Impact of lightweight and conventional jackhammers on the operator

Jackhammer manufacturers have recently developed lightweight (45-60 lbs) jackhammers intended to reduce the required lifting and pushing forces during operation. However, the vibration characteristics of the lightweight jackhammers and their effect on muscle activity are currently unknown. The objective of this study was to compare the measured vibration and muscle activity between: (i) conventional (90 lb) and light weight (60 lb) jackhammers, (ii) different pavement type/thickness combinations, and (iii) pneumatic and hydraulic jackhammers. Five jackhammers were tested on 4 and 6 inch thick asphalt and concrete pavements by four experienced operators. Analysis of the results revealed that both weight classes averaged 9.7 m/s(2) at the 20 Hz weighted 1/3 octave band frequency, and the TLV of daily exposure for either weight class of jackhammer was less than 1.5 hours/per day. There was an approximately 33% difference in vibration measured on the hand of the operators due to pavement thickness, 30% due pavement type, and no difference due to power source. Conventional jackhammers overall produced higher muscle activity than lightweight jackhammers. Although selection of the correct jackhammer for the job involves many factors including pavement type and thickness, the results of this research can be used to assist in selecting the appropriate jackhammer.     

Disability beliefs and help-seeking behavior of depressed Chinese-American patients in a primary care setting

In this study the authors assessed the effects of disability beliefs, conceptualization and labeling of emotional disabilities, and perceived barriers on help-seeking behaviors among depressed Chinese Americans in a primary care setting. Forty-two Chinese Americans participated in semistructured interviews using established psychological measures and open-ended questions adapted from the Explanatory Model Interview Catalogue. The authors found that care utilization appears to be complicated by somatization of emotional problems, variations in causal attribution to depression, barriers to receiving mental health care, and the burden of comorbid physical conditions. Their findings highlight the importance of addressing these issues and educating patients about body-mind dialectic common to depression.     

Family structure and child outcomes: a high definition, wide angle “snapshot”

Using data from the National Survey of America??s Families (NSAF), this research investigates the relationships between a highly defined set of family structures and a broad set of child outcomes at a particular point in time in a child??s life. A detailed classification of family structures is constructed that clarifies key differences among various types of diverse families, and facilitates equivalencies testing and pairwise comparisons across nontraditional family structures. The NSAF contains a large number of observations for less common, but growing, family structures such as single-father families, grandparent-headed households and cohabiters, which makes such detailed analyses feasible and allows further stratification by child age, gender and race. The data also contains information on child behavioral, educational and physical health outcomes, as well as extensive household characteristics, economic resources and parental behaviors and inputs. Results suggest that differences across nontraditional family structures are particularly prominent for child health outcomes and that the gender of the resident parent is empirically important, more so than the presence of a cohabiting or married step-parent. Children in single father families have lesser access to health care yet enjoy better health outcomes than those in other families, even after controlling for economic resources (and inputs). In contrast, few differences are found between grandparent-headed families and other non-parent families. While we explore alternative explanations for these results, our cross-sectional data and complex set of family structure variables preclude isolating causal relationships; instead, our analyses yield empirically important distinctions that point to promising avenues for future research.     

Postural Position Constrains Multimodal Object Exploration in Infants

Recent research has revealed the important role of multimodal object exploration in infants' cognitive and social development. Yet, the real‐time effects of postural position on infants' object exploration have been largely ignored. In the current study, 5‐ to 7‐month‐old infants (N = 29) handled objects while placed in supported sitting, supine, and prone postures, and their spontaneous exploratory behaviors were observed. Infants produced more manual, oral, and visual exploration in sitting compared to lying supine and prone. Moreover, while sitting, infants more often coupled manual exploration with mouthing and visual examination. Infants' opportunities for learning from object exploration are embedded within a real‐time postural context that constrains the quantity and quality of exploratory behavior.     

An economic analysis of the job search decisions for Canadian nurses

The goal of this study is to provide a detailed analysis of the job search decisions of nurses in Canada. The results of this study show that the most important variables influencing the probability of searching for a new job are annual earnings and satisfaction with pay. Socio-economic variables and individual attitudes have an effect for some groups, but these variables are less important. There are differences between women who are and are not currently employed as nurses and this could potentially be a beneficial group to study in terms of policies to recruit and retain nurses in the profession.