Do changes in health reveal the possibility of undiagnosed pancreatic cancer? Development of a risk-prediction model based on healthcare claims data.

Background and objectiveEarly detection methods for pancreatic cancer are lacking. We aimed to develop a prediction model for pancreatic cancer based on changes in health captured by healthcare claims data.MethodsWe conducted a case-control study on 29,646 Medicare-enrolled patients aged 68 years and above with pancreatic ductal adenocarcinoma (PDAC) reported to the Surveillance Epidemiology an End Results (SEER) tumor registries program in 2004-2011 and 88,938 age and sex-matched controls. We developed a prediction model using multivariable logistic regression on Medicare claims for 16 risk factors and pre-diagnostic symptoms of PDAC present within 15 months prior to PDAC diagnosis. Claims within 3 months of PDAC diagnosis were excluded in sensitivity analyses. We evaluated the discriminatory power of the model with the area under the receiver operating curve (AUC) and performed cross-validation by bootstrapping.ResultsThe prediction model on all cases and controls reached AUC of 0.68. Excluding the final 3 months of claims lowered the AUC to 0.58. Among new-onset diabetes patients, the prediction model reached AUC of 0.73, which decreased to 0.63 when claims from the final 3 months were excluded. Performance measures of the prediction models was confirmed by internal validation using the bootstrap method.ConclusionModels based on healthcare claims for clinical risk factors, symptoms and signs of pancreatic cancer are limited in classifying those who go on to diagnosis of pancreatic cancer and those who do not, especially when excluding claims that immediately precede the diagnosis of PDAC

Dynamic tight binding for large-scale electronic-structure calculations of semiconductors at finite temperatures

Calculating the electronic structure of materials at finite temperatures is important for rationalizing their physical properties and assessing their technological capabilities. However, finite-temperature calculations typically require large system sizes or long simulation times. This is challenging for non-empirical theoretical methods because the involved bottleneck of performing many first-principles calculations can pose a steep computational barrier for larger systems. While machine-learning molecular dynamics enables large-scale/long-time simulations of the structural properties, the difficulty of computing in particular the electronic structure of large and disordered materials still remains. In this work, we suggest an adaptation of the tight-binding formalism which allows for computationally efficient calculations of temperature-dependent properties of semiconductors. Our dynamic tight-binding approach utilizes hybrid-orbital basis functions and a modeling of the distance dependence of matrix elements via numerical integration of atomic orbitals. We show that these design choices lead to a dynamic tight-binding model with a minimal amount of parameters which are straightforwardly optimized using density functional theory. Combining dynamic tight-binding with machine learning molecular dynamics and hybrid density functional theory, we find that it accurately describes finite-temperature electronic properties in comparison to experiment for the prototypical semiconductor gallium-arsenide

The Non-linear Dynamics of Meaning-Processing in Social Systems

Social order cannot be considered as a stable phenomenon because it contains an order of reproduced expectations. When the expectations operate upon one another, they generate a non-linear dynamics that processes meaning. Specific meaning can be stabilized, for example, in social institutions, but all meaning arises from a horizon of possible meanings. Using Luhmann's (1984) social systems theory and Rosen's (1985) theory of anticipatory systems, I submit equations for modeling the processing of meaning in inter-human communication. First, a self-referential system can use a model of itself for the anticipation. Under the condition of functional differentiation, the social system can be expected to entertain a set of models; each model can also contain a model of the other models. Two anticipatory mechanisms are then possible: one transversal between the models, and a longitudinal one providing the modeled systems with meaning from the perspective of hindsight. A system containing two anticipatory mechanisms can become hyper-incursive. Without making decisions, however, a hyper-incursive system would be overloaded with uncertainty. Under this pressure, informed decisions tend to replace the "natural preferences" of agents and an order of cultural expectations can increasingly be shaped

Communications Biophysics

Contains reports on five research projects.National Science Foundation (Grant G-16526)National Institutes of Health (Grant MH-04737-02

Der diskrete Charme der Bourgeoisie - Ein Beitrag zur Soziologie des modernen Wirtschaftsbürgertums

Entgegen der These der Auflösungserscheinungen des Bürgertums stellt der Autor die Annahme auf den Prüfstand, dass wir es nach wie vor mit gesellschaftlichen Fraktionierungen bürgerlicher Lebensweisen zu tun haben. Am Beispiel autobiographischer Schriften von deutschen Topmanagern stellt der Text ein modernes Verständnis des Wirtschaftsbürgertums vor, das organisational (durch die Karrieremechanismen der Organisation) und institutionell (im Feld der Wirtschaft) verankert ist. Die moderne Sozialformation des Wirtschaftsbürgertums ist nur noch auf der Grundlage von Organisationen denkbar. Sie lässt sich, jenseits von Klasse und Stand, als Positionselite beschreiben. Anhand der Autobiographien lässt sich die Reproduktion dieser Elite auf Basis einer engen Verknüpfung zwischen familialer Herkunft, an organisationale Karrieren gebundene Leistungsbereitschaft und hoher formaler Bildung nachzeichnen. Die Abgrenzung in der Statusreproduktion zwischen Bildungs- und Wirtschaftsbürgertum weist der Autor am jeweiligen Verhältnis zur Bildung nach; zwar können beide einen hohen Bildungsgrad in Form von Bildungspatenten nachweisen, doch im Falle des Wirtschaftsbürgertums herrscht ein instrumentelles Verhältnis zur Bildung vor. Der hohe Bildungsgrad folgt hier dem Bedürfnis, den Status mittels formaler Bildung abzusichern und damit die Gefahr der eigenen Austauschbarkeit - als Personal der Organisation - zu kompensieren. Der Text macht außerdem generationale Effekte sichtbar; insbesondere indem er darlegt, inwieweit der "moderne Manager" einerseits in der Betonung seines Status seinen Vorgängern gleicht und sich doch gleichzeitig in der Art der Unternehmensführung abgrenzt - indem er bspw. die Managementkonzepte seiner Zeit aufgreift

Informal and formal reconciliation strategies of older peoples’ working carers: the European carers@work project

Faced with a historically unprecedented process of demographic ageing, many European societies implemented pension reforms in recent years to extend working lives. Although aimed at rebalancing public pension systems, this approach has the unintended side effect that it also extends the number of years in which working carers have to juggle the conflicting demands of employment and caregiving. This not only impinges on working carers’ well-being and ability to continue providing care but also affects European enterprises’ capacity to generate growth which increasingly relies on ageing workforces. The focus of this paper will thus be a cross-national comparison of individual reconciliation strategies and workplace-related company policies aimed at enabling working carers to reconcile both conflicting roles in four different European welfare states: Germany, Italy, Poland, and the United Kingdom

Varieties of Capitalism and the Learning Firm: Contemporary Developments in EU and German Company Law - A Comment on the Strine-Bainbridge Debate About Shared Values of Corporate Management and Labor

Research in corporate governance and in labour law has been characterized by a disjuncture in the way that scholars in each field are addressing organizational questions related to the business enterprise. While labour has eventually begun to shift perspectives from aspirations to direct employee involvement in firm management, as has been the case in Germany, to a combination of \u27exit\u27 and \u27voice\u27 strategies involving pension fund management and securities litigation, it remains to be seen whether this new stream will unfold as a viable challenge to an otherwise exclusionary shareholder value paradigm. At the same time, recent suggestions made by Delaware Chancery Court Vice Chancellor Strine, to dare think about potentially shared commitments between management and labor - and UCLA\u27s Stephen Bainbridge\u27s response - underline the viability - and, the contestedness - of attempts at moving the corporate governance debate beyond the confines of corporate law proper. While such a wider view had already famously been encouraged by Dean Clarke in his 1986 treatise on Corporate Law (p. 32), mainstream corporate law does not seem to have endorsed this perspective. This paper takes the questionable divide between management and labor within the framework of a limiting corporate governance concept as starting point to explore the institutional dynamics of the corporation, hereby building on the theory of the innovative enterprise, as developed by management theorists Mary O\u27Sullivan and William Lazonick. Largely due to the sustained distance between corporate and labour law scholars, neither group has effectively addressed their common blind spot: a better understanding of the business enterprise itself. In midst of an unceasing flow of affirmations of the finance paradigm of the corporation on the one hand and \u27voice\u27 strategies by labour on the other, it seems to fall to management theorists to draw lessons from the continuing co-existence of different forms of market organization, in which companies appear to thrive. Exploring the conundrum of \u27risky\u27 business decisions within the firm, management theorists have been arguing for the need to adopt a more sophisticated organizational perspective on companies operating on locally, regionally and transnationally shaped, often highly volatile market segments. Research by comparative political economists has revealed a high degree of connectivity between corporate governance and economic performance without, however, arriving at such favourable results only for shareholder value regimes. Such findings support the view that corporate governance regimes are embedded in differently shaped regulatory frameworks, characterized by distinct institutions, both formal and informal, and enforcement processes. As a result of these findings, arguments to disassociate issues of corporate governance from those of the firm\u27s (social) responsibility [CSR] have been losing ground. Instead, CSR can be taken to be an essential part of understanding a particular business enterprise. It is the merging of a comparative political economy perspective on the corporation with one on the organizational features, structures and processes of the corporation, which can help us better understand the distribution of power and knowledge within the \u27learning firm\u27