A uniform approach to fundamental sequences and hierarchies

In this article we give a unifying approach to the theory of fundamental sequences and their related Hardy hierarchies of number-theoretic functions and we show the equivalence of the new approach with the classical one

The Light Lexicographic path Ordering

We introduce syntactic restrictions of the lexicographic path ordering to obtain the Light Lexicographic Path Ordering. We show that the light lexicographic path ordering leads to a characterisation of the functions computable in space bounded by a polynomial in the size of the inputs

ECONOMIC REFORMS IN POLAND: IMPLICATIONS FOR AGRICULTURE

Throughout the world, agriculture has become integrated into the economy at large. Therefore, it is not possible to analyze the process of economic and political transformation of agriculture without reference to the general thrust and speed of reform (Pasour, 1992). In this paper, we will argue that Poland, like other countries in Central and Eastern Europe, faces a dilemma of economic and political reform. Further, we will discuss some of the central variables which tend to constrain the process of economic transition and recovery. Following we will first discuss some of the central effects of partial and stepwise economic reform. Second, we will analyze the pros and cons of economic shock therapy, i.e., of a rapid switch to a market economic system and its implications for institutional change. Third, we will try to shed light on some of the political economic aspects of transformation. Fourth we will discuss a number of factors constraining the speed of economic recovery. We will conclude with some remarks about the prospects for economic transition in Polish agriculture.Political Economy,

Racial discrimination in the Portuguese labor market: the case of Brazilian qualified workers

The main objective of this dissertation is to uncover the perceptions of Brazilian qualified professionals in regards to racial discrimination during their job search, employment and career paths in the Portuguese labor market. Post-industrial Western societies such as Portugal find themselves in continuous need to analyze labor market mechanisms, as some social groups such as immigrants and ethnic minorities keep experiencing limited and unequal access to these labor markets. Besides difficulties of finding appropriate jobs for their qualifications, immigrants more often than national workers face generally poor career prospects, lower wages, fewer promotion prospects, unfavorable working conditions and frequent verbal or physical harassment. Economic and political shifts within the past decades, have led to several large waves of Brazilian citizens with diverse social backgrounds and professional qualifications migrating to Portugal, most of them aiming at a labor market insertion through employment and studies. Since the early 2000s, Brazilian immigrants have become the largest group of foreigners with legal residency status in Portugal. Recent years of increased safety issues, violence and political turmoil in Brazil and economic recovery in Portugal, have now attracted a new wave of qualified professionals from Brazil aiming at integrating into the Portuguese labor market. Partially due to the timeliness of this new migration wave, little research has been conducted in relation to the specific integration of these skilled Brazilian workers in the Portuguese labor market and possible connections to the discrimination of immigrants in Portugal. During this dissertation, the perceptions of Brazilian qualified workers have been researched in a mixed-method approach through a quantitative survey with 51 respondents and qualitative interviews with six participants. The results of both the qualitative and quantitative studies have shown, that prejudice and discrimination against qualified Brazilians in the Portuguese labor market are common. The perception of racist incidents may differ between immigrants in different work industries, job positions, types of companies and teams. It may also depend on each person’s time spent in Portugal, motivation for migration, language skills, bureaucratic possibilities and other factors of the overall personal and professional life. Nevertheless, it has become evident that nearly every participant has had some encounter with prejudice or discrimination during either the job application process, career path or at the work place.objetivo principal desta dissertação é descobrir as percepções dos profissionais brasileiros qualificados em relação à discriminação racial durante a busca de emprego, dentro do lugar de trabalho e dentro do mercado de trabalho português. As sociedades ocidentais pós-industriais, como Portugal, encontram-se em contínua necessidade de analisar os mecanismos do mercado de trabalho, como alguns grupos sociais marginalizados, especificamente imigrantes e minorias étnicas, continuam tendo acesso limitado e desigual a esses mercados de trabalho. Além das dificuldades de encontrar empregos adequados para as suas qualificações, os imigrantes com mais frequência do que os trabalhadores nacionais enfrentam más perspectivas de carreira, salários baixos, menos perspectivas de promoção, condições de trabalho desfavoráveis e assédio verbal ou físico frequente. Mudanças econômicas e políticas ocorridas nas últimas décadas levaram a grandes vagas de cidadãos brasileiros com diversos origens sociais e qualificações profissionais emigrando para Portugal, a maioria voltada para a inserção no mercado de trabalho por meio do emprego e dos estudos. Desde o início dos anos 2000, os imigrantes brasileiros tornaram-se o maior grupo de estrangeiros com estatuto de residência legal em Portugal. Os últimos anos de aumento das questões de segurança, violência e turbulência política no Brasil e recuperação econômica em Portugal, agora atraíram uma nova onda de profissionais qualificados do Brasil com o objetivo de integrar-se ao mercado de trabalho português. Em parte devido à oportunidade desta nova onda migratória, pouca pesquisa foi conduzida em relação à integração específica desses trabalhadores brasileiros qualificados no mercado de trabalho português e possíveis conexões com a discriminação de imigrantes em Portugal. Durante esta dissertação, as percepções de trabalhadores brasileiros qualificados foram pesquisadas em uma abordagem mista por meio de uma pesquisa quantitativa com 51 entrevistados e entrevistas qualitativas com seis participantes. Os resultados de ambos os estudos qualitativos e quantitativos mostraram que o preconceito e a discriminação contra brasileiros qualificados no mercado de trabalho português são comuns. A percepção de incidentes racistas pode diferir entre imigrantes em diferentes setores de trabalho, cargos, tipos de empresas e equipas. Pode também depender do tempo de cada pessoa gasto em Portugal, motivação para a migração, competências linguísticas, possibilidades burocráticas e outros fatores da vida pessoal e profissional em geral. No entanto, tornou-se evidente que quase todos os participantes tiveram algum encontro com preconceito ou discriminação durante o processo de candidatura de emprego, carreira ou no local de trabalho

Identifying ²²²Rn decay chain events in liquid xenon detectors

In the search for dark matter, detectors have been built over the last years which use liquid xenon as a detection medium. For them, 222Rn and its daughter nuclides pose a dangerous background source, as they can cause signals which look like those expected from dark matter particles. Consequently, it is important to understand, how 222Rn decay chain signals can be identified. As a result, this thesis is dedicated to looking for such signals in two detectors. One of them is the XENON100 detector, which belongs to the leading dark matter direct detection experiments. 222Rn decay chain event rates are used here for quantifying the effectiveness of using distillation techniques to separate radon from xenon. The other detector is called HeidelbergXenon (HeXe), and has been recently built at the Max-Planck-Institut für Kernphysik in order to study the decays of 222Rn and its daughter nuclides in liquid xenon. To achieve this task, a data processor is developed and tested over the course of this thesis. Also, the electronics equipment as well as the photosensors used for measuring with HeXe are characterized. Finally, HeXe data, taken with radon-enriched xenon, is analyzed to look for 222Rn decay chain events

Liquid xenon detector physics with XENON1T and HeXe: electric noise stability, background discrimination studies and measurements of the scintillation pulse shape

Liquefied xenon (LXe) is a popular detection medium for experiments searching for rare interactions proposed by beyond the Standard Model theories. It is employed in dual-phase time projection chambers (TPCs) used by experiments such as XENON1T, which attempt to measure particle dark matter interactions as well as the neutrinoless double-beta decay. A precise understanding of the processes behind the signals of such detectors is necessary to discriminate between background and signal events as well as possible. This work presents analyses regarding LXe TPCs physics. In the first part, the temporal evolution of electric noise in the XENON1T experiment is examined. Furthermore, a selection criterion, which has been developed to exclude interactions happening in the TPC’s gas phase, is extended to higher energy scales. Finally, it is investigated whether the LXe scintillation pulse shape allows to discriminate between nuclear recoils and background electronic recoils which originate from decays in or on TPC reflector panels. The pulse shape is also the topic of the second and final part. There, its electric field strength dependence is measured, using the TPC of the HeidelbergXenon (HeXe) system, for conversion electrons coming from 83mKr decays as well as for alpha-particles from decays of 222Rn and daughters