Anxiety sensitivity, defined as the fear of anxiety-related sensations and their consequences (Reiss & McNally, 1985), has been consistently shown to be associated with risk for anxiety psychopathology as well as other mental health problems. The primary objective of the present secondary prevention trial sought to examine strategies to reduce anxiety sensitivity among persons with elevated anxiety sensitivity by testing the singular and combined efficacy of two commonly used strategies in multi-component interventions for reducing anxiety sensitivity: (a) anxiety psychoeducation emphasizing the benign nature of stress and (b) interoceptive exposure (i.e. repeated inhalations of 35% CO₂ gas mixture). To provide a stringent control for non-specific effects associated with anxiety psychoeducation and interoceptive exposure with CO₂, two control strategies were included in the study design: general health and nutrition education and repeated inhalations of regular room air. Utilizing a 2X2 design, participants were randomly assigned to receive an education component and intervention sessions consisting of one of two gas mixtures. The current study did not support the relative efficacy of hypothesized active intervention strategies. Rather, all conditions led to significant reductions in anxiety sensitivity. In addition, within-condition effect sizes for conditions in the present study were comparable to effect sizes of active interventions that were efficacious in previous research. Findings from the present study support that anxiety sensitivity is malleable following brief, cost-efficient interventions and these reductions are maintained over a one-month follow-up period. Data from the present study suggest that in the presence of stringent control conditions, hypothesized active intervention strategies provided little additional benefit. The present study has implications for methodological considerations for future secondary prevention trials for the reduction of anxiety sensitivity. The absence of stringent control groups might lead to premature conclusions that reductions in anxiety sensitivity are due to the specific effects of active interventions. Further research is needed to elucidate specific effects of intervention strategies for the reduction of anxiety sensitivity in at risk populations in order to refine secondary prevention interventions aimed to reduce risk for psychopathology. / text

A growing body of literature suggests that Virtual Reality is a successful tool for exposure therapy for anxiety disorders. Virtual Reality (VR) researchers posit the construct of presence, interpreting an artificial stimulus as if it were real, as the mechanism that enables anxiety to be felt during virtual reality exposure therapy (VRE). However, empirical studies on the relation between presence and anxiety in VRE have yielded mixed findings. The current study tested the following hypotheses 1) Presence is related to in session anxiety and treatment outcome; 2) Presence mediates the extent that pre-existing (pre-treatment) anxiety is experienced during exposure with VR; 3) Presence is positively related to the amount of phobic elements included within the virtual environment. Results supported presence as the mechanism by which anxiety is experienced in the virtual environment as well as a relation between presence and the phobic elements, but did not support a relation between presence and treatment outcome

Enteric pathogens in pool water can be unintentionally ingested during swimming, increasing the risk of Acute Gastrointestinal Illness. Swimmer activities and behaviors influence pool water ingestion rates, and can be quantified for use in risk assessment. Enteric infection risk estimates help identify data gaps, areas to focus resources, and research needs. Primary objectives of this study were to develop electronic, self-administered "exposure" and "pool operations" questionnaires; to gather swimmer behavior and activity data for use in risk assessment; and to estimate Cryptosporidium parvum infection risk in swimmers. Results were used to identify data gaps and future research needs relative to treated recreational water. To achieve these objectives, 126 swimmers were recruited at four pool sites in Tucson, Arizona, video-taped, and asked to complete a post-swim questionnaire. Forty-six of the 126 swimmers submitted a 24 hr post-swim urine sample for quantifying pool water ingestion. Head submersion frequency and duration and splashes to the face were observed and quantified in video analysis, and activities and behaviors were reported on the exposure questionnaire. Variable data were analyzed for associations with pool water ingestion estimated by urinalysis. Results indicate questionnaires can be self-administered electronically; the exposure questionnaire can be used to estimate ingestion magnitude in place of urinalysis; leisure swimming activities (diving, playing, splashing, wading, sitting) and frequency of face splashes are ingestion exposure factors; and that Cryptosporidium infection risk is greatest among leisure swimmers. Other activities observed and suspected of having associations with ingestion were short submersion durations (<1 sec), and spitting and spouting water. More research and resources focused on improving treated recreational water environments and reducing risks among swimmers are needed. Developing an indicator organism test representative of Cryptosporidium, a monitoring program for treated recreational water, education aimed at leisure swimmer, and routine engineering and administrative controls are recommended. Swimming is a unique activity that can be enjoyed by people of all ages and abilities. Controlling hazards in pool environments reduces Recreational Waterborne Illness risks associated with pool water ingestion and improves the health and safety of swimmers.

Die verbesserte Prognose der Patienten mit akutem Herzinfarkt durch den Einsatz des Herzkatheters (HK) und den damit verbundenen Möglichkeiten der schnellen Revaskularisierung gilt heute als unumstritten. Nicht nur in der Notfallmedizin, sondern ganz besonders in der Diagnostik der koronaren Herzkrankheit (KHK) gilt die Herzkatheteruntersuchung (HKU) als Goldstandard. Bei steigenden Untersuchungszahlen dürfen die Risiken der effektiven Strahlenbelastung dieser apparativen radiologischen Untersuchungsform für den Patienten nicht vernachlässigt werden. Aufgrund der bisher mangelnden Angaben zur Strahlenbelastung bei Herzkatheteruntersuchungen war das Ziel der Studie die prospektive Erfassung der Durchleuchtungszeit, des Flächendosisproduktes und der effektiven Strahlendosis an einer großen Kohorte von Patienten, welche sich zwischen 01/2006 und 01/2009 einer Herzkatheteruntersuchung unterzogen hat. Zusätzliche Aufgabe war es mögliche Einflussfaktoren herauszuarbeiten und ihre Auswirkung auf die Strahlenbelastung mit einzubeziehen und zu diskutieren. Es wurden im Zeitraum von 1/2006 bis 1/2009 n = 32.153 durchgeführte Herzkatheteruntersuchungen erfasst und die Fluoroskopiezeiten und Strahlenbelastungen ermittelt. Die Herzkatheteruntersuchungen wurden in Abhängigkeit des Ziels der Untersuchung in diagnostische, therapeutische und kombinierte Untersuchungen unterteilt. Erfasst wurden die Patienten, die sich in diesem Zeitraum einer Herzkatheteruntersuchung unterzogen haben. Weitere patientenbezogene Daten wie das Geschlecht, Alter, Körpergröße und das Gewicht wurden in die Studie mit eingeschlossen. Des Weiteren wurden die durchgeführte Herzkatheteruntersuchung oder Intervention, das jeweilige Herzkatheterlabor sowie der Untersucher selbst erfasst. Bezüglich der verschiedenen Untersuchungen wurden insgesamt vier Hauptgruppen gebildet. Hierbei zeigte sich, dass diagnostische Herzkatheter signifikant weniger Strahlung benötigen, als therapeutische und kombinierte Interventionen. Zusätzlich von besonderem Interesse waren der Einfluss des Zugangsweges, des Untersuchers sowie der Vergleich unterschiedlichster Untersuchungsarten. Beim Vergleich der Zugangswege konnte aufgezeigt werden, dass der femorale Zugangsweg dem radialen bei rein diagnostischen Herzkatheteruntersuchungen in Bezug auf die primären Endpunkte signifikant überlegen ist. Bei therapeutischen und kombinierten Untersuchungen tritt der Unterschied jedoch in den Hintergrund. Bei der Analyse der Untersucher konnte aufgezeigt werden, dass in den ersten zwei Jahren die erfahrenen Kardiologen signifikant weniger Strahlung verbrauchen, als Unerfahrenere.

In surface hydrology, much attention is paid to the effects of changing water fluxes, however there is less of a focus on the effects of changing energy fluxes. These energy fluxes are an important driver of many hydrological processes such as evapotranspiration and snow sublimation/ablation. The hypothesis that varying energy fluxes are important to the hydrological features of a catchment is tested by an experiment that involves calculating mean transit times for a number of catchments that drain different aspects of a large dome located in the Valles Caldera, New Mexico, called Redondo Peak. These catchments have different orientations and therefore receive different amounts of solar radiation. There is a general correlation between mean transit times, as determined by lumped-parameter convolution, and aspect, suggesting that in the Valles Caldera, transit times might be affected by a variety of features that are influenced by exposure to solar radiation, such as slope steepness, vegetation patterns, and soil depth. To put these transit times into context, I also used a distributed physically-based model to simulate a number of factors simultaneously to determine how hydrological features are influenced by aspect. This modeling excercise has illuminated the aspect-dependence of hydrological features such as the timing and intensity of snowmelt and soil moisture patterns, and it has quantified differences in energy and water fluxes on different aspects. These factors affect both water storage and water fluxes, and are therefore tied to transit times.

Introduction. The relationships among military service, combat intensity and long-term health effects were investigated in a cohort of 6,355 Vietnam-era American Legionnaires who were recruited in 1984 and followed through 1998. First, the effect of Vietnam service on coronary heart disease (CHD) risk was assessed among 3,781 veterans who responded to both questionnaires. Next, the effect of serving in Vietnam and combat exposure was investigated as risk factors for the mortality of the cohort. Finally, potential threats to the validity of this study were evaluated.Methods. Military service and lifestyle factors were assessed by questionnaires in 1984 and 1998. Vital status in 1998 was determined and causes of death were ascertained through the National Death Index. Cox proportional hazards modeling was used to calculate hazard ratios (HR) and 95% confidence intervals (CI) for CHD incidence and mortality in relation to service location and combat exposure, adjusting for age, smoking, alcohol consumption, body mass, and hypertension. Response bias and reliability of self-reported data were examined.Results. Serving in Vietnam was associated with an increased hazard of developing heart disease (HR=1.37, 95% CI: 1.09, 1.73), after controlling for independent risk factors. Vietnam veterans experienced a 50% higher mortality than non-Vietnam veterans during 14-year follow-up (HR=1.48, 95% CI= 1.13 - 1.93), which increased with combat intensity after adjustment for other risk factors, (low combat: HR 1.17, 95% CI 0.79 - 1.73; medium combat HR=1.51, 95% CI 1.05 - 2.17; high combat HR=1.82, 95% CI 1.20 - 2.76). A stronger relationship was observed by level of combat for CHD mortality (low combat: HR =1.48, 95% CI 0.75 - 2.95; medium combat HR= 2.01, 95% CI 1.06 - 3.79; high combat HR= 2.27, 95% CI 1.08 - 4.79). Results showed that non-respondents differed only slightly from respondents for important variables potentially related to exposures and chronic disease outcomes. Furthermore, veteran self-report was moderately to highly reliable when measured over a 14 year period.Conclusions. Vietnam veterans are still experiencing higher rates of adverse health effects, even more than thirty years after their military service. These data support a long term and independent adverse effect of military service in Vietnam on cardiovascular health.

Multinational enterprises (MNEs) are central drivers behind neo-liberal globalisation. These enterprises are usually centred in developed countries, with competitive operations in developing countries. The literature on MNEs and foreign direct investment usually focus on the motivation for investment, decisions on expansion, the structure of ownership of investment, the mode of entry, and the perception of risk. Fluctuation in the exchange rate is a source of uncertainty that affects MNEs' and other enterprises' market values. Enterprises' exposure to changes in the exchange rate has increased with the adoption of floating exchange rates and more intensive involvement in international trade. The conventional belief is that competition in the export market is positively related to a depreciation of the exchange rate, which will in turn be advantageous to the stock market, while the opposite is true for an appreciation of the exchange rate. If the contribution of import or intermediate imported inputs to the final production were quite large, an appreciation of the exchange rate will have a positive effect on input costs and the stock market. This study investigates the exchange rate exposure of multinational enterprises in South Africa to the bilateral exchange rate of the rand against the US dollar and the nominal effective exchange rate of the rand. It presents evidence on the direction and magnitude of currency exposure. From the empirical results presented in this study it can be concluded that the majority of MNEs are not significantly exposed to either one of the exchange rate changes. It has also been found that the majority of enterprises lose market value when their local currency depreciate against the US dollar, while the majority of South African enterprises are positively related to changes in the nominal effective exchange rate of the rand. MNEs that are not significantly exposed to changes in exchange rates could be subject to three possibilities. (1) The most obvious reason is that enterprises are not exposed to changes in the exchange rate. Enterprises in liberated (or •open") countries are more exposed to exchange rate movements as opposed to those in closed countries, such as the USA. (2) Enterprises could be engaged in on and off balance sheet hedging activities, which would reduce exchange rate exposures. (3) The methodology used in a study does not present the correct exposure results. / Thesis (M.Com. (Economics))--North-West University, Potchefstroom Campus, 2005.

Background: Polybrominated diphenyl ethers (PBDEs) are additive flame retardants which are found in household and commercial products. These chemicals have the potential to leach from the product into the environment. Human health effects include neurodevelopmental changes, low birth weight and thyroid hormone changes have also been reported, although continued research in this field is needed. Humans are exposed to PBDEs through various exposure pathways and recent studies have determined that exposure to household dust is also a significant route of exposure for humans. The purpose of this study was to access the risk for PBDE intake through an exposure assessment. Also, a laboratory protocol for the fractionation and determination of PBDEs in household dust was developed and evaluated. Methods: PBDE concentrations in indoor dust were measured and compared to previously published data on the topic. A laboratory protocol for fractionation of indoor dust and determination of PBDEs in indoor dust was developed. The new laboratory method was compared to a previously published lab procedure to determine its effectiveness. A p-value of <0.01 and 95% confidence intervals were used to determine statistical significance. Intake estimates were also determined for adults and children exposed at different rates. Results: PBDEs were detected in all the house dust samples with total concentrations (sum of 12 congeners) ranging from 2,870 to 50,642 ng/g dry mass. The averaged concentrations from the six replicate sieve fractions ranged from 106 to 5,697 ng/g dry weight. Daily dust intake rates, based on previously published estimates, range from 20 to 200 mg/day for children and 0.56 to 50 mg/day for adults. Low and high estimates of the daily intake of PBDEs in children and adults were calculated using the average concentration of total PBDEs found in house dust in this study. The exposure estimates for children were approximately 371 to 3,709 ng PBDEs daily based on a mean value of 18,546 ng/g dry weight. The estimate for adults was approximately 10.4 to 927 ng/g dry weight. Conclusions: The new laboratory protocol produces comparable results for QA/QC materials compared to a previously published protocol. Particulate size does not appear to be a significant factor in PBDE concentration and future analysis may only need dust particles to be sieved to one or two sizes (i.e. 500 um and 125 um). Based on the potential intake calculations for children and adults, dust appears to be a significant route of exposure for PBDEs and analysis of additional dust samples will broaden the scope of available data for this method.

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