Uncertainty-Aware Principal Component Analysis

We present a technique to perform dimensionality reduction on data that is subject to uncertainty. Our method is a generalization of traditional principal component analysis (PCA) to multivariate probability distributions. In comparison to non-linear methods, linear dimensionality reduction techniques have the advantage that the characteristics of such probability distributions remain intact after projection. We derive a representation of the PCA sample covariance matrix that respects potential uncertainty in each of the inputs, building the mathematical foundation of our new method: uncertainty-aware PCA. In addition to the accuracy and performance gained by our approach over sampling-based strategies, our formulation allows us to perform sensitivity analysis with regard to the uncertainty in the data. For this, we propose factor traces as a novel visualization that enables to better understand the influence of uncertainty on the chosen principal components. We provide multiple examples of our technique using real-world datasets. As a special case, we show how to propagate multivariate normal distributions through PCA in closed form. Furthermore, we discuss extensions and limitations of our approach

Zum Verbleib ehemaliger Teilnehmer des Berufspraktischen Jahrs in Bayern : ein Beitrag zu Möglichkeiten und Grenzen von Wirkungsforschung

"Das Berufspraktische Jahr (BPJ) ist eine von den Bildungswerken der Wirtschaft durchgeführte berufsvorbereitende Maßnahme für jüngere Arbeitslose unter 25 Jahren. Es wird in Kooperation mit Betrieben durchgeführt, in denen die Teilnehmer ein Praktikum absolvieren. Die Auswertung einer postalischen Befragung nach dem Ex-Post-Kontrollgruppendesign möchte den Verbleib ehemaliger Teilnehmer des BPJ in Bayern beschreiben und tentative Aussagen zur Maßnahmewirkung machen. Das Design konnte allerdings nur unvollkommen eingelöst werden. Verzerrungen bei der Bildung der Kontrollgruppe und Einschränkungen der Datenqualität vor allem bei zeitlichen Angaben zwingen zu einer vorsichtigen Interpretation. Die Quote der Einmündungen ehemaliger BPJ-Teilnehmer in Beschäftigung oder Ausbildung nach Maßnahmeaustritt ist relativ hoch. Das gilt besonders für Teilnehmer, die vor Maßnahmeeintritt ihre berufliche Ausbildung mehrfach abgebrochen haben. Die hohe Integrationsquote ehemaliger BPJ-Teilnehmer wird jedoch relativiert durch einen verhältnismäßig hohen Anteil atypischer Beschäftigungsverhältnisse, die mit geringerer Beschäftigungssicherheit verbunden sind. Berücksichtigt man diesen Sicherheits- oder Stabilitätsaspekt, dann manifestiert sich die Maßnahmewirkung nicht in einem Integrationsvorsprung der Teilnehmergruppe insgesamt. Diese Wirkung bezieht sich vielmehr auf eine Teilgruppe. Sie erweist sich darin, daß längerfristig Arbeitslose der BPJ-Gruppe eine größere Integrationschance haben als längerfristig Arbeitslose der Vergleichsgruppe. Insgesamt entsteht der Eindruck, daß das BPJ besonders für sogenannte Problemgruppen innerhalb der Teilnehmerschaft eine Hilfe darstellt." (Autorenreferat)Berufsvorbereitungsjahr, Absolventen, beruflicher Verbleib, Berufseinmündung, Berufsvorbereitungsjahr - Erfolgskontrolle, Berufsausbildung, Arbeitslosigkeit, erste Schwelle, Bayern, Bundesrepublik Deutschland

Teacher Participation Styles in Foreign Language Chats and Their Effect on Student Behavior

This paper investigates the impact that a teacher's virtual presence--or lack thereof--has on students' chat behavior with regard to error correction, uptake, target language use, and on-task behavior. The data come from beginning German students engaged in pair and small-group chatting activities at a major American university. Transcripts from chat sessions in a first-semester German class and a second-semester German class were analyzed. The data were triangulated with student surveys and teacher interviews. Results suggest that the teachers' participation styles had a greater influence on learners' chat behavior than simply whether or not the teachers were present and that the form-focused participation style of one of the teachers had an apparently inhibitory effect on learner participation

Where Do We Go from Here? : a Bibliometric Analysis Identifying Implications for Future Research in Circular Economy and Supply Chain Management

The Circular Economy (CE) relies heavily on Supply Chain Management (SCM) as it involves managing the entire value chain and coordinating flows. Despite significant contributions, research on SCM for CE remains fragmented, which hinders a comprehensive exploration. This study presents a bibliometric analysis of 281 publications to examine the intersection between CE and SCM. The main research topics are identified and future directions are suggested. The findings contribute to the literature on CE and SCM by providing a comprehensive overview of the current state of knowledge and the barriers. Valuable implications for future research directions are also provided. Additionally, the implications can guide practitioners, institutions, and policymakers in shaping their SCM strategies and contributing to the ongoing transition to a CE

Zeitforschung aus sozial-ökologischer Perspektive

Welche Bedeutung hat die Zeitforschung für Wissenschaft, Politik und Praxis aus sozial-ökologischer Perspektive? Die zeitpolitische Forschung steht im Mittelpunkt der Betrachtung, da sie sozialen, ökonomischen und ökologischen, aber auch demokratischen Fragestellungen nachgeht, in denen sich sozial-ökologische Aspekte widerspiegeln

Loss-Function Learning for Digital Tissue Deconvolution

The gene expression profile of a tissue averages the expression profiles of all cells in this tissue. Digital tissue deconvolution (DTD) addresses the following inverse problem: Given the expression profile y of a tissue, what is the cellular composition c of that tissue? If X is a matrix whose columns are reference profiles of individual cell types, the composition c can be computed by minimizing L(y − Xc) for a given loss function L. Current methods use predefined all-purpose loss functions. They successfully quantify the dominating cells of a tissue, while often falling short in detecting small cell populations. In this here presented, newly developed approach training data are employed in order to learn the loss function L along with the composition c. This allows for adaption of the loss function to application-specific requirements, such as focusing on small cell populations or distinguishing phenotypically similar cell populations. Loss-function learning is tested on two different single-cell RNA sequencing data sets. The first is generated from melanoma specimens and the second from peripheral blood samples of patients with Chronic Lymphocytic Leukemia (CLL). The CLL data were augmented by bulk sequencing data. It could be demonstrated that the here introduced method quantifies large cell fractions as accurately as existing methods and significantly improves the detection of small cell populations and the distinction of similar cell types. Furthermore, it is shown that the developed DTD models may be applied mutually to both sets of data. As a result the model on the melanoma data is also relevant for the CLL data set and vice versa

How to measure diagnosis-associated information in virtual slides

The distribution of diagnosis-associated information in histological slides is often spatial dependent. A reliable selection of the slide areas containing the most significant information to deriving the associated diagnosis is a major task in virtual microscopy. Three different algorithms can be used to select the appropriate fields of view: 1) Object dependent segmentation combined with graph theory; 2) time series associated texture analysis; and 3) geometrical statistics based upon geometrical primitives. These methods can be applied by sliding technique (i.e., field of view selection with fixed frames), and by cluster analysis. The implementation of these methods requires a standardization of images in terms of vignette correction and gray value distribution as well as determination of appropriate magnification (method 1 only). A principle component analysis of the color space can significantly reduce the necessary computation time. Method 3 is based upon gray value dependent segmentation followed by graph theory application using the construction of (associated) minimum spanning tree and Voronoi’s neighbourhood condition. The three methods have been applied on large sets of histological images comprising different organs (colon, lung, pleura, stomach, thyroid) and different magnifications, The trials resulted in a reproducible and correct selection of fields of view in all three methods. The different algorithms can be combined to a basic technique of field of view selection, and a general theory of “image information” can be derived. The advantages and constraints of the applied methods will be discussed

God´s revealed act of salvation in Jesus Christ

Die 1999 feierlich unterzeichnete 'Gemeinsame Erklärung zur Rechtfertigungslehre' (GE) sowie die 'Gemeinsame offizielle Feststellung' (GOF) des Lutherischen Weltbundes und der katholischen Kirche stellen zwischen Lutheranern und Katholiken einen 'Konsens in Grundwahrheiten der Rechtfertigungslehre' (GE 40; vgl. GOF 1) fest. Dabei bleiben Fragen offen (vgl. GE 43), die u.a. auch auf eine Vertiefung der biblischen Studien abzielen (vgl. GOF 3). Diese Arbeit möchte zu diesem Anliegen einen kleinen Beitrag leisten, indem sie den 'Stellenwert der paulinischen Rechtfertigungsaussagen im Kontext der katholisch-lutherischen Konsensfindung' untersucht. Dabei ergeben sich vor allem aus der Auslegungsgeschichte der paulinischen Rechtfertigung im 20. Jahrhundert folgende vier Interpretationsansätze: (1) Der universalisierende Ansatz weist der Rechtfertigungslehre eine ordnende, allumfassende Rolle zu. (2) Im Gegensatz dazu betont der religionssoziologische Ansatz die situative Bedingtheit der Rechtfertigungslehre - besonders in der paulinischen Heidenmission. (3) Der sühnetheologische Ansatz hält beide erstgenannten Ansätze für ungenügend und betont statt dessen das Konzept der Sühne für die paulinische Soteriologie. (4) Der in der Gegenwart zunehmend vertretene sprachlich differenzierende Ansatz versucht, die unterschiedlichen, soteriologischen Konzepte bei Paulus miteinander in Beziehung zu setzen. Spuren dieser Ansätze lassen sich auch im Leben und in der Theologie des Paulus (vgl. Kap. 2) sowie in der Entwicklung des Rechtfertigungsbegriffes vom Alten Testament bis in die Gegenwart (Kap. 3) zeigen. Für eine Fortentwicklung der ökumenischen Rechtfertigungsdiskussion empfiehlt die Arbeit, den vierten Interpretationsansatz zugrunde zulegen und von da ausgehend, Elemente der anderen Deutungsansätze einfließen zu lassen.A 'consensus in the fundamental truths of the doctrine of justification' (GE 40; cf. GOF 1) between Lutheran and Catholics was solemnly signed in the 'Official Common Statement' (GOF) and 'The Joint Declaration on the Doctrine of Justification' issued by the Lutheran World Association and the Catholic Church in 1999. Several questions however remain open (cf. GE 43) which, among other things, aim at a deepening of biblical studies (cf. GOF 3). This study would like to make a small contribution towards that aim by investigating the 'importance of Paulinian justificatory statements in the context of Catholic-Lutheran consensus building'. The following four interpretive approaches mainly result from the history of the exegesis of St. Paul´s doctrine of justification in the 20th century: (1) The universalizing approach endows the doctrine of justification with an all-embracing and guiding role. (2) By contrast the religious-sociological approach emphasizes the situation-boundness of the doctrine of justification. especially in the case of the Paulinian christianizing of heathens. (3) The atonement-theological approach considers the first-mentioned approaches to be inadequate and instead emphasizes the concept of atonement for the Paulinian soteriology. (4) The approach of linguistic differentiation, which is currently more and more used, tries to bring the various Paulinian soteriological concepts into relation. Traces of the approaches mentioned above can be shown in St. Paul´s life and theology, too (cf. chapter 2) as well as in the development of the concept of justification from the Old Testament up to the present (chapter 3). In order to develop the ecumenical debate on justification further this study recommends to take the fourth approach as a basis, and proceeding from here, to integrate elements of the other interpretative approaches

Grid technology in tissue-based diagnosis: fundamentals and potential developments

Tissue-based diagnosis still remains the most reliable and specific diagnostic medical procedure. It is involved in all technological developments in medicine and biology and incorporates tools of quite different applications. These range from molecular genetics to image acquisition and recognition algorithms (for image analysis), or from tissue culture to electronic communication services. Grid technology seems to possess all features to efficiently target specific constellations of an individual patient in order to obtain a detailed and accurate diagnosis in providing all relevant information and references. Grid technology can be briefly explained by so-called nodes that are linked together and share certain communication rules in using open standards. The number of nodes can vary as well as their functionality, depending on the needs of a specific user at a given point in time. In the beginning of grid technology, the nodes were used as supercomputers in combining and enhancing the computation power. At present, at least five different Grid functions can be distinguished, that comprise 1) computation services, 2) data services, 3) application services, 4) information services, and 5) knowledge services. The general structures and functions of a Grid are described, and their potential implementation into virtual tissue-based diagnosis is analyzed. As a result Grid technology offers a new dimension to access distributed information and knowledge and to improving the quality in tissue-based diagnosis and therefore improving the medical quality