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Background: Deficits of executive function (EF) have been proposed as all or part of the underlying mechanisms of language impairment in at least some types of aphasia. Executive functions also play a role in the recovery process. There is evidence that bilingual persons have some executive functioning advantages compared to monolingual persons. In this paper we combine two lines of recent investigation in order to explore the relationship between executive function and conversational strategies in bilingual aphasia. Aims: The aim of this preliminary research was to compare the executive functioning profiles of bilingual individuals to those of monolingual participants with aphasia. A further aim was to examine evidence in the conversational samples of the participants in relation to the application of a range of executive skills and to link cognitive and conversational profiles using Barkley's (1997) model of executive functions. Methods & Procedures: The performance of two bilingual individuals with aphasia on a test battery of executive function tests was compared with that of eight monolingual persons (seven with aphasia and one with right hemisphere damage). The test battery included measures of behavioural inhibition, working memory, problem solving, and reconstitution. The presence or absence of executive features in the conversational samples of the participants was judged by four raters using conversational analysis methods. Outcomes & Results: Significant differences were found between the scores of the bilingual participants and those of the monolingual participants on measures of behavioural inhibition, working memory, planning and problem solving, and reconstitution. The bilingual participants' scores were mostly within normal limits and suggested well-retained executive functions. Conversation analysis showed evidence of differential application of these executive functions to conversational management. Regardless of severity or type of aphasia, the bilingual participants showed evidence of good topic management, repair, and flexibility compared to the monolingual participants. Conclusions: The results are interpreted in relation to current issues in bilingualism. Our preliminary findings shed light on differential approaches to assessment, therapy, and choice of language for bilingual aphasia. [ABSTRACT FROM AUTHOR]

We validated doubly-labelled water (DLW) by comparison to indirect calorimetry and food intake–mass balance in eight Labrador dogs (24–32 kg) over 4 d. We used several alternative equations for calculating CO2 production, based on the single- and two-pool models and used two alternative methods for evaluating the elimination constants: two-sample and multiple-sampling. In all cases the DLW technique overestimated the direct estimate of CO2 production. The greatest overestimates occurred with the single-pool model. Using two samples, rather than multiple samples, to derive the elimination constants produced slightly more discrepant results. Discrepancies greatly exceeded the measured analytical precision of the DLW estimates. The higher values with DLW probably occurred because the dogs were extremely active during the 1 h in each 24 spent outside the chamber. Estimates of CO2 production from food intake–mass balance, which include this activity, produced a much closer comparison to DLW (lowest mean discrepancy 0·3 % using the observed group mean dilution space ratio and an assumption that the mass changes reflected changes in hydration for all except one animal). We recommend an equilibration time of 6 h and use of the two-pool model based on the observed population dilution space for future studies of energy demands in dogs of this body mass. [ABSTRACT FROM PUBLISHER]

Recent studies suggest that hypercalcemia of sarcoidosis is due to high blood concentrations of calcitriol and that this compound may be synthesized at an extra-renal site. We report that sarcoid lymph node homogenate metabolized calcifediol to a substance indistinguishable from calcitriol, whereas six nonsarcoid lymph nodes failed to produce this compound. [ABSTRACT FROM AUTHOR]

The article cites the practicalities of measuring and interpreting field metabolic rate in dogs. Separation of energy expenditure of a dog for work from its daily energy expenditure when not working is considered necessary for the measurements of field metabolic rate using the doubly-labeled water technique to be correctly interpreted and used to determine energy requirements of working dogs. Total energy expenditure can be separated into components for maintenance, standing and other activities. Time- or energy-budget analysis is also said to be necessary to estimate average daily energy expenditure.