3,172 research outputs found

    Survey Atlas of England and Wales

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    Enhanced radiative strength in the quasi-continuum of 117Sn

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    Radiative strength functions of 117Sn has been measured below the neutron separation energy using the (3He,3He'gamma) reactions. An increase in the slope of the strength functions around E_gamma= 4.5 MeV indicates the onset of a resonance-like structure, giving a significant enhancement of the radiative strength function compared to standard models in the energy region 4.5 <= E_gamma <= 8.0 MeV. For the first time, the functional form of this resonance-like structure has been measured in an odd tin nucleus below neutron threshold in the quasi-continuum region.Comment: 4 pages, 3 figure

    Hummingbirds Budget Energy Flexibly in Response to Changing Resources

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    A key component of individual fitness is the ability to manage energy stores in response to variable resource availability, but because directly measuring energy budgets is difficult, daily energy management is rarely measured. Hummingbirds\u27 energy management is relatively simple to model compared to other endotherms because they have high mass‐specific metabolic rates and store little fat. We determined which aspects of the hummingbird daily energy budget (i.e. thermoregulation, daytime activity costs, night‐time costs) change at the individual level in response to environmental variation. We found that daily energy expenditure varied threefold in two populations of broad‐billed hummingbirds (Cynanthus latirostris). Our model indicated the energy budget was distributed in the following proportions: daytime activity, 59% (range 22%–84%); thermoregulation, 23% (11%–32%); basal metabolism, 7% (3%–16%); and night‐time energy, 17% (6%–37%). Activity costs were higher at the hotter, homogeneous site and during the early‐wet season at both sites. Increased daily energy expenditure was related to decreased nectar availability and not significantly related to temperature or bird mass. With climate change, the indirect energetic costs of shifting resources could have greater impacts on endotherm energy budgets than direct costs such as thermoregulation. Increased foraging and activity costs could decrease the energy available to birds for somatic repair and reproduction, potentially causing differential fitness across seasons and sites

    Detection of functional PTEN lipid phosphatase protein and enzyme activity in squamous cell carcinomas of the head andeck, despite loss of heterozygosity at this locus

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    The human tumour suppressor gene PTEN located at 10q23 is mutated in a variety of tumour types particularly metastatic cases and in the germline of some individuals with Cowdens cancer predisposition syndrome. We have assessed the status of PTEN and associated pathways in cell lines derived from 19 squamous cell carcinomas of the head and neck. Loss of heterozygosity is evident at, or close to the PTEN gene in 5 cases, however there were no mutations in the remaining alleles. Furthermore by Western analysis PTEN protein levels are normal in all of these SCC-HN tumours and cell lines. To assess the possibility that PTEN may be inactivated by another mechanism, we characterized lipid phosphatase levels and from a specific PIP3 biochemical assay it is clear that PTEN is functionally active in all 19 human SCCs. Our data strongly suggest the possibility that a tumour suppressor gene associated with development of SCC-HN, other than PTEN, is located in this chromosomal region. This gene does not appear to be MXI-1, which has been implicated in some other human tumour types. PTEN is an important negative regulator of PI3Kinase, of which subunit alpha is frequently amplified in SCC-HN. To examine the possibility that PI3K is upregulated by amplification in this tumour set we assessed the phosphorylation status of Akt, a downstream target of PI3K. In all cases there is no detectable increase in Akt phosphorylation. Therefore there is no detectable defect in the PI3K pathway in SCC-HN suggesting that the reason for 3q26.3 over-representation may be due to genes other than PI3K110α. © 2001 Cancer Research Campaign http://www.bjcancer.co

    Photoactivation experiment on 197Au and its implications for the dipole strength in heavy nuclei

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    The 197Au(gamma,n) reaction is used as an activation standard for photodisintegration studies on astrophysically relevant nuclei. At the bremsstrahlung facility of the superconducting electron accelerator ELBE (Electron Linear accelerator of high Brilliance and low Emittance) of Forschungszentrum Dresden-Rossendorf, photoactivation measurements on 197Au have been performed with bremsstrahlung endpoint energies from 8.0 to 15.5 MeV. The measured activation yield is compared with previous experiments as well as with calculations using Hauser-Feshbach statistical models. It is shown that the experimental data are best described by a two-Lorentzian parametrization with taking the axial deformation of 197Au into account. The experimental 197Au(gamma,n) reaction yield measured at ELBE via the photoactivation method is found to be consistent with previous experimental data using photon scattering or neutron detection methods.Comment: 9 page

    Secondary metabolite profiling of the model legume Lotus japonicus during its symbiotic interaction with Mesorhizobium loti

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    Plant secondary metabolites, particularly flavonoids, are key components in the early stages of nitrogen-fixing symbiosis. Despite their importance, the endogenous secondary metabolites involved in symbiosis have not yet been identified in the model legume Lotus japonicus. We therefore determined changes in the secondary metabolic profile of Lotus japonicus roots in response to its symbiont. Analysis of the root secondary metabolite profiles 1 week after inoculation with Mesorhizobium loti revealed quantitative changes in the level of 14 phenolic peaks when compared with non-inoculated control plants. These changes affected compounds from most phenolic classes, possibly resulting from interconversion between classes since the total phenolic level remained constant. In addition, the use of 2 M. loti strains differing only in their capacity to synthesise Nod factor revealed that, although Nod factor signalling induced accumulation of a specific subset of 4 phenolic peaks, most changes were induced in response to both rhizobial strains.NR was supported by a Training Network funded by the European Training Network EU-RTN-LOTUS-HPRN-CT-2000-00086. KJW was supported by core funding from the Biotechnology and Biological Science Research Council (BBSRC), UK.Peer Reviewe

    Evolution of level density step structures from 56,57-Fe to 96,97-Mo

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    Level densities have been extracted from primary gamma spectra for 56,57-Fe and 96,97-Mo nuclei using (3-He,alpha gamma) and (3-He,3-He') reactions on 57-Fe and 97-Mo targets. The level density curves reveal step structures above the pairing gap due to the breaking of nucleon Cooper pairs. The location of the step structures in energy and their shapes arise from the interplay between single-particle energies and seniority-conserving and seniority-non-conserving interactions.Comment: 9 pages, including 5 figure

    Criminal Thinking, Psychiatric Symptoms, and Recovery Attitudes Among Community Mental Health Patients

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    Research suggests it is important to consider criminogenic needs among individuals with severe mental illness. This study aimed to determine the severity of criminal thinking in community-based clinical samples, understand the association between criminal thinking and psychiatric and criminal justice outcomes, and compare these associations between consumers enrolled in Assertive Community Treatment (ACT) and Forensic Assertive Community Treatment (FACT) programs. Participants (N = 234) were male and female consumers enrolled in ACT and FACT programs in five states. Results revealed no significant differences in criminal thinking when comparing participants by program type or history of criminal justice involvement. There were significant positive relations between general criminal thinking and psychiatric symptomatology and the number of lifetime arrests, a negative association between recovery attitudes and general criminal thinking, and ACT participants reported a greater number of lifetime psychiatric hospitalizations than FACT participants. Result implications are discussed with specific reference to treatment programming

    Isospin Character of the Pygmy Dipole Resonance in 124Sn

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    The pygmy dipole resonance has been studied in the proton-magic nucleus 124Sn with the (a,a'g) coincidence method at E=136 MeV. The comparison with results of photon-scattering experiments reveals a splitting into two components with different structure: one group of states which is excited in (a,a'g) as well as in (g,g') reactions and a group of states at higher energies which is only excited in (g,g') reactions. Calculations with the self-consistent relativistic quasiparticle time-blocking approximation and the quasiparticle phonon model are in qualitative agreement with the experimental results and predict a low-lying isoscalar component dominated by neutron-skin oscillations and a higher-lying more isovector component on the tail of the giant dipole resonance
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