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21.
The forensic science community raised the need for improved evidence recognition, collection, and visualization analytical instrumentation for field and laboratory use. While the 3D optical techniques for imaging static objects have been extensively studied, there is still a major gap between current knowledge and collecting high‐quality footwear and tire impression evidence. Among optical means for 3D imaging, digital fringe projection (DFP) techniques reconstruct 3D shape from phase information, achieving camera‐pixel spatial resolution. This paper presents a high‐resolution 3D imaging technology using DFP techniques dedicated to footwear and tire impression capture. We developed fully automated software algorithms and a graphical user interface (GUI) that allow anyone without training to operate for high‐quality 3D data capture. We performed accuracy evaluations and comparisons comparing with the commercial high‐end 3D scanner and carried out qualitative tests for various impressions comparing with the current practices. Overall, our technology achieves similar levels of accuracy and resolution with a high‐end commercially available 3D scanner, while having the merits of being (1) more affordable; (2) much easier to operate; and (3) more robust. Compared with the current practice of casting, our technology demonstrates its superiority because it (1) is non‐destructive; (2) collects more evidence detail than casts, especially when an impression is fragile; (3) requires less time and money to collect each piece of evidence; and (4) results in a digital file that can easily be shared with other examiners.  相似文献   
22.
Virtual anthropology (VA) is based on applying anthropological methods currently used to analyse bones to 3D models of human remains. While great advances have been made in this endeavour in the past decade, several interrogations concerning how reliable these models are and what their proper use should be remain unanswered. In this research, a fundamental assumption of VA has been investigated: if the way we perceive and apply an anthropological method is truly similar when looking at bones macroscopically and through various 3D media. In order to answer, 10 skulls of known age and sex were scanned using a computed tomography (CT) scanner and a 3D surface scanner. Two observers separately applied a defined staging method to eight suture sites on these skulls, first looking at the bone macroscopically, then at the 3D surface scan, and finally on the CT scan. Two rounds of observation were carried out by each observer. Intra- and inter-observer error were evaluated, and two sample t-tests used to evaluate if the different types of medium used yielded significantly different observations. The results show a high degree of inter-observer error, and that data obtained from 3D surface scans differ from macroscopic observation (confidence level 95%, P ≤ 0.05). CT scans, in these settings, yielded results comparable to those obtained through macroscopic observations. These results offer many possibilities for future research, including indications on the kind of anthropological methods and anatomical landmarks that might be reliably transferable to the virtual environment. All current methods used in traditional anthropology should be tested, and if they prove unreliable, new techniques to analyse bones from virtual models should be developed.

Key points

  • Large discrepancies between observation on dry bones and computer-generated 3D models (surface scans or CT scans) could lead to the re-evaluation of the suitability of traditional anthropological methods for application on 3D models.
  • This preliminary study evaluates whether macroscopic, 3D surface scans, and CT scans viewings generate different observations.
  • The results indicate that the data are not always coherent across all three media of observation.
  • Explanations include the aspect given to the bone by the 3D software, differences between handling bones in real life versus on a computer, and level of expertise of the observers.
  相似文献   
23.
It may be difficult to distinguish the cause of death in drowning cases without specific findings. The aim of this study was to explore the forensic value of thoracic postmortem computed tomography (PMCT) using routine images and three-dimensional (3D) image reconstructions. The imaging data of PMCT examinations of six drowning cadavers, aged 21–54 years, were analyzed. Twelve victims of sudden death from coronary artery disease (CAD) were chosen as a control group. After 3D bilateral lung images were reconstructed using image processing software, an interactive medical image control system was used to measure and analyze parameters including lung volume, lung volume ratio, mean CT value of the whole lung, and lung CT value distribution curves. Lung volume and lung volume ratio were used to assess the shape changes of the lung. Lung CT value distribution curves showed the corresponding number of pixels of the different CT values in the lung image. Lung volume was not significantly larger in drowning cases (mean 2 958 cm3) than in controls (mean 2 342 cm3). Lung volume ratio values in the drowning group (mean 0.3156) were greater than those in the control group (mean 0.2763); (P = 0.02). There was no significant difference between the drowning and control group in the mean CT value of the whole lung. There were differences between lung CT value distribution curves in drowning victims and controls, with drowning victims showing a single peak and CAD cases showing a bimodal distribution. Thoracic PMCT is helpful for the forensic medical diagnosis of drowning. Lung volume ratio and lung CT value distribution are potential indicators to distinguish between drowning and CAD.  相似文献   
24.
International research collaboration (IRC) is associated with both positive and negative effects on the performance of research in emerging economies. While some authors claim that North–South collaborations improve scientific quality and visibility for Southern countries, others claim that it may entail the reorientation of research to comply with Northern agendas. South–South collaborations are thought to increase the focus on local affairs, therefore leading to a relatively small number of scientific international publications appearing in “high quality” journals. Research on the impact of IRC beyond publications in international journals has been neglected despite the importance of other products in knowledge creation. This research uses a broad range of scientific outputs to empirically assess such assumptions and explore the outcomes of IRC in Colombia. Results from multivariate regressions and nonparametric analyses show that, contrary to common assumptions, Colombian research teams collaborating with partners from the global South report higher scientific production, while those collaborating with Northern countries seem to contribute to local knowledge the most.  相似文献   
25.
The United States is experiencing growing impacts of climate change but currently receives a limited policy response from its national leadership. Within this policy void, many state governments are stepping up and taking action on adaptation planning. Yet we know little about why some states adopt State Adaptation Plans (SAPs), while others do not. This article investigates factors that predict the emergence of SAPs, both in terms of policy adoption and policy intensity (goal ambitiousness). Applying the diffusion of innovation theory, I consider the relative influence of internal state characteristics, regional pressures, and test for conditional effects between government ideologies and severity of the problem. The results show interesting differences between predictors that influence policy adoption and ambitiousness. States are more motivated to adopt a policy when faced with greater climate vulnerability, have more liberal citizenry, and where governments have crossed policy hurdles by previously passing mitigation plans. The intensity of policies and goal setting, moreover, is more likely to be driven by interest group politics and diffuse through policy learning or sharing information among neighboring states in Environmental Protection Agency regions. These findings support an emerging scholarship that uses more complex dependent variables in policy analysis. These variables have the potential to differentiate symbolic from substantive policies and capture finer information about predictors of importance.  相似文献   
26.
This article characterizes the ways in which the actors in charge of designing and implementing public policies intervene to promote the emergence of alternatives to problematic technologies. It is based on a case study conducted in Argentina that focuses on initiatives to promote the development of biological agricultural inputs in the context of increasingly controversial chemical inputs. The study spotlights the political, institutional, and semantic efforts made by policy makers and public administrations to ensure these new inputs find their way into organizations and onto their agendas. Their work consists in attenuating the boundaries between chemical and biological inputs, and reducing opposition by creating categories and organizations that downplay potential dissension and highlight the possible coexistence of technological paradigms. Contrary to what the injunctions of technological substitution suggest, we show that putting alternative technologies on the public agenda depends largely on their inclusion in institutional and regulatory infrastructures originally designed for technologies that are likely to decline. More broadly, it relies on the construction of continuity between the two types of technologies.  相似文献   
27.
Understanding what stimulates agribusiness firms to lobby the government and what makes the government responsive to lobbying are the two issues that have been discussed extensively in the debates concerning determinants of biotechnology policy. This paper examines the factors influencing agribusiness firms' lobbying and government response using econometric modeling on a new data set of 160 leading agribusiness firms in the food, feed, chemical, and seed industries in China. The results show that approximately 10% of agribusiness firms lobbied the government about biotechnology policy and regulations and over half of those that lobbied received a verbal or written acknowledgment from government agencies. Seed and feed companies are more likely to engage in lobbying than chemical companies. Owning GM patents not only has a positive impact on firms' lobbying activities, but firms with these patents are more likely to receive a government response to their lobbying efforts. The experience of selling GM products does not significantly influence lobbying activities or response from the government.  相似文献   
28.
As the emergence of nongovernmental conservation efforts generates conflict among various stakeholders, the causal story that each party articulates regarding conservation and the causes of land degradation reflects their unique interests. This study uses existing literature to evaluate causal stories surrounding a contemporary conservation effort: Montana's American Prairie Reserve. Through qualitative review of web‐based documents and newspaper articles, it generates a preliminary account of key stakeholders' causal stories. The case study suggests that parties who might be disadvantaged by ascribing responsibility for environmental harms in an adversarial fashion may instead elect to articulate causal stories that are more neutral than existing approaches might forecast. The study concludes by suggesting that further development of causal story literature may enable it to better address contemporary conservation efforts.  相似文献   
29.
The U.S. electric power sector has experienced a substantial shift of the generation mix since the turn of the century, moving from heavy reliance on coal‐powered generation to one drawing more from natural gas and, more recently, renewables. This transition has been forged by a mix of macroeconomic factors (recession and recovery); technological breakthroughs (horizontal drilling coupled with hydraulic fracturing; improvements in natural gas plant efficiency); clean energy policies at federal, state, and local levels of government; and private sector demands for carbon‐free energy sources. These factors have combined to reduce carbon emissions from electric power generation substantially this century. In this article we examine the extent of this transition, its causes, as well as the distinct American institutional factors steering it, including energy and environmental federalism, electoral politics, and the political economy of clean energy policy enactment and resistance.  相似文献   
30.
This paper examines the reliability of Structure from Motion (SfM) photogrammetry as a tool in the capture of forensic footwear marks. This is applicable to photogrammetry freeware DigTrace but is equally relevant to other SfM solutions. SfM simply requires a digital camera, a scale bar, and a selection of oblique photographs of the trace in question taken at the scene. The output is a digital three-dimensional point cloud of the surface and any plastic trace thereon. The first section of this paper examines the reliability of photogrammetry to capture the same data when repeatedly used on one impression, while the second part assesses the impact of varying cameras. Using cloud to cloud comparisons that measure the distance between two-point clouds, we assess the variability between models. The results highlight how little variability is evident and therefore speak to the accuracy and consistency of such techniques in the capture of three-dimensional traces. Using this method, 3D footwear impressions can, in many substrates, be collected with a repeatability of 97% with any variation between models less than ~0.5 mm.  相似文献   
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