NMR relaxation behavior and quadrupole coupling constants of 39K and 23Na ions in glycerol. Comparisons with 39K tissue data

The quadrupole coupling constants (qcc) for39K and23Na ions in glycerol have been calculated from linewidths measured as a function of temperature (which in turn results in changes in solution viscosity). The qcc of39K in glycerol is found to be 1.7 MHz, and that of23Na is 1.6 MHz. The relaxation behavior of39K and23Na ions in glycerol shows magnetic field and temperature dependence consistent with the equations for transverse relaxation more commonly used to describe the reorientation of nuclei in a molecular framework with intramolecular field gradients. It is shown, however, that τc is not simply proportional to the ratio of viscosity/temperature (ηT). The 39K qcc in glycerol and the value of 1.3 MHz estimated for this nucleus in aqueous solution are much greater than values of 0.075 to 0.12 MHz calculated from T2 measurements of39K in freshly excised rat tissues. This indicates that, in biological samples, processes such as exchange of potassium between intracellular compartments or diffusion of ions through locally ordered regions play a significant role in determining the effective quadrupole coupling constant and correlation time governing39K relaxation. T1 and T2 measurements of rat muscle at two magnetic fields also indicate that a more complex correlation function may be required to describe the relaxation of39K in tissue. Similar results and conclusions are found for23Na.

Magnetic field effect on quantum corrections to the low-temperature conductivity in mettalic perovskite oxides

The transport and magnetotransport properties of the metallic and ferromagnetic SrRuO3 (SRO) and the metallic and paramagnetic LaNiO3 (LNO) epitaxial thin films have been investigated in fields up to 55 T at temperatures down to 1.8 K . At low temperatures both samples display a well-defined resistivity minimum. We argue that this behavior is due to the increasing relevance of quantum corrections to the conductivity (QCC) as temperature is lowered; this effect being particularly relevant in these oxides due to their short mean free path. However, it is not straightforward to discriminate between contributions of weak localization and renormalization of electron-electron interactions to the QCC through temperature dependence alone. We have taken advantage of the distinct effect of a magnetic field on both mechanisms to demonstrate that in ferromagnetic SRO the weak-localization contribution is suppressed by the large internal field leaving only renormalized electron-electron interactions, whereas in the nonmagnetic LNO thin films the weak-localization term is relevant.

Community College Student and Faculty Information Needs and Information Seeking: an Ethnographic Study

This presentation was offered as part of the CUNY Library Assessment Conference, Reinventing Libraries: Reinventing Assessment, held at the City University of New York in June 2014.

Líderes e motivadores profissionais: novos trabalhadores a serviço do capital (dimensões ideológicas, disciplinares e cooptativas)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Habilidades sociais e características pessoais em escolares de Belém

Este estudo relacionou a frequência da emissão de reação socialmente habilidosa, não-habilidosa passiva e não-habilidosa ativa às variáveis da criança (sexo, idade, condições clínicas). Participaram 57 meninos e 52 meninas, entre seis e 12 anos. O Questionário de Caracterização da Criança (QCC) levantou informações sobre sexo, idade e condições clínicas e o Inventário Multimídia de Habilidades Sociais de Crianças (IMHSC-Del Prette) avaliou as habilidades sociais, respondidos pelos cuidadores e escolares, respectivamente. Utilizou-se os testes U de Mann-Whitney, o coeficiente de correlação de Pearson e o teste t para análises dos dados. Os resultados indicaram: (a) diferenças significativas na adequação das reações habilidosas e não-habilidosas (p < 0,001); (b) aumento do repertório de habilidades sociais conforme o avançar dos anos (p < 0,001); e (c) meninas apresentaram mais frequência de habilidades sociais que meninos (p = 0,040). Não houve associações significativas entre habilidades sociais e condições clínicas (p = 0,539). Verificou-se que sexo e idade podem interferir na presença e desempenho de repertório socialmente habilidoso. Sugerem-se outras técnicas de avaliação que complementem os dados investigados e possibilitem intervenções futuras para amostras semelhantes.

A Comparison of Methodologies from Two Longitudinal Community-Based Randomized Controlled Trials of Similar Interventions in Palliative Care: What Worked and What Did Not

Background: Methodological challenges such as recruitment problems and participant burden make clinical trials in palliative care difficult. In 2001-2004, two community-based randomized controlled trials (RCTs) of case conferences in palliative care settings were independently conducted in Australia-the Queensland Case Conferences trial (QCC) and the Palliative Care Trial (PCT). Design: A structured comparative study of the QCC and PCT was conducted, organized by known practical and organizational barriers to clinical trials in palliative care. Results: Differences in funding dictated study designs and recruitment success; PCT had 6 times the budget of QCC. Sample size attainment. Only PCT achieved the sample size goal. QCC focused on reducing attrition through gatekeeping while PCT maximized participation through detailed recruitment strategies and planned for significant attrition. Testing sustainable interventions. QCC achieved a higher percentage of planned case conferences; the QCC strategy required minimal extra work for clinicians while PCT superimposed conferences on normal work schedules. Minimizing participant burden. Differing strategies of data collection were implemented to reduce participant burden. QCC had short survey instruments. PCT incorporated all data collection into normal clinical nursing encounters. Other. Both studies had acceptable withdrawal rates. Intention-to-treat analyses are planned. Both studies included substudies to validate new outcome measures. Conclusions: Health service interventions in palliative care can be studied using RCTs. Detailed comparative information of strategies, successes and challenges can inform the design of future trials. Key lessons include adequate funding, recruitment focus, sustainable interventions, and mechanisms to minimize participant burden.

Quality Control Circles May Answer Industry's Needs

The concept of the quality control circle (QCC) has worked well in Japanese industry in increasing efficiency, production, and profits. The author explores the QCC, its history and advantages, and tells how it could be adapted quite easily and effectively to the hospitality industry