Multiplication factors in ethylene-filled proportional counters.

Gas multiplication factors were measured in a proportional counter filled with high-purity ethylene in the pressure range 10-40 Torr. The multiplication factors were measured as a function of the reduced electric field S(a). The results show that, within the range of the high values of reduced electric field applied in this work (2648 < or = S(a) < or = 6455 V cm(-1) Torr(-1)), the reduced first Townsend coefficient alpha/P for ethylene may still be considered a function of S(a) alone. Good agreement was found with a model proposed by Akande.

Effects of body temperature on chemosensory activity of the cat carotid body in situ.

The effects of changes in body core temperature (TB) upon the frequency of chemosensory discharges (fx) from one carotid nerve were studied in pentobarbitone anesthetized cats. Raising TB from 35 to 40 degrees C increased fx in some cats, an effect more commonly seen after contralateral carotid neurotomy. In other animals, the simultaneously increased alveolar ventilation counteracted the above effect. A multiple correlation analysis of global data showed predicted increases in fx in response to raising TB at different CO2 levels.

A functional assay for paralytic shellfish toxins that uses recombinant sodium channels.

Saxitoxin (STX) and its derivatives are highly toxic natural compounds produced by dinoflagellates commonly present in marine phytoplankton. During algal blooms ("red tides"), shellfish accumulate saxitoxins leading to paralytic shellfish poisoning (PSP) in human consumers. PSP is a consequence of the high-affinity block of voltage-dependent Na channels in neuronal and muscle cells. PSP poses a significant public health threat and an enormous economic challenge to the shellfish industry worldwide. The standard screening method for marine toxins is the mouse mortality bioassay that is ethically problematic, costly and time-consuming. We report here an alternative, functional assay based on electrical recordings in cultured cells stably expressing a PSP target molecule, the STX-sensitive skeletal muscle Na channel. STX-equivalent concentration in the extracts was calibrated by comparison with purified STX, yielding a highly significant correlation (R=0.95; N=30) between electrophysiological determinations and the values obtained by conventional methods. This simple, economical, and reproducible assay obviates the need to sacrifice millions of animals in mandatory paralytic shellfish toxin screening programs.

La confiabilidad en el líder: un estudio sobre las enfermeras jefes de un hospital / The trustworthiness in the leader: a study on head nurses of a hospital

La confiabilidad en el líder es un concepto multidimensional que hace complejo establecer cuáles son sus antecedentes. Por ello, se buscó obtener consenso entre enfermeras y técnicos paramédicos sobre cuáles son las categorías de conductas que manifiestan los líderes y que favorecen la percepción de que son confiables. Además, se relacionó las categorías de conducta obtenidas con los principales antecedentes de la confiabilidad en los líderes. Se utilizó la técnica delphi y participaron en total 67 funcionarios de diversos servicios de un hospital y fueron distribuidos en 4 grupos. Se obtuvo que la categoría de conducta más importante son la objetividad e imparcialidad en la toma de decisiones de los líderes, lo cual reafirma la importancia de la integridad como antecedente de la confiabilidad de éstos. Finalmente, se discute sobre cómo fortalecer la confiabilidad de los líderes.

The trustworthiness in the leader is a multidimensional concept that makes it complex to determine which are its background. As a result, a consensus among nurses and technical paramedics was considered on the categories of behaviour which the leader manifests and which facilitate the perception that they are trustworthiness. Subsequently, behaviour categories were related with the main records of the trustworthiness in the leaders. The Delphi technique was used and a total of 67 workers of diverse services of a hospital were the participants and they were distributed in 4 groups. It was found that the most important categories of behaviour is the leaders' impartiality and objectivity in decision making process, which reaffirms the importance of integrity and history of reliability of these. Finally, the ways to strengthen the trustworthiness in the leaders are discussed.