605 research outputs found
The shadow economy in Colombia: size and effects on economic growth
Using the currency demand approach size and development of the Colombian shadow economy are estimated over the period from 1976 to 2002. In the 70s the size fluctuated around 20% of official GDP and rose to 50% in the 90s. The most important factors driving the shadow economy are unemployment and taxation. Analyzing the interaction between shadow and official economy, the shadow economy has a positive effect on the official one. Average growth rate of real per capita GDP is 1.11% between 1976 and 2002 and the shadow economy "explains" on average between 0.09 and 0.27 of this growth.Colombian shadow economy; currency demand method; taxation; unemployment; interaction between the shadow and official economy
Nonlinear System Identification through Local Model Approaches: Partitioning Strategies and Parameter Estimation
Sex and Hemisphere - A Neglected, Nature-Determined Relationship in Acute Ischemic Stroke
Background: Sex differences in the structural connectome of the brain are clinically highly relevant, but they have mostly been neglected in stroke trials. We investigated the impact of the interaction sex-by-hemisphere on outcome in stroke patients after intravenous thrombolysis (IVT). Methods: This is an observational study based on consecutively collected supratentorial stroke patients treated with IVT (n = 1,231). The 3-month modified Rankin scale (mRS) was estimated by adjusted binary (mRS 0-2 for good outcome) and ordinal regression analysis. As baseline characteristics differ substantially between the sexes, we aimed for better covariate balance by employing coarsened exact matching. Results: Sex-by-hemisphere predicted good outcome in the entire cohort (726 left, 505 right hemispheric strokes, p valueinteraction 0.032) and in the matched cohort (338 left, 273 right, p valueinteraction 0.003). Ordinal regression suggested a comparable estimate in the matched cohort (p valueinteraction 0.006). Further investigation revealed relevant between-sex and within-sex risk: right hemispheric strokes in men were 1.54 times (95% confidence intervals (CIs) 1.15-2.01) more likely than in women to achieve mRS 0-2. Women with right hemispheric strokes were 0.72 times (95% CI 0.54-0.92) less likely to reach mRS 0-2 than women with left hemispheric strokes. Conversely, men with right hemispheric strokes were 1.35 times (95% CI 1.06-1.70) more likely to achieve mRS 0-2 than men with left hemispheric strokes. Conclusion: This study suggests that outcomes are different in both sexes after IVT when different hemispheres are affected. Further consideration of this hypothesis in clinical trials might help in guiding individualized, injury-specific treatment approaches for acute ischemic stroke.
© 2015 S. Karger AG, Base
Authenticity and provenance studies of copper-bearing andesines using Cu isotope ratios and element analysis by fs-LA-MC-ICPMS and ns-LA-ICPMS
Whereas colored andesine/labradorite had been thought unique to the North American continent, red andesine supposedly coming from the Democratic Republic of the Congo (DR Congo), Mongolia, and Tibet has been on the market for the last 10years. After red Mongolian andesine was proven to be Cu-diffused by heat treatment from colorless andesine starting material, efforts were taken to distinguish minerals sold as Tibetan and Mongolian andesine. Using nanosecond laser ablation-inductively coupled plasma mass spectrometry (ICPMS), the main and trace element composition of andesines from different origins was determined. Mexican, Oregon, and Asian samples were clearly distinguishable by their main element content (CaO, SiO2 Na2O, and K2O), whereas the composition of Mongolian, Tibetan, and DR Congo material was within the same range. Since the Li concentration was shown to be correlated with the Cu concentration, the formerly proposed differentiation by the Ba/Sr vs. Ba/Li ratio does not distinguish between samples from Tibet and Mongolia, but only between red and colorless material. Using femtosecond laser ablation multi-collector ICPMS in high-resolution mode, laboratory diffused samples showed variations up to 3â° for 65Cu/63Cu within one mineral due to the diffusion process. Ar isotope ratio measurements proved that heat treatment will reduce the amount of radiogenic 40Ar in the samples significantly. Only low levels of radiogenic Ar were found in samples collected on-site in both mine locations in Tibet. Together with a high intra-sample variability of the Cu isotope ratio, andesine samples labeled as coming from Tibet are most probably Cu-diffused, using initially colorless Mongolian andesines as starting material. Therefore, at the moment, the only reliable source of colored andesine/labradorite remains the state of Oregon. Figure Cu diffusion can be used to turn a plain, colorless andesine into a red gemstone. Cu and Ar isotope ratios in combination with main and trace elemental analysis can appoint andesine to thrie origin in Oregon, Mexico and Asia. In this study, red andesines sold as coming from Tibet and Mongolia are revealed to be most probably Cu-diffusion treate
Wikis in der internen Kommunikation
Diese Arbeit untersucht den Einsatz von Wiki-Software in der internen Kommunikation der Redaktion von Radio Stimme. Konkret wurden dabei durch qualitative Interviews mit RedakteurInnen von Radio Stimme zwei Aspekte analysiert: erstens der Einfluss auf das Transparenzerleben und zweitens der Einfluss des Wikis auf die Motivation. Aufbauend auf die Darstellung von interner Kommunikation nach Mast und Szyszka wurde fĂŒr das Konzept des Transparenzerlebens nach Karg und die Motivation nach Herzberg et al. operationalisiert und qualitative Interviews durchgefĂŒhrt. Aus den Transkripten entstand ein Kategorienschema, welches auch die Grundlage fĂŒr die Interpretation und die generierten Hypothesen bildet.This paper conducts a qualitative survey on the subject of wiki-software in the field of internal communication. In detail there are two aspects which lead the research: first the concept of âexperienced transparenceâ by Karg and second the concept of motivation by Herzberg et al. within the editorial department of âRadio Stimmeâ. The first and theoretical part of the thesis explains the concepts of internal communication by Mast and Szyszka. This part of the paper also introduces the reader to the field of Wikis and social web applications in general. Furthermore it contains an explanation about the two researched concepts. The second part of the thesis explains first the method of qualitative analysis by Mayring. Afterwards the results of the conducted interviews, the interpretation and the generated hypothesis are presented
Role and clinical utility of pramipexole extended release in the treatment of early Parkinsonâs disease
The aim of this article is to provide a short review of the most relevant pharmacological and clinical data on pramipexole extended release (ER) as well as to address the clinical utility and potential advantages of a once-daily formulation especially in the treatment of early Parkinsonâs disease (PD). Pramipexole is widely established as a symptomatic treatment in early as well as advanced PD. The development of an ER formulation, with stable pramipexole plasma concentration over 24 hours, now offers a bioequivalent once-daily alternative. Double-blind randomized controlled trials in early and advanced PD, have established noninferiority of pramipexole ER compared with immediate release as well as superiority of both formulations over placebo. The overnight switch from the standard to the once-daily formulation was shown to be successful in >80% of patients without requiring any dose adjustments. Potential benefits of the prolonged-release design, which have not yet been formally demonstrated in the pivotal trial program, include improved compliance and a potential for better symptomatic control, particularly in patients with early disease that can be managed with monotherapy
Assessment of model based (input) impedance, pulse wave velocity, and wave reflection in the Asklepios Cohort
Objectives : Arterial stiffness and wave reflection parameters assessed from both invasive and non-invasive pressure and flow readings are used as surrogates for ventricular and vascular load. They have been reported to predict adverse cardiovascular events, but clinical assessment is laborious and may limit widespread use. This study aims to investigate measures of arterial stiffness and central hemodynamics provided by arterial tonometry alone and in combination with aortic root flows derived by echocardiography against surrogates derived by a mathematical pressure and flow model in a healthy middle-aged cohort.
Methods : Measurements of carotid artery tonometry and echocardiography were performed on 2226 ASKLEPIOS study participants and parameters of systemic hemodynamics, arterial stiffness and wave reflection based on pressure and flow were measured. In a second step, the analysis was repeated but echocardiography derived flows were substituted by flows provided by a novel mathematical model. This was followed by a quantitative method comparison.
Results : All investigated parameters showed a significant association between the methods. Overall agreement was acceptable for all parameters (mean differences: -0.0102 (0.033 SD) mmHg*s/ml for characteristic impedance, 0.36 (4.21 SD) mmHg for forward pressure amplitude, 2.26 (3.51 SD) mmHg for backward pressure amplitude and 0.717 (1.25 SD) m/s for pulse wave velocity).
Conclusion : The results indicate that the use of model-based surrogates in a healthy middle aged cohort is feasible and deserves further attention
Psychologies of not Knowing: On the (Re)Production of Oppression via Processes of not Knowing or Ignorance
Social and liberation movements all over the world have acted on the premise that oppression is kept alive, among other ways, through psychological mechanisms. Feminist and critical race epistemologies such as âfeminist standpoint theoriesâ and âepistemological ignoranceâ suggest that there might be different forms of not knowing involved depending on the social location of the (not) knowing subject. In this paper we suggest that the concrete psychological mechanisms involved in not knowing or outright ignorance differ according to oneâs position in the social fabric of oppression and privilege. Drawing on various critical psychological and psychoanalytic reflections, as well as interpreting selected passages from a group discussion among elderly retirement home residents in Vienna, we illustrate how social position is translated into lack of knowledge about systems of oppression and privileg
Privatanleger als Beschleuniger urbaner Wohnkrisen: Bedeutung und Motive von Privatanlegern auf WohnungsmÀrkten abseits der Metropolen am Beispiel Salzburg
Bislang wurde das verstÀrkte Aufkommen von Finanzanlagen auf WohnungsmÀrkten vorwiegend in Metropolen oder auf nationaler Ebene untersucht. Der Fokus lag dabei zumeist auf institutionellen Akteuren. Die Untersuchung von Finanzanlagenin Wohnraum in StÀdten unterhalb der Metropolebene und durch Privatpersonen wurde bislang vernachlÀssigt. In vorliegender Untersuchung stelle ich deshalb die Manifestation von Finanzanlagen auf den WohnungsmÀrkten in einer Stadt abseits der Metropolebene in den Mittelpunkt und setze dabei auf einen Mixed-methods-Ansatz aus quantitativer Grundbuch- und Datenanalyse sowie qualitativen Experteninterviews. Der Beitrag zeigt auf, dass abseits der Metropolen die Nutzung von Wohnraum in ein Investitionsobjekt vorwiegend von privaten Akteuren vollzogen wird. Diese investieren weniger aus Spekulation und in Erwartung von Wertsteigerung, sondern zur privaten und familiÀren Vorsorge und vor allem zur Wertsicherung. Auch diese Form von Finanzanlagen in Wohnraum hat folgenschwere Auswirkungen auf andere Marktakteure. Der gesamte Wohnungsmarkt richtet sich sukzessive auf diesen neuen Investorentypus aus. Immobiliensind somit zunehmend zu einer Anlageform von Vielen geworden.So far, the increased emergence of financial investments on the housing markets has mainly been examined in metropolises or on a national level. Research focused primarily on institutional actors. The investigation of financial investments in housing space in cities below the metropolitan level and by individuals has so far been neglected. In the present study, I therefore focus on the manifestation of financial investments of private investors in housing markets outside the metropolises using a mixed-method approach of quantitative land register and data analysis as well as qualitative expert interviews. The paper shows that apart from the metropolises, the utilization of housing into an investment object is mainly carried out by private actors. They invest less out of speculation and in the expectation of an increase in value, but rather for private retirement or family provision and, above all, to secure value. This form of investment in housing also leads to serious consequences for other market players. The entire housing market is gradually focusing on this new type of investor. Real estate has therefore increasingly become a form of investment for many
Experimental partitioning of halogens and other trace elements between olivine, pyroxenes, amphibole and aqueous fluid at 2 GPa and 900â1,300 °C
We present new partition coefficients for various trace elements including Cl between olivine, pyroxenes, amphibole and coexisting chlorine-bearing aqueous fluid in a series of high-pressure experiments at 2 GPa between 900 and 1,300 °C in natural and synthetic systems. Diamond aggregates were added to the experimental capsule set-up in order to separate the fluid from the solid residue and enable in situ analysis of the quenched solute by LAâICPâMS. The chlorine and fluorine contents in mantle minerals were measured by electron microprobe, and the nature of OH defects was investigated by infrared spectroscopy. Furthermore, a fluorine-rich olivine from one selected sample was investigated by TEM. Results reveal average Cl concentrations in olivine and pyroxenes around 20 ppm and up to 900 ppm F in olivine, making olivine an important repository of halogens in the mantle. Chlorine is always incompatible with Cl partition coefficients D Cl olivine/fluid varying between 10â5 and 10â3, whereas D Cl orthopyroxene/fluid and D Cl clinopyroxene/fluid are ~10â4 and D Cl amphibole/fluid is ~5 Ă 10â3. Furthermore, partitioning results for incompatible trace element show that compatibilities of trace elements are generally ordered as D amph/fluid â D cpx/fluid > D opx/fluid > D ol/fluid but that D mineral/fluid for Li and P is very similar for all observed silicate phases. Infrared spectra of olivine synthesized in a F-free Ti-bearing system show absorption bands at 3,525 and ~3,570 cmâ1. In F ± TiO2-bearing systems, additional absorption bands appear at ~3,535, ~3,595, 3,640 and 3,670 cmâ1. Absorption bands at ~3,530 and ~3,570 cmâ1, previously assigned to humite-like point defects, profit from low synthesis temperatures and the presence of F. The presence of planar defects could not be proved by TEM investigations, but dislocations in the olivine lattice were observed and are suggested to be an important site for halogen incorporation in olivine
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