nn-extension closed subcategories of nn-exangulated categories

Suppose $n \geq 2$ is an integer. We show that $n$-extension closed subcategories of an $n$-exangulated category $(\mathcal{C}, \mathbb{E}, \mathfrak{s})$ inherit an $n$-exangulated structure through restriction of $\mathbb{E}$ and $\mathfrak{s}$. Furthermore, we show that the Obscure Axiom holds for $n$-exangulated categories. This allows us to characterize $n$-exact categories as $n$-exangulated categories with monic inflations and epic deflations. We also show that for an extriangulated category $( \mathcal{C}, \mathbb{E}, \mathfrak{s} )$ condition (WIC), which was introduced by Nakaoka and Palu, is equivalent to $\mathcal{C}$ being weakly idempotent complete. We then apply our results to show that $n$-extension closed subcategories of $n$-exact categories are again $n$-exact. Furthermore, we recover and improve results of Klapproth and results of Zhou.Comment: Comments and suggestions very welcome. 21 Page

Temporal Decision Making in Simultaneous Timing

With two experiments it was examined whether one or two clocks operate the timing of two intervals presented simultaneously. The target interval always preceded the distracter interval, and was longer than it. Thus, the distracter was completely embedded within the target interval. The participants used the method of temporal production. The stimuli to be judged differed in modality which allowed for testing the hypothesis of modality-specific internal clocks that operate in parallel and independent from one another when two stimuli were presented at the same time. The main results of this study were as follows. First, production times of the target interval increased proportionally with production times of the distracter interval. Second, the auditory distracter interval was on average produced in less time than the visual distracter interval. Third, a target interval that was accompanied by an auditory distracter interval was on average produced in less time than a target interval that was accompanied by a visual distracter interval. The results obtained support the hypothesis of multiple clocks being involved in the timing of different intervals presented simultaneously

Podem Algoritmos Padronizar os Logros dos Estudantes do Ensino Médio de Acompanhamento Melhor que as Decisões dos Professores?

Two objectives guided this research. First, this study examined how well teachers’ tracking decisions contribute to the homogenization of their students’ achievements. Second, the study explored whether teachers’ tracking decisions would be outperformed in homogenizing the students’ achievements by statistical models of tracking decisions. These models were akin to teachers’ decisions in that they were based on the same information teachers are supposed to use when making tracking decisions. It was found that the assignments of students to the different tracks made either by teachers or by the models allowed for the homogenization of the students’ achievements for both test scores and school marks. Moreover, the models’ simulations of tracking decisions were more effective in the homogenization of achievement than were the tracking decisions, if the students assigned to the different tracks were at the center of the achievement distribution. For the remaining students, there was no significant difference found between teachers’ tracking decisions and the models’ simulations thereof. The reason why algorithms produced more homogeneous groups was assumed to be due to the higher consistency of model decisions compared to teacher decisions. Dos objetivos guían esta investigación. En primer lugar, este estudio examinó qué tan bien las decisiones de seguimiento de los docentes contribuyen a la homogeneización de los logros de los estudiantes. En segundo lugar, el estudio analizó si los modelos estadísticos de localización tuvieron mejores resultados que las decisiones de seguimiento de los profesores para la homogeneización de los logros de los estudiantes. Estos modelos tenían información similar a las que usaban los profesores cuando toman decisiones de seguimiento. Se encontró que las asignaciones de los estudiantes a diferentes grupos de nivel hechas ya sea por los profesores o por los modelos homogeneizaron los logros de los estudiantes tanto en exámenes como calificaciones escolares. Por otra parte, modelos que usaban algoritmos para tomar decisiones de localización fueron más eficaces en la homogeneización de logros si los estudiantes asignados a los diferentes grupos de nivel estaban en el centro en la curva de distribución de logros. Para el resto de los estudiantes, no hubo diferencias significativas entre las decisiones docentes y los modelos. La razón por la cual los modelos que usaron algoritmos produjeron grupos más homogéneos fue dada la mayor consistencia en los modelos de decisiones en comparación con las decisiones de los maestros.Dois objetivos norteiam esta pesquisa. Em primeiro lugar, este estudo analisou quão bem as decisões dos professores contribuem para a homogeneização desempenho dos alunos. Em segundo lugar, o estudo examinou se modelos estatísticos superaram as decisões dos professores para conseguir a homogeneização do desempenho dos alunos. Estes modelos tinham informações semelhantes aos utilizados pelos professores na tomada de decisões. Verificou-se que a localização dos alunos em diferentes grupos de nível feitas por professores ou por modelos de desempenho homogeneizaram os resultados dos alunos em as provas e  as notas. Além disso, os modelos que usaram algoritmos para decisões de localização foram mais eficazes na homogeneização da logros se os alunos estavam no nível médio da curva de distribuição de logros. Para outros alunos, não houve diferenças significativas. A razão pela qual os modelos de algoritmos usados resultaram em grupos mais homogêneos se deve a maior consistência dos modelos de decisão em comparação com as decisões dos professores

A method for constructing minimal projective resolutions over idempotent subrings

We show how to obtain a minimal projective resolution of finitely generated modules over an idempotent subring $\Gamma_e := (1-e)R(1-e)$ of a semiperfect noetherian basic ring $R$ by a construction inside $\mathsf{mod} R$. This is then applied to investigate homological properties of idempotent subrings $\Gamma_e$ under the assumption of $R/\langle 1-e\rangle$ being a right artinian ring. In particular, we prove the conjecture by Ingalls and Paquette that a simple module $S_e := eR /\operatorname{rad} eR$ with $\operatorname{Ext}_R^1(S_e,S_e) = 0$ is self-orthogonal, that is $\operatorname{Ext}^k_R(S_e,S_e)$ vanishes for all $k \geq 1$, whenever $\operatorname{gl} R$ and $\operatorname{pdim} eR(1-e)_{\Gamma_e}$ are finite. Indeed a slightly more general result is established, which applies to sandwiched idempotent subrings: Suppose $e \in R$ is an idempotent such that all idempotent subrings $\Gamma$ sandwiched between $\Gamma_e$ and $R$, that is $\Gamma_e \subset \Gamma \subset R$, have finite global dimension. Then the simple summands of $S_e$ can be numbered $S_1, \dots, S_n$ such that $\operatorname{Ext}_R^k(S_i, S_j) = 0$ for $1 \leq j \leq i \leq n$ and all $k > 0$

Dark participation: Conception, reception, and extensions

While the new possibilities of online participation were initially described and analyzed from a mainly optimistic perspective, more recent work in communication studies draws a rather bleak picture of the state of communication in today’s online world. The concept of "dark participation" (Quandt, 2018) picks up on this profound change of perspective. In addition to the systematization of negative participatory forms, the concept was also used as a rhetorical device to comment on the change in scientific perspective: the original publication was primarily meant as a call for balance in the analysis of online participation - something that was often neglected in the subsequent debate. Based on a brief summary of the core ideas and the context of the original publication, the current paper revisits the concept of dark participation by discussing its reception and potential extensions. Furthermore, a reassessment of its value and the limitations for analyzing (negative) forms of online participation is presented vis-à-vis related concepts

Quiet engine program flight engine design study

The results are presented of a preliminary flight engine design study based on the Quiet Engine Program high-bypass, low-noise turbofan engines. Engine configurations, weight, noise characteristics, and performance over a range of flight conditions typical of a subsonic transport aircraft were considered. High and low tip speed engines in various acoustically treated nacelle configurations were included

The Role of Lymphostatin/EHEC Factor for Adherence-1 in the Pathogenesis of Gram Negative Infection

Lymphostatin/EHEC factor for adherence-1 is a novel large toxin represented in various Gram negative bacteria, highly associated with the development of infectious diarrhea and hemolytic uremic syndrome. In vitro and in vivo experiments identified lymphostatin/EFA-1 as a toxin with a central role in the pathogenesis of Gram negative bacteria, responsible for bacterial adhesion, intestinal colonization, immunosuppression, and disruption of gut epithelial barrier function

The Prediction of Students’ Track Appropriateness in School - Students’ Ethnicity as a Moderator of the Prediction’s Validity

In Luxembourg and other European countries, school placement decisions made at the end of primary school determine the track a student will follow in secondary school. About one-third of the students in Luxembourg come from immigrant families. Research has shown that this demographical factor influences school placement decisions, as students with an immigration background are more likely to be oriented towards a lower track than are native students (e.g., [1]). It seems reasonable to assume that immigration background may also moderate the predictive validity of school placement decisions. In the present study, we examined whether students’ nationality moderates the predictive validity of school placement decisions in Luxembourg. We compared school placement decisions of three age-cohorts of students with the tracks they attended three to five years later. Subgroup analyses revealed that the predictive validity of school placement decisions was actually affected by nationality. Kappa coefficients, expressing the closeness of the relationship between placement decisions and the actual track, were higher for Luxembourgish students than for students of other nationalities. Additionally, multilevel regression analysis showed that Luxembourgish students were more likely to keep on the track than immigrant students