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.     

Absent Role of the State: Analysis of Social Support to Older People with Disabilities in Rural China

China is experiencing rapid population ageing and already has 44 million older people with disabilities aged over 59 years. Yet social support of these older people with disabilities is undeveloped and not well researched. This article contributes by using a disability rights framework (right to life and protection, economic security and social support) to analyze local cases in rural China. It finds that, although the family is still the main provider of economic and care support to rural older people with disabilities, the absence of a state role in welfare provision has negative impacts on the well‐being of older and younger generations in rural families.     

The Role of Evaluator-Victim Relationships in Children's Evaluations of Peer Provocation

Second-, third-, fifth-, and sixth- grade children evaluated two hypothetical target peers in three provocation scenarios which differed as to the intent of a provocative act (Ambiguous, Accidental, Hostile). In addition to age and gender, evaluator-victim relationship was manipulated with children portrayed as being in a best friend, an acquaintance, or an enemy relationship with the victim, while the agent of the provocation was an unfamiliar peer. Evaluations were assessed in terms of attributions of aggressor's intentions, behavior response of the victim, evaluator's liking for victim, and evaluator's affect. Results indicated that older children evaluated aggressor's intentions and victim's behavior response more negatively than did younger children. Further, attributions of aggressor's intent significantly predicted the victim's subsequent behavioral response. Evaluator's affect was reported to be more negative when evaluating hostile provocation compared to accidental or ambiguous provocation and evaluators in acquaintance and enemy relationships with the victim reported liking the victim more after the provocation than before it occurred. Results are discussed in terms of the social relational and social situational influences on children's evaluations of peer interactions and the need to integrate these contextual factors in children's person perception research.     

Risk Analysis: Celebrating the Accomplishments and Embracing Ongoing Challenges

As part of the celebration of the 40th anniversary of the Society for Risk Analysis and Risk Analysis: An International Journal, this essay reviews the 10 most important accomplishments of risk analysis from 1980 to 2010, outlines major accomplishments in three major categories from 2011 to 2019, discusses how editors circulate authors’ accomplishments, and proposes 10 major risk-related challenges for 2020–2030. Authors conclude that the next decade will severely test the field of risk analysis.     

What about Rural Blight? Housing and Neighborhood Conditions in Southeastern Small Towns

Though the concept of blight clarifies housing and neighborhood changes in rural and small towns experiencing disinvestment and decline, the term is rarely examined outside of urban discourse. This study explores the extent of rural blight and its relationship to community characteristics using survey results from elected officials and staff members of small towns in one southeastern state. We examine the historical background of blight, including its connections to urban renewal, racial bias and stereotyping, and the broken windows theory. Among the small towns in the study, economic blight, particularly dilapidated housing, was prevalent. Social blight, which includes behaviors that are thought to be threatening or criminal in nature, was less common but correlated moderately with economic forms of blight. While social disorganization and collective efficacy theories link a range of demographic characteristics to physical and social disorder, our findings pointed only to a significant relationship between communities with a higher portion of the population who are black and multiple forms of extensive blight. More research is needed to understand the relationship, both observed and perceived, between economic and social blight in rural small towns and how these issues may be remediated through local collective action.