Effect of Lower Third Molar Segmentations on Automated Tooth Development Staging using a Convolutional Neural Network

Staging third molar development is commonly used for age estimation in subadults. Automated developmental stage allocation to the mandibular left third molar in panoramic radiographs has been examined in a pilot study. This method used an AlexNet Deep Convolutional Neural Network (CNN) approach to stage lower left third molars, which had been selected by manually drawn bounding boxes around them. This method (bounding box AlexNet = BA) still contained parts of surrounding structures which may have affected the automated stage allocation performance. We hypothesize that segmenting only the third molar could further improve the automated stage allocation performance. Therefore, the current study aimed to determine and validate the effect of lower third molar segmentations on automated tooth development staging. Retrospectively, 400 panoramic radiographs were collected, processed and segmented in three ways: bounding box (BB), rough (RS), and full (FS) tooth segmentation. A DenseNet201 CNN was used for automated stage allocation. Automated staging results were compared with reference stages – allocated by human observers – overall and per stage. FS rendered the best results with a stage allocation accuracy of 0.61, a mean absolute difference of 0.53 stages and a Cohen's linear κ of 0.84. Misallocated stages were mostly neighboring stages, and DenseNet201 rendered better results than AlexNet by increasing the percentage of correctly allocated stages by 3% (BA compared to BB). FS increased the percentage of correctly allocated stages by 7% compared to BB. In conclusion, full tooth segmentation and a DenseNet CNN optimize automated dental stage allocation for age estimation.     

Methylation-Based Age Prediction Using Pyrosequencing Platform from Seminal Stains in Han Chinese Males

Various methods have been performed to predict an unknown individual's age from biological traces in forensic investigations. A considerably accurate age prediction for the semen donor can help narrow down the search in a sexual assault case. The aim of this study was to develop an assay for age prediction from seminal stains in Han Chinese males. We built a sperm-specific linear regression model using bisulfite pyrosequencing. Validations were conducted with a Mean Absolute Deviation from the chronological age (MAD) of 4.219 years in liquid semen, 4.158 years in fresh seminal stains, 4.393 years in aged seminal stains, and 3.880 years in mixed stains, respectively. Furthermore, our strategy enables accurate age prediction using a forensic casework sample. The strategy indicated that we produced an accurate and reliable age prediction tool for the semen donors in Han Chinese males for forensic purposes.     

Evaluating the use of hypoxia sensitive markers for body fluid stain age prediction

To augment DNA profiling and body fluid identification techniques efforts are being made to increase the amount of information available from a crime scene stain, which includes efforts to identify externally visible characteristics through phenotypic analysis. A key question surrounding crime scene stains is the length of time between deposition of the stain and its subsequent recovery, in that is the stain recovered related to the incident in question or from a previously deposited stain number of weeks earlier? The inability to answer this fundamental question has a detrimental effect upon the successful completion of a criminal investigation. Once a body fluid leaves the body, the oxygen concentration in the environment changes; therefore, it may be that this change could cause a change in the expression of hypoxia-sensitive biomarkers. Here, a range of bloodstains, liquid saliva and liquid semen samples were collected at 0 days, 7 days, 14 days, 21 days and 28 days of degrading at room temperature (19–22 °C), before undergoing total RNA extraction and cDNA synthesis. Blood was recovered from filter paper with 3 mm², with saliva and semen being left in their tubes and swabbed at the appropriate times. All samples then underwent quantitative PCR targeting Vascular Endothelial Growth Factor A (VEGFA) and Hypoxia-Inducible Factor 1 Alpha (HIF1A), with B-Actin (ACTB) as a reference gene. A range of linear and quadratic correlation values was obtained from the qPCR data and used to develop a predictive model with a mean absolute deviation (MAD) of 4.2, 2.1, and 5 days for blood, saliva, and semen respectively. Blind testing indicated that a stain age prediction model based upon VEGFA with ACTB as a reference gene could be used on samples up to four weeks old with a margin of error ranging from 2 days through to 5 days. While a sizeable potential time frame exists using this model; this represents a significant step towards the target of having an accurate stain age prediction model.     

Are 16-year-olds able to cast a congruent vote? Evidence from a “voting at 16” initiative in the city of Ghent (Belgium)

An often used argument against lowering the voting age to the age of 16 is that this age group would lack a sufficiently high level of “political maturity” and therefore would not be able to cast a vote that is in line with their political opinions. In this paper, we use a unique initiative set up by the city of Ghent (Belgium) to invite 16- and 17-year-olds to take part in a mock election to investigate whether adolescents are able to cast an ideologically congruent or “correct” vote. Our results do not show differences in proximity voting between adolescents and adult respondents. Furthermore, we find no evidence of socio-economic stratification in the extent to which adolescents cast a congruent vote. Our conclusion, therefore, is that this recurrent argument against lowering the voting age lacks empirical validity.     

Age structure and political violence: a re-assessment of the “youth bulge” hypothesis

A popular hypothesis in international studies states that a “youth bulge”––an age pyramid dominated by large cohorts between 15 and 29 years of age––increases the risk of political violence. However, empirical evidence on this link remains inconclusive to date. In this article, we systematically assess the youth effect using new data from 183 countries between 1996 and 2015. We find that within countries, a decrease in the youth ratio is generally associated with a decrease in the number of violent deaths from terrorism or other internal conflicts, and vice versa. This is also confirmed in out-of-sample predictions. However, the association is not evident in all constellations and sensitive to modeling issues. In particular, large cohorts of young males can become a disruptive power in countries that increase enrollment in post-primary education. Although this is usually followed by fertility decline, youth bulges often remain at record levels for quite some time due to high birth rates in the past. Strong labor markets can in general suppress the detrimental consequences of youth bulges. However, the combination of growing youth cohorts and educational expansion often leads to increased political violence even in the presence of low youth unemployment.     

养育子女影响了女性劳动力市场参与吗？ ——基于中国劳动力动态调查的实证检验

生育政策调整会影响女性生育率和劳动力市场参与率,进而对经济和社会产生影响。本研究利用中国劳动力动态调查(CLDS)2016年数据,分析不同子女年龄对女性劳动力市场参与的影响。研究发现：学龄前儿童对女性的劳动力市场参与有一定的阻碍效应,这种阻碍效应会在儿童进入正式学龄阶段后逐渐消失;其中,0—3岁子女对女性劳动力市场参与存在显著的负向影响,且对农村女性的负向影响大于城镇女性。因此,为了进一步促成我国生育政策调整目标的实现,需要完善我国女性生育支持行动策略,在推动0—3岁儿童照料支持体系建设的同时,更要关注城乡社会托育服务体系的同步发展。     

Listening and the ambiguities of voice in South African journalism

Political theorists like Bickford (1996) and media theorists like Couldry (2006) have introduced the concept of listening as a complement to long-standing discussions about voice in democracies and in the media which serve the democratic project. This enhanced understanding of voice goes beyond just hearing into giving serious attention to, in particular, marginalised voices. This article reports on an investigation into the ways in which mainstream and community media in the Eastern Cape, South Africa, understand listening as an important part of their role as journalists. Interviews probed the attitudes of journalists and editors towards listening, and also interrogated their own understandings of their role in South Africa, particularly in relation to young people who are finding their political “voice”. The research showed that “listening” as a journalistic practice is seldom understood in anything more than common sense ways and is certainly not an organising principle of reporting and disseminating news. This results in journalism that is events focused, often sensationalist and whose agenda is set powerfully by political actions and actors in the environment. The power of being heard is almost solely in the hands of the journalists, who regard themselves as “the voice of the people”, without actively providing a space for listening to the voices of community members. But, within this generalised environment, there are two very interesting projects in which journalists and editors are actively listening to the issues and stories of citizens and letting them set agendas.     

The influence of sense of coherence,self-care and work satisfaction on secondary traumatic stress and burnout among child and youth residential care workers in Switzerland

The present study aimed to investigate the incidence of post-traumatic and secondary traumatic stress as well as burnout symptoms among child and youth welfare workers in residential care in Switzerland and to assess the predictive value of sense of coherence, self-care, and job satisfaction. A sample of 319 child welfare professionals in Swiss child and youth residential care was assessed using questionnaires that addressed sense of coherence, perceived collective efficacy, self-care, and work satisfaction, as well as symptoms of traumatic stress and burnout. Linear regression analyses were conducted to determine the influence of sense of coherence, self-care and job satisfaction on symptoms of burnout and traumatic stress. Enhancing sense of coherence, work-related self-care and work satisfaction could reduce stress symptoms and increase the well-being of child and youth welfare staff. The authors discuss how child and youth residential care institutions could improve these factors among their staff.     

孕产期劳动保护规定实施现状及其对在职育龄女性二孩生育意愿的影响 —— 以湖南省为例

本文基于湖南省孕产期劳动保护相关规定的落实情况,分析其对在职育龄女性二孩生育意愿的影响。通过分层整群随机抽样的方法对在职育龄女性进行问卷调查,得出如下结论:不同性质单位对各项劳动保护规定的落实情况参差不齐,国有企业女职工孕产期休假、劳动时间和劳动照顾规定的落实情况相对较好;配偶护理假、1小时哺乳时间、对原劳动的适应性和单位对高龄孕产妇的照顾措施显著影响在职育龄女性的二孩生育意愿。因此,相关政府部门应在确保各项劳动保护规定得到良好落实的基础上,不断优化完善各项政策,才能增加职业女性工作与生育间的兼容性,从而促进新生育政策目标的实现。     

School,sexuality and problematic girlhoods: reframing ‘empowerment’ discourse

This paper draws on ethnographic research with teenage schoolgirls in Tanzania to explore the impact of education on their experiences of sexual agency and empowerment. School-based education is frequently presented within international development as a route for empowering girls to exercise agency over their sexuality; yet school itself often constitutes a space in which the same restrictive gendered and sexual norms that exist outside the classroom are reproduced or go unchallenged by those working with girls. Despite the constraints to their agency from both outside and within school, girls themselves do resist the narratives of girlhood and sexuality imposed upon them. Recognising how these dynamics challenge our understanding of sexual empowerment is key to finding ways to support girls in navigating repressive norms beyond the classroom.