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Major Variations (major + variation)
Selected AbstractsStimulation of growth performance without causing stress response in young red sea bream, Pagrus major (Temminck & Schlegel), by photoperiod manipulationAQUACULTURE RESEARCH, Issue 5 2008Amal Kumar Biswas Abstract Three photoperiods (12L:12D, 16L:8D and 24L:0D) were used to investigate the growth performance and stress response in red sea bream, Pagrus major (body weight 200,400 g). Fish were fed a commercial diet to apparent satiation, two times a day for 8 weeks. Fish exposed to a 24L:0D photoperiod showed a significantly higher weight gain (%) than those exposed to other photoperiods (P<0.05). The best specific growth rate and feed conversion efficiency were achieved at 24L:0D and 16L:8D, without significant differences among them. Although fish exposed to 16L:8D showed a significantly higher plasma level of cortisol than those exposed to other photoperiods in the third week, there was no major variation in the cortisol level among the treatments either at the sixth week or at the end of this study. There were no significant differences either in the haematocrit level or the plasma levels of glucose, total cholesterol and total protein among the treatments during this study. The results revealed that the growth performance of red sea bream reared from 200 to 400 g can be stimulated significantly using a continuous (24L:0D) photoperiod without any measurable significant stress response in fish. [source] Are diatoms good integrators of temporal variability in stream water quality?FRESHWATER BIOLOGY, Issue 4 2008ISABELLE LAVOIE Summary 1. Although diatoms have been used for many decades for river monitoring around the world, studies showing evidence that diatoms integrate temporal variability in water chemistry are scarce. 2. The purpose of this study was to evaluate the response of the Eastern Canadian Diatom Index (IDEC: Indice Diatomées de l'Est du Canada) with respect to temporal water chemistry variability using three different spatio-temporal data sets. 3. Along a large phosphorus gradient, the IDEC was highly correlated with averaged water chemistry data. Along within-stream phosphorus gradients, the IDEC integrated phosphorus over various periods of time, depending on the trophic status of the site studied (Boyer, Nicolet or Ste. Anne river) and variability in nutrient concentration. 4. In the Ste. Anne River, where nutrient concentrations were low and generally stable, an input of phosphorus induced a rapid change in diatom community structure and IDEC value within the following week. In the mesotrophic Nicolet River, the observed integration period was approximately 2 weeks. Diatom communities in the eutrophic Boyer River appeared to be adapted to frequent and significant fluctuations in nutrient concentrations. In this system, the IDEC therefore showed a slower response to short term fluctuations and integrated nutrient concentrations over a period of 5 weeks. 5. Our results suggest that the integration period varies as a function of trophic status and nutrient concentration variability in the streams. Oligotrophic streams are more sensitive to nutrient variations and their diatom communities are directly altered by nutrient increase, while diatom communities of eutrophic rivers are less sensitive to nutrient fluctuations and major variations take a longer time to be integrated into index values. 6. The longer integration period in the eutrophic environment may be attributed to the complexity of the diatom community. The results from this study showed that the diversity and evenness of the communities increased with trophic status. [source] Classic and atypical fibrodysplasia ossificans progressiva (FOP) phenotypes are caused by mutations in the bone morphogenetic protein (BMP) type I receptor ACVR1,HUMAN MUTATION, Issue 3 2009Frederick S. Kaplan Abstract Fibrodysplasia ossificans progressiva (FOP) is an autosomal dominant human disorder of bone formation that causes developmental skeletal defects and extensive debilitating bone formation within soft connective tissues (heterotopic ossification) during childhood. All patients with classic clinical features of FOP (great toe malformations and progressive heterotopic ossification) have previously been found to carry the same heterozygous mutation (c.617G>A; p.R206H) in the glycine and serine residue (GS) activation domain of activin A type I receptor/activin-like kinase 2 (ACVR1/ALK2), a bone morphogenetic protein (BMP) type I receptor. Among patients with FOP-like heterotopic ossification and/or toe malformations, we identified patients with clinical features unusual for FOP. These atypical FOP patients form two classes: FOP-plus (classic defining features of FOP plus one or more atypical features) and FOP variants (major variations in one or both of the two classic defining features of FOP). All patients examined have heterozygous ACVR1 missense mutations in conserved amino acids. While the recurrent c.617G>A; p.R206H mutation was found in all cases of classic FOP and most cases of FOP-plus, novel ACVR1 mutations occur in the FOP variants and two cases of FOP-plus. Protein structure homology modeling predicts that each of the amino acid substitutions activates the ACVR1 protein to enhance receptor signaling. We observed genotype-phenotype correlation between some ACVR1 mutations and the age of onset of heterotopic ossification or on embryonic skeletal development. Hum Mutat 0, 1,12, 2008. © 2008 Wiley-Liss, Inc. [source] Effect of Two Types of Control Questions and Two Question Formats on the Outcomes of Polygraph Examinations,JOURNAL OF FORENSIC SCIENCES, Issue 4 2008Frank Horvath Ph.D. Abstract:, Two major variations of polygraph "Control Question" testing, the Zone Comparison (ZoC) and the Modified General Question Test (MGQT) were evaluated. Within each, the type of control question, Exclusive or "time bar" (e.g., "Before you were 21, did you ever...") and Nonexclusive or "no time bar"(e.g., "Did you ever,.?") was manipulated in a mock theft scenario, with 80 male and 40 female subjects randomly assigned to be either innocent or guilty. Polygraphic data collected by experienced field examiners were numerically scored by an evaluator blind to all aspects of the study. Decision accuracy was not related to the type of procedure (ZoC/MGQT) used or the subject's sex. Accuracy was significantly related to the type of control question [,2(2) = 11.46, p = 0.003; ,c = 0.29]. Nonexclusive control questions produced greater accuracy than Exclusive control questions on both innocent and guilty subjects. These results and subjects' self-reports support the general "theory" on which control question (CQ) testing is based. The need for better empirical support of accepted dogma and current field practices is strongly indicated by these findings. [source] An Organizational Echelon Analysis of the Determinants of Red Tape in Public OrganizationsPUBLIC ADMINISTRATION REVIEW, Issue 6 2008Richard M. Walker This article adopts an organizational echelon approach to the study of red tape in public organizations and argues that the nature and extent of red tape will vary at different levels of the organizational hierarchy. These propositions are tested with a multiple-informant survey using a lagged model. The empirical results across the three organizational echelons sampled indicate modest variations in the levels of perceived red tape and major variations in its determinants. Results from the more senior managers uphold prior research findings and hypotheses on the determinants of red tape. This is not surprising because earlier studies typically sampled senior executives. Yet the lower down the organizational hierarchy one travels, the more red tape officials perceive and the more multifaceted the findings on determinants become. The authors conclude that prior empirical work is likely to have underestimated the extent of red tape in public organizations, and oversimplified its determinants. The implications for theory and practice are discussed. [source] | ||||||||||