Optimization of the separation of organic explosives by capillary electrophoresis with artificial neural networks

The separation of 12 explosives by capillary electrophoresis was optimized with the aid of artificial neural networks (ANNs). The selectivity of the separation was manipulated by varying the concentration of sodium dodecyl sulfate (SDS) and the pH of the electrolyte, while maintaining the buffer concentration at 10 mM borate. The concentration of SDS and the electrolyte pH were used as input variables and the mobility of the explosives were used as output variables for the ANN. In total, eight experiments were performed based on a factorial design to train a variety of artificial neural network architectures. A further three experiments were required to train ANN architectures to adequately model the experimental space. A product resolution response surface was constructed based on the predicted mobilities of the best performing ANN. This response surface pointed to two optima; pH 9.0-9.1 and 60-65 mM SDS, and pH 8.4-8.6 and 50-60 mM SDS. Separation of all 12 explosives was achieved at the second optimum. The separation was further improved by changing the capillary to an extended cell detection window and reducing the diameter of the capillary from 75 microm to 50 microm. This provided a more efficient separation without compromising detection sensitivity.     

Effects of self-concept and perceived disapproval of delinquent behavior in school children

It is argued that a multidimensional approach to self-concept may reveal intricate relations between self-concept and delinquent behavior, and that perceived approval of delinquent behaviors from referent groups may be related to the frequency of their occurrence. To evaluate these hypotheses, 1668 students from Grade 7 to Grade 9 responded to a questionnaire that measured their general self-esteem; their self-concept with regard to physical ability, social ability, physical appearance, and academic ability; the frequency they committed 15 delinquent acts; and the perceived approval of committing these acts from their parents, teachers, and friends. Regression analyses indicated that poor academic self-concept and poor relationship with school and parents were related to a higher frequency of delinquent behavior. However, a higher frequency of delinquent behavior was related to a more positive selfconcept with regard to social ability and physical ability. Finally, higher perceived approval from parents and peers was related to more delinquent behavior. Implications of these findings for identifying the antecedents and consequences of delinquent behavior were discussed.Received his Ph.D. from University of Illinois in social, industrial, and organizational psychology. His research interests included cross-cultural psychology, social justice, and the psychology of adolescence.Received his Ph.D. from Purdue University, and his research interests include values, selfconcept, family processes, and the psychology of adolescence.     

香港中文大学的大学通识教育

通识教育虽已有百余年的历史,其理念也得到了广泛的认同,但在实践中却困难重重。香港中文大学自1963年创校以来,一直把通识教育作为本科学位课程中的有机组成部分。1986年香港中文大学对通识教育全面改革,通识课程由大学通识与书院通识组成。2002年,进一步对大学通识教育作出全面检讨,厘清中大通识教育的目标与要求,重新规划整体课程和确立有效管理与素质保证的机制。现时中文大学的大学通识教育课程,由七个学院四十多学系提供二百多门通识科目。各科教师来自不同的专业领域,开设的通识科目都以专业的深度和修养为基础;学系开办通识课程时,除考虑本科教学的目标外,更要注意学科知识与其他学科的联系,以及和现代社会生活经验的关联。同时所有科目均有严格机制定期审视,以保证通识学科的素质。     

Rapid detection of synthetic cannabinoid receptor agonists impregnated into paper by attenuated total reflectance Fourier transform infrared spectroscopy

The last few years have witnessed the change in the modalities of smuggling of synthetic cannabinoid receptor agonists (SCRAs) by impregnating them in mail envelopes and fast parcels. Considering the aforementioned scenario, it is important to develop a portable technique to identifying SCRAs through packages. The purpose of this research was to detect SCRAs impregnated into substrates of paper using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. Three SCRAs that included 5F-PB-22, AB-FUBINACA and AKB-48 were purchased from Sigma Aldrich. The three SCRAs and four cutting agents were impregnated into paper of variable thickness at four concentrations (10, 15, 20, and 25 mg/mL). Spectra were collected over the wavenumber range of 650–4000 cm⁻¹ using ATR-FTIR spectroscopy and were exported to Matlab 2020b where data analysis was applied. The FTIR spectral data was able to show the three SCRAs could be detected on paper using ATR-FTIR spectroscopy and quantitatively modeled using the partial least squares regression algorithm. Principal component analysis showed separate clustering for the compounds that crystallized (5F-PB-22, AB-FUBINACA and caffeine) onto the papers surface from those impregnated into the bulk of the paper (AKB-48 and procaine) with the latter situated near blank papers in score plots. In summary, ATR-FTIR spectroscopy has proven to be a successful non-destructive technique in detecting and quantifying a selection of SCRAs impregnated into paper.     

Otherwise than Hospitality: A Disputation on the Relation of Ethics to Law and Politics

At a time of unprecedented migration and social displacement, following a century ravaged by war and hegemonic shift, the question of hospitality presents itself with unparalleled urgency. Taking his cue from Immanuel Kant’s cosmopolitics, Jacques Derrida addressed this question by deliberating on the nature of the political obligation to the other person. Invoking the work of Emmanuel Levinas, this demand is first of all ethical, and unconditional. But Derrida was also acutely aware of the residual violence of the hospitable gesture, which always takes place in a scene of power. The resultant aporias at the heart of hospitality provoked debate between the two authors at the 2007 Critical Legal Conference, and this paper seeks to elucidate and elaborate on this encounter. At stake are the matters of the potential political forms of hospitality, whether it should always been striven for and, ultimately, how one can conceptually reconcile its ethics with its violence.

Conditional impact of facebook as an information source on political opinions: the case of political reform in Hong Kong

This study is interested in the impact of Facebook as a source for political information on public opinion during political controversies. In a society where the mainstream media are under heavy influence by the dominant power and yet Internet communication is largely open and free, social media may become particularly important for the transmission of critical information and viewpoints. The social media information environment may exhibit an overall ‘anti-establishment bias.’ However, the impact of social media should vary across individuals depending on the extent and character of user selectivity. Analysis of data collected during the political reform debate in Hong Kong (N?=?3,246) show that reliance on Facebook as an information source relates negatively to support for the government’s reform proposal. But the relationship is strongest for people without a strong political orientation and people who do not name any newspapers as their main information source. General theoretical implications of the findings are discussed.     

Distress Intolerance Mediates the Relationship between Child Maltreatment and Nonsuicidal Self-Injury among Chinese Adolescents: A Three-Wave Longitudinal Study

Nonsuicidal self-injury (NSSI) is a serious public health concern among adolescents. Identifying risk factors of NSSI is important to effectively prevent or reduce such behavior. Child maltreatment is one of the most widely recognized risk factors for NSSI. How child maltreatment and NSSI is related, however, is still unclear. The present study tested the temporal relationship between physical and emotional abuse and NSSI, with distress intolerance as the potential mediator. Potential gender differences on these associations were also tested. We assessed all study variables among 2259 Chinese adolescents (53.8% females; M_age?=?15.11 years, SD?=?1.57) for three times at 6-month intervals. The results showed that distress intolerance only mediated the relationship between emotional abuse and NSSI, but not between physical abuse and NSSI. In addition, this mediation effect of distress intolerance was significant only for females. The findings of this study can help researchers and practitioners understand pathways by which child maltreatment impacts adolescent NSSI. Implications for preventions and interventions of NSSI were discussed.     

Super-optimizing china: reunification as an example

Whereas political issues and problems in China are complicated, efforts to “super-optimize” are essential and can be fruitful. The reunification issue is discussed to illustrate even highly politicized problems in China are amenable to super-optimum solutions. At the moment, some reunification options have been proposed: KMT-CCP negotiation on equal footing; KMT's military takeover; CCP's military takeover; the “one country, two systems” formula, convergence by democratization, and incremental convergence through trading and communication. Yet, neither parties find the alternatives desirable in terms of optimal satisfaction. By applying SOS rule # 2 (finding items that will provide large benefits to one side but only small costs to the other side), # 5 (combining the conservative and liberal alternatives where they are not mutually exclusive), and # 6 (removing the source of the conflict), reunification and democratization are made feasible and all parties concerned are better off. The specific proposals are that Taiwan should introduce a wholesale buy-out scheme that costs US$30 billion, that a new republic be established, and that legislative powers should be shared among the majoritarian and non-majoritarian institutions. Together, these arrangements could ensure stability and result in democratization.