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Basic Measures (basic + measure)

Distribution by Scientific Domains

Life Sciences	75%

Selected Abstracts

Clinical utility of an automated pupillometer for assessing and monitoring recipients of liver transplantation

LIVER TRANSPLANTATION, Issue 12 2009
Sheng Yan
Pupil examination has been used as a basic measure in critically ill patients and has great importance for the prognosis and management of disease. An automated pupillometer is a computer-based infrared digital video system by which the accuracy and precision of the pupil examination are markedly improved. We conducted an observational study of pupil assessment with automated pupillometry in clinical liver transplantation settings, including pretransplant evaluations and posttransplant surveillance. Our results showed that unconscious patients (grade 4 hepatic encephalopathy) had a prolonged latency phase (left side: 283 ± 80 milliseconds; right side: 295 ± 96 milliseconds) and a reduced pupillary constrictive ratio (left direct response: 0.23 ± 0.10; left indirect response: 0.21 ± 0.07; right direct response: 0.20 ± 0.08; right indirect response: 0.21 ± 0.08) in comparison with normal and conscious patients. After liver transplantation, the recovery of pupillography in these patients was slower than that in conscious patients. However, the surviving recipients without major complications all had a gradual recovery of pupillary responses, which occurred on the first or second posttransplant day. We also reported 4 cases of futile LT in the absence of pretransplant pupillary responses and other pupillary abnormalities revealed by automated pupillometry in our study. In conclusion, patients with grade 4 hepatic encephalopathy had a sluggish pupil response and a delayed recovery pattern after LT. An automated pupillometer is potentially a supplementary device for pretransplant screening and posttransplant monitoring in patients undergoing LT, but further prospective studies are required. Liver Transpl 15: 1718,1727, 2009. © 2009 AASLD. [source]

Effects of insects on primary production in temperate herbaceous communities: a meta-analysis

ECOLOGICAL ENTOMOLOGY, Issue 5 2003
Malcolm D. Coupe
Abstract., 1. The effects of insects on primary production in temperate herbaceous communities were investigated in a meta-analysis. The following hypotheses were tested: (1) the effect of insects on primary production depends on community type, (2) the effect of insects on primary production varies as a function of productivity, (3) insects have a greater effect on primary production in communities with low species diversity, and (4) insects have a larger effect on primary production during outbreaks. 2. Data were collected from 24 studies in which insecticides were used to suppress insects in self-sown or pastoral communities. Effect sizes were calculated from sprayed and control plot standing crop or yield, expressed as the log response ratio, ln (sprayed plot phytomass/control plot phytomass). 3. There was a significant increase in primary production as a result of insect suppression. Forb-dominated communities showed a more variable response than graminoid communities. During outbreaks, insects had a greater negative impact on primary production. Effect size was unaffected by productivity or plant species richness. 4. Although insects lower primary production in a diversity of temperate herbaceous communities, the basic measures by which such communities are often described have little effect on the proportional impact that insects have on primary production. While outbreaks are significant predictors of higher negative impact on primary production, causes of outbreaks are not always related to traits of the plant community. [source]

Stability of hippocampal place cell activity across the rat estrous cycle,

HIPPOCAMPUS, Issue 2 2005
Jennifer Tropp
Abstract Findings from both in vitro and in vivo studies have shown that estrogen exerts pronounced effects on hippocampal morphology and physiology. The degree to which these molecular findings influence hippocampal processing in freely behaving animals is unclear. The present study assessed the effect of the estrous cycle on hippocampal place cells in naturally cycling rats during two behavioral states. Female Sprague-Dawley rats were trained to alternate on a U-shaped runway for food reinforcement. Single-unit recordings of hippocampal CA1 cells were conducted under two conditions: (1) at rest on a holder, and (2) running on the maze. Spatial firing characteristics of the cells were examined at different stages of the estrous cycle (i.e., diestrus, proestrus, and estrus). Specifically, information was collected on (1) mean firing rates; (2) basic place field parameters; and (3) changes in the firing dynamics of these cells (e.g., burst properties). The findings showed a decrease in mean firing rate on the maze during proestrus. However, other basic measures of spatial tuning and burst properties were unchanged. The current study suggests that there is relative stability of hippocampal place cells across the estrous cycle during a well-trained task. © 2004 Wiley-Liss, Inc. [source]

Do sampling method and sample size affect basic measures of dolphin sociality?

MARINE MAMMAL SCIENCE, Issue 1 2009
Quincy Anne Gibson
Abstract Although the fission,fusion social patterns of bottlenose dolphins have been described, defining and measuring sociality is difficult. No study to date has investigated how much data are necessary to accurately depict social patterns in a fission,fusion species and whether this amount differs depending on the measure used. Using the long-term Shark Bay bottlenose dolphin study we examined four different measures of sociality for mothers and dependent calves (n= 89). Our objectives were to determine (1) the amount of observation time necessary to accurately depict sociality using these measures, (2) correlations among these measures, and (3) if sampling method affects the validity of sociality measurements. A minimum of 10 h and 5 h of observations, respectively, were necessary to accurately capture calf associate numbers and percent time alone. A pairwise comparison of calf sociality measurements from focal and survey data found that calves spent from 0% to 70.2% of their time alone in focal data, but these same calves spent only 0%,7.7% alone in survey data. These findings indicate that (1) results differ depending on the type of sampling method and (2) the amount of observation time necessary to adequately capture individual variation differs depending on the measure of sociality. [source]