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841.
Many studies in the literature have highlighted the utility of virtual 3D databanks as a substitute for real skeletal collections and the important application of radiological records in personal identification. However, none have investigated the accuracy of virtual material compared to skeletal remains in nonmetric variant analysis using 3D models. The present study investigates the accuracy of 20 computed tomography (CT) 3D reconstruction models compared to the real crania, focusing on the quality of the reproduction of the real crania and the possibility to detect 29 dental/cranial morphological variations in 3D images. An interobserver analysis was performed to evaluate trait identification, number, position, and shape. Results demonstrate a false bone loss in 3D models in some cranial regions, specifically the maxillary and occipital bones in 85% and 20% of the samples. Additional analyses revealed several difficulties in the detection of cranial nonmetric traits in 3D models, resulting in incorrect identification in circa 70% of the traits. In particular, pitfalls included the detection of erroneous position, error in presence/absence rates, in number, and in shape. The lowest percentages of correct evaluations were found in traits localized in the lateral side of the cranium and for the infraorbital suture, mastoid foramen, and crenulation. The present study highlights important pitfalls in CT scan when compared with the real crania for nonmetric analysis. This may have crucial consequences in cases where 3D databanks are used as a source of reference population data for nonmetric traits and pathologies and during bone-CT comparisons for identification purposes.  相似文献   
842.
Trigger pull is the force that needs to be exerted on the trigger to discharge a firearm. The measurement of trigger pull can assist in the evaluation of the safety, function, and manufacturing characteristics associated with a firearm during the forensic firearm examination process. Nonetheless, the accuracy and uncertainty of trigger pull measurements may be affected by the measuring device, test procedure, and environmental conditions. In this work, an innovative finger-trigger interface device was developed to facilitate accurate trigger pull measurements. The idea was to reduce the variation related to the position of the measurement device on the trigger in existing measuring methods and devices. Three force sensors based on different technologies were initially evaluated. While two of the three sensors failed to produce data, the miniature capacitive plate sensor exhibited high precision and a linear response over the range of typical trigger pulls. To examine the effects of the finger-trigger interface on trigger pull measurement, different sensor housing prototypes were designed in silico and 3D printed for the construction of three finger-trigger interface devices. The performance of each finger-trigger interface device was evaluated by measuring the trigger pulls of several selected firearms and comparing the data to a previously published study. Our preliminary results demonstrated the novel finger-trigger interface device offered a new way to measure trigger pull in situ with acceptable accuracy and precision.  相似文献   
843.
Although forensic examiners operate in a stressful environment, there is a lack of understanding about workplace stress and feedback. These organizational and human factors can potentially impact forensic science judgments. In this study, 150 practicing forensic examiners from one laboratory were surveyed about their experiences of workplace stress, and the explicit and implicit feedback they receive. Forensic examiners reported that their high stress levels originated more from workplace-related factors (management and/or supervision, backlogs, and the pressure to do many cases) than from personal related factors (family, medical, and/or financial). The findings showed that a few (8%) of the forensic examiners sometimes felt strong implicit feedback about what conclusions were expected from them and that some (14%) also strongly felt that they were more appreciated when they helped to solve a case (e.g., by reaching a “match” as opposed to an “inconclusive” conclusion). Differences were found when comparing workplace stress and feedback levels across three core forensic science fields (forensic biology, chemistry, and latent prints) and across career stages (early, mid, and late). Gaining insights into the stress factors within a workplace and explicit and implicit feedback has implications for developing policies to improve the well-being, motivation, and performance of forensic examiners.  相似文献   
844.
Forensic Technicians provide crime scene investigation services and are exposed to stressful violent crimes, motor vehicle accidents, biological or chemical hazards, and other appalling imagery. Forensic Technicians would likely experience physical and psychological stress after exposure to trauma, and security vulnerabilities similar to Sworn Police Officers. The perceived availability of mental health resources, job-related physical, psychological stress, and traumatic experiences of both Forensic Technicians and Sworn Police Officers from California law enforcement agencies were investigated using a self-reported survey. Responses were evaluated for any significant differences in the perceived stress, job-related physical stress, and resulting psychological impact affecting the participants. The survey contained a mix of True/False, Circle/Check the Appropriate Box, or Likert Scale (1–5) responses. The results were evaluated statistically and discussed. Results indicated Sworn Police Officers and Forensic Technicians have different on-duty stress levels, but similar off-duty stress levels. Nearly two-thirds of 54 job-related stressors were not significantly different between the two occupations. However, Forensic Technicians reported more adverse effects in 17 physical and psychological job-related activities compared with Sworn Police Officers. Forensic Technicians reported lower awareness levels and availability of agency mental health support services than were reported by Sworn Police Officers. This study reports for the first time an unexpected outcome that perceived and job-related psychological stress is greater for Forensic Technicians than Sworn Police Officers. Possible reasons for this disparity will be discussed as well as stress management tools that should be implemented to reduce health risk factors for both career professionals as well as increase public safety.  相似文献   
845.
Lophophora is a member of the Cactaceae family, which contains two species: Lophophora williamsii and L. diffusa. Lophophora williamsii is an illegal plant containing mescaline, a hallucinogenic alkaloid. In this study, a novel method based on a single nucleotide polymorphism (SNP) assay was developed for identifying L. williamsii; this assay reliably detects SNPs within chloroplast DNA (rbcL, matK, and trnL-trnF IGS) and was validated for identifying Lophophora and L. williamsii simultaneously. The chloroplast DNA sequences from four L. williamsii and three L. diffusa plants were obtained and compared using DNA sequence data from approximately 300 other Cactaceae species available in GenBank. From this sequence data, a total of seven SNPs were determined to be suitable for identifying L. williamsii. A multiplex assay was constructed using the ABI PRISM® SNaPshot™ Multiplex Kit (Applied Biosystems, Forster City, CA) to analyze species-specific SNPs. Using this multiplex assay, we clearly distinguished the Lophophora among 19 species in the Cactaceae family. Additionally, L. williamsii was distinguished from L. diffusa. These results suggest that the newly developed assay may help resolve crimes related to illegal distribution and use. This multiplex assay will be useful for the genetic identification of L. williamsii and can complement conventional methods of detecting mescaline.  相似文献   
846.
Dual-credit courses expose high school students to college-level content and provide the opportunity to earn college credits, in part to smooth the transition to college. With the Tennessee Department of Education, we conduct the first randomized controlled trial of the effects of dual-credit math coursework on a range of high school and college outcomes. We find that the dual-credit advanced algebra course alters students’ subsequent high school math course-taking, reducing enrollment in remedial math and boosting enrollment in precalculus and Advanced Placement math courses. We fail to detect an effect of the dual-credit math course on overall rates of college enrollment. However, the course induces some students to choose four-year universities instead of two-year colleges, particularly for those in the middle of the math achievement distribution and those first exposed to the opportunity to take the course in eleventh rather than twelfth grade. We see limited evidence of improvements in early math performance during college.  相似文献   
847.
We conduct the first long-term experimental evaluation of a need-based financial aid program, the privately funded Wisconsin Scholars Grant. Over multiple cohorts, the program failed to increase degree completion and graduate school enrollment up to 10 years after matriculation. The program did reduce time-to-degree for some students and modestly increased the number of STEM degrees earned. The lack of robust effects raises important questions about the conditions necessary for financial aid to benefit students.  相似文献   
848.
Journal of Youth and Adolescence - Young adults experience social role transitions across multiple life domains, and a deeper understanding of the ways in which these simultaneous transition...  相似文献   
849.
Both China and India are adopting information and communication technologies to facilitate openness and transparency in their governments, and hence reduce corruption. Distinctive from their traditional anticorruption approaches, is the innovative e-government approach an effective solution to corruption in these two large developing countries? This paper addresses the question through comparative in-depth interviews with 44 mid- or senior-level officials in the public sector in these two countries. The first study of its kind, our research shows that civil servants in both countries overall think positively about transparency and technology in reducing corruption. However, to what extent these innovative measures will be effective is conditional on various factors, such as political willingness, income inequality, and infrastructure readiness. What is worth noting is that the Chinese respondents were more positive regarding the role of transparency, whereas the Indian respondents were more positive about the role of technology, which may reflect the different facilitators of corruption and the constraints of anticorruption in China and India.  相似文献   
850.
Amidst calls for more scrutiny of the failure of infrastructure public–private partnerships (PPPs), uncertainty about how we can measure failure remains, and little systematic evidence illuminates its likelihood. Our mixed‐methods design explores the notion of failure and identifies the conditions under which it happens. The first phase of our research employs documentary analysis and semistructured expert interviews, and identifies project cancellation as capturing the most severe occurrences of failure. A second phase statistically analyzes a unique World Bank data set capturing the provisions of over 4,000 infrastructure PPPs launched between 1990 and 2015 in 89 countries. We find robust evidence supporting the theoretical claim that PPPs are less likely to be canceled in countries with more veto points among their political institutions to restrain politicians from intervening in policy implementation. Cancellation is a rare, but valid indicator of failure, and the importance of veto players clarifies how political risk operates in this context.  相似文献   
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