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Dominant Predictor (dominant + predictor)

Distribution by Scientific Domains

Medical Sciences	50%
Life Sciences	50%

Selected Abstracts

Representation of accuracy in the dorsal premotor cortex

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 10 2000
Jose E. Gomez
Abstract The endpoint accuracy of a reaching movement strongly affects kinematics, particularly during the final phases of movement. However, where and how accuracy is represented in the central nervous system remains unknown. In this study, the discharge of 150 neurons located primarily in the dorsal premotor cortex (PMd), were recorded from monkeys performing an instructed delay, centre-out reaching task in which movement direction and target size were systematically varied. Linear regression analyses were used to assess the dependence of movement kinematics and cell discharge on target direction, size and tangential velocity (i.e. speed). The speed and timing of the movement were dependent on both direction and target size. Initially direction was the dominant predictor whilst target size became more important as the hand reached the target. A temporal multiple linear regression analysis found significant correlations with target size in 99 of 150 cells. The discharge of 134 cells was directionally tuned and 83 cells modulated with mean speed. Significant correlations of discharge with target size occurred throughout the task as did correlations with direction. However, correlations with direction preferentially occurred early in the task, prior to movement onset, whilst correlations with target size tended to occur late, well after movement onset. This temporal dependency of the firing in relationship to target direction and size mirrored that observed for the kinematics. We conclude that the discharge of PMd cells is highly correlated with the accuracy requirement of the movement. The timing of the correlations suggest that accuracy information is available for the planning and for the on-line control of endpoint accuracy. [source]

Taxonomic level, trophic biology and the regulation of local abundance

GLOBAL ECOLOGY, Issue 3 2001
Michael Kaspari
Abstract 1Taxocenes , monophyletic ecological assemblages , are a key focus of macroecology. Abundance (individuals per area) is a basic property of taxocenes but has received less attention than diversity, although the two are probably related. Abundance reflects a taxocene's ability to harvest and sequester available energy and divide it among individuals. This paper explores how two properties of all taxocenes , trophic makeup and taxonomic level (e.g. genus, tribe, subfamily, family , ) , may contribute to patterns of local abundance at geographical scales. 2Forty-nine ground ant taxocenes, in habitats ranging from New World deserts to rain forests, were surveyed along a three-orders of magnitude productivity gradient using transects of 30 1-m2 quadrats at each site. Abundance , the number of nests per transect , varied over two orders of magnitude. 3Over 80% of the genera collected were omnivores. However, herbivore, omnivore, and predator taxa were added to ant taxocenes in roughly 1 order of magnitude steps up the productivity gradient. Specialist detritivores were added last. 4Net primary productivity and mean monthly temperature both consistently entered regression models predicting abundance. However, while productivity was the dominant predictor of abundance for higher taxa (families, subfamilies), temperature was the dominant predictor of abundance for lower taxa (tribes, genera). The answer to the question ,What regulates the abundance of a taxocene?' is thus sensitive to the taxonomic level of analysis. 5These data support the following scenario. Lower taxa are abiotic specialists given the insufficient number of genomes and generations required for the exploration of the entire abiotic envelope. Higher taxa, in contrast, consist of suites of abiotic specialists arrayed along the entire productivity gradient, with access to productivity everywhere the taxon occurs. If this scenario is true, individual species may respond to global changes in temperature; the higher taxa they belong to may most respond to global changes in productivity. [source]

Lower urinary tract symptoms and risk of prostate cancer in Japanese men

INTERNATIONAL JOURNAL OF UROLOGY, Issue 8 2006
AKIO MATSUBARA
Aim: Our aim was to investigate whether or not men with lower urinary tract symptoms are at increased risk of prostate cancer. Methods: A total of 3511 men aged 50,79 years who underwent mass screening for prostate cancer between 2002 and 2004 for the first time, and completed the International Prostate Symptom Score (IPSS) questionnaire at the time of the prostate specific antigen (PSA) test, were enrolled in the present study. All men with PSA values greater than 4.0 ng/mL were advised and encouraged to undergo transrectal systematic sextant biopsy. The number of cancers subsequently detected was compared between men with IPSS scores of 0,7 and 8,35. Results: Of the 3511 men, 219 (6.2%) had PSA values greater than 4 ng/mL, 178 (5.1%) underwent biopsy, and 51 (1.5%) were found to have prostate cancer. Although the PSA positivity rate for men with IPSS scores of 8,35 was significantly higher than that in the 0,7 group, there were no significant intergroup differences in the cancer detection rates for biopsied men and for total screened subjects. Multivariate logistic regression analysis revealed that prostate volume was the dominant predictor for the detection of prostate cancer, followed by PSA level, but the IPSS made no significant contribution. No significant difference was noted in the IPSS scores between men with cancer and the others of the same age group. Conclusions: Symptomatic Japanese men are not at higher risk of prostate cancer despite their higher PSA values compared with asymptomatic men of the same age group. [source]

Predicting physical activity and outcome expectations in cancer survivors: an application of Self-Determination Theory

PSYCHO-ONCOLOGY, Issue 7 2006
Philip M. Wilson
Abstract The purpose of this study was to examine the contributions of autonomous and controlled motives drawn from Self-Determination Theory (SDT; Intrinsic Motivation and Self-determination in Human Behavior. Plenum Press: New York, 1985; Handbook of Self-determination Research. University of Rochester Press: New York, 2002) towards predicting physical activity behaviours and outcome expectations in adult cancer survivors. Participants were cancer-survivors (N=220) and a non-cancer comparison cohort (N=220) who completed an adapted version of the Treatment Self-Regulation Questionnaire modified for physical activity behaviour (TSRQ-PA), an assessment of the number of minutes engaged in moderate-to-vigorous physical activity (MVPA) weekly, and the anticipated outcomes expected from regular physical activity (OE). Simultaneous multiple regression analyses indicated that autonomous motives was the dominant predictor of OEs across both cancer and non-cancer cohorts (R2adj=0.29,0.43), while MVPA was predicted by autonomous (,'s ranged from 0.21 to 0.34) and controlled (,'s ranged from ,0.04 to ,0.23) motives after controlling for demographic considerations. Cancer status (cancer versus no cancer) did not moderate the motivation,physical activity relationship. Collectively, these findings suggest that the distinction between autonomous and controlled motives is useful and compliments a growing body of evidence supporting SDT as a framework for understanding motivational processes in physical activity contexts with cancer survivors. Copyright © 2005 John Wiley & Sons, Ltd. [source]