40 research outputs found

    Thermal development of latent fingermarks on porous surfaces-Further observations and refinements

    Full text link
    In a further study of the thermal development of fingermarks on paper and similar surfaces, it is demonstrated that direct contact heating of the substrate using coated or ceramic surfaces at temperatures in excess of 230 °C produces results superior to those obtained using hot air. Fingermarks can also be developed in this way on other cellulose-based substrates such as wood and cotton fabric, though ridge detail is difficult to obtain in the latter case. Fluorescence spectroscopy indicates that the phenomena observed during the thermal development of fingermarks can be reproduced simply by heating untreated white copy paper or filter paper, or these papers treated with solutions of sodium chloride or alanine. There is no evidence to suggest that the observed fluorescence of fingermarks heated on paper is due to a reaction of fingermark constituents on or with the paper. Instead, we maintain that the ridge contrast observed first as fluorescence, and later as brown charring, is simply an acceleration of the thermal degradation of the paper. Thermal degradation of cellulose, a major constituent of paper and wood, is known to give rise to a fluorescent product if sufficient oxygen is available [1-5]. However, the absence of atmospheric oxygen has only a slight effect on the thermal development of fingermarks, indicating that there is sufficient oxygen already present in paper to allow the formation of the fluorescent and charred products. In a depletion study comparing thermal development of fingermarks on paper with development using ninhydrin, the thermal technique was found to be as sensitive as ninhydrin for six out of seven donors. When thermal development was used in sequence with ninhydrin and DFO, it was found that only fingermarks that had been developed to the fluorescent stage (a few seconds of heating) could subsequently be developed with the other reagents. In the reverse sequence, no useful further development was noted for fingermarks that were treated thermally after having been developed with ninhydrin or DFO. Aged fingermarks, including marks from 1-year-old university examination papers were successfully developed using the thermal technique. © 2010 Elsevier Ireland Ltd

    Mutation Operators for UML Class Diagrams

    Full text link
    La prueba de mutación es una técnica bien establecida para evaluar la calidad de los casos de prueba al verificar qué tan bien detectan fallas inyectadas en un artefacto de software (mutante). Usando esta técnica, la actividad más crítica es el diseño adecuado de operadores de mutación para que reflejen defectos típicos del artefacto bajo prueba. Este artículo presenta el diseño de un conjunto de operadores de mutación para esquemas conceptuales (CS) basados en diagramas de clase UML (CD). En este documento, los operadores se definen de acuerdo con una clasificación de defectos existente para UML CS y elementos relevantes identificados a partir del metamodelo UML-CD. Los operadores se utilizan posteriormente para generar mutantes de primer orden para un CS bajo prueba. Finalmente, para analizar la utilidad de los operadores de mutación, medimos algunas características básicas de los operadores de mutación con tres CS diferentes bajo prueba.Mutation Testing is a well-established technique for assessing the quality of test cases by checking how well they detect faults injected into a software artefact (mutant). Using this technique, the most critical activity is the adequate design of mutation operators so that they reflect typical defects of the artefact under test. This paper presents the design of a set of mutation operators for Conceptual Schemas (CS) based on UML Class Diagrams (CD). In this paper, the operators are defined in accordance with an existing defects classification for UML CS and relevant elements identified from the UML-CD meta-model. The operators are subsequently used to generate first order mutants for a CS under test. Finally, in order to analyse the usefulness of the mutation operators, we measure some basic characteristics of mutation operators with three different CSs under test.Ljubljan

    The Ischemic Stroke Genetics Study (ISGS) Protocol

    Get PDF
    BACKGROUND: The molecular basis for the genetic risk of ischemic stroke is likely to be multigenic and influenced by environmental factors. Several small case-control studies have suggested associations between ischemic stroke and polymorphisms of genes that code for coagulation cascade proteins and platelet receptors. Our aim is to investigate potential associations between hemostatic gene polymorphisms and ischemic stroke, with particular emphasis on detailed characterization of the phenotype. METHODS/DESIGN: The Ischemic Stroke Genetic Study is a prospective, multicenter genetic association study in adults with recent first-ever ischemic stroke confirmed with computed tomography or magnetic resonance imaging. Patients are evaluated at academic medical centers in the United States and compared with sex- and age-matched controls. Stroke subtypes are determined by central blinded adjudication using standardized, validated mechanistic and syndromic classification systems. The panel of genes to be tested for polymorphisms includes β-fibrinogen and platelet glycoprotein Ia, Iba, and IIb/IIIa. Immortalized cell lines are created to allow for time- and cost-efficient testing of additional candidate genes in the future. DISCUSSION: The study is designed to minimize survival bias and to allow for exploring associations between specific polymorphisms and individual subtypes of ischemic stroke. The data set will also permit the study of genetic determinants of stroke outcome. Having cell lines will permit testing of future candidate risk factor genes

    Revisiting the thermal development of latent fingerprints on porous surfaces: New aspects and refinements

    Full text link
    Although the ability to develop latent fingerprints on paper using heat alone has been noted previously, it has been considered impractical for casework and inferior to other techniques. Here a new refinement of the technique is demonstrated for the high quality development of latent fingerprints on porous surfaces such as paper. Fingerprints deposited on various papers were developed by exposing them to hot air with a temperature in the vicinity of 300°C, for periods of c. 10-20 sec. Several different heating methods were tested. The novel observation was made that after shorter heating times, fluorescent prints could be observed. These became visible after longer heating times, as noted by earlier workers, but with greatly improved contrast compared with their results. Prints from various donors (and aged prints) were developed with excellent ridge contrast. Direct heating methods (such as with a hot plate or press) produced inferior results. The refined technique, which is simple, safe and inexpensive compared with conventional methods, has great potential for use in forensic laboratories. © 2008 American Academy of Forensic Sciences

    The joint flanker effect: sharing tasks with real and imagined co-actors

    Get PDF
    Contains fulltext : 99810.pdf (publisher's version ) (Open Access)The Eriksen flanker task (Eriksen and Eriksen in Percept Psychophys 16:143-149, 1974) was distributed among pairs of participants to investigate whether individuals take into account a co-actor's S-R mapping even when coordination is not required. Participants responded to target letters (Experiment 1) or colors (Experiment 2) surrounded by distractors. When performing their part of the task next to another person performing the complementary part of the task, participants responded more slowly to stimuli containing flankers that were potential targets for their co-actor (incompatible trials), compared to stimuli containing identical, compatible, or neutral flankers. This joint Flanker effect also occurred when participants merely believed to be performing the task with a co-actor (Experiment 3). Furthermore, Experiment 4 demonstrated that people form shared task representations only when they perceive their co-actor as intentionally controlling her actions. These findings substantiate and generalize earlier results on shared task representations and advance our understanding of the basic mechanisms subserving joint action
    corecore