Environmental samples from indoor surfaces can be confounded by dust, which is composed largely of human skin cells and has been documented to contain roughly tens of micrograms of total DNA per gram of dust. This study complements previous published work by providing estimates of the quantity of amplifiable human DNA found in environmental samples from a typical indoor environment, categorized by the intensity of human traffic and visible quantity of dust. Dust was collected by surface swabbing standard 576 cm2 areas in eight locations, and evaluated for total DNA quantity, presence of human DNA (mitochondrial and nuclear loci using conventional PCR), quantity of human nuclear DNA using quantitative PCR, and STR analysis. The total DNA content of 36 dust samples ranged from 9 to 28 ng/cm2, and contained 0.2–1.1 pg/cm2 of human DNA. Overall, human DNA was detected in 97% of 36 dust samples and 61% of samples yielded allele distributions of varying degrees of complexity when subjected to STR analysis. The implications of this study are twofold. First, the presence of dust in evidence can be a significant contamination source in forensic investigations because the human DNA component is of sufficient quality and quantity to produce allele calls in STR analysis. This can be effectively managed by implementing stringent protocols for collection and analysis of potential biological samples. A second implication is the use of dust as a source of evidence for identification of inhabitants within a defined location. In the latter case, a number of additional studies would be necessary to identify relevant pretreatments for environmental dust samples and to develop the necessary deconvolution techniques to separate the composite genotypes obtained. 相似文献
Dr. Jeffreys writes to say that he would be interested to hearof any other tribe whose name is a sobriquet for "wanderer"or "stranger". He has not dealt with Southern Africa, and wewould therefore suggest Angoni. Any reader who can add to thelist may care to get into touch with the writer of this articleat Bamenda, British Cameroons. 相似文献
Scholars have long understood that structuring internal work processes into more hierarchical or team‐based arrangements has consequences for organizational outputs. Building on this insight, this research examines the relationship between how agencies organize their rulemaking routines and the resulting rules. Tracking the job functions of rule contacts for economically significant rules proposed over a four‐year period, the analysis demonstrates that expanding the breadth of personnel types closely involved in a rulemaking is associated with a reduction in the time it takes to promulgate the rule. However, increasing the pace at which rules are finalized is not without cost, as those completed faster appear more likely to be overturned when challenged in court. The article not only adds another dimension to empirical scholarship studying rulemaking, which has largely focused on how forces originating outside the agency affect rules, but also suggests the importance of considering competing priorities in designing rulemaking processes. 相似文献
Preventing climate change and damage from natural disasters typically requires policies with up‐front costs that promise a flow of benefits over time. Why has obtaining such policies in a competitive electoral democracy proved so intractable? We develop a formal model of electoral accountability in this context, in which politicians have private information about their motivations. The model shows why fully rational voters, though certain that incumbents spend less on disaster prevention than is good for them, reelect incumbents at very high rates. In addition, in such equilibria, voters would punish incumbents who spent more on disaster prevention. This equilibrium is consistent with (and implies) some of the major empirical regularities observed in the literature on voting and disaster prevention. We discuss some implications of our analysis for advancing public debates about disaster and climate change mitigation. 相似文献
A common theme of research on participatory democracy and citizen engagement centres on the need for empirical studies that conduct a deep exploration of the nuances and complexities of these processes. This article offers a distinct response to this need through an examination of two ethnographic case studies of a participatory budgeting process in a multilingual, highly diverse community in which Spanish-speaking Latino immigrants were involved. By analyzing participants discourse from the case studies, the findings highlight the risks and rewards of reframing participatory processes as design decisions rather than static procedures. 相似文献
Maternal intimate partner violence (IPV) exposure has been linked to negative parenting outcomes. Studies suggest that parenting stress is an intermediary between IPV exposure and parenting, though past work has relied on small, clinically- referred samples. Moreover, it is unclear if parenting is differentially affected by a mother’s recent versus past history of IPV exposure, or whether a mother’s childhood abuse history moderates the associations of IPV with parenting stress and parenting behaviors. The current study examines whether recent IPV, versus past IPV, has stronger associations with parenting stress and parenting behaviors and tests whether maternal abuse history moderates these associations. Using structural equation modeling, we tested relations between IPV (frequency and recency), parenting stress, and parenting behaviors cross-sectionally and longitudinally in a large community sample of IPV-exposed low-income Hispanic and African American mothers of children aged 0–14 years (N?=?1159). We found that mothers who reported IPV exposure in the past year reported higher negative and lower positive parenting behaviors than mothers who reported less recent exposure. Further, we found that the frequency and timing of IPV exposure affected parenting indirectly through increased parenting stress. However, a childhood history of abuse did not appear to sensitize women to these effects. These findings suggest that psychological interventions aimed at reducing the subjective experience of parenting stress, as well as increased access to resources that reduce objective childcare burden, are important for promoting resilience among families exposed to violence.