Fate of thiamethoxam from treated seeds in mesocosms and response of aquatic invertebrate communities.

Thiamethoxam is a neonicotinoid insecticide widely applied in the Canadian Prairies. It has been detected in surface waters of agro-ecosystems, including wetlands, but the potential effects on non-target invertebrate communities in these wetlands have not been well characterized. In an effort to understand better the fate of thiamethoxam in wetlands and the response of invertebrates (zooplankton and emergent insects), model systems were used to mimic wetland flooding into planted fields. Outdoor mesocosms were treated with a single application of thiamethoxam-treated canola seeds at three treatment levels based on a recommended seeding rate (i.e., 6 kg/ha; 1×, 10×, and 100× seeding rate) and monitored over ten weeks. The mean half-life of thiamethoxam in the water column was 6.2 d. There was no ecologically meaningful impact on zooplankton abundances or community structure among treatments. Statistically significant differences were observed in aquatic insect abundance between control mesocosms and the two greatest thiamethoxam treatments (10× and 100× seeding rate). The observed results indicate exposure to thiamethoxam at environmentally relevant concentrations likely does not represent a significant ecological risk to abundance and community structure of wetland zooplankton and emergent insects.

Surface oil is the primary driver of macroinvertebrate impacts following spills of diluted bitumen in freshwater.

The response of freshwater invertebrates following accidental releases of oil is not well understood. This knowledge gap is more substantial for unconventional oils such as diluted bitumen (dilbit). We evaluated the effects of dilbit on insect emergence and benthic invertebrates by conducting experimental spills in limnocorrals (10-m diameter; ~100-m3) deployed in a boreal lake at the IISD-Experimental Lakes Area, Canada. The study included seven dilbit treatments (spill volumes ranged from 1.5 L [1:66,000, oil:water, v/v] to 180 L [1:590, oil:water, v/v]), two controls, and additional lake reference sites, monitored for 11 weeks. Invertebrate emergence declined at the community level following oil addition in a significantly volume-dependent manner, and by 93-100 % over the 11 weeks following the spill in the highest treatment. Dilbit altered community structure of benthic invertebrates, but not abundance. One-year post-spill and following oil removal using traditional skimming and absorption techniques, benthic richness and abundance were greater among all treatments than the previous year. These results indicate that recovery in community composition is possible following oil removal from a lake ecosystem. Research is needed concerning the mechanisms by which surface oil directly affect adult invertebrates, whether through limiting oviposition, limiting emergence, or both. The response of benthic communities to sediment tar mats is also warranted.

Psychological and social barriers to women in science.

Commitment and creativity in science are not merely a function of an individual's competence or excellence, but are a product of the social environment as well. Acceptance and recognition from significant other people (one's peers and other professionals), and opportunities for stimulating and challenging interaction are essential for developing a strong occupational or professional identiy, and for creating the inner sense of role competence which can lead to greater commitment and productivity in professional work. Unfortunately women, especially those who have experienced interrupted or discontinuous careers, find such opportunities and acceptance difficult to obtain.

Hemispheric specialization in schizophrenics with perceptual aberration.

Higher rates of left-handedness and atypical lateralization in schizophrenics paired with findings of morphological abnormalities in cerebral asymmetry suggest that the normal patterns of hemisphere specialization for processing verbal and spatial information may be anomalous in schizophrenics. The small number of studies that have addressed this question have produced inconsistent findings and varied with subtype diagnosis, gender, type of task employed, task difficulty, and control of handedness. Conflicting research findings also may be due to confounding from the heterogeneity of the schizophrenic construct and variability in clinical symptoms across patients. The present study was designed to control for factors that may have confounded earlier studies. Because the study used perceptual measures, the relationship between symptoms of perceptual aberration and hemisphere advantages was examined using Chapman et al.'s (1978) Perceptual Aberration Scale (PAS). Fifteen male schizophrenic patients and 14 male controls were administered tachistoscopic letter and facial recognition go/no-go reaction time tasks. Left hemisphere advantages were found for both controls and schizophrenics on the letter task. Right hemisphere advantages were found for controls on the facial task but not schizophrenics. Instead, a strong negative correlation was found between schizophrenics' PAS scores and hemisphere advantages (r = -0.685, p < 0.007). Further analysis identified a subgroup of schizophrenics with perceptual aberration who exhibited reversed left hemisphere advantages that increased as the PAS scores increased. Additional research is needed to determine whether this subgroup of schizophrenics constitutes a meaningful subtype with a distinct disease process that disrupts the development of normal cerebral lateralization. The findings provide further evidence for the importance of examining relationships between schizophrenics' performance on cognitive measures and their symptom patterns.

Comparison of the Cosmed K4 b(2) and the Deltatrac II metabolic cart in measuring resting energy expenditure in adults.

BACKGROUND AND AIMS: The objective of the study was to compare data obtained from the Cosmed K4 b(2) and the Deltatrac II metabolic cart for the purpose of determining the validity of the Cosmed K4 b(2) in measuring resting energy expenditure. METHODS: Nine adult subjects (four male, five female) were measured. Resting energy expenditure was measured in consecutive sessions using the Cosmed K4 b(2), the Deltatrac II metabolic cart separately and the Cosmed K4 b(2) and Deltatrac II metabolic cart simultaneously, performed in random order. Resting energy expenditure (REE) data from both devices were then compared with values obtained from predictive equations. RESULTS: Bland and Altman analysis revealed a mean bias for the four variables, REE, respiratory quotient (RQ), V CO(2), V O(2) between data obtained from Cosmed K4 b(2) and Deltatrac II metabolic cart of 268+/-702 kcal/day, -0.0+/-0.2, 26.4+/-118.2 and 51.6+/-126.5 ml/min, respectively. Corresponding limits of agreement for the same four variables were all large. Also, Bland and Altman analysis revealed a larger mean bias between predicted REE and measured REE using Cosmed K4 b(2) data (-194+/-603 kcal/day) than using Deltatrac metabolic cart data (73+/-197 kcal/day). CONCLUSIONS: Variability between the two devices was very high and a degree of measurement error was detected. Data from the Cosmed K4 b(2) provided variable results on comparison with predicted values, thus, would seem an invalid device for measuring adults.

Energy expenditure measurements in ventilated critically ill children: within- and between-day variability.

BACKGROUND: Energy expenditure measurement (EEM) by indirect calorimetry is used as a research and clinical tool in pediatric intensive care units. The aims of the study were to determine if a 30-minute EEM is representative of a 24-hour EEM (within-day variation); to determine if there is any diurnal variation during the 24-hour period of EEM; and to determine if there is a clinically significant between day variation of EEMs. METHODS: To determine within-day variation, energy expenditure was measured for a period of 24 hours for each subject (n = 11). The 24-hour period was then divided into 30-minute periods. The 30-minute means were compared with the 24-hour means. To determine between-day variation, EEMs were made daily for 30 minutes. RESULTS: In the within-day study, the overall mean percent coefficient of variation of the 30-minute measurements was 7.2% +/- 4.5%. There was no significant difference between the 30-minute means and the 24-hour means for each patient (p < .691). In 8 subjects the 30-minute means did not differ from the 24-hour mean by more than 20%. No diurnal variation was observed. The mean percent variation of between day EEM was 21% +/- 16%; the range was 1% to 69%. CONCLUSION: In critically ill ventilated children, clinically relevant within-day variations in EEM are uncommon and a single 30-minute EEM gives an acceptable guide to the level of nutrition support required. Between-day variations can, however, be large and daily EEMs are required.

Autism from the inside.

Our hypothesis is that the endogenous opiate system is malfunctioning in autistic people. Levels of endorphins (and perhaps enkephalins) are fluctuating below and above normal levels leading to sensory deprivation. The sensations from all the sense organs are too great when the endorphin (and enkephalin) level is low making them meaningless or too little when the endorphin level is high leading to lack of sensation. Some of the bizarre repetitive behaviours are endorphin producing activities which cut down distressing sensation, others are attempts to cut down excessive stimuli from the environment, while others remain completely baffling. The thalamus could be one of the regions of the brain where inhibitory neurones and opiate receptors are malfunctioning and the feed back system initiated by the hypothalamus could have been damaged by the same agent. In both cases the damage could have been caused by chemical imbalance about the time of birth affecting the normal action of endorphins, enkephalins and prostaglandins. More boys than girls may be autistic because their brains are less mature at birth or because the male and female opiate systems are distinct.

A review of the role of social support systems in the drug use behavior of Hispanics.

In this article the authors conducted a critical review of ongoing and recently completed drug abuse studies which have examined the importance of social support systems in the drug-using behavior of Hispanics. Published and unpublished preliminary data from these studies are presented and discussed. This critical review of the research literature supports earlier findings that social support systems play an important role in preventing drug abuse among Hispanics. Specifically, this review found that familial factors, peer influences, involvement with religious institutions, and after-school activities have a powerful impact on the drug-using behaviors of Hispanic child, youth and adult drug users. The authors suggest that drug prevention and treatment programs within Hispanic communities will be more successful if they incorporate social support systems into their programs. In conclusion, the authors identify areas in which the role of social support systems in the drug-using behavior of Hispanics need further investigation.

An assessment of human services program outcome measures: are they credible, feasible, useful?

The authors present the results of an assessment of human service program outcome measures included in a county department's formative evaluation system. The criteria of credibility, feasibility, and utility provided the framework for examining measures in the context of the field environment within which programs operate and are evaluated. Recommendations address findings regarding three categories of evaluation measure and their potential application in other agency settings.

Psychological characteristics of the nurse practitioner.

First, present research on the selection and characteristics of practitioners is both controversial and important. We need good answers to be helpful to those planning directions for the future of nursing. Second, we need good descriptive research indicating how applicants for different types of programs vary; how age, experience, and background factors affect the outcome of training. Third, we need multi-criteria for measuring success and effectiveness-criteria that will take into account both competence and commitment and will measure competence in a variety of ways. Fourth, we need more theory for what we are measuring and why we are measuring it. We need predictions from different personality and developmental theories. We need to contrast and combine these theoretical approaches, and we need more complex variables than we currently have. We need constructs and types rather than simple empiricism and single traits. Finally, we should not overlook the fact that the majority of nurse practitioners are women, and thus we are doing research on an interesting group at a significant time in women's history. If we are alert and responsive to what we learn about our subjects, we may also gain a deeper understanding of the lives of adult women and how they are affected by social change and changing times.

Three-dimensional computed tomography in the assessment of fractures of the acetabulum.

Axial CT has, for many years, been shown to be superior to conventional radiology in the demonstration and assessment of acetabular fractures. The more recent development of complex computer programmes has enabled the production of three-dimensional images (3D CT) from sets of contiguous axial scans. 3D CT permits full imaging of the pelvis with the minimum of distress to the patient and with the minimum of radiation exposure. The ability to rotate the 3D images around a variety of axes provides a valuable perceptual link between conventional radiographs and axial CT, and enables the creation of unique images that offer perspectives unobtainable by conventional radiology. The improved visualization of the pelvis leads to more accurate diagnosis of the fracture, and hence better surgical planning and management.

Ego development in adult women.

Ego development in adult women was studied using Loevinger's Sentence Completion Test of Ego Development (SCT). The subjects were 163 women in a university nurse practitioner training program. Ego development scores were correlated with scores from personality tests and with interview data. Higher ego levels were related to personal adjustment, nurturance, responsibility, tolerance, enjoyment of children, inner control, capacity for status, and age. Improvement in ego level scores was found only for those at, or below, the self-aware level. The SCT, as scored for women, seems to be particularly sensitive to differences in responsible caring in relationships, an aspect of personality development often neglected by other tests.

The oversupply of physicians: implications for hospital planning.

In the next ten years, hospitals will have to contend with the impact of group practice, which often competes with hospital-based services. How will a new interdependence between hospitals and group practices affect hospitals' strategic planning?

Evaluation of an Emergency Department Patient Advocacy Program.

In the Patient Advocacy Program at the Adult Emergency Department of The Johns Hopkins Hospital, first year medical and health associate students provide patient teaching, crisis intervention, emotional support, assistance in patient-provider-family communication, resource referrals, information and assistance in maintaining patients' rights. The advocacy program was evaluated through a three-month trial of a Control Group, Patient Advocacy Group, Halo Group and Placebo Group, including 412 study subjects in all. It was hypothesized that patients' satisfaction, behavior and knowledge would improve significantly as a result of the advocate's intervention in this order: Patient Advocacy, Halo, Placebo and Control. Patient interviews and medical reports were used to assess the impact of patient advocacy. Results did not support the hypotheses of either improvement or the ranked order. Competition with traditional roles, identification of advocates with providers rather than patients, and placing the needs of the institution over patients were suggested as explanations for the advocacy program's failure.

Energy expenditure in 100 ventilated, critically ill children: improving the accuracy of predictive equations.

OBJECTIVE: The purpose of this study was to evaluate current methods of predicting energy requirements and to develop and validate new equations derived from energy expenditure measurements of ventilated, critically ill children. DESIGN: Prospective, observational, sequential study. SETTING: Pediatric intensive care unit. PATIENTS: A total of 100 ventilated, critically ill children who fit the criteria of energy expenditure measurement. Additional patients (n = 25) were included in the validation study. INTERVENTION: An indirect calorimeter was used to measure energy expenditure for a period of 30 mins. MEASUREMENTS AND MAIN RESULTS: The mean measured energy expenditure was 185+/-51 kJ/kg per day. Predicted energy expenditure from standard equations was compared with measured energy expenditure by using the Bland and Altman "methods comparison procedure," and poor precision and accuracy were observed. Patient variables were collected at the time of measurement, and multiple regression analysis was performed to determine the independent contribution of each variable to measure energy expenditure. New predictive equations were formulated and validated with additional energy expenditure measurements. Patient variables that did not correlate significantly with energy expenditure were gender, Pediatric Risk of Mortality score, and commencement of nutritional support. An equation was derived from patient variables (age, weight, weight for age Z score, body temperature, number of days after intensive care admission, and primary reason for admission) that correlated significantly (r2 = .898) with measured energy expenditure. A second, simplified equation (energy expenditure kJ/day = ¿17 x age [months]¿ + ¿48 x weight [kg]¿ + ¿292 x body temperature degrees C¿ - 9,677) was produced (r2 = .867). Validation found no significant difference between measured and predicted energy expenditure by the new equations; however, the equations did not predict accurately for patients <2 months of age. CONCLUSION: The new equations provide a more accurate alternative to current predictive methods in assessing energy requirements of ventilated, critically ill children.