A COMPARATIVE ANALYSIS OF RISK PREFERENCE ELICITATION PROCEDURES USING MAIL SURVEY RESULTS

Research Methods/ Statistical Methods, Risk and Uncertainty,

HIV and mobility in the Lake Victoria Basin agricultural sector: A literature review

The Lake Victoria region has the highest HIV prevalence in the East African Community, which comprises Kenya, Uganda, Tanzania, Rwanda, and Burundi. This region also has a significant concentration of commercial agricultural plantations, which rely on mobile workers, an extensive system of out-grower schemes, and linkages with neighboring communities and transportation routes. This paper reviews the relationships between the various components of the plantation system and the spread of HIV, which is a complex and dynamic process. There has been relatively little research on these dynamic interactions, and the relevant policies and programs are generally silent on mobility-induced vulnerability to HIV. As such, this review first examines how the conditions and structure of the migration process may increase HIV vulnerability for migrants, thereby illuminating key challenges. Second, the review considers what may be done to address these issues, particularly within the plantation system. A comprehensive response to HIV would require that the plantation companies engage in efforts against HIV/AIDS across its entire time line (that is, ranging from efforts to prevent infection to attempts to mitigate its full impact on both agricultural workers and the business as a whole). Despite the logic of this argument, we do not yet have strong financial evidence proving that companies should invest in a comprehensive strategy. This critical gap should be addressed. For example, pilot programs on select plantations could be used to show the cost-benefits of addressing HIV/AIDS through a well-designed set of interventions aimed at the different target groups.HIV/AIDS, Mobility, Migrant workers, Agricultural plantations,

Traumatic Bilateral Pneumothoraces due to Sternal Wire Migration

Sternal wound complications after cardiac surgery are associated with increased morbidity and mortality. Wire migrations associated with sternal dehiscence can lead to catastrophic haemorrhage unless intervened in time. We present a case of sternal wire migration causing bilateral pneumothoraces

The Impact of Parents’ Categorization of Their Own Weight and Their Child’s Weight on Healthy Lifestyle Promoting Beliefs and Practices

Objective. To evaluate parents’ beliefs and practices related to childhood obesity and determine if these are influenced by parent’s perception of their own weight or their child’s weight. Methods. Parents of obese ( = 689) or normal weight ( = 1122) children 4–15 years in Georgia, USA, were randomly selected to complete a telephone survey. Frequency of child obesity-related perceptions, beliefs, and practices were assessed, stratified by parent-perceived self-weight and child weight status, and compared using Chisquared tests and multivariate logistic regression. Results. Most parents, regardless of perceived child weight, agreed that child overweight/obesity can cause serious illness (95%) but only one-half believed it was a problem in Georgia. Many (42.4%) failed to recognize obesity in their own children. More parents who perceived their child as overweight versus normal weight reported concern about their child’s diet and activity and indicated readiness for lifestyle change. Parents’ perception of their own weight had little additional impact. Conclusions. While awareness of child overweight as a modifiable health risk is high, many parents fail to recognize it in their own families and communities, reducing the likelihood of positive lifestyle change. Additional efforts to help parents understand their role in facilitating behavior change and to assist them in identifying at-risk children are required

Silicon Carbide Growth Using Laser Chemical Vapor Deposition

Silicon Carbide (SiC) has been grown from methyltrichlorosilane (MTS) and hydrogen using the Georgia Tech Laser Chemical Vapor Deposition (LCVD) system. A morphology study of LCVD-SiC fibers and lines was completed. Graphite and single crystal silicon were used as the substrates. In order to provide guidance to future growth of SiC, thermodynamic calculations for the C-H-Si-Cl system were performed using the SOLGASMIX-PV program.Mechanical Engineerin

Development of an antimicrobial blended white LED system containing pulsed 405-nm LEDs for decontamination applications

This study details the design, build and testing of a prototype antimicrobial blended white light unit containing pulsed red, yellow, green and 405nm LEDs. With a push for alternative methods of disinfection, optical methods have become a topic of interest. Ultra-violet (UV) light is widely known for its antimicrobial properties however; 405nm light has demonstrated significant antimicrobial properties against many common hospital acquired pathogens. In this study, a pulsed, blended, white-light prototype with a high content of 405 nm antimicrobial light, was designed, built and tested. Antimicrobial efficacy testing of the prototype was conducted using Staphylococcus aureus and Pseudomonas. aeruginosa, two bacteria which are common causes of hospital acquired infections. These were exposure to 3 different light outputs from the prototype and the surviving bacteria enumerated. Results showed that the mixed light output provided a much better CRI and light output under which to work. Also, the light output containing 405 nm light provided an antimicrobial effect, with decontamination of 103 CFUml-1 populations of both bacterial species. The other light content (red, yellow, green) had no beneficial or adverse effects on the antimicrobial properties of the 405nm light. The results suggest that with further development, it could be possible to produce an antimicrobial blended white light containing pulsed 405nm light that could supplement or even replace standard white lighting in certain environments

Efficacy of Pulsed 405-nm LEDs for antimicrobial photodynamic inactivation : effects of intensity, frequency, and duty cycle

Objective: This study investigates possible advantages in pulsed over continuous 405-nm LED-light for bacterial inactivation and energy efficiency. Background: Alternative non-antibiotic methods of disinfection and infection control have become of significant interest. Recent studies have demonstrated the application of systems using 405-nm light-emitting diodes for continuous disinfection of the clinical environment, and also for potential treatment of contaminated wounds. Methods: Liquid suspensions of 103 CFU/ml populations of Staphylococcus aureus were subject to pulsed 405-nm light of different frequencies, duty cycles and intensities, and for different lengths of time. Results: Pulsed exposures with the same average irradiance of 16 mWcm2 and varying duty cycle (25%, 50%, 75%), showed very similar performance compared with continuous exposures, with 95-98% reduction of S. aureus achieved for all duty cycles. The pulsing frequency was varied in intervals from 100 Hz - 10 kHz and appeared to have little effect on antimicrobial efficacy. However, when comparing pulsed with continuous exposure, an improvement in inactivation per unit optical energy was achieved, with results showing an increase of approximately 83% in optical efficiency. Conclusions: These results suggest that under pulsed conditions a lower energy consumption and lower perceived brightness could be achieved, thus potentially providing improved operating conditions for medical/infection-control applications without compromising antimicrobial efficacy

Influence of wind-speed on short-duration NO2 measurements using Palmes and Ogawa passive diffusion samplers

We assessed the precision and accuracy of nitrogen dioxide (NO2) concentrations over 2-day, 3-day and 7-day exposure periods measured with the following types of passive diffusion samplers: standard (open) Palmes tubes; standard Ogawa samplers with commercially-prepared Ogawa absorbent pads (Ogawa[S]); and modified Ogawa samplers with absorbent-impregnated stainless steel meshes normally used in Palmes tubes (Ogawa[P]). We deployed these passive samplers close to the inlet of a chemiluminescence NO2 analyser at an urban background site in Glasgow, UK over 32 discrete measurement periods. Duplicate relative standard deviation was < 7% for all passive samplers. The Ogawa[P], Ogawa[S] and Palmes samplers explained 93%, 87% and 58% of temporal variation in analyser concentrations respectively. Uptake rates for Palmes and Ogawa[S] samplers were positively and linearly associated with wind-speed (P < 0.01 and P < 0.05 respectively). Computation of adjusted uptake rates using average wind-speed observed during each sampling period increased the variation in analyser concentrations explained by Palmes and Ogawa[S] estimates to 90% and 92% respectively, suggesting that measurements can be corrected for shortening of diffusion path lengths due to wind-speed to improve the accuracy of estimates of short-term NO2 exposure. Monitoring situations where it is difficult to reliably estimate wind-speed variations, e.g. across multiple sites with different unknown exposures to local winds, and personal exposure monitoring, are likely to benefit from protection of these sampling devices from the effects of wind, for example by use of a mesh or membrane across the open end. The uptake rate of Ogawa[P] samplers was not associated with wind-speed resulting in a high correlation between estimated concentrations and observed analyser concentrations. The use of Palmes meshes in Ogawa[P] samplers reduced the cost of sampler preparation and removed uncertainty associated with the unknown manufacturing process for the commercially-prepared collection pads

Markovian Dynamics on Complex Reaction Networks

Complex networks, comprised of individual elements that interact with each other through reaction channels, are ubiquitous across many scientific and engineering disciplines. Examples include biochemical, pharmacokinetic, epidemiological, ecological, social, neural, and multi-agent networks. A common approach to modeling such networks is by a master equation that governs the dynamic evolution of the joint probability mass function of the underling population process and naturally leads to Markovian dynamics for such process. Due however to the nonlinear nature of most reactions, the computation and analysis of the resulting stochastic population dynamics is a difficult task. This review article provides a coherent and comprehensive coverage of recently developed approaches and methods to tackle this problem. After reviewing a general framework for modeling Markovian reaction networks and giving specific examples, the authors present numerical and computational techniques capable of evaluating or approximating the solution of the master equation, discuss a recently developed approach for studying the stationary behavior of Markovian reaction networks using a potential energy landscape perspective, and provide an introduction to the emerging theory of thermodynamic analysis of such networks. Three representative problems of opinion formation, transcription regulation, and neural network dynamics are used as illustrative examples.Comment: 52 pages, 11 figures, for freely available MATLAB software, see http://www.cis.jhu.edu/~goutsias/CSS%20lab/software.htm