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31.
A random sample of more than 10,000 undergraduate students, selected from 119 4-year colleges, answered a mailed questionnaire about gun possession and gun threats. Approximately 4.3% of the students reported that they had a working firearm at college, and 1.6% of them have been threatened with a gun while at school. Students are more likely to have a firearm at college and to be threatened with a gun while at college if they are male, live off campus, binge drink, engage in risky and aggressive behavior after drinking, and attend institutions in regions of the United States where household firearm prevalence is high. Having a firearm for protection is also strongly associated with being threatened with a gun while at college. Students who reported having firearms at college disproportionately reported that they engaged in behaviors that put themselves and others at risk for injury.  相似文献   
32.
Luks S  Brady HE 《Evaluation review》2003,27(4):395-420
The authors explore how to define a welfare spell and how well surveys measure welfare spells. By comparing survey and administrative data from the Work Pays Demonstration Project in California on the receipt of Aid to Families with Dependent Children (AFDC), they find that a substantial amount of administrative churning occurs in administrative data. Through a mixing model of several break lengths, the authors find that a single definition of a break in welfare is not applicable to all respondents. Additionally, it appears that there is substantial variation in the break lengths respondents utilize. Finally, the authors show that the complexity of defining an accurate break in spells creates difficulties for detecting biases in survey responses.  相似文献   
33.
The cultural makeup of the United States continues to change rapidly, and as minority groups continue to grow, these groups' beliefs and customs must be taken into account when examining death, grief, and bereavement. This article discusses the beliefs, customs, and rituals of Latino, African American, Navajo, Jewish, and Hindu groups to raise awareness of the differences health care professionals may encounter among their grieving clients. Discussion of this small sample of minority groups in the United States is not intended to cover all of the degrees of acculturation within each group. Cultural groups are not homogeneous, and individual variation must always be considered in situations of death, grief, and bereavement. However, because the customs, rituals, and beliefs of the groups to which they belong affect individuals' experiences of death, grief, and bereavement, health care professionals need to be open to learning about them to better understand and help.  相似文献   
34.
The authors report findings from the first national survey of gambling among college students. They collected information from 10,765 students attending 119 scientifically selected colleges included in the 2001 Harvard School of Public Health College Alcohol Study (CAS), which indicated that 42% of responding students gambled in the last school year and 2.6% gambled weekly or more frequently. These findings contradict the widely held opinion based on previous studies that gambling is prevalent among college students. Previous studies used convenience samples that might have overestimated the risk for gambling problems. Male students and students of legal age (> or = 21 y) were more likely than others to gamble. Availability of gambling, measured by the number of types of gambling venues located in the schools' states, influenced their decisions to gamble. The concordance of characteristics associated with both gambling and binge drinking suggested a disposition to take risks that is independent of the risk objects.  相似文献   
35.
The authors examined changes in college students' illicit drug use, patterns of polydrug use, and the relationship between students' ages of initiation of substance use and later use of marijuana and other illicit drugs between 1993 and 2001. Data from 119 US colleges and universities in the Harvard School of Public Health College Alcohol Study were used in the study. They found significant increases in percentages of students' use of marijuana in the past 30 days (from 13% to 17%), past year (from 23% to 30%), and lifetime (from 41% to 47%) between 1993 and 2001, with most of the increase occurring between 1993 and 1997. Past 30-day use of other illicit drugs increased from 4% to 7% and past year use increased from 11% to 14%. More than 98% of marijuana and other illicit drug users used another substance. They also either smoked, were binge drinkers, and/or were users of another illicit drug. Drug prevention programs should emphasize heavy alcohol use and smoking and should start when students are in high school or earlier.  相似文献   
36.
The purpose of this study is to highlight the application of sparse logistic regression models in dealing with prediction of tumour pathological subtypes based on lung cancer patients'' genomic information. We consider sparse logistic regression models to deal with the high dimensionality and correlation between genomic regions. In a hierarchical likelihood (HL) method, it is assumed that the random effects follow a normal distribution and its variance is assumed to follow a gamma distribution. This formulation considers ridge and lasso penalties as special cases. We extend the HL penalty to include a ridge penalty (called ‘HLnet’) in a similar principle of the elastic net penalty, which is constructed from lasso penalty. The results indicate that the HL penalty creates more sparse estimates than lasso penalty with comparable prediction performance, while HLnet and elastic net penalties have the best prediction performance in real data. We illustrate the methods in a lung cancer study.  相似文献   
37.
We built three simulation models that can assist rail transit planners and operators to evaluate high and low probability rail‐centered hazard events that could lead to serious consequences for rail‐centered networks and their surrounding regions. Our key objective is to provide these models to users who, through planning with these models, can prevent events or more effectively react to them. The first of the three models is an industrial systems simulation tool that closely replicates rail passenger traffic flows between New York Penn Station and Trenton, New Jersey. Second, we built and used a line source plume model to trace chemical plumes released by a slow‐moving freight train that could impact rail passengers, as well as people in surrounding areas. Third, we crafted an economic simulation model that estimates the regional economic consequences of a variety of rail‐related hazard events through the year 2020. Each model can work independently of the others. However, used together they help provide a coherent story about what could happen and set the stage for planning that should make rail‐centered transport systems more resistant and resilient to hazard events. We highlight the limitations and opportunities presented by using these models individually or in sequence.  相似文献   
38.
39.
Major accident risks posed by chemical hazards have raised major social concerns in today's China. Land‐use planning has been adopted by many countries as one of the essential elements for accident prevention. This article aims at proposing a method to assess major accident risks to support land‐use planning in the vicinity of chemical installations. This method is based on the definition of risk by the Accidental Risk Assessment Methodology for IndustrieS (ARAMIS) project and it is an expansion application of severity and vulnerability assessment tools. The severity and vulnerability indexes from the ARAMIS methodology are employed to assess both the severity and vulnerability levels, respectively. A risk matrix is devised to support risk ranking and compatibility checking. The method consists of four main steps and is presented in geographical information‐system‐based maps. As an illustration, the proposed method is applied in Dagushan Peninsula, China. The case study indicated that the method could not only aid risk regulations on existing land‐use planning, but also support future land‐use planning by offering alternatives or influencing the plans at the development stage, and thus further enhance the roles and influence of land‐use planning in the accident prevention activities in China.  相似文献   
40.
In this paper I first review the basic tenets of agency theory and theory of managerial capitalism as well as some of the major research in these areas then suggest for areas for future research that go beyond the extant empirical work. First, I suggest that it would be useful to reconsider the basic nature of the agency relationship, taking into account that while equity holders can be considered the principal, the board of directors may be more realistically in need of agent-like controls. Second, the complementary or supplementary nature of the monitoring/incentive alignment relationship has been shown theoretically but the empirical evidence is equivocal and needs future investigation. Third, there has been very limited research on the construct validity of archival measures of the sort used in agency theory. This requires the use of methodologies outside those of the more conventional type used in agency theory (i.e., from economics and finance). Finally, agency theory development would profit greatly by more extensive use of research methods such as laboratory studies and survey methodology and the integration of concepts such as personality and control processes.
Henry L. Tosi Jr.Email:
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