1,450 research outputs found

    The Angular Correlations in the e+ee^+e^- Decay of Excited States in 8Be

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    Motivated by the recent observation of anomalous electron-positron angular correlations in the decay of the 18.15 MeV 1+ excited states in 8Be, we reexamine in detail the Standard Model expectations for these angular correlations. The 18.15 MeV state is above particle threshold, and several multipoles can contribute to its e+ee^+e^- decay. We present the general theoretical expressions for e+ee^+e^- angular distributions for nuclear decay by C0, C1, C2 M1, E1, and E2 multipoles, and we examine their relative contribution to the e+ee^+e^- decay of 8Be at 18.15 MeV. We find that this resonance is dominated by M1 and E1 decay, and that the ratio of M1 to E1 strength is a strong function of energy. This is in contract to the original analysis of the e+ee^+e^- angular distributions, where the M1/E1 ratio was assumed to be a constant over the energy region Ep = 0:8-1:2 MeV. We find that the existence of a `bump' in the measured angular distribution is strongly dependent on the assumed M1/E1 ratio, with the present analysis finding the measured large-angle contributions to the e+ee^+e^- angular distribution to be lower than expectation. Thus, in the current analysis we find no evidence for axion decay in the 18.15 MeV resonance region of 8Be

    Fat storage-inducing transmembrane (FIT or FITM) proteins are related to lipid phosphatase/phosphotransferase enzymes

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    Fat storage-inducing transmembrane (FIT or FITM) proteins have been implicated in the partitioning of triacylglycerol to lipid droplets and the budding of lipid droplets from the ER. At the molecular level, the sole relevant interaction is that FITMs directly bind to triacyglycerol and diacylglycerol, but how they function at the molecular level is not known.Saccharomyces cerevisiaehas two FITM homologues: Scs3p and Yft2p. Scs3p was initially identified because deletion leads to inositol auxotrophy, with an unusual sensitivity to addition of choline. This strongly suggests a role for Scs3p in phospholipid biosynthesis. Looking at the FITM family as widely as possible, we found that FITMs are widespread throughout eukaryotes, indicating presence in the last eukaryotic common ancestor. Protein alignments also showed that FITM sequences contain the active site of lipid phosphatase/phosphotransferase (LPT) enzymes. This large family transfers phosphate-containing headgroups either between lipids or in exchange for water. We confirmed the prediction that FITMs are related to LPTs by showing that single amino-acid substitutions in the presumptive catalytic site prevented their ability to rescue growth of the mutants on low inositol/high choline media when over-expressed. The substitutions also prevented rescue of other phenotypes associated with loss of FITM in yeast, including mistargeting of Opi1p, defective ER morphology, and aberrant lipid droplet budding. These results suggest that Scs3p, Yft2p and FITMs in general are LPT enzymes involved in an as yet unknown critical step in phospholipid metabolism

    HUNGARIAN EXPERIENCE IN STRUCTURAL DESIGN CODING (HISTORICAL ANTECEDENTS OF EUROCODE-2)

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    This paper gives review of the historical antecedents of Eurocode-2 in Hungary and East Europe. The method of permissible stresses, using uniform safety factor was first changed in 1950 in Hungary by the semi-probabilistic method using partial safety factors. This new method was accepted with some resistance on the part of the leading structural engineers. Nevertheless most of the East-European countries accepted the new method with some political overtones', to be follow the Soviet example. The authors assert in the papaer that due to the economic necessities. Hungary and the other East European countries gained experience with the regulations affording less safety than the EC2, and this offers an interesting set of experience to the West European countries which have intoduced or are introducing the semi-probabilistic procedure. The most significant point all the experience is the recognition that only one part of the parameters in the structural analysis determining safety can be handled statistically. During design the statistically not significant data such as the error of the structural model must also be taken into consideration. Based on the experience, the authors propose an alternative design method

    Childhood interleukin-6, C-reactive protein and atopic disorders as risk factors for hypomanic symptoms in young adulthood: a longitudinal birth cohort study

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    Background.\textbf{Background.} There are no existing longitudinal studies of inflammatory markers and atopic disorders in childhood and risk of hypomanic symptoms in adulthood. This study examined if childhood: (1) serum interleukin-6 (IL-6) and C-reactive protein (CRP); and (2) asthma and/or eczema are associated with features of hypomania in young adulthood. Method.\textbf{Method.} Participants in the Avon Longitudinal Study of Parents and Children, a prospective general population UK birth cohort, had non-fasting blood samples for IL-6 and CRP measurement at the age of 9 years (nn = 4645), and parents answered a question about doctor-diagnosed atopic illness before the age of 10 years (nn = 7809). These participants completed the Hypomania Checklist at age 22 years (nn = 3361). Results.\textbf{Results.} After adjusting for age, sex, ethnicity, socio-economic status, past psychological and behavioural problems, body mass index and maternal postnatal depression, participants in the top third of IL-6 values at 9 years, compared with the bottom third, had an increased risk of hypomanic symptoms by age 22 years [adjusted odds ratio 1.77, 95% confidence interval (CI) 1.10-2.85, pp < 0.001]. Higher IL-6 levels in childhood were associated with adult hypomania features in a dose-response fashion. After further adjustment for depression at the age of 18 years this association remained (adjusted odds ratio 1.70, 95% CI 1.03-2.81, pp = 0.038). There was no evidence of an association of hypomanic symptoms with CRP levels, asthma or eczema in childhood. Conclusions.\textbf{Conclusions.} Higher levels of systemic inflammatory marker IL-6 in childhood were associated with hypomanic symptoms in young adulthood, suggesting that inflammation may play a role in the pathophysiology of mania. Inflammatory pathways may be suitable targets for the prevention and intervention for bipolar disorder.The UK Medical Research Council and the Wellcome Trust (grant reference 102215/2/13/2) and the University of Bristol provide core support for ALSPAC. J.F.H. is supported by a Medical Research Council Population Health Scientist Fellowship (grant code: MR/K021362/1)

    Eliciting a predatory response in the eastern corn snake (Pantherophis guttatus) using live and inanimate sensory stimuli: implications for managing invasive populations

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    North America's Eastern corn snake (Pantherophis guttatus) has been introduced to several islands throughout the Caribbean and Australasia where it poses a significant threat to native wildlife. Invasive snake control programs often involve trapping with live bait, a practice that, as well as being costly and labour intensive, raises welfare and ethical concerns. This study assessed corn snake response to live and inanimate sensory stimuli in an attempt to inform possible future trapping of the species and the development of alternative trap lures. We exposed nine individuals to sensory cues in the form of odour, visual, vibration and combined stimuli and measured the response (rate of tongue-flick [RTF]). RTF was significantly higher in odour and combined cues treatments, and there was no significant difference in RTF between live and inanimate cues during odour treatments. Our findings suggest chemical cues are of primary importance in initiating predation and that an inanimate odour stimulus, absent of simultaneous visual and vibratory cues, is a potential low-cost alternative trap lure for the control of invasive corn snake populations

    How does student educational background affect transition into the first year of veterinary school? Academic performance and support needs in university education

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    The first year of university is critical in shaping persistence decisions (whether students continue with and complete their degrees) and plays a formative role in influencing student attitudes and approaches to learning. Previous educational experiences, especially previous university education, shape the students’ ability to adapt to the university environment and the study approaches they require to perform well in highly demanding professional programs such as medicine and veterinary medicine. The aim of this research was to explore the support mechanisms, academic achievements, and perception of students with different educational backgrounds in their first year of veterinary school. Using questionnaire data and examination grades, the effects upon perceptions, needs, and educational attainment in first-year students with and without prior university experience were analyzed to enable an in-depth understanding of their needs. Our findings show that school leavers (successfully completed secondary education, but no prior university experience) were outperformed in early exams by those who had previously graduated from university (even from unrelated degrees). Large variations in student perceptions and support needs were discovered between the two groups: graduate students perceived the difficulty and workload as less challenging and valued financial and IT support. Each student is an individual, but ensuring that universities understand their students and provide both academic and non-academic support is essential. This research explores the needs of veterinary students and offers insights into continued provision of support and improvements that can be made to help students achieve their potential and allow informed "Best Practice"

    Single nucleotide polymorphism discovery in rainbow trout by deep sequencing of a reduced representation library

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    <p>Abstract</p> <p>Background</p> <p>To enhance capabilities for genomic analyses in rainbow trout, such as genomic selection, a large suite of polymorphic markers that are amenable to high-throughput genotyping protocols must be identified. Expressed Sequence Tags (ESTs) have been used for single nucleotide polymorphism (SNP) discovery in salmonids. In those strategies, the salmonid semi-tetraploid genomes often led to assemblies of paralogous sequences and therefore resulted in a high rate of false positive SNP identification. Sequencing genomic DNA using primers identified from ESTs proved to be an effective but time consuming methodology of SNP identification in rainbow trout, therefore not suitable for high throughput SNP discovery. In this study, we employed a high-throughput strategy that used pyrosequencing technology to generate data from a reduced representation library constructed with genomic DNA pooled from 96 unrelated rainbow trout that represent the National Center for Cool and Cold Water Aquaculture (NCCCWA) broodstock population.</p> <p>Results</p> <p>The reduced representation library consisted of 440 bp fragments resulting from complete digestion with the restriction enzyme <it>Hae</it>III; sequencing produced 2,000,000 reads providing an average 6 fold coverage of the estimated 150,000 unique genomic restriction fragments (300,000 fragment ends). Three independent data analyses identified 22,022 to 47,128 putative SNPs on 13,140 to 24,627 independent contigs. A set of 384 putative SNPs, randomly selected from the sets produced by the three analyses were genotyped on individual fish to determine the validation rate of putative SNPs among analyses, distinguish apparent SNPs that actually represent paralogous loci in the tetraploid genome, examine Mendelian segregation, and place the validated SNPs on the rainbow trout linkage map. Approximately 48% (183) of the putative SNPs were validated; 167 markers were successfully incorporated into the rainbow trout linkage map. In addition, 2% of the sequences from the validated markers were associated with rainbow trout transcripts.</p> <p>Conclusion</p> <p>The use of reduced representation libraries and pyrosequencing technology proved to be an effective strategy for the discovery of a high number of putative SNPs in rainbow trout; however, modifications to the technique to decrease the false discovery rate resulting from the evolutionary recent genome duplication would be desirable.</p

    Activation of Ventral Tegmental Area 5-HT2C Receptors Reduces Incentive Motivation

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    FUNDING AND DISCLOSURE The research was funded by Wellcome Trust (WT098012) to LKH; and National Institute of Health (DK056731) and the Marilyn H. Vincent Foundation to MGM. The University of Michigan Transgenic Core facility is partially supported by the NIH-funded University of Michigan Center for Gastrointestinal Research (DK034933). The remaining authors declare no conflict of interest. ACKNOWLEDGMENTS We thank Dr Celine Cansell, Ms Raffaella Chianese and the staff of the Medical Research Facility for technical assistance. We thank Dr Vladimir Orduña for the scientific advice and technical assistance.Peer reviewedPublisher PD

    Schedule-dependent response of neuroblastoma cell lines to combinations of etoposide and cisplatin

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    The growth inhibitory effects of cisplatin and etoposide on neuroblastoma cell lines were investigated in several scheduled combinations. Results were analyzed using median effect and combination index analyses. In all schedules in which cisplatin was administered prior to etoposide a synergistic effect was observed. Conversely, an antagonistic effect was seen in all schedules where etoposide was administered before cisplatin
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