The physical nature of interplanetary dust as inferred by particles collected at 35 km

Particles were collected at an altitude of 35 km by two flights of a volume sampling micrometeorite collector. The collection scheme is very sensitive and is capable of collecting a significant number of particles. Many of the particles collected have chemical compositions similar to solar or to iron meteorites. Morphology of collected particles indicates that both true micrometeorites and ablation products were collected

Neural cell adhesion molecules in rat endocrine tissues and tumor cells: distribution and molecular analysis

The adhesive properties of neural cell adhesion molecules (NCAMs) can be modified by alternative splicing of the primary transcript or posttranslational modifications. In the present study, we describe distinct forms of alternative splicing and posttranslational modification of the extracellular domain of NCAM of various endocrine tissues and derived tumor cells of the rat. Using an antiserum detecting the immunoglobulin-like domains of NCAM as well as a monoclonal antibody recognizing the NCAM-specific polysialic acid (PSA), we observed a similar staining pattern in adrenals, pituitary, and neoplastic endocrine cells. In endocrine tumor cells [pheochromocytoma (PC12), insulinoma (RINA2), and pituitary tumor cells (GH3)], NCAM immunoreactivity was most intense at contact sites between the cells. The immunocytochemical data were substantiated by results of in situ hybridization histochemistry. Specifically, higher levels of NCAM mRNA were detected in the adrenal cortex than in the medulla. In the pituitary, NCAM mRNA was more abundant in the anterior and intermediate lobes than in the neural lobe. The sequence of NCAM mRNAs in endocrine cells was analyzed by polymerase chain reaction and S1 nuclease protection assays. We found that major exons 4-13 of the NCAM mRNA in endocrine tissues and related tumor cell lines were homologous to those in the brain. However, PC12, RINA2, and GH3 tumor cells; normal rat pituitaries; and adrenals contained different amounts of NCAM mRNA with an alternative extra exon, termed VASE (also called pi in mouse) between constitutive exons 7 and 8. In addition, in pituitaries, we detected an alternative exon in splice site a between the constitutive exons 12 and 13, termed a15, with or without an AAG triplett. These sites are thought to be important for the adhesive properties of NCAM. Therefore, these results suggest that modifications of NCAM may be important for adhesive interactions in normal and neoplastic endocrine cells

Automatic Parameter Configuration for Inventory Management in SAP ERP/APO

Companies today generally hold several thousands SKUs (stock-keeping units) in stock. With an ever increasing trend towards highly customized products, the number of SKUs held by companies is likely to increase even more in the future. For each of the SKUs held in stock, a decision has to be made on how to configure each module of the SKU's inventory system. Doing this for each SKU individually seems to be an unfeasible task, given the large numbers of SKUs held in stock by most companies. Therefore, these companies configure inventory systems not on a SKU-basis but on a group basis, where the groups are usually determined using an ABC/XYZ analysis. The configuration using such a rough group basis for several thousand SKUs does not allow for individually customized inventory systems and therefore might not exploit the implemented inventory methods in a software package in an optimal way. In this research project, decision systems allowing an automated inventory system configuration in SAP ERP and SAP APO at the SKU-level are developed. The SAP ERP corporate software package is the market leader for Enterprise Resource Planning systems, offering a wide range of inventory methods for the relevant inventory system modules. The advanced planning and scheduling system of SAP, Advanced Planning and Optimization (APO), provides additional inventory methods that can be chosen for the configuration in the inventory system modules

Business cycles, bank credit and crises

This paper investigates how business cycle volatility affects internal and external funding sources of banks. It argues that excessive credit growth, credit cycles, and bank failures are phenomena related to distinct patterns of banks’ financing options over the cycle

An Observational Test of Two-field Inflation

We study adiabatic and isocurvature perturbation spectra produced by a period of cosmological inflation driven by two scalar fields. We show that there exists a model-independent consistency condition for all two-field models of slow-roll inflation, despite allowing for model-dependent linear processing of curvature and isocurvature perturbations during and after inflation on super-horizon scales. The scale-dependence of all spectra are determined solely in terms of slow-roll parameters during inflation and the dimensionless cross-correlation between curvature and isocurvature perturbations. We present additional model-dependent consistency relations that may be derived in specific two-field models, such as the curvaton scenario.Comment: 6 pages, latex with revtex, no figures; v2, minor changes, to appear in Physical Review

Hybrid dialog: Dialogic learning in large lecture classes

Attendance at classical lectures usually leads to rather poor learning success. A wide variety of studies show that while lectures are as effective as any other method for transmitting information, they are inferior in many other dimensions. Lectures are not as effective as discussion methods in promoting thought and they are ineffective at teaching behavioral skills and subject-related values as well as at awakening interest in a subject. Still ex-cathedra teaching is a favored way to cope with a high student-to-teacher ratio. To solve this conflict between organizational and pedagogical requirements, a group of researchers at the Institute of Teacher Education at the University of Zurich has developed a hybrid course setting using an online learning platform. Their setting incorporates a dialog among students within a large lecture class. Furthermore a feedback loop enables the lecturer to continuously adjust the content of the lecture to the learning process of the students. In this article, the authors first present the structure of this setting and then illustrate how to implement it by the web-based open source learning management system OLAT (Online Learning and Training). Based on their research, they focus on key components for the success of their hybrid dialog. They show how individual and group learning can be fostered with corresponding assignments, assessments, and assigned roles such as moderators. Thus, the authors will define their position that the challenge of a large lecture class can be met while successfully implementing social learning and process-oriented assessments of academic achievement