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151.
The application of field tests and chromatography to the detection of cocaine and some other local anesthetics that have been used to adulterate cocaine is described. Initial screening of samples by field tests, followed by concurrent TLC and GC, enables rapid identification of these compounds to be achieved. In particular, the use of flow-programmed GC shortens the time for analysis compared with conventional GC and requires negligible equilibration time between consecutive runs [12]. The method gives reliable quantitative data.  相似文献   
152.
Samples taken from over 200 seizures of imported illicit heroin preparations of known geographical origin have been examined by gas liquid chromatography (GLC). The chromatographic characteristics were considered in conjunction with the physical appearance of the materials and it was found possible in many instances to discriminate between samples of different origin. Thus by carrying out GLC and HPLC and a visual inspection on a sample of unknown provenance, it may be possible to give an opinion as to its geographical origin.  相似文献   
153.
Despite recent advancements in the criminological study of stalking, few theoretical tests have been conducted to date to explain stalking victimization among men and women separately. The current study individually and simultaneously extends three criminological theories to the study of stalking victimization: self-control, social learning, and control balance theories. Among a sample of 2,766 university students, a series of models were estimated for men and women separately to assess each set of theoretical variables net of control variables. Results reveal consistent significant positive relationships between stalking victimization and low self-control for men; differential peer association (e.g. friends are stalking victims) for men and women; and several social learning variables for only women. However, the control imbalance variables do not explain stalking victimization among men or women, net of other theoretical and control variables. The utility of a multi-theoretical approach to future stalking victimization research is discussed.  相似文献   
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The current study compared perceptions on self-report measures of university mission identity and social justice attitudes between general university students (151 women, 63 men; M age = 19.72, SD = 1.91) and campus ministry students (64 women, 24 men; M age = 19.85, SD = 1.71). Results demonstrated that campus ministry students scored significantly higher on each of four social justice and global/urban engagement subscales. Implications suggest that perceptions of university mission-identity are linked to social justice attitudes, yet campus ministry students compared to regular student samples may be linked to a stronger emphasis on social justice through campus activity.  相似文献   
156.
Climate change is projected to dramatically disrupt rainfall patterns and agricultural yields in sub-Saharan Africa. These shocks to food production can mire farming households in poverty traps. This study investigates whether unconditional cash transfers can help households cope with agricultural production and price shocks. We find that cash empowers poor, rural households facing these negative shocks to employ coping strategies typically used by the non-poor and enables them to substantially increase their food consumption and overall food security. Extending relatively small cash payments unconditionally to the rural poor is a powerful policy option for fostering climate-resilient development.  相似文献   
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Performance characteristics of commercial Y-STR multiplex systems   总被引:2,自引:0,他引:2  
In this work, a number of performance checks were carried out to evaluate the efficacy of commercial Y-short tandem repeats (Y-STR) kits for casework applications. The study evaluated the sensitivity, specificity and stability of the Y-STR markers used and the ability to obtain a male profile from postcoital samples taken at various time points after intercourse. All systems performed well with 1-3 ng of male DNA as recommended by the manufacturers. All systems gave full profiles at 100 pg of input DNA, which is within the realm of low copy number DNA analysis. Moreover all, except Y-Plex12, gave full profiles with 30-50 pg of male DNA. No increased performance was obtained with any of the systems by increasing the cycle number beyond that recommended by the various manufacturers. When up to 1 microg of female DNA was used (in the absence of male DNA) no female DNA cross reactivity was observed with the Y-Plex 12 and Y-Filer systems. PowerPlex Y produced female DNA derived products near the DYS438 and within the DYS392 loci at a rare allele position with high input DNA levels (300 ng and 1 microg, respectively). Male/female DNA admixture experiments indicated the particularly high specificity of the Y-Filer and PowerPlex Y systems under conditions of several thousand fold female DNA excess. All systems were able to detect the minor alleles in male/male DNA admixtures at a 1:5 dilution with the PowerPlex Y and Y-Filer being able to detect some minor alleles at 1:20. Species testing indicated some limited, minor cross reactivity of the commercial systems with some domestic male mammals although it is easily recognizable and would not pose any problems in casework analysis. As expected a significant number of cross-reacting products were obtained with nonhuman primate species. All Y-STR multiplex systems tested were able to produce complete Y-STR profiles from bloodstains and semen stains exposed up to 6 weeks when the samples were protected against precipitation and sunlight. However, exposure of the samples to precipitation either in the presence or absence of sunlight resulted in Y-STR profile loss over time, with total profile loss occurring with all systems after 3 weeks or more. Complete Y-STR profiles of the male donors up to 72 h postcoitus were obtained with all of the multiplex systems tested, except for Y-Plex12, which gave partial profiles.  相似文献   
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