TrueAllele® Genotype Identification on DNA Mixtures Containing up to Five Unknown Contributors

Computer methods have been developed for mathematically interpreting mixed and low‐template DNA. The genotype modeling approach computationally separates out the contributors to a mixture, with uncertainty represented through probability. Comparison of inferred genotypes calculates a likelihood ratio (LR), which measures identification information. This study statistically examined the genotype modeling performance of Cybergenetics TrueAllele^® computer system. High‐ and low‐template DNA mixtures of known randomized composition containing 2, 3, 4, and 5 contributors were tested. Sensitivity, specificity, and reproducibility were established through LR quantification in each of these eight groups. Covariance analysis found LR behavior to be relatively invariant to DNA amount or contributor number. Analysis of variance found that consistent solutions were produced, once a sufficient number of contributors were considered. This study demonstrates the reliability of TrueAllele interpretation on complex DNA mixtures of representative casework composition. The results can help predict an information outcome for a DNA mixture analysis.     

群体性暴力事件形成计算分析

当前,随着社会转型的不断深化,我国进入了群体性暴力事件的高发期。为进一步了解此类事件的形成机制,降低群体性暴力事件对社会稳定带来的负面影响,作者在agent建模、社会燃烧理论以及羊群效应等理论的基础上搭建了一个群体性暴力事件的形成模型,仿真了无警力条件下群体性暴力事件自发形成的过程。大量仿真结果表明,在群体性暴力事件发生现场的区域内人员密度、“点燃”事件的类型、所在地区的可目视范围以及当地社会环境中的舆论导向等因素均会对群体性暴力事件的产生及发展带来不同程度的影响。该结果将为相关部门预防与处置群体性暴力事件提供重要的理论依据。     

Need-efficiency trade-offs in the allocation of resources: Ideological and attributional differences in public aid decision making

We examined whether ideological differences influenced perceptions of the underlying causes of public aid applicants’ predicaments, and whether in turn ideology-patterned attributions accounted for how resource allocators prioritized need- and efficiency-related goals in allocating aid. To examine the need-efficiency trade-off, participants (N=112) divided a hypothetical pool of aid applicants for subsidized health insurance into two “incorrect” allocation outcomes: false alarms (allocate aid to unneedy applicants) and misses (deny aid to needy applicants). Moreover, to examine beliefs about the absolute percentage of aid applicants who are truly in need of societal assistance, participants divided the remaining aid applicants into two “correct” allocation outcomes: hits (allocate aid to needy applicants) and correct rejections (deny aid to unneedy applicants). Results of a series of structural equation models indicated that conservatism was linked to the causal belief that aid applicants’ predicaments arise from dispositional rather than situational factors, which in turn predicted a preference for making efficiency-related over need-related resource allocation judgments (e.g., preferring misses to false alarms) and the belief that a relatively small number of aid applicants are truly in need of societal assistance (e.g., preferring correct rejections to hits). Results are discussed in terms of how ideologically driven attributions influence the manner in which people resolve need-efficiency trade-offs inherent in the context of public aid decision making.     

Modeling the longitudinal impact of legal sanctions on narcotics use and property crime

Structural equation models are used to confirm the suppressive effects of legal sanctions, e.g., probation and parole, on narcotics use and property crime. Both concurrent and longitudinal effects of legal sanctions are tested within two different models, which together span the entire addiction career. The findings indicate that (1) the suppressive effects of legal sanctions are evident only when legal sanctions are operationalized as parole or probation officer contact where urine monitoring is utilized; (2) only concurrent suppressive effects are statistically significant, and longitudinal suppressive effects are not; (3) both narcotics use and property crime are suppressed by legal sanctions, although the latter is less responsive than the former to intervention by the criminal justice system; and (4) suppressive effects tend to be more pronounced later in the addiction career. The significance of the findings and the implications for criminological theory related to issues regarding surveillance effects are emphasized.     

THE ECOLOGY OF GANG TERRITORIAL BOUNDARIES*

Within any type of system, the actors in the system inevitably compete over resources. With competition comes the possibility of conflict. To minimize such effects, actors often will partition the system into geographic territories. It is against the larger ecological backdrop of competition and conflict that we examine territory formation among urban street gangs. Although previous studies have examined the social and built environment where gangs form, and how the presence of a gang influences local levels of violence, we know little about how competitive interactions are tied to the formation and maintenance of gang territories. We use formal spatial Lotka–Volterra competition models to derive hypotheses about competition‐driven territory formation. By using data on 563 between‐gang shootings, involving 13 rival street gangs in the Hollenbeck Policing Division of Los Angeles, we show that violence strongly clusters along the boundaries between gangs in a way that is quantitatively predicted by the theory. The results suggest that even weak competitive interactions between gangs are sufficient to drive gang territory formation without recourse to other processes or assumptions.     

Gang Membership,Drug Selling,and Violence in Neighborhood Context

A prominent perspective in the gang literature suggests that gang member involvement in drug selling does not necessarily increase violent behavior. In addition it is unclear from previous research whether neighborhood disadvantage strengthens that relationship. We address these issues by testing hypotheses regarding the confluence of neighborhood disadvantage, gang membership, drug selling, and violent behavior. A three‐level hierarchical model is estimated from the first five waves of the 1997 National Longitudinal Survey of Youth, matched with block‐group characteristics from the 2000 U.S. Census. Results indicate that (1) gang members who sell drugs are significantly more violent than gang members that don’t sell drugs and drug sellers that don’t belong to gangs; (2) drug sellers that don’t belong to gangs and gang members who don’t sell drugs engage in comparable levels of violence; and (3) an increase in neighborhood disadvantaged intensifies the effect of gang membership on violence, especially among gang members that sell drugs.     

A Stone’s Throw from the Metropolis: Re-Examining Small-Agency Homeland Security Practices

Police agencies nationwide have enhanced their homeland security preparedness capacity since the 9/11 attacks. Evidence suggests that departments have not uniformly adopted measures to prepare for and respond to critical incidents. Rather, larger agencies are more likely than their smaller peers to take such steps. Small agencies do not constitute a homogenous group; some experience geographic isolation while others are near major metropolitan areas. Unclear is whether small agencies (25 or fewer full-time sworn personnel), those that are commonly found to be less prepared, benefit from proximity to large-agency peers. This study examined whether physical and relational proximity to large departments contributed to homeland security preparedness in over 300 small departments. A structural equation model revealed that interactions with large agencies facilitated preparedness but physical proximity had no direct effect. Increasing geographic isolation from large-agency peers indirectly affected preparedness by stifling the level of inter-department interactions.     

颅骨三维模型制作和数据库的构建

目的采用激光扫描深度图像法和CT影像法,制作颅骨模型,并建立无身源颅骨模型数据库。方法收集各省(区)送检的59例无身源颅骨样本,采用三维激光扫描仪进行颅骨深度图像的采集;采用多排螺旋CT进行颅骨断层影像数据的采集。分别经处理后建立颅骨三维模型。利用3D打印技术实现数字颅骨模型的实体复制。建立具有颅骨信息查询和三维模型显示的无身源颅骨模型数据库。结果采用深度图像法可以获得颅骨的外表面模型,且通过调整扫描仪的参数使细节特征更清晰。采用CT断层影像法可以重建颅骨的内、外部结构,且对于牙齿具有更好的重建结果。建立数据库并将59例无身源颅骨样本信息和三维模型纳入数据库。结论三维建模和3D打印技术可实现对颅骨的重建和模型复制。无身源颅骨数据库的构建,可实现存储和管理颅骨样本的各类信息和三维数据,有助于查询和信息共享,对法医学实践有积极的应用价值。     

STREET NETWORK STRUCTURE AND CRIME RISK: AN AGENT‐BASED INVESTIGATION OF THE ENCOUNTER AND ENCLOSURE HYPOTHESES

Street networks shape day‐to‐day activities in complex ways, dictating where, when, and in what contexts potential victims, offenders, and crime preventers interact with one another. Identifying generalizable principles of such influence offers considerable utility to theorists, policy makers, and practitioners. Unfortunately, key difficulties associated with the observation of these interactions, and control of the settings within which they take place, limit traditional empirical approaches that aim to uncover mechanisms linking street network structure with crime risk. By drawing on parallel advances in the formal analyses of street networks and the computational modeling of crime events interactions, we present a theoretically informed and empirically validated agent‐based model of residential burglary that permits investigation of the relationship between street network structure and crime commission and prevention through guardianship. Through the use of this model, we explore the validity of competing theoretical accounts of street network permeability and crime risk—the encounter (eyes on the street) and enclosure (defensible space) hypotheses. The results of our analyses provide support for both hypotheses, but in doing so, they reveal that the relationship between street network permeability and crime is likely nonlinear. We discuss the ramifications of these findings for both criminological theory and crime prevention practice.     

交付的法律性质--兼论原因理论的发展

在罗马法上 ,交付本身并未被赋予所有权移转的意思。罗马法通过对原因的要求来控制交付的效力。按照罗马法法律渊源本身对交付原因的定位 ,交付的性质原则上应该是要因的。由于对罗马法上的清偿原因缺乏充分的了解 ,中世纪的法学提出了误信原因的原因理论 ,从而使在要因交付的框架下孕育出抽象的无因理论成为了可能。