Dual-phase lag effects on thermal damage to biological tissues caused by laser irradiation

A dual-phase lag (DPL) bioheat conduction model, together with the broad beam irradiation method and the rate process equation, is proposed to investigate thermal damage in laser-irradiated biological tissues. It is shown that the DPL bioheat conduction model could predict significantly different temperature and thermal damage in tissues from the hyperbolic thermal wave and Fourier's heat conduction models. It is also found that the DPL bioheat conduction equations can be reduced to the Fourier heat conduction equations only if both phase lag times of the temperature gradient (τ_T) and the heat flux (τ_q) are zero. This is different from the DPL model for pure conduction materials, for which it can be reduced to the Fourier's heat conduction model provided that τ_q=τ_T. Effects of laser parameters and blood perfusion on the thermal damage simulated in tissues are also studied. The result shows that the overall effects of the blood flow on the thermal response and damage are similar to those of the time delay τ_T.     

Linear and non-linear parameterization of EEG during monitoring of carotid endarterectomy

In this paper, new quantitative linear (HLF ratio: high frequency/low frequency spectral power ratio) and non-linear parameters (ZC: zero crossing and FD: fractal dimension) which can assist the physician in real-time decision whether a shunt is required or not during intra-operative EEG monitoring of carotid endarterectomy are presented. The results obtained with the new parameters are compared with those achieved by other indexes proposed in the literature. The HLF ratio and ZC parameters yielded the best results with a 100% of correct identification of both shunt and no-shunt situations. The ZC can be also easily implemented in the real-time monitoring of EEG.     

Predicting RNA secondary structure based on the class information and Hopfield network

One of the models for RNA secondary structure prediction is to view it as maximum independent set problem, which can be approximately solved by Hopfield network. However, when predicting native molecules, the model is not always accurate and the heuristic method of Hopfield network is not always stable. It is because that the class information is lost and the accuracy is not determined by the number of base pairs only. Secondary structures of non-coding RNAs are believed conservative on the same class. However, software and web servers nowadays for RNA secondary structure prediction do not consider the class information. In this paper, we involve class information in the initialization of Hopfield network. When the initialization is improved, the promising experimental result shows the efficacy and superiority of our proposed methods.     

Mediation Analyses: Applications in Nutrition Research and Reading the Literature

Mediation analysis is a newer statistical tool that is becoming more prominent in nutrition research. Its use provides insight into the relationship among variables in a potential causal chain. For intervention studies, it can define the influence of different programmatic components and, in doing so, allows investigators to identify and refine a program's critical aspects. We present an overview of mediation analysis, compare mediators with other variables (confounders, moderators, and covariates), and illustrate how mediation analysis permits interpretation of the change process. A framework is outlined for the critical appraisal of articles purporting to use mediation analysis. The framework's utility is demonstrated by searching the nutrition literature and identifying articles citing mediation cross referenced with the terms “nutrition,” “diet,” “food,” and “obesity.” Seventy-two articles were identified that involved human subjects and behavior outcomes, and almost half mentioned mediation without tests to define its presence. Tabulation of the 40 articles appropriately assessing mediation demonstrates an increase in these techniques' appearance and the breadth of nutrition topics addressed. Mediation analysis is an important new statistical tool. Familiarity with its methodology and a framework for assessing articles will allow readers to critically appraise the literature and make informed independent evaluations of works using these techniques.     

Factors Influencing Dietary Protein Sources in the PREMIER Trial Population

Previous research suggests that protein intake, particularly plant protein, may benefit blood pressure control. However, very little has been published regarding protein sources in diets of US adults and factors influencing these choices. The purpose of this report is to describe specific sources of animal and plant proteins in diets of PREMIER clinical trial participants at baseline and how the PREMIER intervention, along with participant demographics, affected protein sources. Adult participants (n=809) who completed the 18-month PREMIER lifestyle intervention trial and had at least one diet recall at each of three study visits were included. Participants were recruited from four clinical centers in the Eastern, Southern, and Northeastern regions of United States. The PREMIER trial, conducted from 1999 to 2002, compared the impact on blood pressure of two structured behavioral interventions focusing on the traditional lifestyle modifications for blood pressure control with or without the Dietary Approaches to Stop Hypertension dietary pattern. Protein sources were assessed by two unannounced 24-hour recalls at each of three study visits. Differences in protein sources were mainly related to participant demographics, with relatively moderate impact of the intervention. The top four protein sources for all the study participants were poultry, dairy, refined grains and beef, each contributing approximately 10% to 17% in descending order to the total protein intake at baseline. Animal and plant protein each comprised approximately 66% and 34%, respectively, to the total daily protein intake at baseline, and such overall contribution pattern remained relatively constant over time. However, sex, race, age, and body weight status all influenced contribution patterns from different food groups significantly. These influences significantly impact choice and are essential elements to consider when designing intervention programs to alter protein contributions from animal vs plant sources.     

Review of the Nutritional Implications of Farmers' Markets and Community Gardens: A Call for Evaluation and Research Efforts

The development and promotion of farmers' markets and community gardens is growing in popularity as a strategy to increase community-wide fruit and vegetable consumption. Despite large numbers of farmers' markets and community gardens in the United States, as well as widespread enthusiasm for their use as a health promotion tool, little is known about their influcence on dietary intake. This review examines the current scientific literature on the implications of farmers' market programs and community gardens on nutrition-related outcomes in adults. Studies published between January 1980 and January 2009 were identified via PubMed and Agricola database searches and by examining reference lists from relevant studies. Studies were included in this review if they took place in the United States and qualitatively or quantitatively examined nutrition-related outcomes, including dietary intake; attitudes and beliefs regarding buying, preparing, or eating fruits and vegetables; and behaviors and perceptions related to obtaining produce from a farmers' market or community garden. Studies focusing on garden-based youth programs were excluded. In total, 16 studies were identified for inclusion in this review. Seven studies focused on the impact of farmers' market nutrition programs for Special Supplemental Nutrition Program for Women, Infants, and Children participants, five focused on the influence of farmers' market programs for seniors, and four focused on community gardens. Findings from this review reveal that few well-designed research studies (eg, those incorporating control groups) utilizing valid and reliable dietary assessment methods to evaluate the influence of farmers' markets and community gardens on nutrition-related outcomes have been completed. Recommendations for future research on the dietary influences of farmers' markets and community gardens are provided.