Detection and correction of a migration anomaly on a 310 genetic analyzer

During STR analysis on the 310 Genetic Analyzer, retarded migration of GS500ROX size standards and alleles in some samples was observed. The contribution of reagents, capillary and performance optimized polymer POP 4 to the observed anomaly was experimentally eliminated. Variation in electrophoresis temperature between 55 degrees C and 65 degrees C did not alter the rate of migration of GX500ROX size standard and sample alleles. An eroded connector for the cathode mounted on the heat plate assembly caused the abnormal migration. Hence, it is important to verify the mobility of all fragments in the size standard for each sample to avoid any erroneous allele calls by the automated data analysis software.     

Y-chromosome STR system, Y-PLEX 12, for forensic casework: development and validation

The Y-PLEX 12 system, developed for use in human identification, enables simultaneous amplification of eleven polymorphic short tandem repeat (STR) loci, namely DYS392, DYS390, DYS385 a/b, DYS393, DYS389I, DYS391, DYS389II, DYS 19, DYS439 and DYS438, residing on the Y chromosome and Amelogenin. Amelogenin provides results for gender identification and serves as internal control for PCR. The validation studies were performed according to the DNA Advisory Board's (DAB) Quality Assurance Standards. The minimal sensitivity of the Y-PLEX 12 system was 0.1 ng of male DNA. The mean stutter values ranged between 3.76-15.72%. A full male profile was observed in mixture samples containing 0.5 ng of male DNA and up to 400 ng of female DNA. Amelogenin did not adversely affect the amplification of Y-STRs in mixture samples containing male and female DNA. The primers for the Y-STR loci present in Y-PLEX 12 are specific for human DNA and some higher primates. None of the primate samples tested provided a complete profile at all 11 Y-STR loci amplified with the Y-PLEX 12 system. Y-PLEX 12 is a sensitive, valid, reliable, and robust multiplex system for forensic analysis, and it can be used in human forensic and male lineage identification cases.     

Analysis of food expenditure patterns of industrial workers and their families in a developing country

This paper employs data from a single socio‐economic group within the Indian population to throw some light on three related topics—the impact of urbanization on the demand for food, the nature of the income‐elasticity of expenditure on food for this group, and the importance of particular socio‐economic variables as determinants of the demand for food.

The income‐elasticity of demand for food has become liable to maltreatment in the process of development planning; all too often an estimate of this parameter is employed unquestioningly to evaluate the food requirements of developing countries, although it is well known that as incomes rise the income‐elasticity of demand for food falls. The following pages show that, like other characteristics of a developing system, the income‐elasticity of the demand for food is far from being a ‘fixed’ parameter. Firstly, as development proceeds, it is subject to change in a particular manner and direction. Secondly, the particular value of the income‐elasticity is subject to considerable variation within the country at a point in time. Thirdly, other variables than income exert significant pressure on behaviour, as evidenced by food expenditure patterns.     

DNA Detectives

Credit-card-size devices will soon analyze DNA right at a crime scene identifying the perpetrators before they can strike again.     

Distribution of HLA-DQA1, polymarker, CSF1PO, vWA, TH01, TPOX, D16S539, D7S820, D13S317, and D5S818 alleles in East Bengali and West Punjabi populations from Indo-Pak Subcontinent

Blood samples were collected from 115 individuals residing in the Pakistani state of West Punjab and 81 Bengali individuals residing in the state of East Bengal, India. These samples were analyzed for the loci HLA-DQA1, PM (LDLR, GYPA, HBGG, D7S8, and GC) and eight short tandem repeats: CSF1PO, TPOX, THO1, vWA, D16S539, D7S820, D13S317, and D5S818. Departures from Hardy-Weinberg (HWE) were observed in Punjabi population at LDLR, THO1, D13S317, D5S818, and D16S539 and at CSF1PO and THO1 in Bengali population.     

Utility of the Y-STR typing systems Y-PLEX 6 and Y-PLEX 5 in forensic casework and 11 Y-STR haplotype database for three major population groups in the United States

The Y-PLEX 6 and Y-PLEX 5 systems enable analysis for 11 Y-STR loci. We present here the utility of these systems in forensic casework. A total of 188 samples, including 127 evidence samples, were analyzed using either or both of the systems. The evidence sample types included fingernail scrapings, sperm or seminal fluid, epithelial cells, blood and other tissues. The Y-STR typing systems provided useful probative results in difficult cases. A reference database for Caucasian (n = 517), African American (n = 535), and Hispanic (n = 245) population groups within the United States was generated for estimating the haplotype frequency in forensic casework. Among the individuals profiled, 311 Caucasians, 412 African Americans, and 194 Hispanics provided unique profiles in their respective population datasets. This is the first report describing the haplotype database for the set of 11 Y-STR loci recommended by the Scientific Working Group on DNA Analysis Methods (SWGDAM). Linkage analysis reveals that the frequencies from forensically important autosomal loci can be multiplied with the Y-STR haplotype frequency. The results from Y-PLEX systems have been accepted in courts in the United States.