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Putative Effects (putative + effects)

Distribution by Scientific Domains

Medical Sciences	50%
Life Sciences	50%

Selected Abstracts

Trends in water quality and discharge confound long-term warming effects on river macroinvertebrates

FRESHWATER BIOLOGY, Issue 2 2009
ISABELLE DURANCE
Summary 1.,Climate-change effects on rivers and streams might interact with other pressures, such as pollution, but long-term investigations are scarce. We assessed trends among macroinvertebrates in 50 southern English streams in relation to temperature, discharge and water quality over 18 years (1989,2007). 2.,Long-term records, coupled with estimates from inter-site calibrations of 3,4 years, showed that mean stream temperatures in the study area had increased by 2.1,2.9 °C in winter and 1.1,1.5 °C in summer over the 26 year period from 1980 to 2006, with trends in winter strongest. 3.,While invertebrate assemblages in surface-fed streams were constant, those in chalk-streams changed significantly during 1989,2007. Invertebrate trends correlated significantly with temperature, but effects were spurious because (i) assemblages gained taxa typical of faster flow or well-oxygenated conditions, contrary to expectations from warming; (ii) more invertebrate families increased in abundance than declined and (iii) concomitant changes in water quality (e.g. declining orthophosphate, ammonia and biochemical oxygen demand), or at some sites changes in discharge, explained more variation in invertebrate abundance and composition than did temperature. 4.,These patterns were reconfirmed in both group- and site-specific analyses. 5.,We conclude that recent winter-biased warming in southern English chalk-streams has been insufficient to affect invertebrates negatively over a period of improving water quality. This implies that positive management can minimize some climate-change impacts on stream ecosystems. Chalk-stream invertebrates are sensitive, nevertheless, to variations in discharge, and detectable changes could occur if climate change alters flow pattern. 6.,Because climatic trends now characterize many inter-annual time-series, we caution other investigators to examine whether putative effects on ecological systems are real or linked spuriously to other causes of change. [source]

Brain dopaminergic modulation associated with executive function in Parkinson's disease,

MOVEMENT DISORDERS, Issue 13 2009
Karim Farid MD
Abstract The progressive development of deficits in executive functions, including action planning, is a well-known complication of Parkinson's disease. A dysfunction of the prefrontal lobe, which is known to be involved in the control of inhibitory processes, could explain the difficulties in initiating behavior or inhibiting ongoing actions in patients with PD. The strong dopaminergic innervation of the prefrontal cortex raises questions about the putative effects of dopa therapy on this cognitive impairment. In the present study, we used fMRI to examine the functional influence of dopa therapy on neural activity during a go/no-go task in nine patients with and without levodopa treatment and in matched controls. Whereas the patient and control subjects exhibited the same performance during the go/no-go task, different patterns of brain activation were observed depending on the dopaminergic status. The drug-off state was characterized by more widely distributed brain activity, mainly in the bilateral caudate. Levodopa did not fully restore normal brain activation and induced changes in the pattern of cingulate cortex activity, which was more pronounced in the rostral part in the drug-off state and in the caudal part after levodopa intake. These results support the idea of a critical role for dopamine in the control of executive functions in patients with PD. © 2009 Movement Disorder Society [source]

Digit ratios (2D:4D) determined by computer-assisted analysis are more reliable than those using physical measurements, photocopies, and printed scans

AMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 3 2009
Heather C. Allaway
Prenatal androgens influence the second to fourth digit ratio (2D:4D) of hands with men having lower ratios than women. Numerous methods are used to assess 2D:4D including, physical measurements with calipers, and measurements made from photocopies, scanned images, digital photographs, radiographs, and scaled tubes. Although each method appears relatively reliable, agreement upon a gold standard is necessary to better explore the putative effects of prenatal androgens. Our objective was to assess the level of intra and interobserver reliability when evaluating 2D:4D using four techniques: (1) physical measurements, (2) photocopies, (3) printed scanned images, and (4) computer-assisted image analysis. Physical measurements, photocopies, and printed scanned images were measured with Vernier calipers. Scanned images were also measured with computer-based calipers. Measurements were made in 30 men and 30 women at two different time points, by three experienced observers. Intraclass correlation coefficients were used to assess the level of reliability. Intraobserver reliability was best for computer-assisted (0.957), followed by photocopies (0.939), physical measurements (0.925), and printed scans (0.842; P = 0.015). Interobserver reliability was also greatest for computer-assisted (0.892), followed by photocopies (0.858), physical measurements (0.795), and printed scans (0.761; P = 0.001). Mean 2D:4D from physical measurements were higher than all other techniques (P < 0.0001). Digit ratios determined from computer-assisted, physical measurements, and printed scans were more reliable in men than women (P = 0.009, P = 0.017, and P = 0.012, respectively). In summary, 2D:4D determined from computer-assisted analysis yielded the most accurate and consistent measurements among observers. Investigations of 2D:4D should use computer-assisted measurements over alternate methods whenever possible. Am. J. Hum. Biol., 2009. © 2009 Wiley-Liss, Inc. [source]

Patient personality predicts postoperative stay after colorectal cancer resection

COLORECTAL DISEASE, Issue 2 2008
A. Sharma
Abstract Objective, Postoperative length of stay (LOS) is an important outcome after colorectal cancer surgery. The aim of this study was to evaluate the putative effects of personality, mood, coping and quality of life on LOS. Method, A consecutive series of 110 eligible patients undergoing elective resection for colorectal cancer were invited to participate in the study. A battery of psychometric questionnaires including the Hospital Anxiety and Depression Scale, the Functional Assessment of Cancer Therapy (colorectal), the Courtauld Emotional Control Scale, the Positive and Negative Affectivity Scale and the Eysenck Personality Questionnaire (EPQ) were administered 5,12 days before surgery. Nonparametric correlations were computed for psychometric scores, demographic variables and the LOS. Factors found to be significantly correlated on this analysis were entered into a multiple regression model to determine the independent predictors of LOS. Results, One hundred and four patients with colorectal cancer participated. Seventy were male (67%) and the mean age was 68 years (range 39,86). The median LOS was 10 days (range 4,108). LOS was negatively correlated with pre- and postoperative albumin levels, PANAS +ve affect, Functional Assessment of Cancer Therapy questionnaire with the colorectal module functional well-being score and EPQ extroversion score. LOS was strongly positively correlated with postoperative morbidity. LOS was positively correlated with CECS anger score, age and being male. Postoperative morbidity (, = 0.379, P = 0.007) and extroversion (, = ,0.318, P = 0.05) were independent predictors of LOS. Conclusion, Personality as measured by EPQ predicts postoperative LOS in patients with colorectal cancer. Extroverts have a higher pain threshold and this may be part of the explanation. [source]