An evaluation of sleep hypnotic and stimulant effect on human performance using a computerized psychological test battery

This study evaluated the administration-time-dependent effects of a stimulant (Dexedrine 5-mg), a sleep-inducer (Halcion 0.25-mg) and placebo (control) on human performance. The investigation was conducted on 12 diurnally active (0700-2300) male adults (23-38 yrs) using a double-blind, randomized sixway-crossover three-treatment, two-timepoint (0830 vs 2030) design. Performance tests were conducted hourly during sleepless 13-hour studies using a computer generated, controlled and scored multi-task cognitive performance assessment battery (PAB) developed at the Walter Reed Army Institute of Research. Specific tests were Simple and Choice Reaction Time, Serial Addition/Subtraction, Spatial Orientation, Logical Reasoning, Time Estimation, Response Timing and the Stanford Sleepiness Scale. The major index of performance was "Throughput", a combined measure of speed and accuracy.^ For the Placebo condition, Single and Group Cosinor Analysis documented circadian rhythms in cognitive performance for the majority of tests, both for individuals and for the group. Performance was best around 1830-2030 and most variable around 0530-0700 when sleepiness was greatest (0300).^ Morning Dexedrine dosing marginally enhanced performance an average of 3% with reference to the corresponding in time control level. Dexedrine AM also increased alertness by 10% over the AM control. Dexedrine PM failed to improve performance with reference to the corresponding PM control baseline. With regard to AM and PM Dexedrine administrations, AM performance was 6% better with subjects 25% more alert.^ Morning Halcion administration caused a 7% performance decrement and 16% increase in sleepiness and a 13% decrement and 10% increase in sleepiness when administered in the evening compared to corresponding in time control data. Performance was 9% worse and sleepiness 24% greater after evening versus morning Halcion administration.^ These results suggest that for evening Halcion dosing, the overnight sleep deprivation occurring in coincidence with the nadir in performance due to circadian rhythmicity together with the CNS depressant effects combine to produce performance degradation. For Dexedrine, morning administration resulted in only marginal performance enhancement; Dexedrine in the evening was less effective, suggesting the 5-mg dose level may be too low to counteract the partial sleep deprivation and nocturnal nadir in performance. ^

THE EFFECT OF PERSON-ENVIRONMENT FIT ON THE PSYCHOLOGICAL WELL-BEING OF PSYCHIATRIC AIDES WORKING IN A STATE HOSPITAL (COPING RESOURCES, SOCIAL SUPPORT, OCCUPATIONAL STRESS, LOCUS-OF-CONTROL)

This study addressed two purposes: (1) to determine the effect of person-environment fit on the psychological well-being of psychiatric aides and (2) to determine what role the coping resources of social support and control have on the above relationship. Two hundred and ten psychiatric aides working in a state hospital in Texas responded to a questionnaire pertaining to these issues.^ Person-environment fit, as a measure of occupational stress, was assessed through a modified version of the Work Environment Scale (WES). The WES subscales used in this study were: involvement, autonomy, job pressure, job clarity, and physical comfort. Psychological well-being was measured with the General Well-Being Schedule which was developed by the National Center for Health Statistics. Co-worker and supervisor support were measured through the WES and finally, control was assessed through Rotter's Locus of Control Scale.^ The results of this study were as follows: (1) all person-environment (p-e) dimensions appeared to have linear relationships with psychological well-being; (2) the p-e fit - well-being relationship did not appear to be confounded by demographic factors; (3) all p-e fit dimensions were significantly related to well-being except for autonomy; (4) p-e fit was more strongly related to well-being than the environmental measure alone; (5) supervisor support and non-work related support were found to have additive effects on the relationship between p-e fit and well-being, however no interaction or buffering effects were observed; (6) locus of control was found to have additive effects in the prediction of well-being and showed interactive effects with work pressure, involvement and physical comfort; and (7) the testing of the overall study model which included many of the components mentioned above yielded an R('2) = .27.^ Implications of these findings are discussed, future research suggested and applications proposed. ^

AN INVESTIGATION OF THE POSSIBLE RELATIONSHIP BETWEEN CERTAIN PHYSIOLOGICAL AND PSYCHOLOGICAL MEASURES AND SMOKING CESSATION IN A SELF - SELECTED POPULATION

This study focused on the possible relationship between certain physiological and psychological variables and the cessation of smoking. The population studied was employees enrolled in a multimodality smoking cessation program at the local offices of a major American corporation. In order to be eligible to participate, each individual must have become a non-smoker by the end of the smoking cessation program.^ Three physiological measures were taken on each individual while performing a relaxation exercise; (1) Electromyogram (EMG), (2) Galvanic Skin Response (GSR), and (3) Skin Temperature. The psychological measure consisted of the variable "anxiety" in the Cattell 16-PF personality inventory. Individual's self report of their smoking status was verified through a test for expired carbon monoxide levels.^ For the total population (N-31) no significant relationships were found between the physiological and psychological variable measured and cessation; however, with the removal of two cases discovered during the post-test interview to be influenced by external factors of high caffeine level and a severe family crisis, the measure of EMG, attained significance in discriminating between the successful and unsuccessful in Smoking Cessation. ^

Posttraumatic stress disorder among veterans of the Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF) wars: Psychological comorbidities, postdeployment social support and unit support

Much attention has been given to treating Operation Iraqi Freedom/Operation Enduring (OIF/OEF) Veterans with posttraumatic stress disorder (PTSD). However, little attention is given to those Veterans who do not meet diagnostic criteria for PTSD but who may still benefit from intervention. Research is needed to investigate the impact of how different racial/ethnic backgrounds, different levels of social support and comorbid mental health disorders impact OIF/OEF Veterans with varying levels of PTSD. The purpose of this dissertation is to examine the association of comorbid Axis I disorders, race/ethnicity, different levels of postdeployment social support and unit support on OIF/OEF Veterans with varying levels of PTSD. Data for this dissertation were from postdeployment screenings of OIF/OEF Veterans from a large Veterans Affairs hospital in southeast Texas. To examine the study hypotheses, we conducted multinomial logistic regressions of the clinician reported data. ^ The first article examined the prevalence of subthreshold and full levels of PTSD and compared Axis I and alcohol use comorbidity rates among 1,362 OIF/OEF Veterans with varying levels of PTSD. Results suggest that OIF/OEF Veterans with subthreshold PTSD experience similar levels of psychological distress as those with full PTSD and highlight the need to provide timely and appropriate mental health services to individuals who may not meet the diagnostic criteria for full PTSD. ^ These results suggest that OIF/OEF Veterans of all race/ethnicities can benefit from strong social support systems. Postdeployment social support was found to be a protective factor against the development of PTSD among White, Black and Hispanic veterans while deployment unit support was a protective factor only among Black Veterans. The second article investigated the association between postdeployment social support and unit support with varying levels of PTSD by race/ethnicity among 1,115 OIF/OEF Veterans. ^ The results of this study can help to formulate treatment and interventions for OIF/OEF Veterans with varying levels of PTSD and social support systems.^

Hearing aid use and adherence: A systematic review of the literature concerning the socioeconomic and psychological influences on hearing aid use and barriers to use

The current hearing health situation in the United States does not provide adequate support to individuals with hearing loss. More research is needed to give more support to these individuals. By conducting a systematic review of relevant literature from 1990 to present, I identified many factors that influence an individual's use of hearing aids. There are two research questions in this study: 1. Does the provision of screening and access to hearing aids decrease the negative effects of hearing loss? 2. Why is it difficult for people with hearing loss to adapt to and use hearing aids? The population of interest was adults (>18 years old) with hearing loss. Factors that influenced use of hearing aids for this population included age, gender, socioeconomic status, education, perceived severity of hearing loss, cost of hearing aids, screening, perceived benefit, stigmatization, perceived control, cognitive capability, personality, and social support. Research suggests that more efficient screening of at-risk individuals and the provision of better access to these individuals would prevent many of the negative effects of hearing loss.^

An assessment of post-disaster psychological stress in hazardous waste operations and emergency response (HAZWOPER) workers

Personnel involved in natural or man-made disaster response and recovery efforts may be exposed to a wide variety of physical and mental stressors that can exhibit long-lasting and detrimental psychopathological outcomes. In a disaster situation, huge numbers of "secondary" responders can be involved in contaminant clean-up and debris removal and can be at risk of developing stress-related mental health outcomes. The Occupational Safety and Health Administration (OSHA) worker training hierarchy typically required for response workers, known as "Hazardous Waste Operations and Emergency Response" (HAZWOPER), does not address the mental health and safety concerns of workers. This study focused on the prevalence of traumatic stress experienced by secondary responders that had received or expressed interest in receiving HAZWOPER training through the National Institute of Environmental Health Sciences Worker Education and Training Program (NIEHS WETP). ^ The study involved the modification of two preexisting and validated survey tools to assess secondary responder awareness of physical, mental, and traumatic stressors on mental health and sought to determine if a need existed to include traumatic stress-related mental health education in the current HAZWOPER training regimen. The study evaluated post-traumatic stress disorder (PTSD), resiliency, mental distress, and negative effects within a secondary responder population of 176 respondents. Elevated PTSD levels were seen in the study population as compared to a general responder population (32.9% positive vs. 8%-22.5% positive). Results indicated that HAZWOPER-trained disaster responders were likely to test positive for PTSD, whereas, untrained responders with no disaster experience and responders who possessed either training or disaster experience only were likely to test PTSD negative. A majority (68.75%) of the population tested below the mean resiliency to cope score (80.4) of the average worker population. Results indicated that those who were trained only or who possessed both training and disaster work experience were more likely to have lower resiliency scores than those with no training or experience. There were direct correlations between being PTSD positive and having worked at a disaster site and experiencing mental distress and negative effects. However, HAZWOPER training status does not significantly correlate with mental distress or negative effect. ^ The survey indicated clear support (91% of respondents) for mental health education. The development of a pre- and post-deployment training module is recommended. Such training could provide responders with the necessary knowledge and skills to recognize the symptomology of PTSD, mental stressors, and physical and traumatic stressors, thus empowering them to employ protective strategies or seek professional help if needed. It is further recommended that pre-deployment mental health education be included in the current HAZWOPER 24- and 40-hour course curriculums, as well as, consideration be given towards integrating a stand-alone post-deployment mental health education training course into the current HAZWOPER hierarchy.^

Work instability. Presentation of an empirical model about its psychological impact

Research on the impact that work instability has on workers has the limitation of assess the relations among different variables separately, without examining the possible mediation relationships that can exists between them. The aim of this article is to test a conceptual model of the mediating relations between the uneasiness due to work instability and the psychological impact, in the framework of interactive stress theory, conducting a Path Analysis. 191 workers participated on the study, with a mean age of 31 years-old (SD = 11). Results showed that the proposed model didn't fit to the data. Alternative models were explored, consistent with the original conceptual model and the empiric evidence. A new causal model is proposed, where Uneasiness due to Work Instability as an independent variable, Personal Strain and Personal Resources as intervenient variables, and Anger, Hopelessness, and Satisfaction as dependent ones. The theoretical and empirical importance of the resulting model is discussed.

Work instability. Presentation of an empirical model about its psychological impact

Research on the impact that work instability has on workers has the limitation of assess the relations among different variables separately, without examining the possible mediation relationships that can exists between them. The aim of this article is to test a conceptual model of the mediating relations between the uneasiness due to work instability and the psychological impact, in the framework of interactive stress theory, conducting a Path Analysis. 191 workers participated on the study, with a mean age of 31 years-old (SD = 11). Results showed that the proposed model didn't fit to the data. Alternative models were explored, consistent with the original conceptual model and the empiric evidence. A new causal model is proposed, where Uneasiness due to Work Instability as an independent variable, Personal Strain and Personal Resources as intervenient variables, and Anger, Hopelessness, and Satisfaction as dependent ones. The theoretical and empirical importance of the resulting model is discussed.

Work instability. Presentation of an empirical model about its psychological impact

Research on the impact that work instability has on workers has the limitation of assess the relations among different variables separately, without examining the possible mediation relationships that can exists between them. The aim of this article is to test a conceptual model of the mediating relations between the uneasiness due to work instability and the psychological impact, in the framework of interactive stress theory, conducting a Path Analysis. 191 workers participated on the study, with a mean age of 31 years-old (SD = 11). Results showed that the proposed model didn't fit to the data. Alternative models were explored, consistent with the original conceptual model and the empiric evidence. A new causal model is proposed, where Uneasiness due to Work Instability as an independent variable, Personal Strain and Personal Resources as intervenient variables, and Anger, Hopelessness, and Satisfaction as dependent ones. The theoretical and empirical importance of the resulting model is discussed.

How does contract design affect the uptake of microcredit among the ultra-poor? : experimental evidence from the river islands of Northern Bangladesh

Despite the professed claims of microcredit alleviating poverty, little is known about what kind of credit contract is suitable for extremely poor households, also called the ultra-poor. To fill this knowledge gap, we initiated a field experiment in the river islands of northern Bangladesh, where a substantial portion of dwellers could be categorized as ultra-poor due to cyclic floods. We randomly offered four types of loans to such dwellers: regular small cash loans with one-year maturity, large cash loans with three-year maturity both with and without a one-year grace period, and in-kind livestock loans with three-year maturity and a one-year grace period. We compared uptake rates as well as the determinants of uptake and found that the uptake rate is the lowest for the regular contract, followed by the in-kind contract. Contrary to prior belief, we also found that the microcredit demand by the ultra-poor is not necessarily small, and in particular the ultra-poor are significantly more likely to join a microcredit program than the moderately poor if a grace period with longer maturity is attached to a large amount of credit, irrespective of whether the credit is provided in cash or in kind. This paper provides evidence that a typical microcredit contract with one-year maturity and without a grace period is not attractive to the ultra-poor. Microfinance institutions may need to design better credit contracts to address the poor's needs.

Conformance monitoring, contract of objectives, tube in the sky

Ponencia invitada sobre asignacion y gestion de losts en el curso de verano de la UPM Research in Decisión Support Systems for future Air Traffic Management

Zero-G Gauging systems. CONTRACT No 17/8/4

Various systems for measuring propellant content in spacecrafts under weightlessness conditions are reviewed. The cavity resonator method is found to be the most suitable measurement; technique. This method is analyzed in detail. A determination of errors intrinsec to the method is carried out.

Assessment of irrigators’ preferences for different water supply risk management tools: option contract and insurance.

Irrigators face the risk of not having enough water to meet their crops’ demand. There are different mechanisms to cope with this risk, including water markets (option contracts) or insurance. A farmer will purchase them when the expected utility change derived from the tool is positive. This paper presents a theoretical assessment of the farmer’s expected utility under two different option contracts, a drought insurance and a combination of an option contract and the insurance. We analyze the conditions that determine farmer’s reference for one instrument or the other and perform a numerical application that is relevant for a Spanish region.