Volatile Organic Compounds,Spectral Characterization and Morphology of Ammonium Nitrate Fuel Oil (ANFO) Samples

Ammonium nitrate fuel oil is an explosive mixture found in most antipersonnel landmines (APL) buried throughout the Colombian territory. During more than 50 years of internal conflict, the Colombian government has found that trained dogs are the most effective method to detect APL. However, the olfactive signature in ANFO is unknown and also if there are differences in detection related to the explosive manufacturing origin. Therefore, this work begins with the analytical validation of the method used to determine ammonia, in its derivatized form as carbamate, released by home-made ANFO using HS-SPME-GC-FID. Once validated, the method was used to identify ammonia and other organic volatile compounds present in ANFO, under laboratory and simulated field conditions. The validation process includes the evaluation of the optimum conditions for the derivation and extraction of butylcarbamate, the determination of the working ranges with linear response in FID, the limits of detection and quantification, the sensitivity, and the precision. The results of the validation established linearity and sensitivity in a concentration between 20 and 120 mg/L, as well as low limits of detection and quantification of 6.4 and 21.4 mg/L, respectively. Also, an intermediate precision of 11% for butylcarbamate with a repeatability of 8%. The validated method showed in real samples of home-made ANFO besides ammonia, the presence of low molecular methylamines, and also exhibited differences in volatile compositions according to the origin. The objective of this work is to offer a reliable analytical methodology for the extraction and analysis of volatile compounds from ANFO.     

Postmortem changes in the level of calcium pumping adenosine triphosphatase in rat heart sarcoplasmic reticulum

The activity of calcium pumping adenosine triphosphatase (Ca2+-ATPase) in cardiac sarcoplasmic reticulum plays a pivotal role in myocardiac contraction-relaxation. The Ca2+-ATPase activity is controlled by phosphorylation and dephosphorylation of a sarcoplasmic reticulum protein "phospholamban" in response to neurotransmitters and drugs. To clarify the role of Ca2+-ATPase in the development of cardiac rigor mortis, we examined the changes of cardiac rigidity and cardiac sarcoplasmic reticulum Ca2+-ATPase activity up to 5 h after the decapitation of rats. Fifteen minutes after decapitation, the rats showed a cardiac rigidity on left ventricles. After 30 min, rigidity was obvious over the whole heart. After 1 h, the rigidity reached a high degree which was maintained for the rest of the observation period. On the other hand, the Ca2+-ATPase activity controlled by phosphorylation and dephosphorylation of phospholamban did not change for the whole observation period (5 h). Another Ca2+-ATPase activity representing the total amount of Ca2+-ATPase in sarcoplasmic reticulum gradually decreased. The data suggest that no significant phosphorylation or dephosphorylation of phospholamban occurs for a short time, at least for 5 h, after death and that the Ca2+-ATPase tends to relax the myocardium against the development of cardiac rigor mortis.     

The Development of Future Orientation is Associated with Faster Decline in Hopelessness during Adolescence

Hopelessness is implicated in multiple psychological disorders. Little is known, however, about the trajectory of hopelessness during adolescence or how emergent future orientation may influence its trajectory. Parallel process latent growth curve modelling tested whether (i) trajectories of future orientation and hopelessness and (ii) within-individual change in future orientation and hopelessness were related. The study was comprised of 472 adolescents [52% female, 47% Caucasian, 47% received free lunch] recruited at ages 12–13 who completed measures of future orientation and hopelessness at five annual assessments. The results indicate that a general decline in hopelessness across adolescence occurs quicker for those experiencing faster development of future orientation, when controlling for age, sex, low socio-economic status in addition to stressful life events in childhood and adolescence. Stressful childhood life events were associated with worse future orientation at baseline and negative life events experienced during adolescence were associated with both an increase in the trajectory of hopelessness as well as a decrease in the trajectory of future orientation. This study provides compelling evidence that the development of future orientation during adolescence is associated with a faster decline in hopelessness.     

Measuring majority power and veto power of voting rules

We study voting rules with respect to how they allow or limit a majority from dominating minorities: whether a voting rule makes a majority powerful and whether minorities can veto the candidates they do not prefer. For a given voting rule, the minimal share of voters that guarantees a victory to one of the majority’s most preferred candidates is the measure of majority power; and the minimal share of voters that allows the minority to veto each of their least preferred candidates is the measure of veto power. We find tight bounds on such minimal shares for voting rules that are popular in the literature and used in real elections. We order the rules according to majority power and veto power. Instant-runoff voting has both the highest majority power and the highest veto power; plurality rule has the lowest. In general, the greater is the majority power of a voting rule, the greater its veto power. The three exceptions are: voting with proportional veto power, Black’s rule and Borda’s rule, which have relatively weak majority power and strong veto power, thus providing minority protection. Our results can shed light on how voting rules provide different incentives for voter participation and candidate nomination.

     

Public Perceptions of Income Inequality in Hong Kong: trends,causes and implications

This article examines the patterns and changes in public perceptions of domestic income inequality in Hong Kong in the past two decades and explains individual variations in these perceptions. It found that the perceived seriousness of income disparities had been persistently high, while the perceived unjustness of income disparities showed a fluctuating trend. Our findings lent partial support to the structural position thesis that the privileged groups are less likely than the underprivileged groups to consider existing income disparities to be serious and unjust. Nonetheless, the popular understanding of poverty is still biased towards ‘individual’ explanations, and this perhaps explains why the government is less willing to tackle the economic and political foundations of poverty in Hong Kong.     

洪泽湖水污染现状与水源地保护

洪泽湖是江苏省淮安等城市主要的水源地,由于受到淮河等人湖客水和流域内工业、农业与城乡生活污水影响,湖水水质已经下降为劣V类,远远低于国家规定的水源地水质要求。加强洪泽湖水源地保护刻不容缓。该文在对洪泽湖水污染现状调查分析的基础上,从法规、机制、管理等多方面提出了加强洪泽湖水源地保护的措施。     

对中国非正规就业发展的探讨

中国非正规就业面临缺乏法律保障和制度支撑、非正规就业劳动关系和劳动制度不规范、城乡劳动力市场的分割成为非正规部门劳动力市场发展的体制性障碍等问题。要从制定系统和长远的非正规就业规划和完善非正规就业方面的立法人手,打破城乡劳动力市场的分割、健全社会保障体系、强化社会服务和增强劳动力培训的针对性和实用性等,积极发展非正规就业,缓解中国城乡就业压力。     

把握马克思主义大众化的关键

马克思主义大众化包括了多个环节.只有把握好其中关键,才能提高推进马克思主义大众化的实效.从过程角度看,把握马克思主义大众化的关键环节包括五个方面:坚持发展的马克思主义是马克思主义大众化的前提,理论与实践相结合是马克思主义大众化的根本途径,加强社会主义文化建设是马克思主义大众化的基础,推进中国共产党的建设是马克思主义大众化的关键,秉持以人为本的发展理念是马克思主义大众化的旨归.     

领导-成员交换(Leader-member Exchange,LMX)理论研究新进展

三十多年来,许多组织学者致力于上下级之间动态关系的研究,LMX理论则是这一研究领域的核心。以往有关LMX理论的研究大都在个体水平上考察LMX的主效应,近些年来,这一有关LMX理论的研究出现了一些新的动向。文章从测量工具、分析水平以及作用机制方面对LMX理论研究的新进展进行了概述,并进一步指出未来的研究应该从概念、测量方法、认知调节变量等方面加以改进。