Thomas J. Bierma

National General Practice Study of Epilepsy and Epileptic Seizures: Objectives and Study Methodology of the Largest Reported Prospective Cohort Study of Epilepsy

Most available data on the prognosis of epileptic seizures come from hospital-based clinics in which patients with chronic or severe disease are over-represented. The National General Practice Study of Epilepsy and Epileptic Seizures is a large prospective community-based study of people with newly diagnosed seizures which aims to address questions related to the early prognosis of epilepsy. 275 general practitioners throughout the United Kingdom have registered a total of 1,195 patients. In this paper we discuss the background to the study and the methodology used.

Producing biodiesel using whole-cell biocatalysts in separate hydrolysis and methanolysis reactions.

This research examined the effect of using separate hydrolysis and methanolysis reactions for biodiesel production using a whole-cell biocatalysts derived from Rhizopus Oryzae (ATCC 10260). Biodiesel yield from separate hydrolysis and methanolysis was compared to transesterification reactions where both hydrolysis and methanolysis reactions occur in the same reactor. All reactions were conducted at room temperature. The effect of substituting ethanol for methanol was also studied. Separating the hydrolysis and methanolysis reactions did not significantly increase biodiesel yields; however, this approach successfully converted about 99% of triglycerides into fatty acid methyl esters (FAME) and free fatty acids (FFA). Use of ethanol in place of methanol did not significantly improve the biodiesel yield. However, there is evidence that ethanol may either esterify FFA more quickly than methanol, or result in a more stable ester. The best biodiesel yield was about 90% when a transesterification reaction using methanol was followed by one hydrolysis and one ethanolysis reaction; however, this is only slightly higher than the 88% biodiesel yield of two transesterification reactions in series (using methanol as alcohol).

A New Direction in Low-Back Pain Research

This article suggests reasons for the difficulty in understanding and preventing low-back pain (LBP), provides a framework for understanding the causes of reported LBP, and highlights an important new direction in research that could accelerate progress in reducing LBP. Fundamental to understanding LBP is the recognition that it is a symptom not an underlying condition. Worker reports of LBP depend not only on the extent and nature of underlying injury but also the workers perceptions and the likelihood of reporting the symptoms. Each of these factors, in turn, depends on a number of other proximal and distal factors. Identifying the root causes of underlying injury is essential to improving prevention programs. Yet, many of the methods used to study LBP and its causes have serious shortcomings, adding to the confusion over appropriate preventive strategies. An important gap in LBP research has been the factors influencing preventive behaviors for both workers and managers. If workers or managers attribute the causes of LBP to the wrong factors, preventive behaviors will be misdirected and ineffective. Attribution theory, a relatively recent application in the occupational health field, offers promise for identifying incorrect attributions and modifying these attributions so that appropriate protective actions are taken.

Routine Blood Chemistry Screen: A Diagnostic Aid for Alzheimer's Disease

Results of blood chemistry screens of 47 Alzheimers disease patients were compared to those of 71 non-Alzheimers disease patients with other dementias. Only kidney-related tests differed between the groups (urea nitrogen, creatinine, uric acid and albumin) with the Alzheimers disease patients nearer the normal ranges. Multivariate analyses were used to examine whether the simultaneous use of the analytes could aid in diagnosing Alzheimers disease. Linear and quadratic discriminant analysis and logistic regression were used to evaluate a number of models. A linear discriminant model of albumin, uric acid, lactate dehydrogenase, and age demonstrated 70-75% classification accuracy using randomly selected test populations of 20%.

Use of a whole-cell biocatalyst to produce biodiesel in a water-containing system

This study examined the use of a whole-cell biocatalyst to transesterify triglycerides, including high-Free Fatty Acid (FFA) waste greases, in a water-containing system. The whole-cell biocatalyst derived from Rhizopus oryzae (ATCC10260) was grown and reacted at room temperature without immobilization. The effectiveness of improving biodiesel yield through alteration of reaction temperature, additional alcohol, and additional transesterification reaction was also examined. Results showed that whole-cell biocatalyst was able to produce biodiesel with a yield of about 75% for virgin canola oil, 80% for waste vegetable oil and 55% for brown grease with a 72-hr transesterification reaction using no excess methanol. Elevating the reaction temperature to 35°C significantly diminished the yield. An additional dose of methanol with another 24 hours of reaction time or a second 72-hr reaction resulted in biodiesel yield approaching 90% and only 3% residual glycerides (mono-, di- and tri-glycerides). These results suggest that whole-cell biocatalysts are able to transesterify waste oils or greases that are high in FFA and contain water. Brown (trap) grease and similar degraded or complex greases may be good candidates for further whole-cell biocatalyst research.

Accuracy and Precision of Home Radon Monitoring and the Effectiveness of EPA Monitoring Guidelines

EPA has provided guidelines to homeowners for monitoring and mitigating radon in the home. The effectiveness of these guidelines is dependent, in part, on the accuracy and precision of monitoring methods. This paper proposes a model for radon monitoring accuracy and precision based upon a review of the monitoring literature. The model is then used to quantify the extent of potential misclassification of homes by radon level from the application of EPA guidelines. Short-term monitoring performed in the basement during winter produced conservative (higher than actual) radon estimates, on average. For homes with annual concentrations of 4 pCi/L, approximately 30 percent will still have short-term results under 4 pCi/L. Underestimation of radon levels is cut by 50 percent or more by the use of monitors on first floor and basement (confirmatory monitoring) as opposed to monitoring the basement alone (screening monitoring). However, following the screening/confirmatory monitoring sequence suggested by EPA incre...

Biogas production from switchgrass under experimental conditions simulating U.S. digester operations

Lignocellulosic feedstocks have high energy content and have been co-digested with sewage or manure biosolids in Europe for many years. However, it is unclear whether the current U.S. anaerobic digesters are capable of co-digesting lignocellulosic feedstocks without experiencing operational problems. We evaluated co-digestion of switchgrass with sewage biosolids under laboratory conditions similar to common U.S. digesters. Results indicated that finely-ground or ensiled switchgrass could be readily co-digested with sewage biosolids under typical U.S. digester conditions. Concentration up to 4% solids (representing up to 47% of VS added) achieved good specific methane yields and up to 74% energy conversion efficiency while maintaining acceptable VS removal. No evidence of solids accumulation, mixing problems, or floating debris was noted. However, fine-grinding switchgrass is energy intensive and likely to be cost-prohibitive. Moreover, ensiling produced a wide array of particle sizes and the effects of ensiling could not be fully separated from effects due to smaller particle size. Coarsely ground switchgrass, however, did not digest well. It had a low specific methane yield and quickly led to digester operational problems, even at the 2% solids level. Further research is needed to identify pretreatment methods that are more practical than fine-grinding. Ensiling appears promising, and should be studied under full-scale ensiling and digestion conditions to assure that observed effects were not due to smaller particle sizes achieved under laboratory conditions. Other, low-cost pretreatment methods also deserve study as a means of allowing lignocellulosic feedstocks to be co-digested in current U.S. anaerobic digesters.

Factor VIII: C Relationships to Selected Lipids, Age, and Gender in Healthy Adults

The relationships between cholesterol, high-density lipoprotein-cholesterol (HDL-C), age, gender, estrogen use, and coagulation factor VIII (VIII:C) were examined in a group (n = 230) of healthy adults, age 21 to 68. No relationships were noted between factor VIII:C and cholesterol or estrogen usage; Factor VIII:C and age were positively related. A significant negative correlation was found between factor VIII:C and HDL-C in the group after the adjustment of age and gender. The study suggests possible relationship of VIII:C to development of arterial disease during the aging process.The relationships between cholesterol, high-density lipoprotein-cholesterol (HDL-C), age, gender, estrogen use, and coagulation factor VIII (VIII:C) were examined in a group (n = 230) of healthy adults, age 21 to 68. No relationships were noted between factor VIII:C and cholesterol or estrogen usage; Factor VIII:C and age were positively related. A significant negative correlation was found between factor VIII:C and HDL-C in the group after the adjustment of age and gender. The study suggests possible relationship of VIII:C to development of arterial disease during the aging process.

“Standards” as a Service Marketing Tool

Abstract Standards have the potential to be a significant tool in the marketing of services, just as they have been in the marketing of products. Ranging from regulatory to voluntary, product-based to producer-based, standards can increase the competitive position of a product by reducing customer uncertainty. However, the lack of a framework for understanding and designing standards has limited their application in service industries. Examination of existing standards suggests a framework of five key dimensions. Through the example of chemical management services (CMS) we show how this can be done, resulting in three options for the CMS industry. Using this framework as a guide, other service industries can determine if a standard would provide significant competitive advantage and, if so, design the optimal standard for their market conditions.