6 resultados para humic substance

em Aston University Research Archive


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Substance use has an effect on an individual's propensity to commit acquisitive crime with recent studies showing substance users more likely to leave forensic material at a crime scene. An examination of acquisitive crime solved in Northamptonshire, U.K., during 2006 enabled 70 crime scene behavior characteristics to be analyzed for substance and nonsubstance use offenders. Logistical regression analyses have identified statistically significant crime scene behavior predictors that were found to be either present at or absent from the crime scene when the offender was a substance user. Most significant predictors present were indicative of a lack of preparation by the offender, irrational behavior, and a desire to steal high value, easily disposed of, property. Most significant predictors absent from the crime scene were indicative of more planning, preparation, and execution by the offender. Consideration is given to how this crime scene behavior might be used by police investigators to identify offenders.

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Humic substances are the major organic constituents of soils and sediments. They are heterogeneous, polyfunctional, polydisperse, macromolecular and have no accurately known chemical structure. Their interactions with radionuclides are particularly important since they provide leaching mechanisms from disposal sites. The central theme to this research is the interaction of heavy metal actinide analogues with humic materials. Studies described focus on selected aspects of the characteristics and properties of humic substances. Some novel approaches to experiments and data analysis are pursued. Several humic substances are studied; all but one are humic acids, and those used most extensively were obtained commercially. Some routine characterisation techniques are applied to samples in the first instance. Humic substances are coloured, but their ultra-violet and visible absorption spectra are featureless. Yet, they fluoresce over a wide range of wavelengths. Enhanced fluorescence in the presence of luminescent europium(III) ions is explained by energy transfer from irradiated humic acid to the metal ion in a photophysical model. Nuclear magnetic resonance spectroscopy is applied to the study of humic acids and their complexes with heavy metals. Proton and carbon-13 NMR provides some structural and functionality information; Paramagnetic lanthanide ions affect these spectra. Some heavy metals are studied as NMR nuclei, but measurements are restricted by their sensitivity. A humic acid is fractionated yielding a broad molecular weight distribution. Electrophoretic mobilities and particle radii determined by Laser Doppler Electrophoretic Light Scattering are sensitive to the conditions of the supporting media, and the concentration and particle size distribution of humic substances. In potentiometric titrations of humate dispersions, the organic matter responds slowly and the mineral acid addition is buffered. Proton concentration data is modelled and a mechanism is proposed involving two key stages, both resulting in proton release after some conformational changes.

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The present dissertation investigates the influence of brand as well as substance-related marketing attributes on prescription pharmaceutical sales within a state-controlled market. For this purpose, a systematic literature review was conducted in the first instance, during which knowledge about the most relevant research within this field was gathered. Consequently, over 538 publications were reviewed and indicated as being potentially relevant, leading to an eventual count of 98 core publications. However, most of these studies had been conducted in the mainly unrestricted US market. These findings were then summarised and statistically evaluated. In a second step, based on the literature review, a qualitative study, containing focus and Delphi groups, was then performed. The participants in these studies were involved in pharmaceutical marketing within a state-controlled prescriptions pharmaceuticals market. Consequently, the findings were slightly different to those derived by the systematic literature review. Based on this second step, seven hypotheses were proposed. In the third step, these hypotheses were tested, using collected data and a secondary market dataset provided by a market research institute. A statistical analysis was then performed, applying descriptive as well as multiple regression analytical methods. The evaluation of the results resulted in a conceptual model of physician targeting, leading to several theoretical, methodological and managerial implications.

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Background: The spectrum approach was used to examine contributions of comorbid symptom dimensions of substance abuse and eating disorder to abnormal prefrontal-cortical and subcortical-striatal activity to happy and fear faces previously demonstrated in bipolar disorder (BD). Method: Fourteen remitted BD-type I and sixteen healthy individuals viewed neutral, mild and intense happy and fear faces in two event-related fMRI experiments. All individuals completed Substance-Use and Eating-Disorder Spectrum measures. Region-of-Interest analyses for bilateral prefrontal and subcortical-striatal regions were performed. Results: BD individuals scored significantly higher on these spectrum measures than healthy individuals (p < 0.05), and were distinguished by activity in prefrontal and subcortical-striatal regions. BD relative to healthy individuals showed reduced dorsal prefrontal-cortical activity to all faces. Only BD individuals showed greater subcortical-striatal activity to happy and neutral faces. In BD individuals, negative correlations were shown between substance use severity and right PFC activity to intense happy faces (p < 0.04), and between substance use severity and right caudate nucleus activity to neutral faces (p < 0.03). Positive correlations were shown between eating disorder and right ventral putamen activity to intense happy (p < 0.02) and neutral faces (p < 0.03). Exploratory analyses revealed few significant relationships between illness variables and medication upon neural activity in BD individuals. Limitations: Small sample size of predominantly medicated BD individuals. Conclusion: This study is the first to report relationships between comorbid symptom dimensions of substance abuse and eating disorder and prefrontal-cortical and subcortical-striatal activity to facial expressions in BD. Our findings suggest that these comorbid features may contribute to observed patterns of functional abnormalities in neural systems underlying mood regulation in BD.

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The electoral challenge of the far right is an enduringly problematic feature of contemporary French politics. In the first rounds of the 2012 presidential and parliamentary elections, the Front National (FN) under new leader Marine Le Pen attracted a combined total of ten million votes, bringing its ultra-nationalist policies to the centre of national political debate. This article examines the FN's impact on these elections and its implications for French politics. Drawing on official FN programmes, detailed election results and a range of opinion polling data, it assesses the strength of support for Le Pen and her party and seeks to explain their electoral appeal. In particular, it subjects to analysis the claim that the new leader has ‘de-demonised’ the FN, transforming it from perennial outsider to normal participant in mainstream French politics; and it reflects on the strategic dilemma posed for the centre-right by this newly invigorated far-right challenge.