4,395 research outputs found

    Applications of fuzzy theories to multi-objective system optimization

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    Most of the computer aided design techniques developed so far deal with the optimization of a single objective function over the feasible design space. However, there often exist several engineering design problems which require a simultaneous consideration of several objective functions. This work presents several techniques of multiobjective optimization. In addition, a new formulation, based on fuzzy theories, is also introduced for the solution of multiobjective system optimization problems. The fuzzy formulation is useful in dealing with systems which are described imprecisely using fuzzy terms such as, 'sufficiently large', 'very strong', or 'satisfactory'. The proposed theory translates the imprecise linguistic statements and multiple objectives into equivalent crisp mathematical statements using fuzzy logic. The effectiveness of all the methodologies and theories presented is illustrated by formulating and solving two different engineering design problems. The first one involves the flight trajectory optimization and the main rotor design of helicopters. The second one is concerned with the integrated kinematic-dynamic synthesis of planar mechanisms. The use and effectiveness of nonlinear membership functions in fuzzy formulation is also demonstrated. The numerical results indicate that the fuzzy formulation could yield results which are qualitatively different from those provided by the crisp formulation. It is felt that the fuzzy formulation will handle real life design problems on a more rational basis

    The Integrated Psychosocial Model of Criminal Social Identity (IPM-CSI)

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    The integrated psychosocial model of criminal social identity attempts to synthesize, distil, and extend our knowledge and understanding of why people develop criminal social identity, with a particular focus on the psychological and social factors involved. We suggest that the development of criminal social identity results from a complex interplay of four important groups of psychosocial factors: (1) an identity crisis which results in weak bonds with society, peer rejection, and is associated with poor parental attachment and supervision; (2) exposure to a criminal/antisocial environment in the form of associations with criminal friends before, during, and/or after incarceration; (3) a need for identification with a criminal group in order to protect one’s self-esteem; and (4) the moderating role of personality traits in the relationship between criminal/antisocial environment and the development of criminal social identity. The model produces testable hypotheses and points to potential opportunities for intervention and prevention. Directions for future research are discussed

    A Bifactorial Solution to the Psychopathy Checklist: Screening Version in a Sample of Civil Psychiatric Patients

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    Background There is considerable debate about the underlying factor structure of the Psychopathy Checklist: Screening Version (PCL: SV). An established view is that it reflects a unitary construct underpinned by two correlated factors. More recent research has, however, undermined this conceptualisation. Aims Our aim was to compare 10 competing models of the PCL: SV in a sample of civil psychiatric patients. Method Ten distinct factor models were specified and tested using conventional confirmatory factor analytic techniques, along with confirmatory bifactor modelling. Results A bifactor model, including two general factors (interpersonal–affective and antisocial–lifestyle), and four subordinate factors (interpersonal, affective, antisocial and lifestyle) provided the best fit to the data. The reliability of the conceptualisation was supported through the use of composite reliability, and the differential relationships exhibited between the general factors and measures of personality, impulsivity and mental health. Conclusions Our findings provide further weight to taking the two general psychopathy factors into account when interpreting the PCL: SV for clinical purposes

    Psychopathy, Gang membership, And moral disengagement among juvenile offenders

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    Purpose – The purpose of this paper is to investigate the impact of psychopathy factors and gang membership on moral disengagement while controlling for age, ethnicity, having run away from home, family member and/or friend arrests, substance misuse, parental physical fights, violence exposure (victimization and witnessing), and maternal warmth and hostility. Design/methodology/approach – The research is based on data collected from serious juvenile offenders (n=769) as part of the Pathways to Desistance Study. Findings – Six independent variables made a unique statistically significant contribution to the model: gang membership, age, gender, violence exposure, and psychopathy Factors 1 and 2. Psychopathy Factor 1 was the strongest predictor of moral disengagement. Originality/value – Results indicate that youth with heightened psychopathic traits make greater use of strategies to rationalize and justify their harmful behaviour against others. Implications in relation to theory and previous studies are discussed

    Gender Differences in Risk and Protective factors for Resolved Plans and Preparations for Suicide among University Students

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    Background. Identifying the psychological predictors of suicide risk is essential because these variables may be amenable to change in treatment, unlike demographic or historical factors. Aims. The aim of this study was to examine the predictors of past two-week suicidal ideation for males and females separately. Method. Participants were 1184 healthy adults who completed an online survey. Results. A significant association between suicidal ideation and gender was found, such that mean levels were significantly higher in females than males. Separate regression analyses accounted for significant amounts of variance in suicide ideation, 54% for males and 68% for females. Moreover, the analyses revealed that suicide resilience Factor 2 (Emotional Stability) was a protective factor for both males and females; however, defeat, goal disengagement, and depression were independently associated with suicide ideation in males but not females. By contrast, entrapment, perceived burdensomeness, and hopelessness Factor 3 (Future Expectations) were significant risk factors only in females. Conclusions. The findings have clinical and practical implications, which may guide future practice, and supports the notion of targeted prevention and intervention strategies

    Graphene Q-switched mode-locked waveguide laser operating at 1535 nm

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    A diode-pumped Er,Yb:glass waveguide laser, Q-switched mode-locked using a graphene saturable absorber is presented. Mode-locked pulses at a repetition rate of 6.8 GHz are achieved at an output power of 27 mW and a wavelength of 1535 nm

    Facets of Psychopathy in Relation to Trauma-Exposure and Posttraumatic Stress Symptomology in a Sample of Incarcerated Male Offenders

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    Purpose: The aim was to investigate the moderating role of psychopathy facets on the relationship between traumatic exposure and posttraumatic stress disorder (PTSD) symptomology. Design/methodology/approach: Participants were male prisoners incarcerated in the U.K. Findings: The analysis revealed differential associations between the two facets of psychopathy, with potentially traumatic events and symptoms of PTSD. Specifically, neither primary psychopathy nor trauma exposure were significantly related to PTSD, while secondary psychopathy was positively and significantly related with PTSD symptoms. Furthermore, the effect of trauma exposure on PTSD was found to depend on the level of secondary psychopathy. More specifically, trauma exposure was strongly and positively associated with PTSD symptoms for low levels of secondary psychopathy and negatively associated with PTSD symptomology for individuals with high levels of secondary psychopathy. Originality/value: The findings clarify linkages among psychopathy facets, trauma, and PTSD, and extend our understanding of the presentation of PTSD in male prisoners

    Aggregatibacter actinomycetemcomitans leukotoxin induces cytosol acidification in LFA-1 expressing immune cells

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    Studies have suggested that Aggregatibacter actinomycetemcomitans leukotoxin (LtxA) kills human lymphocyte function-associated antigen 1 (LFA-1; CD11a/CD18)-bearing immune cells through a lysosomal-mediated mechanism. Lysosomes are membrane-bound cellular organelles that contain an array of acid hydrolases that are capable of breaking down biomolecules. The lysosomal membrane bilayer confines the pH-sensitive enzymes within an optimal acidic (pH 4.8) environment thereby protecting the slightly basic cytosol (pH 6.8-7.5). In the current study, we have probed the effect of LtxA-induced cytolysis on lysosomal integrity in two different K562 erythroleukemia cell lines. K562-puro/LFA-1 cells were stably transfected with CD11a and CD18 cDNA to express LFA-1 on the cell surface while K562-puro, which does not express LFA-1, served as a control. Following treatment with 100 ng ml-1 LtxA cells were analyzed by live cell imaging in conjunction with time-lapse confocal microscopy and by flow cytometry. Using a pH-sensitive indicator (pHrodo®) we demonstrated that the toxin causes a decrease in the intracellular pH in K562-puro/LFA-1 cells that is noticeable within the first 15 min of treatment. This process correlated with the disappearance of lysosomes in the cytosol as determined by both acridine orange and LysoTracker® Red DND-99 staining. These changes were not observed in K562-puro cells or when heat inactivated toxin was added to K562-puro/LFA-1. Our results suggest that LtxA induces lysosomal damage, cytosol acidification, which is followed by cell death in K562-puro/LFA-1 cells. © 2016 John Wiley & Sons A/S

    Can we use Hare’s psychopathy model within forensic and non-forensic populations? An empirical investigation

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    Although psychopathy construct (SRP-SF) was assessed among various samples, prior research did not investigate whether the model proposed by Hare and colleagues can be used to capture psychopathy scores derived from forensic and non-forensic populations. The main objective of the current study was to test dimensionality, construct validity, and factorial invariance of the SRP-SF within prison (N = 730) and student (N = 2,506) samples. Our results indicate that the SRP-SF measure cannot be used in the same way within forensic and non-forensic samples, which may be due to the inclusion of criminal/antisocial traits as an integral part of psychopathy

    Prevalence of HPV in Oesophageal Biopsies and its Correlation with Expression Of P16INK4A

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    Background: The association of Human papillomavirus (HPV ) and p16INK4a is well established with cervical malignancies and has been studied in oral mucosa also. Koilocytosis, that is considered to be a hallmark of HPV infection is also seen in oesophageal mucosa. Aims: This study was designed to determine the prevalence of HPV in biopsies from inflammatory and neoplastic lesions of oesophagus and correlate it with expression of p16INK4a. Materials and Methods: The study included 102 oesophageal biopsies. Haematoxylin & Eosin stained sections were examined for morphological details including koilocytosis. Immunohistochemistry for HPV and p16INK4a were done on 50 biopsies. HPV positivity was graded and scoring for p16INK4a was done. Results: Various grades of koilocytosis was noted in 68.75%, 94.73% and 72.91% controls, inflammatory and neoplastic lesions respectively. IHC for HPV was positive in 80% control, 75% inflammatory and 100% cases of neoplastic lesion. Complete score for p16INK4a was 0.60, 0.59 and 3.63 in control, inflammatory and neoplastic lesion. The difference in expression of p16INK4a between neoplastic and inflammatory lesion was statistically significant. Conclusion: Expression of p16INK4a protein showed good correlation with HPV infection in inflammatory and neoplastic lesions. Thus IHC for p16INK4a which is easily available can be used as an indirect evidence of HPV infection in neoplastic lesion where expensive molecular technique for HPV DNA measurement is not feasibl
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