Toward Enhanced Machine-Based Release in X-ray Sterilization.

Trends toward the use of irradiator parameter release (also called machine-based release) put pressure on equipment manufacturers to guarantee accuracy and reliability of monitored process parameters. In the specific case of X-ray processing, relevance of these monitored parameters is questionable due to the additional difficulty coming from the fact that the X-ray converter does not have associated parameters or a monitored feedback mechanism. To bridge this gap, this article presents a novel method to verify in real-time consistency of certain X-ray field properties.

Reliability of isokinetic tests of velocity- and contraction intensity-dependent plantar flexor mechanical properties.

"Flexibility" tests are traditionally performed voluntarily relaxed by rotating a joint slowly; however, functional activities are performed rapidly with voluntary/reflexive muscle activity. Here, we describe the reliabilities and differences in maximum ankle range of motion (ROM ) and plantar flexor mechanical properties at several velocities and levels of voluntary force from a new test protocol on a commercially available dynamometer. Fifteen participants had their ankle joint dorsiflexed at 5, 30, and 60° s in two conditions: voluntarily relaxed and while producing 40% and 60% of maximal eccentric torque.

A chemical structure-based approach for estimating the added levels of flavourings to foods for the purpose of assessing consumer intake.

Intake assessment and hazard profile of chemical substances are the two critical inputs in a safety assessment. Human intake assessment presents challenges that stem either from the absence of data or from numerous sources of variability and uncertainty, which have led regulators to adopt conservative approaches that inevitably overestimate intake. Refinements of intake assessments produce more realistic estimates and help prioritise areas of concern and better direct investment of resources.

Effects of Resistance Training Movement Pattern and Velocity on Isometric Muscular Rate of Force Development: A Systematic Review with Meta-analysis and Meta-regression.

Background: Muscular rate of force development (RFD) is positively influenced by resistance training. However, the effects of movement patterns and velocities of training exercises are unknown.

Objectives: To determine the effects of velocity, the intent for fast force production, and movement pattern of training exercises on the improvement in isometric RFD from chronic resistance training.

The effect of isokinetic dynamometer deceleration phase on maximum ankle joint range of motion and plantar flexor mechanical properties tested at different angular velocities.

During range of motion (max-ROM) tests performed on an isokinetic dynamometer, the mechanical delay between the button press (by the participant to signal their max-ROM) and the stopping of joint rotation resulting from system inertia induces errors in both max-ROM and maximum passive joint moment. The present study aimed to quantify these errors by comparing data when max-ROM was obtained from the joint position data, as usual (max-ROM), to data where max-ROM was defined as the first point of dynamometer arm deceleration (max-ROM). Fifteen participants performed isokinetic ankle joint max-ROM tests at 5, 30 and 60° s.

Adipocyte-Specific GH Receptor-Null (AdGHRKO) Mice Have Enhanced Insulin Sensitivity With Reduced Liver Triglycerides.

Global GH receptor-null or knockout (GHRKO) mice have been extensively studied owing to their unique phenotype (dwarf and obese but remarkably insulin sensitive and long-lived). To better understand the influence of adipose tissue (AT) on the GHRKO phenotype, we previously generated fat-specific GHRKO (FaGHRKO) mice using the adipocyte protein-2 (aP2) promoter driving Cre expression. Unlike global GHRKO mice, FaGHRKO mice are larger than control mice and have an increase in white AT (WAT) mass and adipocyte size as well as an increase in brown AT mass.

Increased fibrosis: A novel means by which GH influences white adipose tissue function.

Objective: White adipose tissue (WAT) fibrosis - the buildup of extracellular matrix (ECM) proteins, primarily collagen - is now a recognized hallmark of tissue dysfunction and is increased with obesity and lipodystrophy. While growth hormone (GH) is known to increase collagen in several tissues, no previous research has addressed its effect on ECM in WAT. Thus, the purpose of this study is to determine if GH influences WAT fibrosis.

Cadmium exposure and tobacco consumption: Biomarkers and risk assessment.

To investigate whether cadmium has an independent role in diseases associated with tobacco consumption, epidemiology data were reviewed, biomonitoring data were analyzed, and probabilistic risk assessment (PRA) was performed. Results from previous epidemiology studies have indicated that there are adverse health effects potentially in common between cadmium exposure and tobacco consumption. Analysis of publically available biomonitoring data showed that blood (B-Cd) and urine (U-Cd) cadmium were higher in cigarette smokers compared with smokeless tobacco (SLT) consumers, and B-Cd and U-Cd in SLT consumers were not significantly different than in non-consumers of tobacco.

Arsenic exposure and tobacco consumption: Biomarkers and risk assessment.

Arsenic is measurable in tobacco and cigarette mainstream smoke (MSS). Whether arsenic has an independent role in diseases associated with tobacco consumption is not known. Epidemiology and biomonitoring data and probabilistic risk assessment (PRA) methods were used to investigate this potential association.

Race/ethnicity and mental health in the first decade of the 21st century.

Recent empirical studies on mental health generally report racial/ ethnic differences in depression rates but typically do not control for potential confounding by sample contextual variations in historical epoch, geographical location, and social demography. An empirical study of race/ethnicity differences in psychological distress is reported as an attempt to control these contexts by using a sample that is homogeneous in age, historical epoch, geography, and social demography (954 youth ages 18-19 living in a single, large urban community). No mean differences in psychological distress were observed among four racial/ethnic groups: Asians, African Americans, Latinos, and non-Hispanic Whites.

A probabilistic risk assessment approach used to prioritize chemical constituents in mainstream smoke of cigarettes sold in China.

The chemical and physical complexity of cigarette mainstream smoke (MSS) presents a challenge in the understanding of risk for smoking-related diseases. Quantitative risk assessment is a useful tool for assessing the toxicological risks that may be presented by smoking currently available commercial cigarettes. In this study, yields of a selected group of chemical constituents were quantified in machine-generated MSS from 30 brands of cigarettes sold in China.

Differential exposure biomarker levels among cigarette smokers and smokeless tobacco consumers in the National Health and Nutrition Examination Survey 1999-2008.

Assessment of biomarkers is an appropriate way to estimate exposure to cigarette mainstream smoke and smokeless tobacco (SLT) constituents in tobacco consumers. Using the US National Health and Nutrition Examination Survey (NHANES, 1999-2008), biomarkers of volatile organic compounds, halogenated aromatic hydrocarbons (HAHs), polycyclic aromatic hydrocarbons (PAHs), acrylamide, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), and metals were evaluated. In general, biomarker levels in SLT consumers were significantly lower than in smokers (excluding NNK and some HAHs) and were not significantly different compared with nonconsumers (excluding NNK and some PAHs).

A Bayesian statistical analysis of mouse dermal tumor promotion assay data for evaluating cigarette smoke condensate.

The mouse dermal assay has long been used to assess the dermal tumorigenicity of cigarette smoke condensate (CSC). This mouse skin model has been developed for use in carcinogenicity testing utilizing the SENCAR mouse as the standard strain. Though the model has limitations, it remains as the most relevant method available to study the dermal tumor promoting potential of mainstream cigarette smoke.

Community violence and psychological distress: the protective effects of emotional social support and sense of personal control among older adolescents.

This empirical study investigated three mechanisms of protection (preventive, compensatory, buffering) for two factors (emotional social support, sense of personal control) in the relationship between exposure to community violence and psychological distress among 947 diverse, older adolescents. Findings indicate that social support and sense of personal control do provide protection; however, the primary mechanism is compensatory (for support r = -.35; for control, r = -.

Trauma, protection, and distress in late adolescence: a multi-determinant approach.

This empirical study investigated the multivariable relationship between psychological distress and the combination of a set of four trauma events (victim of violence, witness of violence, victim of accidents, and interpersonal loss) and a set of four protective factors (emotional social support, sense of personal efficacy, easygoing temperament, and gender) among a sample of 1,066 graduating high school seniors in a large urban community. Each of the eight independent variables had a statistically significant zero-order correlation with psychological distress. The set of eight variables (four trauma and four protective) had a multiple correlation of R = .

Mental health services: use and disparity among diverse college students.

Objective: In this empirical study, the authors examined (1) actual use of counseling for emotional problems and (2) the assumptions that ethnicity, sex, social class, and psychological distress are associated with disparities in use of counseling.

Participants: Participants were 1,773 diverse undergraduate students at an urban university.

Methods: The authors collected data via self-administered questionnaires between 1999 and 2005; they used a cross-sectional correlational research design, including analysis of variance statistical procedures.

Adolescents' psychological response to the experience of community interpersonal violence: a cross-national and a cross-cultural comparison.

A comparative cross-national study investigating the level of experience with community interpersonal violence, level of psychological distress, and the relationship between exposure and distress among adolescents is presented. Participants were 617 first-year college students comprising African Americans and Jamaican Americans living in New York City, and Jamaicans living in Kingston, Jamaica. The three groups are similar in terms of age, gender, educational level, and race; they differ in location of residence, culture, and immigration status.

Mechanism of 24,25-dihydroxyvitamin D3-mediated inhibition of rapid, 1,25-dihydroxyvitamin D3-induced responses: role of reactive oxygen species.

In intestine, 24,25(OH)(2)D(3), which is made under conditions of calcium-, phosphate-, and 1,25(OH)(2)D(3) sufficiency, inhibits the stimulatory actions of 1,25(OH)(2)D(3) on phosphate and calcium absorption. In the current work, we provide evidence that 24,25(OH)(2)D(3)-mediated signal transduction occurs mechanistically through increased H(2)O(2) production which involves binding of 24,25(OH)(2)D(3) to catalase and resultant decreases in enzyme activity. Physiological levels of H(2)O(2) mimicked the action of 24,25(OH)(2)D(3) on inhibiting 1,25(OH)(2)D(3)-stimulated phosphate uptake in isolated enterocytes.

Exposure to community violence and upper respiratory illness in older adolescents.

Purpose: To examine the relationship between exposure to chronic community violence and upper respiratory illness (URI) symptoms among urban adolescents of color; and to test the generality of a model of the relationship between social stress and URI.

Method: The research used a cross-sectional correlational design. The sample was 769 first-semester first-year students in an urban nonresidential 4-year college from the academic years 1999-2002.

Psychological effects of attack on the World Trade Center: analysis before and after.

Four different studies using a total sample of 711 from the same New York City student population tested a model that has emerged from previous research on disasters. The model suggests that postdisaster psychological distress is a function of exposure to the disaster, predisaster psychological distress, acute distress following the disaster, time elapsed between disaster and observation of distress, and additional traumatic experiences since the disaster. Although findings replicate those of previous cross-sectional studies regarding association of exposure and distress after the disaster, before and after studies did not detect an effect on postdisaster psychological distress of the World Trade Center attack.

The association of ecological variables and psychological distress with exposure to community violence among adolescents.

Ecological theory suggests that exposure to community violence should be related to individual, family, and community characteristics; traumatic stress theory suggests that exposure to community violence should be related to level of psychological distress. A correlational study of 468 older adolescents in New York City tested these hypotheses. Exposure was found to be moderately related to level of psychological distress, but was not related to family or neighborhood characteristics.

Assessment of the aquatic and terrestrial toxicity of five biodegradable polymers.

Radiofrequency countermeasures (i.e., chaff) may be released by fighter jets during tactical countermeasures training.

Impact of exposure to community violence and psychological symptoms on college performance among students of color.

This study examined longitudinal relationships among exposure to chronic community violence during high school, psychological distress during the first semester of college, and academic performance during the first three semesters of college. The sample comprised 385 students of color in a large city. Exposure to community violence and psychological distress were measured with additive scales; academic performance (school persistence, grade point average) was obtained from transcripts.

The relationship between exposure to community violence and psychological distress among adolescents: a meta-analysis.

This article is concerned with the "size of the relationship" between exposure to chronic community violence and psychological symptoms among adolescents. It analyzes all relevant empirical studies in the published literature during the last 20 years; uses quantitative methods to summarize findings; and estimates the effect size using meta-analysis. The 37 independent samples (n = 17,322) were coded on 19 categories, including size and characteristics of sample, and characteristics of the independent and dependent variables.