Measuring acid volatile sulphide in floodplain lake sediments: effect of reaction time, sample size and aeration

Chemosphere ◽  
2002 ◽  
Vol 47 (4) ◽  
pp. 395-400 ◽  
Author(s):  
C van Griethuysen ◽  
F Gillissen ◽  
A.A Koelmans
2019 ◽  
Vol 34 (6) ◽  
pp. 998-998
Author(s):  
L Bennett ◽  
C Bernick ◽  
W Ng

Abstract Objective Repetitive head injuries common in combat sports have been associated with increased risk for cognitive dysfunction. Interestingly, the Professional Fighter’s Brain Health Study (PFBHS) team has observed improvements in fighters’ cognitive performance following their transition to inactive fighting status. As this phenomenon was explored, it was hypothesized that fighters’ cognitive performance will initially improve following their discontinuation of fighting. Methods Longitudinal demographic, fighting history, and cognitive functioning data from 31 fighters who discontinued fighting during their participation in the PFBHS. Cognitive functioning was assessed via CNS Vital Signs and C3/iComet computerized batteries. Number of professional fights, as well as inactive fighting status, was determined using published professional online records. Fighters were considered inactive if they had gone two or more years without a professional match. Results Paired-samples t test was conducted to evaluate cognitive functioning in fighters at time 1 (actively fighting) and time 2 (inactive fighting status). When comparing cognitive function at across time points, performance on CNS Vital Signs measures of verbal memory, processing speed, psychomotor speed, and reaction time, as well as C3/iComet measures of set-shifting and complex reaction time, significantly improved at time 2 (all p’s < 0.05). Interestingly, performance did not improve across time points on a C3/iComet measure of processing speed (Trailmaking Test Part A). Conclusions Cognitive performance improved on most measures when fighters transitioned to inactive fighting status. Given the limited sample size, future analysis is necessary to evaluate the relationship between fighting status and cognitive performance in a larger sample size.


2002 ◽  
Vol 13 (1) ◽  
pp. 71-77 ◽  
Author(s):  
José M. Godoy ◽  
Carlos R. Padovani ◽  
Jean R. D. Guimarães ◽  
José C. A. Pereira ◽  
Luis M. Vieira ◽  
...  

2002 ◽  
Vol 756 ◽  
Author(s):  
A. Weibel ◽  
R. Bouchet ◽  
P. Knauth

ABSTRACTWe have systematically investigated the influence of various parameters (pressure, temperature, time, sample size) on the hot pressing process of TiO2nanoceramics. This study is backed by thermodilatometric experiments and microscopic observations of the microstructure. Impedance spectra of TiO2nanoceramics with different porosity are also presented.


1991 ◽  
Vol 43 (4) ◽  
pp. 907-912 ◽  
Author(s):  
Jeff Miller

To remove the influence of spuriously long response times, many investigators compute “restricted means”, obtained by throwing out any response time more than 2.0, 2.5, or 3.0 standard deviations from the overall sample average. Because reaction time distributions are skewed, however, the computation of restricted means introduces a bias: the restricted mean underestimates the true average of the population of response times. This problem may be very serious when investigators compare restricted means across conditions with different numbers of observations, because the bias increases with sample size. Simulations show that there is substantial differential bias when comparing conditions with fewer than 10 observations against conditions with more than 20. With strongly skewed distributions and a cutoff of 3.0 standard deviations, differential bias can influence comparisons of conditions with even more observations.


2002 ◽  
Vol 21 (10) ◽  
pp. 2165-2171 ◽  
Author(s):  
Elske M. De Haas ◽  
Bas Reuvers ◽  
Caroline T. A. Moermond ◽  
Albert A. Koelmans ◽  
Michiel H. S. Kraak

Perception ◽  
1993 ◽  
Vol 22 (11) ◽  
pp. 1287-1298 ◽  
Author(s):  
Hans-Christoph Nothdurft

Subjects were asked to detect faces or facial expressions from patterns with a variable number of nonfaces or faces expressing different emotions. In most tests, reaction time was found to increase steeply with sample size, thus indicating serial-search characteristics for the patterns tested. There were, however, considerable differences in the slopes of the graphs (search time versus sample size), which could be attributed to visual (but not face) cues that are discriminated at similar speeds. Slopes did not change when patterns were presented upside down, although such a modification strongly affects the perception of faces and facial expressions.


2005 ◽  
Vol 162 (2) ◽  
pp. 211-228 ◽  
Author(s):  
Elske M. de Haas ◽  
R. van Haaren ◽  
Albert A. Koelmans ◽  
Michiel H.S. Kraak ◽  
W. Admiraal

1991 ◽  
Vol 10 (4) ◽  
pp. 363-372 ◽  
Author(s):  
Matti E. Räsänen ◽  
Jukka S. Salo ◽  
Högne Jungner

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