259 research outputs found

    Landscape phage, phage display, stripped phage, biosensors, detection, affinity reagent, nanotechnology, Salmonella typhimurium, Bacillus anthracis

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    Filamentous phage, such as fd used in this study, are thread-shaped bacterial viruses. Their outer coat is a tube formed by thousands equal copies of the major coat protein pVIII. We constructed libraries of random peptides fused to all pVIII domains and selected phages that act as probes specific for a panel of test antigens and biological threat agents. Because the viral carrier is infective, phage borne bio-selective probes can be cloned individually and propagated indefinitely without needs of their chemical synthesis or reconstructing. We demonstrated the feasibility of using landscape phages and their stripped fusion proteins as new bioselective materials that combine unique characteristics of affinity reagents and self assembling membrane proteins. Biorecognition layers fabricated from phage-derived probes bind biological agents and generate detectable signals. The performance of phage-derived materials as biorecognition films was illustrated by detection of streptavidin-coated beads, Bacillus anthracis spores and Salmonella typhimurium cells. With further refinement, the phage-derived analytical platforms for detecting and monitoring of numerous threat agents may be developed, since the biodetector films may be obtained from landscape phages selected against any bacteria, virus or toxin. As elements of field-use detectors, they are superior to antibodies, since they are inexpensive, highly specific and strong binders, resistant to high temperatures and environmental stresses.Comment: Submitted on behalf of TIMA Editions (http://irevues.inist.fr/tima-editions

    Measuring deviant sexual interest in Adolescents using the emotional Stroop task.

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    Adolescent sexual abusers are a heterogeneous group of offenders that often receive generic assessment and treatment services that are modeled on research findings from adult sex offender samples. The emotional Stroop task has been used to measure deviant sexual interest in adult samples. The purpose of the present study was to test whether the emotional Stroop task could also be used to assess deviant sexual interest in adolescent samples. Three groups of adolescents (a) sexual abusers (n = 24); (b) offending controls (n = 21); and (c) nonoffending controls (n = 21) completed two emotional Stroop tasks related to deviant sexual interest and tests of executive function. Adolescent sexual abusers were significantly slower to color-name some word stimuli than both adolescent offending controls and adolescent nonoffending controls. However, the task was unable to differentiate between the groups on most of the Stroop word categories. Very little research has been conducted with adolescent offender samples and the emotional Stroop task. Reaction time (RT) and Stroop bias outcome data for adolescent samples appear to be more unsystematic and weaker than has been observed in previous adult data. Based on potential difficulties with reading and development, the emotional Stroop task may not be a task suitable for measuring deviant sexual interest in adolescent samples

    Risk assessment for the spread of Serratia marcescens within dental-unit waterline systems using Vermamoeba vermiformis

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    Vermamoeba vermiformis is associated with the biofilm ecology of dental-unit waterlines (DUWLs). This study investigated whether V. vermiformis is able to act as a vector for potentially pathogenic bacteria and so aid their dispersal within DUWL systems. Clinical dental water was initially examined for Legionella species by inoculating it onto Legionella selective-medium plates. The molecular identity/profile of the glassy colonies obtained indicated none of these isolates were Legionella species. During this work bacterial colonies were identified as a non-pigmented Serratia marcescens. As the water was from a clinical DUWL which had been treated with Alpron™ this prompted the question as to whether S. marcescens had developed resistance to the biocide. Exposure to Alpron™ indicated that this dental biocide was effective, under laboratory conditions, against S. marcescens at up to 1x108 colony forming units/millilitre (cfu/ml). V. vermiformis was cultured for eight weeks on cells of S. marcescens and Escherichia coli. Subsequent electron microscopy showed that V. vermiformis grew equally well on S. marcescens and E. coli (p = 0.0001). Failure to detect the presence of S. marcescens within the encysted amoebae suggests that V. vermiformis is unlikely to act as a vector supporting the growth of this newly isolated, nosocomial bacterium

    Investigating the effect of child maltreatment on early adolescent peer-on-peer sexual aggression: testing a multiple mediator model in a non-incarcerated sample of Danish adolescents

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    Objective: The aim of the present study was to investigate the relationship between child maltreatment and severe early adolescent peer-on-peer sexual aggression, using a multiple mediator model. Methods: The study comprised 330 male Grade 9 students with a mean age of 14.9 years (SD=0.5). Results: Estimates from the mediation model indicated significant indirect effects of child physical abuse on sexual aggression via peer influence and insecure-hostile masculinity. No significant total effect of child sexual abuse and child neglect on sexual aggression was found. Conclusions: Findings of the present study identify risk factors that are potentially changeable and therefore of value in informing the design of prevention programs aiming at early adolescent peer-on-peer sexual aggression in at-risk youth

    Developing an ecologically relevant heterogeneous biofilm model for dental-unit waterlines

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    This study monitored the biodiversity of microbes cultured from a heterogeneous biofilm which had formed on the lumen of a section of dental waterline tubing over a period of 910 days. By day two bacterial counts on the outlet-water showed that contamination of the system had occurred. After 14 days, a biofilm comparable to that of clinical waterlines, consisting of bacteria, fungi and amoebae had formed. This showed that the proprietary silver coating applied to the lumenal surface of the commercial waterline tubing failed to prevent biofilm formation. Molecular barcoding of isolated culturable microorganisms showed some degree of the diversity of taxa in the biofilm, including the opportunistic pathogen Legionella pneumophila. Whilst the system used for isolation and identification of contaminating microorganisms may underestimate the diversity of organisms in the biofilm, their similarity to those found in the clinical environment makes this a promising test-bed for future biocide testing

    Validity of the Modified Child Psychopathy Scale for Juvenile Justice Center Residents

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    Adult psychopathy has proven to be an important clinical and forensic construct, but much less is known about juvenile psychopathy. In the present study, we examined the construct validity of the self report modified Child Psychopathy Scale mCPS; Lynam (Psychological Bulletin 120:(2), 209–234, 1997) in a sample of 57 adolescents residing in a Dutch juvenile justice center, aged between 13 and 22 years. The mCPS total score was reliably related to high externalizing problems, low empathy, high anger and aggression, high impulsivity, high (violent) delinquency, and high alcohol/drug use. Unique relations were found for the antisocial-impulsive (mCPS Factor 2), but not the callous-unemotional facet of psychopathy (mCPS Factor 1). Our findings support the validity of the mCPS in that it encompasses the antisocial-impulsive facet of psychopathy, but it is less clear whether the mCPS sufficiently captures the affective-interpersonal facet of psychopathy

    Free will, punishment and criminal responsibility

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    Retributive attitudes are deeply held and widespread in the general population and most legal systems incorporate retributive elements. It is probably also the dominant theory of punishment among contemporary philosophers of criminal justice. However, retributivism relies on conceptions of free will and responsibility that have, for millennia, fundamentally divided those who have thought seriously about the subject. Our legal system upholds the principle that the responsibility of the offender has to be proven beyond reasonable doubt, before the accused can be punished. In view of the intractable doubts surrounding the soundness of retributivism’s very conception of responsibility, my thesis argues that it is ethically dubious to punish individuals for solely retributive reasons. Instead, my thesis proposes that a person should only be punished if the main theories of punishment agree that punishing that person is appropriate – I call this ‘the convergence requirement’. This approach, I argue, is in accordance with the considerations underlying the beyond reasonable doubt standard. In addition to considering the question of ‘whom to punish’ my thesis considers what methods of responding to criminal behaviour are acceptable. In particular, it attempts to explain, without appealing to the contested notions of free will or retributive desert, what is problematic about ‘manipulative’ methods of dealing with criminal offenders (focussing in particular on the possibility of modifying their behaviour through neurological interventions). The final part of this thesis also gives an overview of some of the practical implications for Scots criminal law of taking doubts about free will and retributivism seriously. Given the severe treatment that offenders undergo within the Scottish penal system (e.g. deprivation of liberty, stigma) and the high rate of recidivism, it is important to consider whether our current penal practices are justified, what alternatives are available and what goals and values should guide attempts at reforming the system

    Governing Ecological Connectivity in Cross-Scale Dependent Systems.

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    Ecosystem management and governance of cross-scale dependent systems require integrating knowledge about ecological connectivity in its multiple forms and scales. Although scientists, managers, and policymakers are increasingly recognizing the importance of connectivity, governmental organizations may not be currently equipped to manage ecosystems with strong cross-boundary dependencies. Managing the different aspects of connectivity requires building social connectivity to increase the flow of information, as well as the capacity to coordinate planning, funding, and actions among both formal and informal governance bodies. We use estuaries in particular the San Francisco Estuary, in California, in the United States, as examples of cross-scale dependent systems affected by many intertwined aspects of connectivity. We describe the different types of estuarine connectivity observed in both natural and human-affected states and discuss the human dimensions of restoring beneficial physical and ecological processes. Finally, we provide recommendations for policy, practice, and research on how to restore functional connectivity to estuaries
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