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PubMed2006

A pilot study of the activity patterns of five elderly persons after a housing adaptation.

The importance of an accessible home environment for occupational performance has been emphasized in occupational therapy, but knowledge about how accessibility can affect a person's activity patterns is limited. The purpose of this study was to describe the activity patterns of five elderly persons aged between 70 and 84 years and their views about accessibility and usability of their homes before and after a housing adaptation. Two different questionnaires, 'Accessibility in My Home' and the 'Occupational Questionnaire' were used for data collection. Adaptations in the home included: removing thresholds, installing new taps in the bathroom and kitchen and broadening doorways. After the adaptations the five participants reported that they increased their outside activities, reduced naps during the day and slept better at night. The results showed that the participants performed more and new activities when their home environment had become accessible. Activities performed were also perceived as more important after the housing adaptation. There is a need to replicate the study with a larger sample. Further research is needed on the impact of home adaptations on the activity patterns of elderly people.

Acclimatization↗
PubMed1996

Reproducibility of technetium-99m mercaptoacetyltriglycine clearance.

The aim of this paper was to determine the reproducibility (precision) of technetium-99m mercaptoacetyltriglycine (MAG3) clearance and to compare it with that of chromium-51 ethylenediamine tetra-acetic acid (EDTA). Twelve young volunteers (aged between 21 and 34 years), without any history of medical problems, were enrolled in this study. The test was performed twice, at an interval of 8 days and under similar physiological conditions. After the intravenous injection of both tracers, 15 blood samples were taken between 3 and 240 min. A biexponential fit was adapted to the plasma disappearance curves (5- to 120-min samples for 99mTc-MAG3 and 10- to 240-min samples for 51Cr-EDTA); the clearances were calculated according to Sapirstein and corrected for body surface area. The mean clearance values were 110 (range 85-130) and 226 (range 109-319)ml/min/1.73 m2, respectively, for 51Cr-EDTA and 99mTc-MAG3. For 51Cr-EDTA clearance, the mean difference between the first and the second measurement was -2.1% of the mean of the two successive values (SD: 8.4%). In ten cases, the difference was less than 12%; in two cases, the differences were 15% and 18%, respectively. For 99mTc-MAG3 clearance, the mean difference between the first and the second measurement was -20% of the mean of the two successive values (SD: 25%). In six cases, the difference was less than 12%; in four cases, between 15% and 40%; and in two cases, more than 60%. Methodological factors (impurities contained in the commercial kit, variable protein binding) as well as physiological factors (pH of urine, sodium load, stress) may explain the lack of precision of the 99mTc-MAG3 clearance. It is concluded that changes in 99mTc-MAG3 plasma clearance should be interpreted with care in daily routine.

Adult↗
PubMed1994

Sources of stress and psychological well-being in high-dependency nursing.

The present study examined occupational stress in four areas of high-dependency nursing: theatres, liver/renal, haematology/oncology and elective surgery. A total of 60 nurses from one large NHS hospital completed questionnaires on sources and levels of stress, psychological well-being and ways of coping; interviews with a small sub-sample were carried out. The results indicated that the amount of stress experienced was similar across all four departments, but its sources varied. Theatre nurses experienced less stress through patients' death and dying. Other factors which influenced both the level and sources of stress included post-qualification training, number of children and partnership-status. Nurses with post-qualification training perceived higher levels of stress. Social support was found to influence psychological well-being. Nurses who were living with a partner or were married experienced fewer stress symptoms than those with no partner, and nurses with two children experienced significantly less stress through dealing with patients and relatives. Reactions to stress elicited a range of adaptive and maladaptive coping styles. Nurses sampled indicated universal support for the introduction of 'nurse-for-a-day' and management 'swap-overs' as practised in Boston, USA. This study recommends sending nurses on management and administration courses and stress-management programmes.

Activities of Daily Living↗
PubMed1985

Dining arrangements and behavior of severely mentally retarded adults.

The behavior of 12 severely and profoundly mentally retarded men and women living in a 64-bed community residence was studied during large group (congregate) and small group dining arrangements. Four adaptive and four maladaptive mealtime behaviors were recorded using a coded partial interval time sampling procedure, employing a with-subject reversal design. Adaptive dining behaviors increased (15.9% to 93.6%) and maladaptive behaviors associated with meals decreased (28.8% to 8.5%) during small group dining periods. The relation of client behavior to variables in addition to group size is discussed.

Activities of Daily Living↗
PubMed1987

Adapting to the unemployed role: a longitudinal investigation.

A sample of unemployed British men was interviewed for a third time after an average of 25 months continuous unemployment. As predicted, it was found that mental health, indexed in terms of affective well-being, had improved slightly since the previous interview. Adaptation of this kind was greater for men who had previously reported lower commitment to having a job and greater contact outside their immediate family, and also for those at the extremes of the age range. Measured availability of money and quality of social relationships were not related to adaptation. Changes in aspiration, autonomy and competence were considered likely to underpin the improvement in well-being. The need to study these additional components of mental health was emphasized, in order to determine when improvements in reported well-being should be considered 'healthy' or 'unhealthy'.

Adaptation, Psychological↗
PubMed1985

Physiological characterization of adaptive clones in evolving populations of the yeast, Saccharomyces cerevisiae.

Populations of a diploid strain of S. cerevisiae were grown in glucose-limited continuous culture for more than 260 generations. A series of seven sequential adaptive changes were identified by monitoring the frequency of cycloheximide resistance in these populations. Samples were taken from the continuous cultures following each adaptive shift and characterized physiologically to determine (1) the range of phenotypes that can be selected in a precisely defined constant environment and (2) the order and predictability of the occurrence of the adaptive mutations in evolving populations. The clones were characterized with respect to the growth parameters, maximum growth rate, saturation coefficient and yield, as well as for changes in cell size and geometry and rate of glucose uptake. The maximum growth rates of the seven adaptive clones were very similar, but in contrast the saturation coefficients differed substantially. Surprisingly, not all clones showed reductions in the saturation coefficients, in comparison to the immediately preceding clones, as would be predicted from classical continuous culture kinetics. In addition, yield estimates first increased and then decreased for later isolated adaptive clones. In general, the results suggest epistatic interactions between the adaptive clones, consistent with earlier published results. The rate of glucose uptake, as measured by 14C-xylose uptake, increased dramatically after the selection and fixation of seven adaptive clones. Progressive decreases in cell volume and changes in cell geometry, resulting in increased surface area to volume ratios, were also observed in the adaptive clones, but these changes were not always seen in other haploid and diploid yeast populations evolving under the same conditions. Such changes may be easily explainable in terms of the characteristics of the glucose-limited environment. The significance of the results to the evolution of microorganisms under nutrient-limiting conditions is discussed.

Biological Transport↗
PubMed1993

Experience of a laboratory service for drug screening in urine.

The use of a drug screening service has been investigated over a nine month period during which 1500 urine samples from 765 patients were analysed. Preliminary drug screening of urine samples was performed by EMIT immunoassays adapted for use on the Cobas Bio analyser; further identification and confirmation were carried out by Toxi-Lab thin-layer chromatography and capillary gas chromatography. A large number of positive results were obtained for benzodiazepines, cannabinoids, methadone and opiates (mainly dihydrocodeine). Only a limited number of urines gave positive results for amphetamine and related stimulants; cocaine metabolite was rarely detected in samples. The service proved to be of considerable value in the management of drug misusers, and for the identification of new substances taken by the local population.

Enzyme Multiplied Immunoassay Technique↗
PubMed2003

Analysis of low-molecular-mass organic acids using capillary zone electrophoresis-electrospray ionization mass spectrometry.

A capillary zone electrophoresis-electrospray ionization-mass spectrometry (CZE-ESI-MS) method was developed to facilitate identification and determination of eleven low-molecular-mass (LMW) organic acids (i.e. oxalic, lactic, malonic, maleic, citric, tartaric, adipic, glutaric, gluconic, isosaccharinic and succinic acid) in different sample matrices. This CZE method was adapted to suit MS conditions. Sheath liquid, sheath flow and MS parameters were optimized to achieve high mass spectrometric sensitivity. The CZE-ESI-MS procedure showed good sensitivity (limit of detection of < 0.05-0.7 mg/l for all acids), linearity (r2 = 0.9925-0.9998) and reproducibility (2.09-5.34% RSD). The applicability of the CZE-ESI-MS was demonstrated on LMW organic acids in an ale sample. In addition the (here presented) method also provided quantification of fumaric, galacturonic and 2-ketoglutaric acid with high sensitivity.

Acids↗
PubMed1998

Microscale titrimetric and spectrophotometric methods for determination of ionization constants and partition coefficients of new drug candidates.

This study describes the adaptation of conventional titrimetric and spectrophotometric techniques to a microscale for the determination of drug ionization constants (pKa) and partition coefficients (log P). The apparatus for determining pKa and compound purity (or equivalent weight) consists of a three-port conical glass microvial maintained at 25 degrees C, a pH microelectrode, and a microinjection pump equipped with a 10 microL gastight syringe for titrant delivery. Sample mixing and protection from atmospheric CO2, which is particularly important at the microscale, is accomplished using a fine stream of water-saturated N2 bubbles. Simple titrimetric procedures combined with ionic equilibria models which allow the accurate determination of pKa and purity (or equivalent weight) using sample sizes in the microgram range and solution volumes of 10-100 microL were developed and validated using acetic acid and tromethamine. Simultaneous determinations of pKa, purity or equivalent weight, and octanol/water partition coefficient were shown to be possible from a single sample of a test solute by adapting the pH-metric technique to a microscale. Using benzoic acid as a model compound, a pKa of 4.24 and octanol/water partition coefficient of 64 were obtained, in close agreement with the literature values. The principles employed in titrimetric analysis were also applied to demonstrate the spectrophotometric determination of benzoic acid's pKa and partition coefficient using only 6 micrograms of compound. The microscale titration method was then used to determine the two pKa values of an "unknown" diprotic acid containing a carboxyl and an aromatic SH group. The phenyl thiol pKa was confirmed using the microscale spectrophotometric procedure.

1-Octanol↗
PubMedDate not supplied

A spectral analysis of function composition and its implications for sampling in direct volume visualization.

In this paper we investigate the effects of function composition in the form g(f(x)) = h(x) by means of a spectral analysis of h. We decompose the spectral description of h(x) into a scalar product of the spectral description of g(x) and a term that solely depends on f(x) and that is independent of g(x). We then use the method of stationary phase to derive the essential maximum frequency of g(f(x)) bounding the main portion of the energy of its spectrum. This limit is the product of the maximum frequency of g(x) and the maximum derivative of f(x). This leads to a proper sampling of the composition h of the two functions g and f. We apply our theoretical results to a fundamental open problem in volume rendering-the proper sampling of the rendering integral after the application of a transfer function. In particular, we demonstrate how the sampling criterion can be incorporated in adaptive ray integration, visualization with multi-dimensional transfer functions, and pre-integrated volume rendering.

Algorithms↗
PubMed2004

Predicting ethnic variation in adaptation to later life: styles of socioemotional functioning and constrained heterotypy.

It is an axiom of social gerontology that populations of older individuals become increasingly differentiated as they age. Adaptations to physical and social losses and the increased dependency that typically accompany greater age are likely to be similarly heterogeneous, with different individuals adjusting to the aging process in widely diverse ways. In this paper we consider how individuals with diverse emotional and regulatory profiles, different levels of religiosity, and varied patterns of social relatedness fare as they age. Specifically, we examine the relation between ethnicity and patterns of socioemotional adaptation in a large, ethnically diverse sample (N = 1118) of community-dwelling older adults. Cluster analysis was applied to 11 measures of socioemotional functioning. Ten qualitatively different profiles were extracted and then related to a measure of physical resiliency. Consistent with ethnographic and psychological theory, individuals from different ethnic backgrounds were unevenly distributed across the clusters. Resilient participants of African descent (African Americans, Jamaicans, Trinidadians, Barbadians) were more likely to manifest patterns of adaptation characterized by religious beliefs, while resilient US-born Whites and Immigrant Whites were more likely to be resilient as a result of non-religious social connectedness. Taken together, although these data underscore the diversity of adaptation to later life, we suggest that patterns of successful adaptation vary systematically across ethnic groups. Implications for the continued study of ethnicity in aging and directions for future research are given.

Adaptation, Psychological↗
PubMed1983

Psychological stress activates phosphorylase in the heart of the conscious pig without increasing heart rate and blood pressure.

The present study uses a technique that enables the collection of multiple freeze-biopsy samples from the myocardium of the conscious pig (i.e., through a thoracic window). This technique enables sequential analysis of the metabolic state of the myocardium during different behavioral conditions. The results demonstrate that with daily adaptations to an unfamiliar environment (i.e., stress reduction), the phosphorylase activation ratio (phosphorylase a/total phosphorylase) in the quiescent pig declines steadily from approximately 80% to 30% (r = -0.91, P less than 0.01). This decline occurs with both the mean resting heart rate and left ventricular blood pressure remaining constant. The decline is seen within individual subjects during the whole adaptation sequence as well as between subjects whose samples were taken either early or late in the adaptation series. The dissociation of hemodynamic functional and metabolic activation in the unadapted, psychologically stressed pig may be associated with the occurrence of increased vulnerability of the ischemic heart to ventricular fibrillation, a phenomenon previously observed under the same behavioral conditions.

Animals↗
PubMed2005

Fluorescence, browning index, and color in infant formulas during storage.

Free and total fluorescent compounds, browning index, and color formation were measured in milk-based powdered infant formulas (IF) during 2 years of storage at 20 and 37 degrees C. The excitation spectra from 415 nm emission show three peaks (ex lambda1 = 270 nm, lambda2 = 325/315 nm, lambda3 = 350 nm) and from 347 nm excitation two emission peaks (415 and 520 nm), and no wavelength shifts were observed. Temperature and time of storage exert in general no significant effect on the development of fluorescence emission intensity and browning index. However, an important increase in pentodilysine was recorded-probably because of the iron and ascorbic acid contents of the samples-as well as in browning index in adapted IF. In both IF a color increase (deltaE) throughout storage was observed, this increase being greater in samples stored at 37 degrees C than in those stored at 20 degrees C. The increase in color with time fitted a linear regression model. Color appeared to be an indicator of sufficient sensitivity to measure the effect of temperature or storage time.

Color↗
PubMed2001

Stochastic modelling as a tool for planning animal-health surveys and interpreting screening-test results.

Traditionally, the planning of surveys (in particular, sample-size calculations) has relied on assumptions including the assumption of perfect screening tests. This paper presents a novel approach that can be used for planning animal-health surveys and interpreting screening-test results in the context of these surveys. A stochastic simulation model developed to assess the properties of herd-level sampling schemes and surveys has been adapted for large surveys aimed at substantiating freedom from infection at a national or regional level. We use a Bayesian approach to derive the post-survey probability of freedom from infection from the pre-survey probability of freedom and the likelihood ratio that is associated with screening-test results. We applied the model to two consecutive surveys conducted in 1998 and 1999 in Switzerland to substantiate freedom from infectious bovine rhinotracheitis (IBR) in the cattle population of about 56000 herds (median herd size of 15 cattle > 2 yr of age in 1999). In 1998, serum samples were taken from five cattle > 2 yr in 4672 herds, and in 1999 from all cattle > 2 yr old in 648 herds; samples were analysed by ELISA. The survey of 1999 provided less evidence than that of 1998 to support a status of freedom from infection; also, the characteristics of both herd-level sampling schemes were similar. We argue that the rationale for survey planning depends on the pre-survey probability of freedom from infection (i.e. our level of confidence that the infection does not occur in the targeted animal population). In consequence, surveys should be tailored to individual populations in the respective countries or regions. The model has been developed in an Excel spreadsheet to allow flexibility of use, and adaptation to many other animal-health issues.

Animals↗
PubMed2004

Presence of HIV-1 neutralizing IgA antibodies in primary HIV-1 infected patients.

The initial control of viral replication during primary HIV-1 infection is dominated by CD8+ T-cell mediated responses. Neutralizing IgG to autologous virus is first detected in serum weeks after this response when the viraemia has already declined. However, the mucosal and systemic HIV-1 neutralizing IgA response during primary HIV-1 infection in patients treated with HAART has not been studied previously. The presence of HIV-1 neutralizing IgA antibodies in serum (n=10 patients) and semen (n=6 patients) samples was tested against a laboratory adapted HIV-1 isolate and against primary HIV-1 isolates, representing different clades and phenotypes. The patients received HAART during the study period and were followed from primary HIV-1 infection and up to 72 weeks. Overall, HIV-1 neutralizing IgA activity could be demonstrated in serum from 5 of 10 primary HIV-1 infected patients at inclusion, although the response was restricted to only 1 of the 4 tested isolates. In semen samples, HIV-1 neutralizing IgA activity was seen in 2 of 5 patients against at least 1 of the HIV-1 isolates. In conclusion, a restricted but early neutralizing IgA response can be detected in serum and semen in primary infected patients treated with HAART.

Antibodies, Anti-Idiotypic↗
PubMed2006

Adaptation to different human populations by HIV-1 revealed by codon-based analyses.

Several codon-based methods are available for detecting adaptive evolution in protein-coding sequences, but to date none specifically identify sites that are selected differentially in two populations, although such comparisons between populations have been historically useful in identifying the action of natural selection. We have developed two fixed effects maximum likelihood methods: one for identifying codon positions showing selection patterns that persist in a population and another for detecting whether selection is operating differentially on individual codons of a gene sampled from two different populations. Applying these methods to two HIV populations infecting genetically distinct human hosts, we have found that few of the positively selected amino acid sites persist in the population; the other changes are detected only at the tips of the phylogenetic tree and appear deleterious in the long term. Additionally, we have identified seven amino acid sites in protease and reverse transcriptase that are selected differentially in the two samples, demonstrating specific population-level adaptation of HIV to human populations.

Adaptation, Physiological↗
PubMed2005

Cross-cultural adaptation and validation of multiple sclerosis quality of life questionnaire (MSQOL-54) in a Turkish multiple sclerosis sample.

OBJECTIVE: Multiple sclerosis (MS) is a chronic progressive disease with multiple neurological impairments. The disease can also dramatically affect the health-related quality of life of patients. The objective of this study was to investigate the validation of the translated and cross-culturally adapted MSQOL-54 in 183 Turkish MS patients. METHODS: 183 adults classified as having definite MS patients were enrolled into the study. Patients were classified into four severity groups according to the expanded disability status scale (EDSS); group I (EDSS 0-4), group II (EDSS 4.5-5.5), group III (EDSS 6-6.5) and group IV (EDSS 7-8). MSQOL-54 questionnaire were translated and culturally adapted into Turkish. Associations between age, gender, disease duration, EDSS score, marital status, education and health insurance and the MSQOL-54 physical and mental health composite scores were determined. RESULTS: The mean age of the 183 patients (138 female and 45 male) was 39+/-10 years. The questionnaire was well accepted but small cultural adaptations were required. EDSS scores showed significant associations with the MSQOL-54 physical and mental health composite scores. From the different EDSS groups only, the group I (EDSS 0-4) score was significantly associated with the physical health composite as well as the disease duration showed significant correlation with the physical and mental composite scores. None of the other EDSS groups and the other parameters showed correlation with physical health composite or mental health composite. CONCLUSION: Assessment of quality of life of MS patients in addition to disease severity and disability level is important, because it provides unique information that is important to patients and to clinicians. A translation of an existing MS-targeted HRQOL measure from US English into Turkish was easily administered and well accepted in a Turkish MS sample.

Adolescent↗
PubMed2005

Calculation of rotational partition functions by an efficient Monte Carlo importance sampling technique.

The evaluation of the classical rotational partition function represented by a configuration integral over all external and internal rotational degrees of freedom of nonrigid chain polyatomic molecules is described. The method of Pitzer and Gwinn is used to correct the classical partition function for quantum mechanical effects at low temperatures. The internal rotor hindrance and all coupling arising from the external and internal rotational degrees of freedom are explicitly taken into account. Importance sampling Monte Carlo based on the adaptive VEGAS algorithm to perform multidimensional integration is implemented within the TINKER program package. A multidimensional potential energy hypersurface is calculated with the MM3(2000) molecular mechanics force field. Numerical tests are performed on a number of small n-alkanes (from ethane to octane), for which the absolute entropies calculated at three different temperatures are compared both with the experimental values and with the previous theoretical results. The application of a more efficient importance sampling technique developed here results in a substantial reduction of statistical errors in the evaluation of the configuration integral for a given number of Monte Carlo steps. Error estimates for the calculated entropies are given, and possible sources of systematic errors, and their importance for a reliable prediction of the absolute entropy, are discussed.

Algorithms↗