Narrow-linewidth, singlemode erbium-doped fibre laser withintracavity wave mixing in saturable absorber

Narrow-linewidth, single longitudinal mode operation is demonstrated in an erbium-doped fibre laser with an intracavity nonlinear absorptive wave mixing of the counter propagating beams. An unpumped length of erbium-doped fibre serves as the saturable absorber. Linewidths of the order of a few kilohertz are obtained     

Argument and Decision Making in Computer-Mediated Groups

Following Gouran (1994), the authors proposed four hypotheses that predict the probability of computer-mediated groups (CMGs) endorsing proposals based on (a) the number of reasons offered for them, (b) the number of members advancing these reasons, (c) the net number of positive reactions to the reasons advanced, and (d) the development of support for the reasons. Results from 11 groups that had long collaborated exclusively through computer-mediated means indicated that members in support of a proposal relative to those in opposition as well as the development of their arguments were significant predictors of decision outcomes. Moreover, the number of responses for/against a proposal and the difference in the positive and negative reactions to decision proposals were good independent predictors of decision outcomes.     

Lipid profile in Venezuelan preschoolers by socioeconomic status

Epidemiological studies have shown that unfavorable serum lipids levels in childhood are predictors of development of atherosclerosis lesions in adulthood. We assessed the lipid profile of 297 Venezuelan preschool children (4-7 years old) from two socioeconomic levels in order to compare them by this characteristic. Their social level was determined according to modified Graffar method, and two groups were obtained: high socioeconomic status (HSES, n=103) and low socioeconomic status (LSES, n=194). Nutritional anthropometric evaluation was performed by weight to height, and NCHS/OMS cut-off point was used. Lipid profile was determined by colorimetric biochemical methods and atherogenic risks factors were calculated. Underweight for HSES was 5.8% and for LSES: 14.9%, while normal status was 78.6% and 70.1%, and overweight was 15.5% and 14.9%, respectively. Mean values for triglycerides were 0.66 +/- 0.27and 0.76 +/- 0.31 mmol/L, total cholesterol (TC): 3.61 +/- 0.65 and 2.98 +/- 0.71 mmol/L, HDL-C: 1.04 +/- 0.18 and 0.62 +/- 0.16 mmol/L, LDL-C: 2.27 +/- 0.61 and 2.01 +/- 0.71 mmol/L, TC/HDL-C: 3.5 +/- 0.78 and 5.0 +/- 1.5; LDL-C/HDL-C: 2.0 +/- 0.71 and 3.4 +/- 1.4 with significant differences between HSES and LSES as shown respectively. A significant association was found (p < 0.01) between lipid values and socioeconomic status, being the LSES preschoolers those with the higher atherogenic risk. Its pattern was of lower HDL-C levels, and higher TC/HDL-C and LDL-C/HDL-C ratio. Comparisons of lipid profile by nutritional status or gender did not show significant differences. Findings indicate that children from low socioeconomic status are at a higher risk for cardiovascular disease and atherosclerosis than children from high socioeconomic status.     

Applying a Genetic Algorithm-Based Multiobjective Approach for Time-Cost Optimization

Reducing both project cost and time (duration) is critical in a competitive environment. However, a trade-off between project time and cost is required. This in turn requires contracting organizations to carefully evaluate various approaches to attaining an optimal time-cost equilibrium. Although several analytical models have been developed for time-cost optimization (TCO), they mainly focus on projects where the contract duration is fixed. The optimization objective in those cases is therefore restricted to identifying the minimum total cost only. With the increasing popularity of alternative project delivery systems, clients and contractors are targeting the increased benefits and opportunities of seeking an earlier project completion. The multiobjective model for TCO proposed in this paper is powered by techniques using genetic algorithms (GAs). The proposed model integrates the adaptive weights derived from previous generations, and induces a search pressure toward an ideal point. The concept of the GA-based multiobjective TCO model is illustrated through a simple manual simulation, and the results indicate that the model could assist decision-makers in concurrently arriving at an optimal project duration and total cost.     

Lymphocyte subpopulations in preschool Venezuelan children of high socioeconomic status

Nutrition is a critical determinant of immune response being the most common cause of immunodeficiency in the world. 104 preschool children, apparently healthy, from a private school were chosen to determine lymphocyte subpopulations and to evaluate its relationship to the anthropometric nutritional status and serum zinc. Nutritional status was measured by the indicator weight for height, lymphocyte subpopulations by flow cytometry and serum zinc by atomic absorption spectrophotometry A high percentage of the population (87.5%) belonged to socioeconomic level II (Graffar). Nutritional deficit was present in 9.5 percent of the studied children, while 16.2% were overweight. Values for lymphocytes subpopulations and serum zinc were within reference ranges, similar to other reports and there were no significant differences by sex, age or nutritional status. Low concentrations of serum zinc were present in 6.7% of children. There was a tendency to lower values of the T lymphocyte populations in hypozincemic children but it did not reach statistical significance. As there are not reference values for lymphocyte subpopulation in Venezuelan children, these results could be used as reference for future investigations. Continuity of research is needed to understand relationship of micronutrients levels and immune response.     

Reactions of α-Arylhydrazono-β-oxo-β-phenyl-propionitriles

ω-Cyanoacetophenone was coupled with a variety of aromatic diazonium chlorides to give the corresponding arylazo derivatives 1 a – g . Analysis of the IR and UV spectra of these compounds indicated that they exist mainly as the corresponding arylhydrazones. Compounds 1 a – d, f, g reacted with diazomethane to yield the N-methyl-arylhydrazones 2 a – f . 3-Amino-4-arylazo-5-phenylpyrazoles 5 a – g and 4-arylazo-5-imino-1,3-diphenyl-2-pyrazolines 6 a – g were obtained by the interaction of 1 a – g with hydrazine hydrate and with phenylhydrazine, respectively.     

Data Fault Detection in Wireless Sensor Networks Using Machine Learning Techniques

Wireless Personal Communications - Wireless Sensor Network (WSN) is a wireless network that consists of spatially distributed autonomous devices with sophisticated subsystem called sensors to...     

Employee drug use, demographic characteristics, work reactions, and absenteeism.

Investigated the relationships between employee use of illicit drugs, perceptions of and reactions to the work environment, and employee absenteeism and tardiness above and beyond that accounted for by demographic and work reaction variables. 162 employees in a large work organization completed demographic and background information and assessments of work perceptions and reactions and absenteeism and tardiness. Drug use was assessed with a questionnaire and urine testing. Employee drug use accounted for additional statistically significant variance in overall absenteeism and in absenteeism due to injuries and suspensions, as well as days tardy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)