Towards shared datasets for normalization research

In this paper we present a Dutch and English dataset that can serve as a gold standard for evaluating text normalization approaches. With the combination of text messages, message board posts and tweets, these datasets represent a variety of user generated content. All data was manually normalized to their standard form using newly-developed guidelines. We perform automatic lexical normalization experiments on these datasets using statistical machine translation techniques. We focus on both the word and character level and find that we can improve the BLEU score with ca. 20% for both languages. In order for this user generated content data to be released publicly to the research community some issues first need to be resolved. These are discussed in closer detail by focussing on the current legislation and by investigating previous similar data collection projects. With this discussion we hope to shed some light on various difficulties researchers are facing when trying to share social media data

Extending difference of votes rules on three voting models.

In a voting situation where there are only two competing alternatives, simple majority rule outputs the alternatives with the most votes or declares a tie if both alternatives receive the same number of votes. For any non-negative integer k, the difference of votes rule Mk outputs the alternative that beats the competing alternative by more than k votes. Llamazares (2006) gives a characterization of the difference of votes rules in terms of five axioms. In this thesis, we extend Llamazares\u27 result by completely describing the class of voting rules that satisfy only two out of his five axioms. In addition, we state and prove Llamazares\u27 theorem in voting models where either there is an infinite number of votes or each voter is allowed to express an intensity level for one alternative over the other. Finally, we will use a computer simulation to compare different voting methods to simple majority rule, in order to analyze the probability that the voting rules would output different results

Managing trees on arable land

The cultivation of several plant species on the same area of land, at the same time, is called Agroforestry (AFS). In the less developed countries and the countries of the tropics and subtropics, AFS are the main form of land management. Reasons can be found in the low degree of mechanization and the low costs of labor. AFS used to be widespread in the industrial nations, too. Over the years, however, these traditional forms have been converted into highly efficient agricultural sites. Agricultural and forest production has been separated spatially. In Germany, this was mainly due to land consolidation, which resulted in large, uniform, and easy-to-farm fields. In recent years, however, this situation has been reconsidered. The positive environmental benefits and the aspect of biodiversity protection of agroforestry systems have been recognized. There are numerous ecological, economic, and social aspects, which make agroforestry attractive again. However, a competitive situation always arises when plants are cultivated together. In addition, there are multiple forms of AFS. Special attention must be paid to the planting of the woody, perennial component, as it remains on the field for several years. Against this background, this thesis deals with the possibilities of establishing the wood component in an AFS as a short rotation strip. Combinations of different tillage and weed management practices on willow growth and yield were tested. Furthermore, the influence of shade, which is listed as one of the three main influencing factors in AFS, is discussed. Agricultural crops behave differently, on shade casts by the woody component on the understory crop, depending on their need for light. To test this, maize was used as a shade-intolerant C4 plant, which reaches its light saturation close to maximum solar irradiance. In contrast, potato was tested as a more shade-tolerant C3 plant. Observations on growth, yield and quality should provide information on their suitability for cultivation under shady conditions in AFS. Various hypotheses were developed and examined for the purpose of testing. In the following, the most central research results will be briefly outlined. When establishing a short rotation coppice with willows, an adequate combination of soil tillage and weed management showed to be important for high yields, whereas the necessary weed management depends on the used soil tillage. Until today, there are no other recommendations for the establishment of a willow short-rotation coppice except ploughing in autumn, harrowing in spring and broad herbicide application. In the current discourse on biodiversity improvement and climate change, forms of reduced tillage (chisel plough + ley crop, no-till) with adapted herbicide-saving weed control (e.g. chemical treatment within the rows and mechanical treatment between the rows, or only mechanical weed control), were tested as alternatives that ensure successful SRC growth and, as a result, high yields while saving pesticides and fossil energy. When grown together, trees will shade the under-story agricultural crops. Some crops can deal better with this light reduction than others. Maize (Zea mays L.), as a plant with a high light saturation point, is already negatively influenced in its growth, the biomass, biogas, and methane yield, as well as the quality determining compounds (dry matter content, crude protein, crude ash) by low amounts of shade. While potatoes (Solanum tuberosum L.), known as shade-tolerant plants, can produce yields and qualities comparable to those of unshaded plants with lower levels of solar irradiance (caused by shading). It could be shown that it is possible to make a valuable contribution to biodiversity with AFS. By using adapted combinations of soil tillage and weed management systems, fossil fuels can be saved through reduced tillage. The use of chemical plant protection in the tree strips can be reduced by the sole application within the SRC strips or avoided altogether by mechanical weed control. In high-valuable timber systems there is usually no weed management necessary. Additionally, the trees strips offer a habitat and food basis for small vertebrates and some arthropods (hymenoptera, coleoptera, lepidoptera and diptera). The permanent planting of the strips reduces greenhouse gases and thus counteracts climate change. Influences of shade on crop yield and quality was only proven for plant-specific shade levels. In such AFS, the influence of shade usually only occurs in later tree ages (and crown thickness). Therefore, AFS are a valuable form of land management to reduce current environmental problems on a national and global scale, while adequate yields can be achieved at the same time.Der gemeinsame Anbau von mehreren Kulturen auf ein und derselben Fläche zur selben Zeit wird als Agroforstsystem (AFS) bezeichnet. In den weniger entwickelten Ländern und Ländern der Tropen und Subtropen sind AFS die hauptsächliche Form der Landbewirtschaftung. Dies geht auf den geringen Mechanisierungsgrad und kostengünstige Arbeitskräfte zurück. In den Industrienationen waren AFS früher ebenfalls weitverbreitet. Allerdings wurden diese traditionellen Formen über die Jahre in hocheffiziente Formen der Landbewirtschaftung überführt. Die landwirtschaftliche und die forstwirtschaftliche Produktion wurden räumlich getrennt. Dies geschah in Deutschland überwiegend durch die Flurbereinigung, bei der große, uniforme und einfach zu bewirtschaftende Schläge entstanden. In den letzten Jahren ist es allerdings zu einem Umdenken gekommen. Der positive Nutzen von AFS für die Umwelt und den Schutz der Biodiversität wurde nachweislich anerkannt. Es gibt zahlreiche ökologische, ökonomische und soziale Aspekte, die Agroforst wieder attraktiv machen. Allerdings entsteht immer eine Konkurrenzsituation, wenn Pflanzen gemeinsam angebaut werden. Zudem gibt es eine mannigfaltige Form an Ausprägungen von AFS. Der Anlage der verholzenden, mehrjährigen Komponente gilt ein besonderes Augenmerk, da diese einmal etabliert, für mehrere Jahre auf der Fläche verbleibt. Vor diesem Hintergrund beschäftigt sich diese Arbeit mit den Möglichkeiten der Etablierung der Holzkomponente als Kurzumtriebsstreifen in einem AFS. Behandelt werden dafür Kombinationen aus verschiedene Bodenbearbeitungs- und Unkrautmaßnahmen auf Wachstum und Ertrag von Weiden. Des Weiteren wird der Einfluss von Schatten untersucht, der als einer der drei Haupteinflussfaktoren in AFS gelistet wird. Landwirtschaftliche Kulturen reagieren, je nach ihrem Lichtbedarf, unterschiedlich auf Schatten, den die verholzende Komponente auf die unterwüchsige Kultur wirft. Um dies zu testen wurde Mais als schattenintolerante C4-Pflanze getestet, die ihre Lichtsättigung nahe der maximalen Einstrahlung erreicht. Dem gegenüber wurde die Kartoffel als eine schattentolerantere C3-Pflanze untersucht. Beobachtungen an Wachstum, Ertrag und der Qualität der Inhaltsstoffe sollen Auskunft über deren Eignung zum Anbau unter den schattigen Bedingungen in AFS geben. Zur Überprüfung wurden verschiedene Hypothesen aufgestellt und untersucht. Im Folgenden soll kurz auf die zentralsten Forschungsergebnisse eingegangen werden. Wenn eine Kurzumtriebsplantage mit Weiden etabliert werden soll, ist eine angepasste Kombination aus Bodenbearbeitung und Unkrautkontrolle wichtig für hohe Erträge, wobei die nötige Unkrautkontrolle auf die Bodenbearbeitung abgestimmt sein muss. Bisher gibt es keine anderen Empfehlungen, wie das herkömmliche Etablierungsverfahren aus pflügen, eggen und einer flächigen Herbizidapplikation. In der derzeitigen Diskussion über die Steigerung der biologischen Vielfalt und Eindämmung des Klimawandels, wurde die Eignung reduzierter Formen der Bodenbearbeitung (Grubber + Untersaat, No-Till) mit angepasstem, reduziertem Herbizideinsatz (z.B. chemische Behandlung in den Reihen und mechanische Behandlung zwischen den Reihen, sowie rein mechanische Bekämpfung) auf das erfolgreiche Wachstum von Weiden-KUP und den damit verbundenen Erträgen getestet. Wenn Bäume und landwirtschaftliche Kulturen gleichzeitig angebaut werden, beschatten die Bäume die unterwüchsigen Kulturen. Mais (Zea mays L.) als Pflanze mit einem hohen Lichtsättigungspunkt wird bereits durch geringen Schatten in ihrem Wachstum, dem Biomasse-, Biogas- und Methanertrag sowie den qualitätsbestimmenden Inhaltsstoffen negativ beeinflusst. Während Kartoffeln (Solanum tuberosum L.), die als schattentolerante Pflanzen bekannt sind, in der Lage sind mit geringeren Einstrahlungsmengen, hervorgerufen durch Beschattung, vergleichbare Erträge und Qualitäten zu erzeugen, wie unbeschattete Pflanzen. Es konnte gezeigt werden, dass es möglich ist mit AFS einen Beitrag zur Biodiversitätssteigerung zu schaffen. Durch den Einsatz aufeinander abgestimmter Bodenbearbeitungs- und Unkrautregulierungssystemen können fossile Kraftstoffe im Falle von reduzierter Bodenbearbeitungen eingespart werden. Die Ausbringung von Herbiziden in den Baumstreifen kann durch die alleinige Applikation in den Setzlingsreihen reduziert oder durch rein mechanische Alternativen ganz vermieden werden. In Wertholzstreifen erfolgt im Normalfall keine chemische Unkrautregulierung. Zusätzlich bieten die Baumstreifen Habitate und Nahrungsgrundlagen für kleine Wirbeltiere und zahlreiche Arthropodenklassen (Hymenoptera, Coleoptera, Lepidoptera und Diptera). Die dauerhafte Bepflanzung der Baumstreifen ermöglicht die Reduzierung von Klimagasen und kann so dem Klimawandel entgegenwirken. Erst ab einer pflanzenspezifischen Höhe der Beschattung treten Veränderungen der Ernteerträge und -qualitäten der landwirtschaftlichen Kulturen ein. In AFS tritt dieser Einfluss zudem auch erst mit vorangeschrittenem Baumalter (und Kronenvolumen) ein. Deshalb sind AFS eine wertvolle Form der Landbewirtschaftung, um die derzeitigen Umweltprobleme sowohl auf nationaler als auch auf globaler Ebene zu reduzieren, während gleichzeitig angemessene Erträge erzielt werden können

Positive Solutions, Existence Of Smallest Eigenvalues, And Comparison Of Smallest Eigenvalues Of A Fourth Order Three Point Boundary Value Problem

The existence of smallest positive eigenvalues is established for the linear differential equations $u^{(4)}+\lambda_{1} q(t)u=0$ and $u^{(4)}+\lambda_{2} r(t)u=0$, $0\leq t \leq 1$, with each satisfying the boundary conditions $u(0)=u\u27(p)=u\u27\u27(1)=u\u27\u27\u27(1)=0$ where $1-\frac{\sqrt{3}}{3}\le p \u3c 1$. A comparison theorem for smallest positive eigenvalues is then obtained. Using the same theorems, we will extend the problem to the fifth order via the Green\u27s Function and again via Substitution. Applying the comparison theorems and the properties of $u_0$-positive operators to determine the existence of smallest eigenvalues. The existence of these smallest eigenvalues is then applied to characterize extremal points of the differential equation $u^{(4)} + q(t)u = 0$ satisfying boundary conditions $u(0) = u\u27(p) = u\u27\u27(b) = u\u27\u27\u27(b)= 0$ where $1-\frac

Linking health literacy and health disparities: conceptual implications and empirical results

Health literacy, defined as “(…) the degree to which individuals have the capacity to obtain, process and understand basic health information and services needed to make appropriate health decisions.” (IOM, 2004), has been found to be an important concept in explaining differences in health. Limited health literacy has been linked, amongst others, to worse general health (Wolf, Gazmararian, & Baker, 2005), less usage of preventive healthcare services (Bennett, Chen, Soroui, & White, 2009), higher risk of hospital admissions (Scott, Gazmararian, Williams, & Baker, 2002), and eventually higher mortality (Baker et al., 2007). Particular in groups that are afflicted by socioeconomic disadvantages limited health literacy has been found to be more prevalent, thus lending itself as an important factor to consider when talking about health disparities in general. Research on the concept of health literacy in the last twenty years has largely evolved in the United States (US) and conceptualizations, as well as the development of measurements, have been so far predominantly developed in the US. Only little research has yet focused on its transferability to other contexts to explore whether underlying constructs and relevant measures will show the same patterns. Further, in how far commonly found relationships between health literacy and health outcomes or behaviors will also hold true in other countries than the US. The work presented in this dissertation sets out to test in how far health literacy can be transferred to other contexts and how far patterns found concur with those found in the US. Further, it aims at contributing to the still ongoing debate on the conceptualization and operationalization of health literacy, as well as on the conceptual pathways that link health literacy to differences in health. By providing the results of two studies that aimed at validating a short measure of functional health literacy in two different countries, this dissertation provides evidence on the fact that commonly used measures of health literacy are also valid when used in other contexts. Further, that the concept of health literacy and its underlying constructs are transferable to other parts of the world (Part I). Having established a potential cross-cultural and linguistic validity of the concept of health literacy, two studies are presented that aimed at testing the relationship between health literacy and healthcare costs in a sample of diabetes patients in Switzerland. Thereby, testing whether hypothesized relationships would also hold true in the Swiss context. Further, to contribute to the empirical literature by providing evidence on a still largely understudied relationship in the field of health literacy. Results confirmed hypothesized relationships, showing that lower levels of health literacy indeed were related to higher healthcare costs (Part II). The dissertation also aims at contributing to the current discussion in how far health literacy contributes to differences in health outcomes. In particular those that are often associated with other social determinants that are closely linked to unjust distribution of wealth or education. In the US for example ethnic and racial minorities have been most often found to be afflicted by the negative outcomes of health. Health literacy as a potential explanatory variable in this relationship has been widely discussed, yet little is known about its exact role in this relationship. The dissertation presents a conceptual discussion on the relevant issues that may have prevented health literacy to be more systematically integrated into research on disparities and to not fully leverage its potential for interventions in the field. Further, by means of a systematic review the work at hand aims to outline the current empirical knowledge on health literacy and health disparities. Results of this review indeed point to the fact that little systematic evidence is yet available, due to the lack of systematic testing of potential pathways describing how health literacy contributes to disparities. Further, disparities as such are only seldom sufficiently described in the literature and are predominantly treated as confounders. Lastly, a study is presented that tested for differences in health literacy by comparing three immigrant groups in Switzerland to the general Swiss population, and explored in how far the interplay between health literacy and acculturation might explain health differences. This dissertation contributes to the discussion on the conceptualization and operationalization of health literacy by providing evidence on its transferability and that its underlying constructs might be sufficiently applicable to other contexts. Further, the relationships identified do not only have implications for researchers but for healthcare practitioners and policy makers as well. In particular the relationship found between health literacy and costs has the potential to significantly leverage health literacy as a topic on the healthcare agenda. Finally, by discussing and identifying gaps on current knowledge on how health literacy contributes to disparities, and by identifying differential effects by means of different measures, this work presents a first careful stepping stone on how to systematically disentangle potential pathways linking health literacy to health disparities

Normalization of Dutch user-generated content

Abstract This paper describes a phrase-based machine translation approach to normalize Dutch user-generated content (UGC). We compiled a corpus of three different social media genres (text messages, message board posts and tweets) to have a sample of this recent domain. We describe the various characteristics of this noisy text material and explain how it has been manually normalized using newly developed guidelines. For the automatic normalization task we focus on text messages, and find that a cascaded SMT system where a token-based module is followed by a translation at the character level gives the best word error rate reduction. After these initial experiments, we investigate the system's robustness on the complete domain of UGC by testing it on the other two social media genres, and find that the cascaded approach performs best on these genres as well. To our knowledge, we deliver the first proof-of-concept system for Dutch UGC normalization, which can serve as a baseline for future work

Religiosity as a bridge or barrier to immigrant children's educational achievement?

Immigrant children in Europe remain in a position of educational disadvantage. Most studies underscore the role of the parents' education level and their socio-economic status in the educational achievement of their children. This paper adds to the literature by exploring other factors that reduce or contribute to educational inequality among immigrant children. Using research from the United States as a reference point, we specifically examine religiosity as a device for social mobility. Religiosity may be conducive to educational attainment in two ways: (1) religious organizations may provide guidance, support and beneficial social norms that foster the formation of social capital and sanction deviant behaviour; (2) religious participation may induce an internal locus of control that encourages students to focus on learning and resist counterproductive peer influence. Other scholars argue that ethno-religious in-group ties can be a mobility trap when human capital and socio-economic status in an immigrant community is low. Using the German National Educational Panel Study (NEPS), we take a cross-sectional perspective to test these arguments for Christian and Muslim students of immigrant origin living in Germany. Our analyses reveal that religiosity is primarily relevant for Muslims' mathematical test performance. We find that students and parents' religiosity are not necessarily a barrier to good mathematical test performance. Yet our multidimensional measure of religiosity consisting of religious engagement, praying and subjective religiosity allows us to uncover distinct relationships depending on the form of religiosity. Christians' and Muslims' frequency of praying is positively linked to academic performance. Self-rated religiosity, however, is correlated with worse performance. Finally, we find that religious community engagement is related to better academic performance only when the share of co-ethnics in a residential area is low

TFE and Spt4/5 open and close the RNA polymerase clamp during the transcription cycle

Transcription is an intrinsically dynamic process and requires the coordinated interplay of RNA polymerases (RNAPs) with nucleic acids and transcription factors. Classical structural biology techniques have revealed detailed snapshots of a subset of conformational states of the RNAP as they exist in crystals. A detailed view of the conformational space sampled by the RNAP and the molecular mechanisms of the basal transcription factors E (TFE) and Spt4/5 through conformational constraints has remained elusive. We monitored the conformational changes of the flexible clamp of the RNAP by combining a fluorescently labeled recombinant 12-subunit RNAP system with single-molecule FRET measurements. We measured and compared the distances across the DNA binding channel of the archaeal RNAP. Our results show that the transition of the closed to the open initiation complex, which occurs concomitant with DNA melting, is coordinated with an opening of the RNAP clamp that is stimulated by TFE. We show that the clamp in elongation complexes is modulated by the nontemplate strand and by the processivity factor Spt4/5, both of which stimulate transcription processivity. Taken together, our results reveal an intricate network of interactions within transcription complexes between RNAP, transcription factors, and nucleic acids that allosterically modulate the RNAP during the transcription cycle

Conformational changes of the archaeal RNA polymerase throughout the transcription cycle

Der erste Schritt der Genexpression ist die Transkription, bei der DNA in RNA umgeschrieben wird und die durch das Enzym RNA Polymerase (RNAP)ausgeführt wird. Die Transkription ist ein sehr dynamischer Prozess und wird durch das Zusammenspiel von RNA Polymerase und den Transkriptionsfaktoren reguliert. RNA Polymerasen bestehen aus mehreren Untereinheiten, die sich in funktionelle Einheiten gliedern, aber auch multiple flexible Elemente aufweisen, die im Laufe des Transkriptionszyklus Konformationsänderungen durchlaufen. Besonders eine dieser Domänen - die RNA Polymerase Clamp - ist strukturell sehr flexibel. Röntgenkristallstrukturen sowie Strukturen, die aus Kryo-Elektronenmikroskopie-Untersuchungen hervorgegangen sind, zeigen die Clamp in unterschiedlichen Konformationszuständen. Zudem ist die RNAP Clamp Ziel regulatorischer Transkriptionsfaktoren, wie z.B. TFE und Spt4/5, die an die Clamp assoziieren. Dies hebt die besondere Bedeutung der RNAP Clamp für die Funktion der RNAP hervor. Jedoch blieben die molekularen Mechanismen der Transkriptionsfaktoren bisher schwer nachvollziehbar. In dieser Arbeit wurde mit Hilfe von Einzelmolekül-Fluoreszenzresonanzenergietransfer (FRET)-Messungen die Position der RNAP Clamp aus dem archaeellen Organismus Methanocaldococcus jannaschii in Abhängigkeit von unterschiedlichen Nukleinsäuren, Transkriptionsfaktoren, Zusammensetzung der RNA Polymerase und der Stufe im Transkriptionszyklus untersucht. Zunächst wurde die RNAP Clamp in einer freien Konfiguration mit unterschiedlicher Untereinheitenkomposition gemessen und anschließend der Einfluss des Transkriptionsfaktors TFE und des Elongationsfaktors Spt4/5 auf die Position der Clamp untersucht. Es wurde gezeigt, dass die RNAP Clamp beim Übergang vom geschlossenen zum offenen Prä-Initiationskomplex, das in DNA-Schmelzen resultiert, sich öffnet und das Öffnen durch TFE stimuliert wird. In Elongationskomplexen wird die RNAP Clamp durch den nicht-kodogenen Strang sowie durch Spt4/5 reguliert. TFE und Spt4/5 verschieben das Gleichgewicht in Richtung einer Hauptkonformation und beeinflussen die Struktur der RNAP möglicherweise durch einen allosterischen Schalter, womit eine mechanistische Erklärung für die Funktion der Faktoren geliefert wird. Insgesamt nimmt die RNAP Clamp vier unterschiedliche Konformationen ein, die von den Untereinheiten Rpo4/7, vom nicht-kodogenen Strang und den Transkriptionsfaktoren TFE und Spt4/5 abhängig sind.Transcription is the first step in gene expression in which the DNA is transcribed into RNA and which is carried out by the enzyme RNA Polymerase (RNAP). Transcription is an intrinsically dynamic process which is regulated by the interplay of the RNAP and its transcription factors. RNAPs consist of multiple subunits that contain flexible domains. Further these domains undergo conformational changes throughout the transcription cycle. One of the RNAP domains - RNAP clamp - is a structurally mobile element. Both X-ray structures and cryo-electron microscopy reveal the clamp in multiple conformational states. Furthermore the RNAP clamp is a target for regulatory transcription factors e.g. for TFE and Spt4/5, which both associate to the clamp. This emphasizes that the clamp is an important functional regulator. But the molecular mechanisms of the transcription factors have remained elusive. In this work, single-molecule fluorescence resonance energy transfer (FRET) was used to monitor archaeal 12-subunit RNAP clamp conformations in the presence of different nucleic acids, transcription factors, compositions of the RNAP and to study these conformations at each step in transcription initiation and elongation. The RNAP clamp conformation was investigated in a free RNAP with different subunit-compositions and the influence of the transcription factor TFE and the elongation factor Spt4/5 on the clamp conformation was measured. The transition from the closed to the open pre-initiation complex, resulting in DNA-melting, leads to a clamp opening, which is stimulated by TFE. The RNAP clamp is modulated by the non-template strand and by Spt4/5 in elongation complexes. TFE or Spt4/5 shift the equilibria towards one of the main conformations suggesting that both prompt an allosteric switch that influences the structure of the RNAP and thereby provide a mechanistic rationale for the function of these factors. Taken altogether, the RNAP clamp adopts four different conformational states which are dependent on the subunits Rpo4/7, the non-template strand and the transcription factors TFE and Spt4/5