2,858 research outputs found

    Multiparameter digitized video microscopy of toxic and hypoxic injury in single cells.

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    There is no clear picture of the critical events that lead to the transition from reversible to irreversible injury. Many studies have suggested that a rise in cytosolic free Ca2+ initiates plasma membrane bleb formation and a sequence of events that lead ultimately to cell death. In recent studies, we have measured changes in cytosolic free Ca2+, mitochondrial membrane potential, cytosolic pH, and cell surface blebbing in relation to the onset of irreversible injury and cell death following anoxic and toxic injury to single hepatocytes by using multiparameter digitized video microscopy (MDVM). MDVM is an emerging new technology that permits single living cells to be labeled with multiple probes whose fluorescence is responsive to specific cellular parameters of interest. Fluorescence images specific for each probe are collected over time, digitized, and stored. Image analysis and processing then permits quantitation of the spatial distribution of the various parameters with the single living cells. Our results indicate the following: The formation of plasma membrane blebs accompanies all types of injury in hepatocytes. Cell death is a rapid event initiated by rupture of a plasma membrane bleb, and it is coincident with the onset of irreversible injury. An increase of cytosolic free Ca2+ is not the stimulus for bleb formation or the final common pathway leading to cell death. A decrease of mitochondrial membrane potential precedes the loss of cell viability. Cytosolic pH falls by more than 1 pH unit during chemical hypoxia. This acidosis protects against the onset of cell death

    Young Muslim women's experiences of Islam and physical education in Greece and Britain: a comparative study

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    Previous research suggests that Muslim women can experience particular problems when taking physical education (PE) lessons, for example with dress codes, mixed-teaching and exercise during Ramadan; and they can face restrictions in extra-curricular activities for cultural and religious reasons. The area is under-researched and there is little evidence of comparative studies that explore similarities and differences in cross-national experiences, which is the aim of this paper. Two studies conducted in Greece and Britain that explored the views of Muslim women on school experiences of physical education are compared. Both studies focused on diaspora communities, Greek Turkish girls and British Asian women, living in predominantly non-Muslim countries. Growing concerns about global divisions between 'Muslims and the West' make this a particularly pertinent study. Qualitative data were collected by interviews with 24 Greek Muslim women, and 20 British Muslim women. \ud <P> \ud Physical education has national curriculum status and a similar rationale in both countries but with different cultures of formality and tradition, which impacted on pupils' experiences. Data suggested that Greek and British groups held positive views towards physical education but were restricted on their participation in extra-curricular activities. For the British women religious identity and consciousness of Islamic requirements were more evident than for the Greek women. Differences in stages of acculturation, historical and socio-cultural contexts contributed to less problematic encounters with physical education for Greek Muslims who appeared more closely assimilated into the dominant culture

    Instability tests for air-jet textured yarns

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    The air-jet texturing process is briefly introduced and its advantages over other texturing processes are summarized. Characteristics of air-jet textured yarns are stated with special reference to the stability of the yarns. Test methods used in industry and research to determine the "stability" or "instability" of air-jet textured yarns are critically reviewed. These methods involve different basic principles and therefore inevitably give different results. There is no consensus on a standard method. Effects of various test parameters, such as specimen length, test duration, and the alternatives of using a single yarn, a hank, or a skein as a test specimen are investigated. An improved test method is suggested as a standard instability test, and various existing methods are compared with it. Results of all the methods show similar trends for varying values of air pressure. Other yarn characteristics such as linear density, breaking elongation, and tenacity are also determined, and their indications of yarn quality are compared with the indications of instability tests. Stability test results alone provide misleading information regarding air-jet textured yarn quality

    The Wicked Machinery of Government: Malta and the Problems of Continuity under the New Model Administration

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    This is a study focused on the early years of British rule in Malta (1800-1813). It explores the application to the island of the “new model” of colonial government, one based on direct rule from London mediated by the continuation of existing laws and institutions. Systemic deficiencies are identified. These tended to undermine the effectiveness of direct British rule. This study also reveals, in the context of legal and constitutional continuity, unresolved tensions between modernity and tradition. The political stability of the island was damaged and the possibility of continued British possession was threatened

    Efficacy of alemtuzumab over 6 years in relapsing–remitting multiple sclerosis patients who relapsed between courses 1 and 2: Post hoc analysis of the CARE-MS studies

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    Background: Alemtuzumab is administered as two annual courses for relapsing–remitting multiple sclerosis (MS). Patients may relapse before completing the two-course regimen. Objective: The objective was to evaluate 6-year outcomes in patients who relapsed between alemtuzumab Courses 1 and 2 (early relapsers). Methods: Post hoc analysis of patients from the Comparison of Alemtuzumab and Rebif¼ Efficacy in Multiple Sclerosis (CARE-MS) studies who enrolled in the extension. Results: Early relapsers (CARE-MS I: 15%; CARE-MS II: 24%) had more relapses in 1–2 years pre-alemtuzumab and higher mean baseline Expanded Disability Status Scale score than patients without relapse. Their annualized relapse rate declined from Year 1 (CARE-MS I: 1.3; CARE-MS II: 1.2) to Year 2 following Course 2 (0.3; 0.5) and remained low thereafter. Over 6 years, 60% remained free of 6-month confirmed disability worsening; 24% (CARE-MS I) and 34% (CARE-MS II) achieved 6-month confirmed disability improvement. During Year 6, 69% (CARE-MS I) and 68% (CARE-MS II) were free of magnetic resonance imaging (MRI) disease activity. Median percent yearly brain volume loss (Year 1: −0.67% (CARE-MS I); −0.47% (CARE-MS II)) declined after Course 2 (Year 6: −0.24%; −0.13%). Conclusion: Early relapsers’ outcomes improved after completing the second alemtuzumab course. These findings support administering the approved two-course regimen to maximize clinical benefit. ClinicalTrials.gov registration numbers: CARE-MS I, II, extension: NCT00530348, NCT00548405, NCT00930553

    Heavily electron-doped electronic structure and isotropic superconducting gap in AxFe2Se2 (A=K,Cs)

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    The low energy band structure and Fermi surface of the newly discovered superconductor, AxFe2Se2 (A=K,Cs), have been studied by angle-resolved photoemission spectroscopy. Compared with iron pnictide superconductors, AxFe2Se2 (A=K,Cs) is the most heavily electron-doped with Tc~30 K. Only electron pockets are observed with an almost isotropic superconducting gap of ~10.3 meV, while there is no hole Fermi surface near the zone center, which indicates the inter-pocket hopping or Fermi surface nesting is not a necessary ingredient for the unconventional superconductivity in iron-based superconductors. Thus, the sign changed s±_\pm pairing symmetry, a leading candidate proposed for iron-based superconductors, becomes conceptually irrelevant in describing the superconducting state here. A more conventional s-wave pairing is a better description.Comment: 4 pages, 4 figures, published online in Nature Materials 201
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