5,607 research outputs found

    Universality of dispersive spin-resonance mode in superconducting BaFe2As2

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    Spin fluctuations in superconducting BaFe2(As1-xPx)2 (x=0.34, Tc = 29.5 K) are studied using inelastic neutron scattering. Well-defined commensurate magnetic signals are observed at ({\pi},0), which is consistent with the nesting vector of the Fermi surface. Antiferromagnetic (AFM) spin fluctuations in the normal state exhibit a three-dimensional character reminiscent of the AFM order in nondoped BaFe2As2. A clear spin gap is observed in the superconducting phase forming a peak whose energy is significantly dispersed along the c-axis. The bandwidth of dispersion becomes larger with approaching the AFM ordered phase universally in all superconducting BaFe2As2, indicating that the dispersive feature is attributed to three-dimensional AFM correlations. The results suggest a strong relationship between the magnetism and superconductivity.Comment: 5 pages, 5 figure

    Ground state magnetic structure of Mn3_3Ge

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    We have used spherical neutron polarimetry to investigate the magnetic structure of the Mn spins in the hexagonal semimetal Mn3_3Ge, which exhibits a large intrinsic anomalous Hall effect. Our analysis of the polarimetric data finds a strong preference for a spin structure with E1gE_{1g} symmetry relative to the D6hD_{6h} point group. We show that weak ferromagnetism is an inevitable consequence of the symmetry of the observed magnetic structure, and that sixth order anisotropy is needed to select a unique ground state

    Stillbirth should be given greater priority on the global health agenda

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    Stillbirths are largely excluded from international measures of mortality and morbidity. Zeshan Qureshi and colleagues argue that stillbirth should be higher on the global health agenda

    Introduction of the Canadian CT Head Rule Reduces CT Scan Use in Minor Head Injury

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    Background: The burden of traumatic brain injury (TBI) is rising in  developing countries. Minor head injuries accounts for majority of non-fatal head injury and is associated with significant resource use. The utility of the CT scan in cases of mild head injury is undetermined although a big  proportion of our patients are offered the investigation. We hypothesized that the introduction of the Canadian CT head rule (CCTHR) will reduce the utilization rate.Methods: Eighty four eligible patients diagnosed with minor head injury were recruited at the Accident and Emergency Department. The proportion of CT scan orders before (Group I-42 patients) and after (Group II- 42 patients) the introduction of the CCTHR was determined. Treatment in  Group I patients followed the primary physician orders while group II patients were offered CT scans only if they presented with ‘high risk’ features of the CCTHR. Group II patients with ‘moderate’ risk factors were admitted for observation or discharged as appropriate to the rule.Results: The proportion of CT scans ordered in Group I was 95.2% while that in Group II was 21.4%. The proportion of patients with moderate risk factors Group I was 90.5%, representing the proportion of patients who did not require a CT scan. None of the patients required neurosurgical  intervention and all had good recovery on follow up.Conclusion: The proportion of mild head injury patients requiring a CT scan at AKUH is 21.4%. Limiting CT scans to only this group was not associated with adverse outcomes. It is the recommended that CT scan rates for mild head injury be capped at 25% to save time and money currently being expended.Key Words: Canadian CT Head Rule, Minor Head Injury, Outcome

    Peculiar histopathological features of giardiasis in distal duodenal biopsies

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    Histological changes in 20 Giardia positive duodenal biopsies (Group A) were compared with 50, Giardia negative duodenal biopsies (Group B), taken during the same period. Stool examinations in Group B were negative for Giardia. Surface epithelium, villous and crypt architecture and cellular infiltrates were examined and compared between the groups. Atrophic changes in the villi were more common in Group A as compared to B(P \u3c 0.0001). Intraepithelial neutrophil infiltration (P \u3c 0.001), infiltration of the lamina propria with plasma cells (P \u3c 0.5), and presence of eosinophils in the lamina propria (P \u3c 0.001) were significant findings in group A. Some of the changes were related to the density of Giardia colonization e.g., the goblet cell depletion (P \u3c 0.05) and the density of plasma cell infiltration in lamina propria (P \u3c 0.01). Erosions and ulcerations were less commonly seen in group A. Thus we conclude that giardiasis manifests its peculiar features in the distal duodenal mucosa and a biopsy of this region is an important diagnostic tool for detection of this disease

    Discrete-time rewards model-checked

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    This paper presents a model-checking approach for analyzing discrete-time Markov reward models. For this purpose, the temporal logic probabilistic CTL is extended with reward constraints. This allows to formulate complex measures – involving expected as well as accumulated rewards – in a precise and succinct way. Algorithms to efficiently analyze such formulae are introduced. The approach is illustrated by model-checking a probabilistic cost model of the IPv4 zeroconf protocol for distributed address assignment in ad-hoc networks
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