1,042 research outputs found

    Implicit theories and offender representativeness in judgments about sexual crime

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    Implicit theories structure the way people understand and respond to various human actions. Typically, people believe attributes are either fixed (entitists) or malleable (incrementalists). The present study aimed to examine: (a) whether attitudes towards sexual offenders differ depending upon one’s implicit theory about human nature and sexual offenders, and (b) whether implicit theories are associated with judgments made about different types of child abuser. A sample of 252 community participants was recruited. Their attitudes, implicit theories, and political orientation were assessed via self-report. One of three vignettes describing an incidence of child sexual abuse was then presented. The cases were identical except the perpetrator was either an adult male, an adult female, or a male juvenile. Participants then made judgments about the offender's deserved sentence and moral character. Entitists (across both domains) held more negative attitudes than incrementalists, although the magnitude of the difference was greatest when examining implicit theories about sexual offenders. Compared to those with an incremental theory of sexual offenders, entity theorists judged sexual offending to be more: (a) indicative of the perpetrator’s moral character, and (b) deserving of punishment. However, scores were greater towards the adult male relative to the adult female and juvenile. The findings suggest that implicit theories about sexual offenders are domain-specific. They also indicate that judgments made by those with an entity theory (about sexual offenders) are affected by whether a case is representative of a stereotypical sexual offender. Implications of the findings are discussed, along with limitations and future research

    Temperature Dependence of Backbone Dynamics in Human Ileal Bile Acid-Binding Protein: Implications for the Mechanism of Ligand Binding

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    Human ileal bile acid-binding protein (I-BABP), a member of the family of intracellular lipid binding proteins plays a key role in the cellular trafficking and metabolic regulation of bile salts. The protein has two internal and, according to a recent study, an additional superficial binding site and binds di- and trihydroxy bile salts with positive cooperativity and a high degree of site-selectivity. Previously, in the apo form, we have identified an extensive network of conformational fluctuations on the millisecond time scale, which cease upon ligation. Additionally, ligand binding at room temperature was found to be accompanied by a slight rigidification of picosecond-nanosecond (ps-ns) backbone flexibility. In the current study, temperature-dependent N-15 NMR spin relaxation measurements were used to gain more insight into the role of dynamics in human I-BABP-bile salt recognition. According to our analysis, residues sensing a conformational exchange in the apo state can be grouped into two clusters with slightly different exchange rates. The entropy-enthalpy compensation observed for both clusters suggests a disorder-order transition between a ground and a sparsely populated higher energy state in the absence of ligands. Analysis of the faster, ps-ns motion of N-15-H-1 bond vectors indicates an unusual nonlinear temperature-dependence for both ligation states. Intriguingly, while bile salt binding results in a more uniform response to temperature change throughout the protein, the temperature derivative of the generalized order parameter shows different responses to temperature increase for the two forms of the protein in the investigated temperature range. Analysis of both slow and fast motions in human I-BABP indicates largely different energy landscapes for the apo and halo states suggesting that optimization of binding interactions might be achieved by altering the dynamic behavior of specific segments in the protein

    An initial event in insect innate immune response: structural and biological studies of interactions between β-1,3-glucan and the N-terminal domain of β-1,3-glucan recognition protein

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    In response to invading microorganisms, insect β-1,3-glucan recognition protein (βGRP), a soluble receptor in the hemolymph, binds to the surfaces of bacteria and fungi and activates serine protease cascades that promote destruction of pathogens by means of melanization or expression of antimicrobial peptides. Here we report on the NMR solution structure of the N-terminal domain of βGRP (N-βGRP) from Indian meal moth (Plodia interpunctella), which is sufficient to activate the prophenoloxidase (proPO) pathway resulting in melanin formation. NMR and isothermal calorimetric titrations of N-βGRP with laminarihexaose, a glucose hexamer containing β-1,3 links, suggest a weak binding of the ligand. However, addition of laminarin, a glucose polysaccharide (~ 6 kDa) containing β-1,3 and β-1,6 links that activates the proPO pathway, to N-βGRP results in the loss of NMR cross-peaks from the backbone 15N-1H groups of the protein, suggesting the formation of a large complex. Analytical ultra centrifugation (AUC) studies of formation of N-βGRP:laminarin complex show that ligand-binding induces sel-fassociation of the protein:carbohydrate complex into a macro structure, likely containing six protein and three laminarin molecules (~ 102 kDa). The macro complex is quite stable, as it does not undergo dissociation upon dilution to sub-micromolar concentrations. The structural model thus derived from the present studies for N-βGRP:laminarin complex in solution differs from the one in which a single N-βGRP molecule has been proposed to bind to a triple helical form of laminarin on the basis of an X-ray crystallographic structure of N-βGRP:laminarihexaose complex [Kanagawa, M., Satoh, T., Ikeda, A., Adachi, Y., Ohno, N., and Yamaguchi, Y. (2011) J. Biol. Chem. 286, 29158-29165]. AUC studies and phenoloxidase activation measurements carried out with the designed mutants of N-βGRP indicate that electrostatic interactions involving Asp45, Arg54, and Asp68 between the ligand-bound protein molecules contribute in part to the stability of N-βGRP:laminarin macro complex and that a decreased stability is accompanied by a reduced activation of the proPO pathway. Increased β-1,6 branching in laminarin also results in destabilization of the macro complex. These novel findings suggest that ligand-induced self-association of βGRP:β-1,3-glucan complex may form a platform on a microbial surface for recruitment of downstream proteases, as a means of amplification of the initial signal of pathogen recognition for the activation of the proPO pathway

    Accessible Content and Accessibility Experiences: The Interplay of Declarative and Experiential Information in Judgment

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    Recall tasks render 2 distinct sources of information available: the recalled content and the experienced ease or difficulty with which it can be brought to mind. Because retrieving many pieces of information is more difficult than retrieving only a few, reliance on accessible content and subjective accessibility experiences leads to opposite judgmental outcomes. People are likely to base judgments on accessibility experiences when they adopt a heuristic processing strategy and the informational value of the experience is not called into question. When the experience is considered nondiagnostic, or when a systematic processing strategy is adopted, people rely on accessible content. Implications for the operation of the availability heuristic and the emergence of knowledge accessibility effects are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68686/2/10.1207_s15327957pspr0202_2.pd

    Entrepreneurial passion and a firm’s innovation strategies

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    Drawing upon the role of affect in the entrepreneurship model and the broaden-and-build theory of positive emotions, this study surveyed 195 entrepreneurs in Vietnam and found that entrepreneurial passion has a positive effect on a firm’s exploratory innovation strategies and a complex inverted U-shaped effect on the exploitative innovation strategies. These results extend the literature on entrepreneurial emotions and underscore the need to depart from the simplistic linear association between entrepreneurial passion and firm-level indicators. Furthermore, this study enriches our understanding of three types of entrepreneurs’ social identities by supporting their contingent effects on the links between passion and innovation strategies

    No Interaction of Barrier-to-Autointegration Factor (BAF) with HIV-1 MA, Cone-Rod Homeobox (Crx) or MAN1-C in Absence of DNA

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    Barrier-to-autointegration factor is a cellular protein that protects retroviral DNA from autointegration. Its cellular role is not well understood, but genetic studies show that it is essential and depletion or knockout results in lethal nuclear defects. In addition to binding DNA, BAF interacts with the LEM domain, a domain shared among a family of lamin-associated polypeptides. BAF has also been reported to interact with several other viral and cellular proteins suggesting that these interactions may be functionally relevant. We find that, contrary to previous reports, BAF does not interact with HIV-1 MA, cone-rod homeobox (Crx) or MAN1-C. The reported interactions can be explained by indirect association through DNA binding and are unlikely to be biologically relevant. A mutation that causes a premature aging syndrome lies on the previously reported MAN1-C binding surface of BAF. The absence of direct binding of BAF to MAN1-C eliminates disruption of this interaction as the cause of the premature aging phenotype

    Determination of Conformational Equilibria in Proteins Using Residual Dipolar Couplings

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    In order to carry out their functions, proteins often undergo significant conformational fluctuations that enable them to interact with their partners. The accurate characterization of these motions is key in order to understand the mechanisms by which macromolecular recognition events take place. Nuclear magnetic resonance spectroscopy offers a variety of powerful methods to achieve this result. We discuss a method of using residual dipolar couplings as replica-averaged restraints in molecular dynamics simulations to determine large amplitude motions of proteins, including those involved in the conformational equilibria that are established through interconversions between different states. By applying this method to ribonuclease A, we show that it enables one to characterize the ample fluctuations in interdomain orientations expected to play an important functional role

    Diverging Mechanisms of Activation of Chemokine Receptors Revealed by Novel Chemokine Agonists

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    CXCL8/interleukin-8 is a pro-inflammatory chemokine that triggers pleiotropic responses, including inflammation, angiogenesis, wound healing and tumorigenesis. We engineered the first selective CXCR1 agonists on the basis of residue substitutions in the conserved ELR triad and CXC motif of CXCL8. Our data reveal that the molecular mechanisms of activation of CXCR1 and CXCR2 are distinct: the N-loop of CXCL8 is the major determinant for CXCR1 activation, whereas the N-terminus of CXCL8 (ELR and CXC) is essential for CXCR2 activation. We also found that activation of CXCR1 cross-desensitized CXCR2 responses in human neutrophils co-expressing both receptors, indicating that these novel CXCR1 agonists represent a new class of anti-inflammatory agents. Further, these selective CXCR1 agonists will aid at elucidating the functional significance of CXCR1 in vivo under pathophysiological conditions
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