1,061 research outputs found
Comparison of techniques for computing shell-model effective operators
Different techniques for calculating effective operators within the framework
of the shell model using the same effective interaction and the same excitation
spaces are presented. Starting with the large-basis no-core approach, we
compare the time-honored perturbation-expansion approach and a model-space
truncation approach. Results for the electric quadrupole and magnetic dipole
operators are presented for Li. The convergence trends and dependence of
the effective operators on differing excitation spaces and Pauli Q-operators is
studied. In addition, the dependence of the electric-quadrupole effective
charge on the harmonic-oscillator frequency and the mass number, for A=5,6, is
investigated in the model-space truncation approach.Comment: 18 pages. REVTEX. 4 PostScript figure
The TOBY Study. Whole body hypothermia for the treatment of perinatal asphyxial encephalopathy: A randomised controlled trial
<p>Abstract</p> <p>Background</p> <p>A hypoxic-ischaemic insult occurring around the time of birth may result in an encephalopathic state characterised by the need for resuscitation at birth, neurological depression, seizures and electroencephalographic abnormalities. There is an increasing risk of death or neurodevelopmental abnormalities with more severe encephalopathy. Current management consists of maintaining physiological parameters within the normal range and treating seizures with anticonvulsants.</p> <p>Studies in adult and newborn animals have shown that a reduction of body temperature of 3–4°C after cerebral insults is associated with improved histological and behavioural outcome. Pilot studies in infants with encephalopathy of head cooling combined with mild whole body hypothermia and of moderate whole body cooling to 33.5°C have been reported. No complications were noted but the group sizes were too small to evaluate benefit.</p> <p>Methods/Design</p> <p>TOBY is a multi-centre, prospective, randomised study of term infants after perinatal asphyxia comparing those allocated to "intensive care plus total body cooling for 72 hours" with those allocated to "intensive care without cooling".</p> <p>Full-term infants will be randomised within 6 hours of birth to either a control group with the rectal temperature kept at 37 +/- 0.2°C or to whole body cooling, with rectal temperature kept at 33–34°C for 72 hours. Term infants showing signs of moderate or severe encephalopathy +/- seizures have their eligibility confirmed by cerebral function monitoring. Outcomes will be assessed at 18 months of age using neurological and neurodevelopmental testing methods.</p> <p>Sample size</p> <p>At least 236 infants would be needed to demonstrate a 30% reduction in the relative risk of mortality or serious disability at 18 months.</p> <p>Recruitment was ahead of target by seven months and approvals were obtained allowing recruitment to continue to the end of the planned recruitment phase. 325 infants were recruited.</p> <p>Primary outcome</p> <p>Combined rate of mortality and severe neurodevelopmental impairment in survivors at 18 months of age. Neurodevelopmental impairment will be defined as any of:</p> <p>• Bayley mental developmental scale score less than 70</p> <p>• Gross Motor Function Classification System Levels III – V</p> <p>• Bilateral cortical visual impairments</p> <p>Trial Registration</p> <p>Current Controlled Trials ISRCTN89547571</p
Therapeutic hypothermia translates from ancient history in to practice
Acute postasphyxial encephalopathy around the time of birth remains a major cause of death and disability. The possibility that hypothermia may be able to prevent or lessen asphyxial brain injury is a “dream revisited”. In this review, a historical perspective is provided from the first reported use of therapeutic hypothermia for brain injuries in antiquity, to the present day. The first uncontrolled trials of cooling for resuscitation were reported more than 50 y ago. The seminal insight that led to the modern revival of studies of neuroprotection was that after profound asphyxia, many brain cells show initial recovery from the insult during a short “latent” phase, typically lasting ~6 h, only to die hours to days later during a “secondary” deterioration phase characterized by seizures, cytotoxic edema, and progressive failure of cerebral oxidative metabolism. Studies designed around this conceptual framework showed that mild hypothermia initiated as early as possible before the onset of secondary deterioration, and continued for a sufficient duration to allow the secondary deterioration to resolve, is associated with potent, long-lasting neuroprotection. There is now compelling evidence from randomized controlled trials that mild induced hypothermia significantly improves intact survival and neurodevelopmental outcomes to midchildhood
Structure and flexibility of the endosomal Vps34 complex reveals the basis of its function on membranes
Phosphatidylinositol 3-kinase Vps34 complexes regulate intracellular membrane trafficking in endocytic sorting, cytokinesis and autophagy. We present the 4.4 Ă… crystal structure of the 385 kDa endosomal complex II (PIK3C3-CII), consisting of Vps34, Vps15 (p150), Vps30/Atg6 (Beclin 1) and Vps38 (UVRAG). The subunits form a Y-shaped complex, centered on the Vps34 C2 domain. Vps34 and Vps15 intertwine in one arm where the Vps15 kinase domain engages the Vps34 activation loop to regulate its activity. Vps30 and Vps38 form the other arm that brackets the Vps15/Vps34 heterodimer, suggesting a path for complex assembly. Hydrogen-Deuterium Exchange Mass Spectrometry (HDX-MS) revealed conformational changes accompanying membrane binding and identified a Vps30 loop that is critical for the ability of complex II to phosphorylate giant liposomes on which complex I is inactive
Stress ocupacional no ensino : um estudo com professores dos 3º ciclo e ensino secundário
Este trabalho foi realizado com 689 professores portugueses, a leccionarem nos terceiro ciclo e ensino secundário. Foram avaliados indicadores de stress, “burnout”, saĂşde fĂsica e satisfação profissional. Observaram-se valores significativos de stress ocupacional (perto de 40%), e de “burnout” (10% na exaustĂŁo emocional, 3% na baixa realização pessoal e 1% na despersonalização), vários problemas de saĂşde fĂsica e valores de insatisfação profissional perto dos 20%. As análises de regressĂŁo mĂşltipla apontaram diferentes variáveis preditoras para as trĂŞs dimensões do “burnout” (62% de variância explicada na exaustĂŁo emocional, 16% na realização pessoal e 13% na despersonalização). As análises discriminantes e “t-test” para amostras independentes demonstraram maior stress ocupacional nas mulheres, nos professores mais velhos, nos profissionais com vĂnculos profissionais mais precários, nos professores com mais horas de trabalho e com mais alunos em sala de aula. No final, apresentam-se as limitações do estudo e as implicações para a investigação futura.(undefined
Occupational stress in health professionals: a study with Portuguese Nurses
Este trabalho analisa o estresse ocupacional em 286 enfermeiros de hospitais e centros de saĂşde portugueses. Avaliaram-se as fontes de estresse, o burnout, os problemas de saĂşde fĂsica, a satisfação e a realização profissional. Os resultados apontaram 30% de enfermeiros com experiĂŞncias significativas de estresse e 15% com problemas de exaustĂŁo emocional. As análises de regressĂŁo mĂşltipla apontaram maior capacidade preditiva das dimensões de estresse na exaustĂŁo emocional, na saĂşde fĂsica, na satisfação e na realização profissional. As análises comparativas evidenciaram maiores problemas de stresse e reacções mais negativas ao trabalho nas mulheres, nos enfermeiros mais novos e com menor experiĂŞncia, nos trabalhadores com contratos a prazo, nos profissionais que realizam trabalho por turnos e nos que trabalham mais horas.This work analyses occupational stress in 286 nurses from hospitals and health care centres in Portugal. The
following dimensions were evaluated: stress, burnout, physical health problems, satisfaction and professional fulfilment.
Results revealed significant stress experiences in 30% of the professionals, and emotional exhaustion problems in 15%.
Multiple regression analysis pointed out stress as an important predictor of emotional exhaustion, physical health, satisfaction
and professional fulfilment. Comparative analysis suggested more occupational stress and professional negative experiences
in the following groups: female nurses, younger and less experienced nurses, those with short-term working contracts, nurses
working on a shift-basis system, and nurses working during long hours.(undefined
A megbocsátás pszichológiája: kialakulása, hatásai és fejlesztése
A megbocsátás az interperszonális sĂ©relmekre adott egyik lehetsĂ©ges válasznak tekinthetĹ‘, melynek fĂłkuszában a sĂ©relmet elszenvedĹ‘ szemĂ©ly kognitĂv, Ă©rzelmi Ă©s viselkedĂ©ses válaszaiban bekövetkezĹ‘ proszociális változás áll. A megbocsátás mentális Ă©s fizikai egĂ©szsĂ©gre kifejtett pozitĂv hatása jĂłl dokumentált. Magas szintje alacsony szorongás- Ă©s depressziĂłszinttel társul, illetve sikeresen csökkenti a stresszre adott fizikai választ (kortizol Ă©s kardiovaszkuláris reaktivitás). A megbocsátást - hatásai alapján - olyan emĂłciĂł fĂłkuszĂş megkĂĽzdĂ©si mĂłdkĂ©nt definiálhatjuk, mely sikeresen csökkenti az interperszonális sĂ©relem nyomán kialakult stresszreakciĂłt. Az utĂłbbi Ă©vekben számos intervenciĂłs technikát dolgoztak ki, melyek a megbocsátás támogatását, illetve fejlesztĂ©sĂ©t tűztĂ©k ki cĂ©lkĂ©nt. Ezek a mĂłdszerek általában sikeresen növelik a megbocsátásra valĂł hajlandĂłságot.</o:p
How does one become spiritual? The Spiritual Modeling Inventory of Life Environments (SMILE)
We report psychometric properties, correlates and underlying theory of the Spiritual Modeling Index of Life Environments (SMILE), a measure of perceptions of spiritual models, defined as everyday and prominent people who have functioned for respondents as exemplars of spiritual qualities, such as compassion, self-control, or faith. Demographic, spiritual, and personality correlates were examined in an ethnically diverse sample of college students from California, Connecticut, and Tennessee (N=1010). A summary measure of model influence was constructed from perceived models within family, school, religious organization, and among prominent individuals from both tradition and media. The SMILE, based on concepts from Bandura\u27s (1986) Social Cognitive Theory, was well-received by respondents. The summary measure demonstrated good 7-week test/retest reliability (r=.83); patterns of correlation supporting convergent, divergent, and criterion-related validity; demographic differences in expected directions; and substantial individual heterogeneity. Implications are discussed for further research and for pastoral, educational, and health-focused interventions
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