Statistics Anxiety and Self-Concept of Beginning Students in the Social Sciences - A Matter of Gender and Socio-Cultural Background?

It is still largely underresearched whether different groups of students in the social sciences begin their studies in higher education with diverging attitudes towards statistics. In this article, we analyze whether gender and socio-cultural background affect statistics anxiety and statistics self-concept at the start of studies. A survey among 504 first-year students from two fields of study and two universities in Germany revealed considerable differences in students' attitudinal preconditions for learning depending on gender and, to a minor degree, depending on migration background. Based on these results, we discuss implications for teaching in higher education. 16.12.2015 | Manuel Förster & Andreas Maur (Mainz

Distorted Voronoi languages

Förster M, Riedel F. Distorted Voronoi languages. Working Papers. Institute of Mathematical Economics. Vol 458. Bielefeld: Center for Mathematical Economics; 2011.In a recent paper, Jäger, Metzger, and Riedel (2011) study communication games of common interest when signals are simple and types complex. They characterize strict Nash equilibria as so-called Voronoi languages that consist of Voronoi tesselations of the type set and Bayesian estimators on the side of receivers. In this note, we introduce conflicts of interest in the same setting. We characterize strict Nash equilibria as distorted Voronoi languages that use all messages. For large conflicts, such informative equilibria need not exist. If the bias is sufficiently small, however, these equilibria do exist. This establishes the robustness of the results in Jäger, Metzger, and Riedel (2011) to biased interests. We finally give examples of strict Nash equilibria, one of them using simulations to illustrate an equilibrium with many messages and non-uniformly distributed types

Spectroscopic study of the magnetic ground state of Nb1−y_{1-y}Fe2+y_{2+y}

We have investigated single crystals and polycrystals from the series Nb$_{1-y}$Fe$_{2+y}$, $-0.004 \leq y \leq 0.018$ by electron spin resonance, muon spin relaxation and M\"ossbauer spectroscopy. Our data establish that at lowest temperatures all samples exhibit bulk magnetic order. Slight Fe-excess induces low-moment ferromagnetism, consistent with bulk magnetometry ($\simeq 0.06 ~\mu_B/{\rm Fe}$), Nb--rich and stoichiometric NbFe$_2$ display spin density wave order with small magnetic moment amplitudes of the order $\sim 0.001 - 0.01 ~\mu_B/{\rm Fe}$. This provides microscopic evidence for a modulated magnetic state on the border of ferromagnetism in NbFe$_2$.Comment: 7 pages, 9 figure

Migration background and economic knowledge of beginning university students

Während es für den Schulbereich eine Vielzahl von Studien gibt, die dem Zusammenhang von Migrationshintergrund (MH) und schulischen Leistungen nachgehen, liegen für den Hochschulbereich kaum belastbare Befunde vor. Dies gilt insbesondere für die bundesweit am meisten nachgefragten Studiengänge der Wirtschaftswissenschaften, die zugleich einen vergleichsweise hohen Anteil an Studierenden mit MH aufweisen. Der Beitrag berichtet Befunde zu den Eingangsvoraussetzungen von N = 1,395 StudieneinsteigerInnen mit und ohne MH an 10 deutschen Hochschulen. Wie sich zeigt, haben Personen mit MH zwar keine signifikant schlechtere Note in der Hochschulzugangsberechtigung, aber sie bringen im Vergleich mit jenen ohne MH ein geringeres ökonomisches Vorwissen mit, insbesondere dann, wenn Deutsch nicht als Familiensprache genutzt wird. (DIPF/Orig.)Although a large number of studies have been conducted on the connection between migration background (MB) and academic performance at school level, reliable findings about this connection at the higher education level are scarce. This is particularly the case for business and economics, which is the most popular field of study in Germany and attracts a large number of students with a MB. In this article, investigation is made into the relationship between the final secondary school grade point average of N = 1,395 beginning students at 10 universities in Germany and their economic knowledge while controlling for MB. Students with a MB did not have significantly worse grades; however, they had less economic knowledge than those without a MB, especially when German was not their family language. (DIPF/Orig.

Domain Adaptation via Minimax Entropy for Real/Bogus Classification of Astronomical Alerts

Time domain astronomy is advancing towards the analysis of multiple massive datasets in real time, prompting the development of multi-stream machine learning models. In this work, we study Domain Adaptation (DA) for real/bogus classification of astronomical alerts using four different datasets: HiTS, DES, ATLAS, and ZTF. We study the domain shift between these datasets, and improve a naive deep learning classification model by using a fine tuning approach and semi-supervised deep DA via Minimax Entropy (MME). We compare the balanced accuracy of these models for different source-target scenarios. We find that both the fine tuning and MME models improve significantly the base model with as few as one labeled item per class coming from the target dataset, but that the MME does not compromise its performance on the source dataset

EasyClone 2.0:expanded toolkit of integrative vectors for stable gene expression in industrial Saccharomyces cerevisiae strains

Saccharomyces cerevisiae is one of the key cell factories for production of chemicals and active pharmaceuticals. For large-scale fermentations, particularly in biorefinery applications, it is desirable to use stress-tolerant industrial strains. However, such strains are less amenable for metabolic engineering than the standard laboratory strains. To enable easy delivery and overexpression of genes in a wide range of industrial S. cerevisiae strains, we constructed a set of integrative vectors with long homology arms and dominant selection markers. The vectors integrate into previously validated chromosomal locations via double cross-over and result in homogenous stable expression of the integrated genes, as shown for several unrelated industrial strains. Cre-mediated marker rescue is possible for removing markers positioned on different chromosomes. To demonstrate the applicability of the presented vector set for metabolic engineering of industrial yeast, we constructed xylose-utilizing strains overexpressing xylose isomerase, xylose transporter and five genes of the pentose phosphate pathway. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s10295-015-1684-8) contains supplementary material, which is available to authorized users

Structure of the human signal peptidase complex reveals the determinants for signal peptide cleavage

The signal peptidase complex (SPC) is an essential membrane complex in the endoplasmic reticulum (ER), where it removes signal peptides (SPs) from a large variety of secretory pre-proteins with exquisite specificity. Although the determinants of this process have been established empirically, the molecular details of SP recognition and removal remain elusive. Here, we show that the human SPC exists in two functional paralogs with distinct proteolytic subunits. We determined the atomic structures of both paralogs using electron cryo-microscopy and structural proteomics. The active site is formed by a catalytic triad and abuts the ER membrane, where a transmembrane window collectively formed by all subunits locally thins the bilayer. Molecular dynamics simulations indicate that this unique architecture generates specificity for SPs based on the length of their hydrophobic segments

Tribological system for cold sheet metal forming based on volatile lubricants and laser structured surfaces

AbschlussberichtA novel tribological system has been developed, in which volatile lubricants (carbon dioxide - CO2 or nitrogen- N2) are used as a substitute for mineral oil-based lubricants in deep drawing processes. This process enables the introduction of an intermediate medium under high pressure through flow-optimized, laser-drilled micro holes into the contact surfaces. This eliminates the need for subsequent, cost-intensive cleaning processes, as the volatile lubricants evaporate without leaving any residue during expansion to ambient pressure. The design of initial micro hole geometries was based on simulations of the flow behaviour of the lubricants passing through, which in turn were validated using pressure reactor tests. In addition, the wetting behaviour of CO2 on relevant surfaces (tool surface and sheet material surface) was investigated experimentally using the captive-bubble-method. Thus, the optimal design of the micro holes (diameter, hole geometry and number of micro holes) could be determined using flat strip drawing tests. The optimal micro hole geometry determined in this way is suited for the use of both CO2 and N2 as volatile lubricant. Furthermore, extensive investigations for the production of the required micro hole geometry by laser drilling were carried out. The fundamentals for drilling micro holes in steel with high aspect ratios could be developed using an ultrashort pulsed research laser with very high pulse energy. Further experiments were conducted using an ultrashort pulsed prototype laser of the kW-class specially developed to increase productivity when drilling a multitude of micro holes with higher average laser power. The novel tribological system has been characterised by means of strip drawing tests and stretch bending tests. For both, CO2 (liquid) and N2 (gaseous), relatively low friction values could be achieved compared to conventional lubricants. It could be shown that deep drawing with both CO2 and N2 as dry lubricants is possible. Here, usage of the volatile lubricants not only allows the replacement of mineral oil based lubricants, but even improves the tribological system with regard to frictional forces in sheet metal forming. The feasibility of the new tribological system has been proven by performing deep drawing tests of rectangular cups. These tests showed a significantly enlarged process window of the forming process, which emphasise the tremendous potential of this new tribological system.12816