用MSCT沿鼻骨斜面多平面重组技术鉴定鼻骨线性骨折

目的探讨多层螺旋CT(MSCT)沿鼻骨斜面多平面重组(MPR)技术在鼻骨线性骨折法医学鉴定中的应用价值。方法以MSCT轴位平扫和沿鼻骨斜面多平面重组(MPR),对98例头面部外伤患者进行检查。结果 MSCT轴位平扫诊断:鼻骨正常和线性骨折(单侧或双侧)分别为29例和69例,阳性率70.4%。MSCT沿鼻骨斜面多平面重组(MPR)复诊:鼻骨正常的和线性骨折分别为19例和79例,阳性率80.6%。结论采用MSCT沿鼻骨斜面多平面重组技术可发现常规MSCT轴位平扫未能检见的鼻骨线性骨折,对法医学鉴定具有更高的应用价值。     

Recommendations for Maintaining a Dermestid Beetle Colony (Dermestes maculatus) for Processing Human Remains

Dermestid beetles (Dermestes maculatus De Geer 1774) are small carrion insects characterized by a rounded or oval-shaped body and white abdomen with black markings. Given their natural propensity to consume soft tissue throughout various stages of decomposition, biological anthropologists have sought to use dermestids as a forensic processing method in addition to traditional chemical tissue removal techniques. Although useful, most of the existing academic literature regarding the upkeep of dermestid colonies for skeletal remains processing either lack specificity or are outdated. Additionally, nonacademic sources that contain information regarding dermestid maintenance are often disjointed, resulting in a difficulty to replicate habitat construction and ideal environmental conditions. Therefore, this technical note presents recommendations for anthropologists interested in establishing and maintaining a D. maculatus population. These recommendations are based on our experiences using several dermestid colonies to process five unembalmed human heads, procured from an anatomical gift company for a larger study on gunshot trauma. Aspects of the dermestids’ environment that are crucial for the management of a healthy colony include the type of bedding, food, water, and containment method used, in addition to maintaining appropriate temperature ranges (24–27°C) and humidity levels (35–73%). Although habitat construction and dermestid maintenance involve materials that are relatively inexpensive and readily available, setting up and maintaining a D. maculatus colony can be laborious and time consuming and should only be undertaken when the volume of casework is such that this investment would be offset.     

Rainfall,population density and voter turnout

We create a dataset linking rainfall amounts to constituency-level election data for Irish general elections over the period 1989–2016. Rainfall is shown to significantly reduce voter turnout. The marginal effect of rainfall on turnout is greater in densely populated constituencies, where a rainy day decreases turnout by as much as three percentage points (or five percent). Using a theoretical framework based on a rational voting model, we propose two possible explanations for this effect. Firstly, if rural voters have higher civic duty than urban voters, they may be immune to rain on election day. Secondly, mode of transport may play a role. Urban voters are more likely to travel on foot or bicycle, whereas rural voters typically travel by car. Therefore, the cost to voting associated with rainfall may be higher in urban areas. Constituency-level data on mode of transport from 1997 to 2016 provides some empirical support for this hypothesis.     

The End of Sprawl? Not so Fast

This article takes a careful look at the recent state of sprawl among America’s 178 largest metropolitan areas through the lens of four sets of questions: (a) Measured at the metropolitan level, is sprawl really declining? Is it declining everywhere, or just in selected metropolitan areas? (b) If sprawl is indeed declining, are more compact growth forms on the rise? (c) If sprawl is indeed declining, is it the result of antisprawl land use and development policies? (d) Which metropolitan-level land market, demographic, and economic factors are most associated with changes in sprawl? It concludes that sprawl is indeed declining when measured by average population densities, but that the decline has been much less widespread if measured in terms of population growth in core-area neighborhoods, changing density gradient intercept and slope estimates, and increased employment clustering. In terms of policy, it finds no evidence that local regulatory regimes or growth management programs have had any effect on sprawl, but finds that the consistent administration of local regulatory programs in ways that incentivize infill development and send consistent signals to developers does contribute to reduced sprawl.     

骨缺损修复材料的研究现状

由肿瘤切除和创伤造成的骨缺损是日常医疗活动中常见的现象。目前,骨缺损修复的研究方向主要在骨缺损的材料上,从修复质量、免疫排斥和疾病传播等多方面来衡量,自体骨都是最佳的选择,成为骨移植的金标准。但由于供骨量有限,取骨又造成第二术区的创伤,因而它的临床应用受到了很大的限制。同种异体骨的来源比自体骨多,但与宿主间的免疫排斥反应和疾病传播是其缺点。异种骨的来源广泛,免疫原性性强、处理过程复杂和骨诱导性小是其不足之处。人工合成骨成型迅速,在计算机辅助设计和辅助制作的帮助下,能更好的合成与缺损骨形态接近的骨移植替代材料,人工合成骨的骨诱导性和仿生物性骨结构方面还不能令人满意。近年来复合骨移植和组织工程骨研究的快速发展给骨缺损修复带来了新的希望。用异体骨、异种骨或人工合成骨、金属钛网等作为支架,以富含原始骨细胞和骨生成因子的自体骨髓为填充材料修复骨缺损已取得相对满意的临床效果。组织工程骨则利用自体的原始骨细胞作为种子细胞在体外经过适当扩增,复合组织相容性好的支架材料和相关生长因子,植入体内后通过细胞分化和参与骨改建,最后形成新骨以修复骨缺损,但组织工程骨也面临着如何在骨内形成血管和神经如何支配的问题。总之,骨缺损修复材料研究的大方向为:最小的自体创伤;最大程度的仿自体骨,并不断接近自体骨的形态、结构和功能,朝着这个目标,人类的不懈努力,必将解决自身健康需要的复杂问题-修复骨缺损。     

骨骼种属鉴定的组织学研究

目的 探求骨骼残渣的种属鉴定的组织学方法。方法 对人体不同部位骨骼,及常见动物骨骼的 77张骨组织学切片,在光镜下进行了骨组织学形态学研究。结果 不同动物骨组织学的形态学特征存在明显差异,其主要差别有：内、外环骨板的形态和相对厚度;哈氏系统之间的骨板的形态和哈氏系统的大小;哈氏环层骨板的数量及骨陷窝的数量等。结论 骨组织学的特征,不仅可以区分人与动物骨骼的残渣,也可以对不同动物的骨骼残渣进行区分。     

Time burnt away: The impact of heat-induced changes on skeletal age-at-death diagnostic features

This paper investigates the established notion that bone calcination has a major impact on age estimation while low-intensity burns have a mere negligible impact. Few systematic researches have been carried out so far about this topic so the true impact of heat-induced changes on diagnostic age features is mostly unknown.The agreement between pre-burning and post-burning observations of age features was investigated on 51 human skeletons (22 males and 29 females with ages-at-death ranging from 61 to 93 years old) subjected to experimental burns. These skeletons belong to the 21st Century Identified Skeletal Collection housed at the Laboratory of Forensic Anthropology of the Department of Life Sciences, University of Coimbra, Portugal. The Suchey-Brooks method based on the pubic symphysis and the method developed on the auricular surface by Buckberry and Chamberlain (2002) were scrutinized.The Suchey-Brooks method provided better agreement between pre- and post-burn observations than the method from Buckberry and Chamberlain (2002). However, it became clear that heat-induced changes affected both methods regardless of heat intensity since both calcined bones and bones burnt at lower intensities often showed less than perfect agreement. Therefore, this research demonstrates that the analysis of age-at-death can be impaired in burnt bones, even those not subjected to calcination, with clear impact for forensic and archaeological investigations.     

北京市经济持续增长下的城-近郊人口分布合理性研究

本文利用北京市城区人口密度与近郊区人口密度的比作为反映人口分布的指标，通过对城近郊区人口密度及其变动与经济发展、城市交通、人均居住面积、绿地面积等因素的相关分析，阐明了人口分布变动主要取决于经济发展水平，城市交通、人均居住面积、绿地面积等因素是通过经济变量作用于人口因素，或人口因素通过经济变量作用于其他。最后，本文利用城近郊人口密度梯度与GDP的logistic曲线估计，对人口分布的合理性做进一步的分析。     

Assessment of Maceration Techniques Used to Remove Soft Tissue from Bone in Cut Mark Analysis

Maceration techniques employed in forensics must be effective without compromising the bone's integrity and morphology, and prevent destruction of evidence. Techniques must also be fast, safe, easily obtainable and inexpensive; not all techniques currently employed are appropriate for forensic use. To evaluate the most suitable approach, seven techniques including current and new methodologies were applied to fresh, fleshed porcine ribs exhibiting cut marks. A sample size of 30 specimens per technique was examined under scanning electron microscopy at the cut mark and the surrounding uncompromised regions; a scoring system of effectiveness was applied. The previously unpublished microwave method fared best for bone and cut mark preservation. Sodium hypochlorite destroyed cut marks, and was deemed unsuitable for forensic analysis. No single technique fulfilled all criteria; however, this study provides a benchmark for forensic anthropologists to select the most appropriate method for their situation, while maintaining the high standards required by forensic science.     

A Silver‐Stain Modification of Standard Histological Slide Preparation for Use in Anthropology Analyses

The traditional histology method typically employed by forensic anthropologists involves plastic embedding of undecalcified bone. The embedded sample is then cut by a diamond blade saw and ground to the required thickness of ~50–100 microns using a grinder. There are several limitations to this method: Cement lines may be blurred; depth‐of‐field artifacts may result from viewing thick sections; and medicolegal offices with limited budgets may not be able to invest in additional equipment or training for this method. A silver nitrate stain modification of the standard histology preparation technique of decalcified bone is presented. The benefits of this technique are that: Cement lines are viewed clearly; no depth‐of‐field artifacts are present; and because this is a modification of the standard technique used by histology laboratories typically employed by medicolegal offices, no additional equipment or training is required.