Stock return autocorrelations revisited: A quantile regression approach

The aim of this study is to provide a comprehensive description of the dependence pattern of stock returns by studying a range of quantiles of the conditional return distribution using quantile autoregression. This enables us in particular to study the behavior of extreme quantiles associated with large positive and negative returns in contrast to the central quantile which is closely related to the conditional mean in the least-squares regression framework. Our empirical results are based on 30 years of daily, weekly and monthly returns of the stocks comprised in the Dow Jones Stoxx 600 index. We find that lower quantiles exhibit positive dependence on past returns while upper quantiles are marked by negative dependence. This pattern holds when accounting for stock specific characteristics such as market capitalization, industry, or exposure to market risk. --stock return distribution,quantile autoregression,overreaction and underreaction

Species-Specific Differences in the Susceptibility of Fungi to the Antifungal Protein AFP Depend on C-3 Saturation of Glycosylceramides

AFP is an antimicrobial peptide (AMP) produced by the filamentous fungus Aspergillus giganteus and is a very potent inhibitor of fungal growth that does not affect the viability of bacteria, plant, or mammalian cells. It targets chitin synthesis and causes plasma membrane permeabilization in many human- and plant-pathogenic fungi, but its exact mode of action is not known. After adoption of the “damage-response framework of microbial pathogenesis” regarding the analysis of interactions between AMPs and microorganisms, we have recently proposed that the cytotoxic capacity of a given AMP depends not only on the presence/absence of its target(s) in the host and the AMP concentration applied but also on other variables, such as microbial survival strategies. We show here using the examples of three filamentous fungi (Aspergillus niger, Aspergillus fumigatus, and Fusarium graminearum) and two yeasts (Saccharomyces cerevisiae and Pichia pastoris) that the important parameters defining the AFP susceptibilities of these fungi are (i) the presence/absence of glycosylceramides, (ii) the presence/absence of Δ3(E) desaturation of the fatty acid chain therein, and (iii) the (dis)ability of these fungi to respond to AFP inhibitory effects with the fortification of their cell walls via increased chitin and β-(1,3)-glucan synthesis. These observations support the idea of the adoption of the damage-response framework to holistically understand the outcome of AFP inhibitory effects.TU Berlin, Open-Access-Mittel - 201

Design Study for Multifunctional 3D Re‐entrant Auxetics

The increasing demands of safety, cost reduction, or weight reduction on components call for new, multifunctional materials. Mechanical metamaterials, such as auxetic materials, provide enhanced properties due to a specially tailored microstructure. The negative Poisson's ratio of auxetics, for instance, increases the impact and thermal shock resistance. Herein, a parametrized model of a modified auxetic structure is simulated using the finite-element software ABAQUS. Three out of five geometry parameters are varied between a minimum and maximum value to establish their impact on the energy absorption capacity and the Poisson's ratio using design of experiment (DoE). All eight resulting structures are additively manufactured by selective laser melting (SLM) and experimentally investigated under uniaxial compression to validate the simulations. The size of a unit cell has the biggest impact on both target values. Energy absorption capacity and Poisson's ratio are directly competing in optimization; hence, a compromise is necessary. The quasistatic compression experiments verify the simulation results up to the first collapse. Afterward, the specimens are brittle, which is not accounted for in the simulations, and this may result from the high process complexity of SLM manufacturing

A First Step toward the Automatic Understanding of Social Touch for Naturalistic Human–Robot Interaction

Social robots should be able to automatically understand and respond to human touch. The meaning of touch does not only depend on the form of touch but also on the context in which the touch takes place. To gain more insight into the factors that are relevant to interpret the meaning of touch within a social context we elicited touch behaviors by letting participants interact with a robot pet companion in the context of different affective scenarios. In a contextualized lab setting, participants (n = 31) acted as if they were coming home in different emotional states (i.e., stressed, depressed, relaxed, and excited) without being given specific instructions on the kinds of behaviors that they should display. Based on video footage of the interactions and interviews we explored the use of touch behaviors, the expressed social messages, and the expected robot pet responses. Results show that emotional state influenced the social messages that were communicated to the robot pet as well as the expected responses. Furthermore, it was found that multimodal cues were used to communicate with the robot pet, that is, participants often talked to the robot pet while touching it and making eye contact. Additionally, the findings of this study indicate that the categorization of touch behaviors into discrete touch gesture categories based on dictionary definitions is not a suitable approach to capture the complex nature of touch behaviors in less controlled settings. These findings can inform the design of a behavioral model for robot pet companions and future directions to interpret touch behaviors in less controlled settings are discussed

Neoadjuvant Therapy in Pancreatic Cancer: Review Article

Context Pancreatic cancer is still associated with a high mortality and morbidity for affected patients. To this date the role of neoadjuvant therapy in the standard treatment of pancreatic cancer remains elusive. The aim of our study was to review the latest results and current approaches in neoadjuvant therapy of pancreatic cancer. Methods We performed a literature review for neoadjuvant therapy in pancreatic cancer. We divided the results into resectable disease and local advanced pancreatic cancer. Results Neoadjuvant therapy in pancreatic cancer is safe. But currently no standard guidelines exist in neoadjuvant approaches on pancreatic cancer. For local advanced pancreatic cancer the available data tends to show a positive effect on survival rates for neoadjuvant approaches. Conclusion For resectable disease we found no benefit of neoadjuvant therapy. The negative or positive effects of neoadjuvant treatment in pancreatic cancer remain unclear for the lack of sufficient and prospective data.Image: University of Luebeck logo. Luebeck, Germany

MRP8 and MRP14, phagocyte-specific danger signals, are sensitive biomarkers of disease activity in cryopyrin-associated periodic syndromes

To assess the sensitivity of the phagocyte-specific molecules myeloid-related protein (MRP) 8 and MRP14 (calprotectin) for monitoring disease activity during anti-interleukin (IL)-1 therapies in patients with cryopyrin-associated periodic syndromes (CAPS), including familial cold autoinflammatory syndrome (FCAS), Muckle-Wells syndrome (MWS) and chronic infantile neurological, cutaneous and articular (CINCA) syndrome

THREE DIMENSIONAL PACKAGING OF BARE IC INTO PRINTED CIRCUIT BOARDS FOR SIP

ABSTRACT The demand to miniaturize products especially for mobile applications and autonomous systems is continuing to drive the evolution of electronic products and manufacturing methods. To further the miniaturization of future products the integration of functions on miniaturized subsystems, i.e. System-inPackage (SiP) is a promising approach. Here, use of recent manufacturing methods allows to merge the SiP concept with a volumetric integration of IC´s. Up to now, most of the systems make use of single-or double-sided populated system carriers. A new challenge is to incorporate not only passive components, but as well active circuitry (IC´s) and the necessary thermal management. Ultra thin chips (i.e. silicon dies thinned down to <50µm total thickness) lend themselves to reach these goals. Chips with that thickness can be embedded in the dielectric layers of modern laminate PCB´s. Micro via technology allows to contact the embedded chip to the outer faces of the system circuitry. The aspects of embedding and making the electrical contact as well as the thermal management are highlighted. Results on FEM simulations and technical achievements are presented

Limits in categories of Vietoris coalgebras

Motivated by the need to reason about hybrid systems, we study limits in categories of coalgebras whose underlying functor is a Vietoris polynomial one - intuitively, the topological analogue of a Kripke polynomial functor. Among other results, we prove that every Vietoris polynomial functor admits a final coalgebra if it respects certain conditions concerning separation axioms and compactness. When the functor is restricted to some of the categories induced by these conditions the resulting categories of coalgebras are even complete. As a practical application, we use these developments in the specification and analysis of non-deterministic hybrid systems, in particular to obtain suitable notions of stability, and behaviour.publishe

Epithelial cell cluster size affects force distribution in response to EGF-induced collective contractility

Several factors present in the extracellular environment regulate epithelial cell adhesion and dynamics. Among them, growth factors such as EGF, upon binding to their receptors at the cell surface, get internalized and directly activate the acto-myosin machinery. In this study we present the effects of EGF on the contractility of epithelial cancer cell colonies in confined geometry of different sizes. We show that the extent to which EGF triggers contractility scales with the cluster size and thus the number of cells. Moreover, the collective contractility results in a radial distribution of traction forces, which are dependent on integrin β1 peripheral adhesions and transmitted to neighboring cells through adherens junctions. Taken together, EGF-induced contractility acts on the mechanical crosstalk and linkage between the cell-cell and cell-matrix compartments, regulating collective responses