16,432 research outputs found

    Water-soaked porous evidence:a comparison of processing methods

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    This study compared the U.K. Home Office formulation for physical developer (PD) against Oil Red O (ORO) and a modified formulation of physical developer (MPD) that uses Tween 20 instead of Synperonic-N for enhancing fingermarks. Three different donors deposited fingermarks on porous surfaces (white paper, leaflets, and cardboard), with aging periods varying from 7 to 28 days. None of the techniques that were tested provided enhancement of latent fingermarks on leaflets, whereas poor-quality enhancement was observed on cardboard. In contrast, all techniques were more successful on white paper surfaces. The results obtained on white paper suggested that PD and MPD performed similarly, with PD detecting 82.3% of the deposited fingermarks and MPD detecting 86.5% of the deposited fingermarks. PD yielded a higher percentage (38.5%) of fingermarks with fine ridge detail (i.e., those with grade 2 or above) than MPD (35.4%). ORO, however, yielded poor results, enhancing only 4.5% of latent fingermarks, but showed no ridge detail in any of the enhancements (i.e., only showed grade 1 enhancements.

    Entrainment characteristics of unsteady subsonic jets

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    The effectiveness of jet unsteadiness in enhancing flow entrainment was assessed. It was conducted that entrainment depends on the type and amount of jet unsteadiness. Apparently, the mere introduction of jet unsteadiness by small sinusoidal flow angle variations is insufficient to enhance entrainment but, it should be noted that the results were obtained at measuring stations which are all many nozzle widths downstream of the jet nozzle. Thus, no fully conclusive statement can be made at this time about the entrainment close to the nozzle. The high entrainment of the fluidically oscillated jet was caused by the high-frequency content of this square wave type of oscillation but more detailed measurements are clearly needed, in particular for the fluidically oscillated and the pulsed jets. Practical ejector application requires the proper trade-off between entrainment and primary nozzle thrust efficiency

    Debt and Risk Preference: A Household Level Analysis

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    We explore the relationship between risk preference and the level of unsecured debt at the household level within the context of a two period theoretical framework, which predicts that debt is a function of risk aversion. We test the predictions of our theoretical framework for a sample of households drawn from the U.S. Panel Study of Income Dynamics (PSID) and the U.S. Survey of Consumer Finances (SCF). Using a sequence of questions from the 1996 PSID and the 1989 to 2004 SCF, we construct measures of risk preference allowing us to explore the implications of interpersonal differences in risk preference for the accumulation of unsecured debt at the household level. Our empirical findings, which accord with our theoretical priors, suggest that risk preference is an important determinant of the level of unsecured debt acquired at the household level with risk aversion serving to reduce the level of unsecured debt accumulated by households

    Combinatorial Bounds and Characterizations of Splitting Authentication Codes

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    We present several generalizations of results for splitting authentication codes by studying the aspect of multi-fold security. As the two primary results, we prove a combinatorial lower bound on the number of encoding rules and a combinatorial characterization of optimal splitting authentication codes that are multi-fold secure against spoofing attacks. The characterization is based on a new type of combinatorial designs, which we introduce and for which basic necessary conditions are given regarding their existence.Comment: 13 pages; to appear in "Cryptography and Communications

    Beta event-related desynchronization as an index of individual differences in processing human facial expression: further investigations of autistic traits in typically developing adults

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    The human mirror neuron system (hMNS) has been associated with various forms of social cognition and affective processing including vicarious experience. It has also been proposed that a faulty hMNS may underlie some of the deficits seen in the autism spectrum disorders (ASDs). In the present study we set out to investigate whether emotional facial expressions could modulate a putative EEG index of hMNS activation (mu suppression) and if so, would this differ according to the individual level of autistic traits [high versus low Autism Spectrum Quotient (AQ) score]. Participants were presented with 3 s films of actors opening and closing their hands (classic hMNS mu-suppression protocol) while simultaneously wearing happy, angry, or neutral expressions. Mu-suppression was measured in the alpha and low beta bands. The low AQ group displayed greater low beta event-related desynchronization (ERD) to both angry and neutral expressions. The high AQ group displayed greater low beta ERD to angry than to happy expressions. There was also significantly more low beta ERD to happy faces for the low than for the high AQ group. In conclusion, an interesting interaction between AQ group and emotional expression revealed that hMNS activation can be modulated by emotional facial expressions and that this is differentiated according to individual differences in the level of autistic traits. The EEG index of hMNS activation (mu suppression) seems to be a sensitive measure of the variability in facial processing in typically developing individuals with high and low self-reported traits of autism

    Major Galaxy Mergers Only Trigger the Most Luminous AGN

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    Using multiwavelength surveys of active galactic nuclei across a wide range of bolometric luminosities (10^{43}<L_{bol}(erg/s<5x10^{46}) and redshifts (0<z<3), we find a strong, redshift-independent correlation between the AGN luminosity and the fraction of host galaxies undergoing a major merger. That is, only the most luminous AGN phases are connected to major mergers, while less luminous AGN appear to be driven by secular processes. Combining this trend with AGN luminosity functions to assess the overall cosmic growth of black holes, we find that ~50% by mass is associated with major mergers, while only 10% of AGN by number, the most luminous, are connected to these violent events. Our results suggest that to reach the highest AGN luminosities -where the most massive black holes accreted the bulk of their mass - a major merger appears to be required. The luminosity dependence of the fraction of AGN triggered by major mergers can successfully explain why the observed scatter in the M-\sigma relation for elliptical galaxies is significantly lower than in spirals. The lack of a significant redshift dependence of the L_{bol}-f_{merger} relation suggests that downsizing, i.e., the general decline in AGN and star formation activity with decreasing redshift, is driven by a decline in the frequency of major mergers combined with a decrease in the availability of gas at lower redshifts.Comment: Accepted for publication by Astrophysical Journal Letters, 6 pages in emulateapj format, 3 figure

    The ethics of sociocultural risk research

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    In socio-cultural risk research, an epistemological tension often follows if real hazards in the world are juxtaposed against the essentially socially constructed nature of all risk. In this editorial, we consider how this paradox is manifest at a practical level in a number of ethical dilemmas for the risk researcher. (1) In terms of strategies for seeking informed consent, and for addressing the power inequalities involved in interpretative and analytical work, researchers can find themselves pushing at the boundaries of standard understandings of ethical practices and ways of engaging informants in their studies. (2) Impact on participants is another key area of concern, since the subject matter on which data are collected in risk research may be a source of uncertainty, anxiety or unwanted self knowledge. (3) Risk researchers also face the possibility of institutional repercussions of raising risk issues with people who usually normalize the risks, thereby stimulating distrust in the institutions or organizations with formal responsibilities for risk management. There are no simple formulae to guide the researcher in dealing with such ethical issues and paradoxes. It is important, though, to recognize their specificity in risk studies, including the ambiguous status of questions about vulnerability since judgements about 'who is vulnerable' and 'in what ways' are themselves influenced by the situational framings and understandings of participants and researchers

    Walter Pater’s Marius the Epicurean: a study of the novel major themes

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    This thesis is concerned with Walter Pater’s only completed, novel, Marius the Epicurean. Although the novel is set in the Antonine period of Ancient Rome, it is to some extent an account of Pater's own philosophical development, and I have considered it, first, as autobiography. After a discussion of the textual history of the novel, and its place in Pater’s proposed fictional trilogy, I have examined the philosophical content in more detail, tracing the course of Marius's philosophic 'Journey', and relating it to Pater's reading of German philosophy. I have then gone on to look at it as a religious' novel, examining it as a reflection of Pater's, anthropological attitude towards religion, and also as a reflection of nineteenth century religious controversy. Pater was looking for a 'religious phase possible for the modern mind', and I have attempted to assess how far he followed Arnold in replacing conventional religious belief by 'culture', defining, in doing this, what 'culture' meant to Pater. Finally, I have discussed Marius in relation to Pater's other fiction, tracing recurring themes, in particular the themes of death, the woman and corruption. Thus the thesis attempts to isolate particular aspects of this novel, and then to relate them to wider issues

    Preliminary Test of Prescribed Burning for Control of Maple Leaf Cutter (Lepidoptera: Incurvariidae)

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    Leaf litter burning in the spring resulted in 87.5% mortality of maple leaf cutter pupae, Paraclemensia acerifoliella (Fitch). No apparent damage was observed on sugar maple or beech trees within the burn area

    Alien Registration- Simmons, William K. (Portland, Cumberland County)

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    https://digitalmaine.com/alien_docs/22028/thumbnail.jp
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