The ID effect on youth access to cigarettes

OBJECTIVE: To estimate the effect on cigarette sales rates when minors present identification (ID). DESIGN: Controlled experiment in which minors attempting to purchase cigarettes either carried a valid photo ID (documenting they were minors) or carried no ID, and were instructed to show the ID or admit having no ID if the clerk requested proof of age. SETTING: Census of retail stores in six urban and suburban Colorado counties. SUBJECTS: Retail cigarette clerks, uninformed of the study. MAIN OUTCOME MEASURES: Relative risk (RR) of cigarette sale to a minor when ID was requested and presented versus requested but not presented. RESULTS: When clerks requested ID, sales were more than six times as frequent if minors presented ID than if they did not (12.2% v 2.0%, RR 6.2, p < 0.0001). The relative risk remained substantially unchanged under adjustment for demographic and circumstantial covariates. CONCLUSIONS: Presentation of photo ID in compliance checks increases illegal cigarette sales to minors. The impact may vary among states or locales and depends strongly on how often clerks request proof of age. Clerk training and responsible cigarette sales practices should include age calculations from photo ID. Programmes relying on investigative purchase attempts to estimate actual rates of cigarette sales to minors should ascertain and replicate local ID presenting behaviours that minors typically use during genuine attempts to buy cigarettes.     

Preimplantation genetic diagnosis in Marfan syndrome

Melanoma has a better prognosis in women than in men, may be exacerbated by pregnancy, and has been to reported to respond to hormonal manipulations. Laboratory investigations have demonstrated that both animal and human melanomas may respond to changes in the hormonal milieu. Steroid hormone binding activity has been demonstrated in some human melanomas, but only a small percentage of melanomas respond to hormonal manipulation. Randomized trials suggest a possible role for tamoxifen in combination with chemotherapy for metastatic melanoma and for megestrol acetate as an adjuvant. Nevertheless, it appears that the use of steroid hormones in the management of melanoma is limited.     

The molecular genetics of schizophrenia: an update

OBJECTIVE: This paper aims to summarise the latest molecular genetic findings in schizophrenia, while providing background information on a number of relevant methodological issues. METHOD: Accumulative genetic data indicate that schizophrenia is a genetically complex disease with an unclear mode of transmission. The development and rapid progression of molecular genetics have provided a wide variety of methods to search for genes predisposing to human disease. The genetic basis for a number of the simpler diseases has been identified and characterised using these methods. More recently, progress has been made in identifying genes predisposing to the genetically more complex diseases such as diabetes mellitus, multiple sclerosis, bipolar disorder and schizophrenia. RESULTS: The latest findings on chromosomes 3, 6, 8, 13, 18 and 22 and on the X chromosome are reviewed. CONCLUSIONS: There is now suggestive support for three susceptibility loci (6p24-22, 8p22-21 and 22q12-q13.1) for schizophrenia, and it is likely that other regions will emerge from studies now in progress. Finding and then characterising genes within these loci will require long-term commitment and systematic efforts in clinical, laboratory and analytical fields.     

A self-organizing pattern retrieval system and its applications

This article is an overview of research on the design and application of a Self-Organizing Pattern Retrieval System. This system is a nontraditional form of database for several reasons: (1) the objects (patterns) stored in the database are complex data structures such as graphs, or matrices as opposed to relations, sets, lists or frames; (2) the system attempts to optimize its internal structure for retrieval efficiency by taking advantage of classificatory information (common patterns) it discovers about the patterns in the database; and (3) the system is representation-independent, allowing the user to use whatever representation scheme he desires as long as he provides a small set of I/O routines and comparison functions for the representation. This system has been applied to the organization of molecules and reactions in organic chemistry. the system is able to select valid precursors to molecules based on its knowledge of real-world reactions. It is also able to suggest new chemical reactions based on generalizations from its knowledge base. the system has also been applied to the retrieval, generalization, and classification of chess positions. Its ability to recognize the tactical similarity of positions is compared with that of a chess master. the design objectives of a system for classifying Radio Frequency Interference required by NASA's SETI (Search for ExtraTerrestrial Intelligence) project is also discussed.     

Integrated fusion environmental and safety systems studies

An integrated environmental and safety (E&S) systems module is being developed at the Berkeley Fusion Environmental and Safety Group with the objectives of providing overall E&S assessment and incorporating E&S characteristics into optimization in fusion reactor design studies. The module includes features such as modularization, quantification of figures-of-merit, and fast calculational schemes because of emphasis on compatibility with systems-level analyses. Initial results indicate the potential for trade-offs and optimizations involving E&S and reactor performance indices in moderately large design windows.     

Infant Mortality, Freaks, and Wear-Out: Application of Modern Semiconductor Reliability Methods to Ceramic Multilayer Capacitors

An overview of the methods of modern semiconductor reliability and accelerated life testing based on the lognormal distribution is given, Bimodal distributions due to the presence of freak failure populations are also discussed, along with the Fowlkes test for a bimodal lognormal distribution. A novel analysis of recent published results on capacitor reliability is given, based on the known properties of the lognormal and Weibull distributions as well as recent experience in their application to semiconductor device reliability. For test periods of 168 and 1000 h, estimates of the required voltages and temperature stresses as well as sample sizes are made to ensure a hazard rate of less than 100 FIT (failures per unit time) per capacitor after 40 yr of operation. The results show that the customary accelerated test at twice the rated voltage and 125°C for 1000 h, is insufficient. Comparison with data from a recent highly accelerated life test (HALT) indicates that the HALT procedures may be useful as an effective screen. Bimodal failure distributions are shown to be due to the presence of freak (early failure) populations of about 10%.