Automated Texture Recognition of Quartz Sand Grains for Forensic Applications*

Quartz sand surface texture analysis has been automated for the first time for forensic application. The derived Basic Image Features (BIFs) provide computer-generated texture recognition from preexisting data sets. The technique was applied to two distinct classification problems; first, the ability of the system to discriminate between (quartz) sand grains with upturned plate features (indicative of eolian, global sand sea environments) and grains that do not exhibit these features. A success rate of grain classification of 98.8% was achieved. Second, to test the ability of the computer recognition system to identify specific energy levels of formation of the upturned plate surface texture features. Such recognition ability has to date been beyond manual geological interpretation. The discrimination performance was enhanced to an exact classification success rate of 81%. The enhanced potential for routine forensic investigation of the provenance of common quartz sand is indicated.     

Immigration and the Changing Nature of Homicide in US Cities, 1980–2010

Objectives

Previous research has neglected to consider whether trends in immigration are related to changes in the nature of homicide. This is important because there is considerable variability in the temporal trends of homicide subtypes disaggregated by circumstance. In the current study, we address this issue by investigating whether within-city changes in immigration are related to temporal variations in rates of overall and circumstance-specific homicide for a sample of large US cities during the period between 1980 and 2010.

Methods

Fixed-effects negative binomial and two-stage least squares (2SLS) instrumental variable regression models are used to analyze data from 156 large US cities observed during the 1980–2010 period.

Results

Findings from the analyses suggest that temporal change in overall homicide and drug homicide rates are significantly related to changes in immigration. Specifically, increases in immigration are associated with declining rates for each of the preceding outcome measures. Moreover, for several of the homicide types, findings suggest that the effects of changes in immigration vary across places, with the largest negative associations appearing in cities that had relatively high initial (i.e., 1970) immigration levels.

Conclusions

There is support for the thesis that changes in immigration in recent decades are related to changes in rates of lethal violence. However, it appears that the relationship is contingent and varied, not general.     

Perceptions of Law Enforcement Officers in Seeking Mental Health Treatment in a Right-to-Work State

The high stress environment of law enforcement places officers at risk for a variety of mental and physical health problems; however, officers are reluctant to seek out treatment. The purpose of this study was to identify which factors associated with law enforcement officers had predictive value in the level of stigma perceived in seeking mental health treatment by currently employed, certified peace officers in Arizona. The factors included sex, age, race/ethnicity, years employed as an officer, size of the department, current rank/position within the department, the type of government operating the agency, and payment of union dues. The study included 454 participants. Participation included the completion of demographic data, the Self-Stigma of Seeking Psychological Help (SSOSH), and the Perceptions of Stigmatization by Others for Seeking Help (PSOSH). Using standard multiple regression, the most significant finding was the relationship between the size of the department and levels of stigma (p = .014); such that, the size was inversely related to the levels of perceived stigma. As the agency size increased, the perceptions of stigma decreased. Such a finding has several implications for law enforcement agencies related to preparedness and training.     

青年的概念

文章讨论了"青年"概念的使用和有用性,讨论了年轻人被概念化的方式,探讨了青年向成年过渡的假设,提出将青年概念看作是一个社会过程的观点.青年时期是重要的,它是成年的临界点,同时它又有很大的问题.媒体话语中的青年流行概念不仅再现了青年而且实际上建构了青年的经历和意义.     

Promoting the Information Society: The EU Directive on Electronic Commerce

On 8 June 2000, the EU adopted the landmark 'electronic commerce' directive, a legal framework for the development of information society services. This article examines the rationale and evolution of EU policy for e-commerce and the key features of the directive. These include establishing the responsibilities of service and intermediary service providers, procedures for concluding on-line contracts and redress and enforcement mechanisms. It also explores the extent to which the directive clarifies the national law applicable to cross-frontier transactions and the relationship between the directive and private international law. The directive makes an important contribution to encouraging trust in the new technologies by establishing an EU-wide model for e-commerce, but it is by no means clear that it goes far enough. The continuing divergence of consumer protection policies and uncertainties about jurisdiction, securing redress, the liabilities of service providers and the status of contracts based upon web-site advertisements may continue to discourage the development of e-commerce in the Community.     

Budgeting for Social Security Or: When Are Savings Really Savings?

Policy and budgetary debate about Social Security is greatly affected by understandings of how the program is financed and, therefore, what steps would make it more affordable in the future. Unfortunately, both the standard justifications for and criticisms of buildups in the Social Security trust funds do not reflect the extent to which such buildups in fact would help finance future program costs. This article argues for a different standard, based explicitly on the fiscal capacity of the federal government and the effect of the government's obligations to pay interest on that capacity. I explain how both this definition of the role of the trust funds, and a broader understanding of fiscal capacity, would affect analysis of Social Security's condition and of possible reforms.