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51.
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.  相似文献   
52.
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.  相似文献   
53.
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.  相似文献   
54.
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 (= 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.  相似文献   
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56.
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.  相似文献   
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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.  相似文献   
59.
Intimate Partner Violence (IPV) is a serious international problem. Stith, S. M., McCollum, E. E., and Rosen, K. H. received funding from the US National Institute of Mental Health to develop and test a program for couples experiencing IPV: Domestic Violence Focused Couples Treatment (DVFCT). This article provides an overview of DVFCT, and presents three case studies illustrating how DVFCT has been adapted for use in Colombia, Iran, and Finland. This article emphasizes the need for adapting treatment models to be culturally informed, provides practice-based evidence for DVFCT as a treatment model, and highlights the importance of careful screening and assessment when working with couples who have experienced violence, no matter the country or location where treatment is being conducted.  相似文献   
60.
The idea that language skills support school readiness, predicting later self‐regulation and academic success, is widely accepted. Although vocabulary is often emphasized in the developmental literature, the ability to use language appropriately in the classroom, or social communication skills, may also be critical. This article examined longitudinal contributions of children's vocabulary and social communication skills, from preschool to kindergarten, to kindergarten academic achievement (reading and math) and self‐regulation (executive functions and learning behaviors). Participants were 164 children (14% Latinx, 30% Black, 56% White; 57% girls) enrolled in Head Start programs. Results revealed that initial levels and growth in vocabulary and communication skills predicted better academic achievement. Social communication skills uniquely predicted self‐regulation, after accounting for vocabulary. We discuss potential mechanisms for these links and recommend that strategies to build social communication skills be incorporated in preschool interventions promoting school readiness.  相似文献   
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