The Quest for Comparability: Studying the Invariance of the Teachers’ Sense of Self-Efficacy (TSES) Measure across Countries

Teachers’ self-efficacy is an important motivational construct that is positively related to a variety of outcomes for both the teachers and their students. This study addresses challenges associated with the commonly used ‘Teachers’ Sense of Self-Efficacy (TSES)’ measure across countries and provides a synergism between substantive research on teachers’ self-efficacy and the novel methodological approach of exploratory structural equation modeling (ESEM). These challenges include adequately representing the conceptual overlap between the facets of self-efficacy in a measurement model (cross-loadings) and comparing means and factor structures across countries (measurement invariance). On the basis of the OECD Teaching and Learning International Survey (TALIS) 2013 data set comprising 32 countries (N = 164,687), we investigate the effects of cross-loadings in the TSES measurement model on the results of measurement invariance testing and the estimation of relations to external constructs (i.e., working experience, job satisfaction). To further test the robustness of our results, we replicate the 32-countries analyses for three selected sub-groups of countries (i.e., Nordic, East and South-East Asian, and Anglo-Saxon country clusters). For each of the TALIS 2013 participating countries, we found that the factor structure of the self-efficacy measure is better represented by ESEM than by confirmatory factor analysis (CFA) models that do not allow for cross-loadings. For both ESEM and CFA, only metric invariance could be achieved. Nevertheless, invariance levels beyond metric invariance are better achieved with ESEM within selected country clusters. Moreover, the existence of cross-loadings did not affect the relations between the dimensions of teachers’ self-efficacy and external constructs. Overall, this study shows that a conceptual overlap between the facets of self-efficacy exists and can be well-represented by ESEM. We further argue for the cross-cultural generalizability of the corresponding measurement model.     

Die Verteilung der Chromosomen auf die Tochterzellkerne multipolarer Mitosen in euploiden Gewebekulturen von Microtus agrestis

In kidney epithelial cultures from female Microtus agrestis, 3,55% of all mitoses are multipolar, 94% of them tripolar. Feulgen photometric measurements of 21 tripolar mitoses reveal a total DNA amount corresponding to the mitotic diploid value (4c) in 5 cases, and to the tetraploid value (8c) in 16 cases, Diploid tripolar mitoses divide into one daughter nucleus with a diploid DNA value (2c) and two nuclei each with a haploid DNA value (1c). Most tetraploid tripolar mitoses divide into one daughter nucleus with a diploid DNA value (2c) and two nuclei with a triploid DNA value (3c). Also the sex chromosomes are distributed to the daughter nuclei in the relation of 2∶3∶3. This can be seen in anaphase figures as well as in interphase nuclei presumably derived from tripolar mitoses, showing chromocenters according to the number of X-chromosomes. In two cases of tripolar tetraploid mitoses the resulting nuclei have a haploid, a triploid and a tetraploid DNA value. The DNA replication pattern is always identical in the daughter nuclei of diploid and tetraploid tripolar mitoses. — Our observations suggest segregation and distribution of haploid chromosome sets or multiples of haploid sets to the daughter nuclei of multipolar mitoses. They also show a possible way of formation of haploid and triploid cells in a basically diploid tissue. Presumably triploid nuclei (with 3 chromocenters) are capable of DNA synthesis.     

Sexchromatin in polyploiden Zellen

Ohne Zusammenfassung

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Sexchromatin in polyploiden Zellen

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Herrn Professor H. v. Hayek zum 65. Geburtstag gewidmet.

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Nach einem Referat, gehalten auf der gemeinsamen 9. Tagung der Deutschen Gesellschaft für Anthropologie und der Gesellschaft für Konstitutionsforschung.     

Der Zellzyklus in Fibroblastenkulturen vom Menschen

Summary Autoradiography using H³-Thymidin and Feulgen photometry of nuclear DNA-content were carried out on human euploid fibroblast cultures.The average durations of S- and G2-periods are about 9 hours and 5 hours respectively, with only minor variation. The duration of G1-period may vary from a few hours to more than 20 hours.A combined study of H³-thymidin uptake and Feulgen photometry on the same cell nuclei showed that all cells whose DNA-content places them into the S-period are labelled when they are fixed immediate after a H³-thymidin puls. After continuous H³-thymidin uptake for 5 hours, all S- and G2-nuclei are labelled, whereas the G1-nuclei remain unlabelled.The Feulgen histogramm as well as grain counts over labelled nuclei indicate a constant rate of DNA synthesis during S-period.     

Endogenous pararetroviral sequences in tomato (<Emphasis Type="Italic">Solanum lycopersicum</Emphasis>) and related species

Background  

Endogenous pararetroviral sequences (EPRVs) are a recently discovered class of repetitive sequences that is broadly distributed in the plant kingdom. The potential contribution of EPRVs to plant pathogenicity or, conversely, to virus resistance is just beginning to be explored. Some members of the family Solanaceae are particularly rich in EPRVs. In previous work, EPRVs have been characterized molecularly in various species of Nicotiana including N.tabacum (tobacco) and Solanum tuberosum (potato). Here we describe a family of EPRVs in cultivated tomato (Solanum lycopersicum L.) and a wild relative (S.habrochaites).     

Do tigers displace leopards? If so, why?

We investigated predictions concerning the competitive relationships between tigers Panthera tigris and leopards Panthera pardus in Bardia National Park, Nepal, based on spatial distributions of scats and territorial markings (sign), analyses of scat content and census of wild ungulate prey. Medium-sized ungulates, in particular chital Axis axis, was the main food of both predators, but leopards consumed significantly larger proportions of domestic animals, small mammals, and birds than tigers. Tiger sign were never found outside the park, while leopard sign occurred both inside and outside, and were significantly closer to the park border than tiger sign. Significantly higher prey densities at locations of tiger sign than that of leopards were mainly due to a preference of the latter species for the park border areas. Our results imply that interference competition––and not competition for food––was a limiting factor for the leopard population, whose distribution was restricted to the margins of the tiger territories. We suggest that the composition of the prey base is a key factor in understanding the different results and interpretations reported in studies on tiger/leopard coexistence. There are two potential mechanisms that link interference competition and prey: (1) low abundance of large ungulate prey decreases foraging efficiency of tigers, leading to increased energetic stress and aggression towards leopards; and (2) increased diet overlap due to scarcity of large prey leads to increased encounter rates and increased levels of interference competition.     

CIN85 regulates dopamine receptor endocytosis and governs behaviour in mice

Despite extensive investigations of Cbl‐interacting protein of 85 kDa (CIN85) in receptor trafficking and cytoskeletal dynamics, little is known about its functions in vivo. Here, we report the study of a mouse deficient of the two CIN85 isoforms expressed in the central nervous system, exposing a function of CIN85 in dopamine receptor endocytosis. Mice lacking CIN85 exon 2 (CIN85^Δex2) show hyperactivity phenotypes, characterized by increased physical activity and exploratory behaviour. Interestingly, CIN85^Δex2 animals display abnormally high levels of dopamine and D2 dopamine receptors (D2DRs) in the striatum, an important centre for the coordination of animal behaviour. Importantly, CIN85 localizes to the post‐synaptic compartment of striatal neurons in which it co‐clusters with D2DRs. Moreover, it interacts with endocytic regulators such as dynamin and endophilins in the striatum. Absence of striatal CIN85 causes insufficient complex formation of endophilins with D2DRs in the striatum and ultimately decreased D2DR endocytosis in striatal neurons in response to dopamine stimulation. These findings indicate an important function of CIN85 in the regulation of dopamine receptor functions and provide a molecular explanation for the hyperactive behaviour of CIN85^Δex2 mice.