ES and NS chickens, regarded as basal values), shackling (P2) (second sampling point for both ES and NS chickens), stunning (P3) (third sampling point for ES chickens), and ventral neck incision in stunned (P4) (fourth sampling point for ES chickens) and no stun (P5) (third sampling point for NS chickens). Ten birds were sampled at each sampling point (50 birds in total). Both stunned and no stun birds were shackled. Results show that shackling (P2) did not significantly affect the AD, NAD and CORT levels. However, electrical stunning elevated both the AD and CORT levels significantly, but not NAD. Neck cut had negligible effect on the AD and NAD in NS and ES broilers, but significantly increased CORT compared with the basal CORT value. In conclusion, the study demonstrated that head-only electrical stunning using a water bath might elevate AD and CORT. The study concluded that, as measured by AD and NAD, slaughter with or without stunning may not induce a physiological stress response in broilers.Keywords: corticosterone, adrenaline, noradrenaline, primary processing, poultr

    INVESTIGATION OF MORPHOLOGICAL AND ANATOMICAL CHANGES IN CATHARANTHUS ROSEUS (L.) G. DON DUE TO COLCHICINE INDUCED POLYPLOIDY

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    Catharanthus roseus (L.) G. Don is valuable medicinal plant grown as an ornamental plant. The study was carried out at Gulf Coast Research and Education Center, University of Florida, USA. to evaluate the morphological and anatomical changes from induced polyploidy in periwinkle for this purpose colchicine was applied at four different concentrations 0.0, 0.05, 0.1 and 0.2% for seedling treatment. The results showed that raising colchicine doses caused an increasing of survival percentage and tetraploid plants number. Polyploids showed an increment in leaf thickness, stomatal size, pollen diameter and pollen viability compared to diploid plants. Flow cytometry verified the existence of tetraploids and mixoploids from various colchicine-treated plants especially 0.2 which was found efficient on inducing polyploidy in the plants followed by 0.1% as compared to other concentration under study

    Interstellar hydrocarbons: degradation chemistry in diffuse clouds

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    Laboratory astrophysics and astrochemistr

    Development and impact of a clinical instructional video on self-confidence in luxator use amongst dental undergraduates

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    Objectives The aim was to develop a clinical instructional video to increase the self-reported confidence levels of dental undergraduates in different aspects of using a luxator. Methods Distribution of a questionnaire allowed fourth- and final-year dental students (N = 165) at the University of Leeds to report their confidence in different aspects of luxator use. After the development and distribution of a clinical instructional video, student could evaluate the effectiveness of the video and report their confidence levels through a second questionnaire and focus group interviews. The pre- and post-video questionnaire results were compared using descriptive statistics. Reflexive thematic analysis was used to analyse data collected through focus group interviews. Results The response rate of completed questionnaires was 49% pre-video (N = 82) and 29% post-video (N = 49). The mean percentage of students who reported high confidence levels was lower before viewing the video (26.8%) than after (69.4%). The reasons behind reported confidence levels varied for each individual. The video was considered to be highly effective in allowing visualisation of technique and viewed as a valuable resource for revision. Whilst students perceived that the video had a positive impact on their self-confidence, they still expressed need for small-group practical teaching regarding luxators. Conclusions The utilisation of a clinical instructional video resource increased the self-reported confidence levels of dental undergraduates in different aspects of using a luxator
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