The study of metabolite-to-parent drug ratios of methamphetamine and methylenedioxymethamphetamine in hair

The metabolite-to-parent drug ratios were determined in the hair of 2444 methamphetamine (MA) abusers who had produced MA-positive hair results from 2001 to May 2005 and in the hair of 53 ecstasy abusers who had produced positive methylenedioxymethamphetamine (MDMA) hair results from 2002 to May 2005. For the hair analyses, hair strands were washed, cut into small pieces and extracted for 20 h in 1 mL methanol containing 1% HCl. Drugs in the extract were determined by gas chromatography-mass spectrometry (GC-MS) using selective ion monitoring after derivatization with trifluoroacetic anhydride. The six range groups were divided as follows on the basis of MA concentrations in hair (n = 2389): 0.5-5 ng/mg (n = 950), 5-10 ng/mg (n = 582), 10-20 ng/mg (n = 503), 20-30 ng/mg (n = 160), 30-40 ng/mg (n = 80), more than 40 ng/mg (n = 114) to assess the correlations between MA concentrations and metabolite-to-parent drug ratios. In groups of higher MA concentrations, lower ratios of AP/MA were found, and there was a statistically significant difference among six range groups. Comparisons of age groups (tens, twenties, thirties, forties, fifties, and sixties) and male and female subjects for the ratios of AP/MA showed a statistically significant difference. The detection of metabolites and the parent drug with reasonable ratios was found to be a useful indicator for distinguishing internal drug incorporation from external contamination. In our study, MA users can produce 0.4-116% (mean = 9%) of amphetamine (AP) concentrations in hair, and ecstasy users 1-110% (mean = 12%) of methylenedioxyamphetamine (MDA) in appropriately washed hair samples.     

Impurity profiling of ecstasy tablets seized in Hong Kong by gas chromatography-mass spectrometry

In Hong Kong, ecstasy tablets are more commonly known as "Fing Tau Yuen", literally meaning "Shake Head Pills". The tablets contain mainly amphetamine-type stimulants (ATS) including 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), methamphetamine (MA) and/or ketamine. Adulterant such as caffeine was also detected in the tablets. This paper reports a study on the impurity profiles of ecstasy tablets from 89 seizures in Hong Kong from 2002 to early 2004. Tablet samples were extracted by diethyl ether under alkaline condition and then analyzed by gas GC-MS. The chromatograms obtained were compared. A total of 19 identified impurities were selected as markers for impurity profiling. They are different precursors, intermediates and by-products. The data matrices were examined by hierarchical cluster analysis (HCA), and then the ecstasy tablets were classified into different groups. Cluster analysis of ecstasy tablets is shown to be capable of providing intelligence on clandestine laboratory networks.     

Time–frequency nexus between globalization,financial development,natural resources and carbon emissions in Vietnam

Economic Change and Restructuring - Economic covariates exhibit asymmetric and time-varying patterns in the real world. As a result, it is critical to consider these effects when estimating...     

The Prewar School Civic Education Policy in Hong Kong： A Historical Comparative Analysis

The civic education policy at the school level in Hong Kong had emerged before the Second World War, but the Hong Kong Education Department did not really implement this civic education policy. From the statist and colonial perspectives, this phenomenon was due to several factors, such as： （1） how the Hong Kong Government coped with the whole historical period and scenarios; （2） how it implemented the related policy; （3） whether civic education policy really became part of the government agendas; and （4） whether education did clarify some crucial historical questions. This paper wants to make certain about these questions. In fact, the Republic of China adopted modern schooling system which civic education was one of school subject. But it was not the education policy of the colonial Hong Kong Government. Historical reasons about this issue require reconstructive explanation. Under this study, the understanding of misinterpreted history can be amended correctly.     

A Chinese movie mogul and the transformation of his movie empire—the Loke Wan Tho family and the Cathay Organisation in Southern China and Southeast Asia (1915–2000)*

The Cathay Organisation was a household name in the Chinese film industry. At its peak, it operated 75 cinemas and two movie studios, with a film distribution network spanning Malaysia, Burma, Thailand, Vietnam, Hong Kong, and Taiwan, as well as Europe and Latin America. In the public’s mind, Cathay was synonymous with its charismatic founder, Loke Wan Tho (1915–1964). Well versed in literature and ornithology, Loke appeared as a British gentleman, always meticulously dressed and elegantly mannered in his dealings with political leaders and movie celebrities. But underneath its gracious surface, Cathay was constantly struggling to sustain itself against problems that arose due to its rapid expansion. Although Cathay often produced impressive movies with graceful stars, high production costs could not be supported by the box-office revenues. By tracing the transformation of Cathay, this article will examine the dynamics of a Chinese family business in its attempt to survive amidst political chaos in Southeast Asia. Surviving generational succession, corporate consolidation and waves of political crises, Cathay’s story not only mirrors the transformation of an overseas Chinese family business over the past 100 years but also reflects a larger historical picture.     

The Use of Scale‐Invariance Feature Transform Approach to Recognize and Retrieve Incomplete Shoeprints

Shoeprints left at the crime scene provide valuable information in criminal investigation due to the distinctive patterns in the sole. Those shoeprints are often incomplete and noisy. In this study, scale‐invariance feature transform is proposed and evaluated for recognition and retrieval of partial and noisy shoeprint images. The proposed method first constructs different scale spaces to detect local extrema in the underlying shoeprint images. Those local extrema are considered as useful key points in the image. Next, the features of those key points are extracted to represent their local patterns around key points. Then, the system computes the cross‐correlation between the query image and each shoeprint image in the database. Experimental results show that full‐size prints and prints from the toe area perform best among all shoeprints. Furthermore, this system also demonstrates its robustness against noise because there is a very slight difference in comparison between original shoeprints and noisy shoeprints.     

Third World multinationals revisited: A research critique and future agenda

ABSTRACT In this work we test the hypothesis that Israel has a strategic dependency on territorial labour. We also look at the situation of dependency on this commuting labour in both the occupied territories and Israel and, subsequently, examine the strategic impact of the growth in Israeli capital on the future of this labour market.     

Exposure to internet pornography and sexually aggressive behaviour: protective roles of social support among Korean adolescents

ABSTRACT

Adolescents’ exposure to internet pornography and its negative effects on healthy sexual development have been extensively investigated. However, little research has addressed the identification of protective factors that can buffer these negative effects. Based on the conceptualisation of a stress-buffering model of social support, this study empirically tested whether social support would provide a buffer against negative effects of internet pornography on sexually aggressive behaviours in adolescents. Results from an online survey of two-hundred-ten (210) Korean high school students revealed that social support from parents and friends performed buffering roles, and the buffering effect of friend support was the strongest. Based on these results, practical implications for healthy adolescent sexual development were discussed.     

Discouraging Disadvantaged Fathers’ Employment: An Unintended Consequence of Policies Designed to Support Families

Substantial declines in employment and earnings among disadvantaged men may be exacerbated by child support enforcement policies that are designed to help support families but may have the unintended consequence of discouraging fathers’ employment. Disentangling causal effects is challenging because high child support debt may be both a cause and a consequence of unemployment and low child support order compliance. We used childbirth costs charged in unmarried mothers’ Medicaid‐covered childbirths, from Wisconsin administrative records, as an exogenous source of variation to identify the impact of debt. We found that greater debt has a substantial negative effect on fathers’ formal employment and child support payments, and that this effect is mediated by fathers’ prebirth earnings histories.     

Assessment of histomorphological features of the sternal end of the fourth rib for age estimation in Koreans

The aim of this study was to assess the histomorphological features of the fourth rib and to develop age-predicting equations for Koreans. Sixty-four rib samples (36 males and 28 females) obtained from forensic cases were used for developing equations. Two thin sections (<100-microm thick) per sample were prepared by manual grinding. Multivariate analysis of covariance revealed statistically significant differences in age-adjusted histomorphological variables between sexes. Using stepwise regression analysis, osteon population density and average osteon area were correlated with unknown sex (r2 = 0.826), and sex plus two histomorphological variables provided the best results for an age-predicting equation given the assumption of knowing the sex of a specimen (r2 = 0.839). Average Haversian canal area had little influence on age estimation for male or female samples, and relative cortical area was not significantly related to age for any specimen.