One academic year under COVID-19 conditions: two multicenter cross-sectional evaluation studies among medical students in Bavarian medical schools, Germany students’ needs, difficulties, and concerns about digital teaching and learning

BACKGROUND: Since March 2020, COVID-19 has created a need for adaptation in many areas of life. This study explores medical students’ perspectives on digital teaching under conditions of the COVID-19 pandemic. It focuses on expectations and concerns about digital teaching, the evaluation of specific aspects of teaching, and requests for future teaching. METHODS: Six German faculties have joined forces within the Bavarian network for medical education to develop and deploy a common core questionnaire. Cross-sectional surveys were conducted at the end of the summer semester 2020 and winter semester 2020/21. Medical students from different semesters participated in the online survey. Data was analyzed descriptively and/or inferentially. Item differences across semesters were examined using contingency tables and Chi(2) tests. Mean values were compared using the independent samples t-test; answer frequencies in retrospective and prospective concerns were compared using contingency tables and Chi(2) tests with Yates’ correction. RESULTS: In the summer semester 2020, 1565 students and in winter semester 2020/21, 1727 students took part in the survey. Students’ main prospective concern was lack of social exchange between fellow students (70%), but also with teachers. Second and third most often concerns were a lack of practical training (68%) and lack of integration of on-site digital teaching (50%). Approximately 7% of the students lacked sufficient access to technical equipment.. Approximately 39% of the students lacked a sufficient internet connection for synchronous digital teaching, 17% for asynchronous digital teaching. On-site teaching was the preferred form of teaching (60%), and there was a preference for asynchronous (24%) over synchronous (15%) digital teaching. Teaching recordings (79%) were particularly popular to complement future on-site teaching. CONCLUSIONS: The following areas of education under COVID-19 conditions are highly important to medical students: adequacy of information sharing, integration of opportunities for exchange with fellow students and teachers, possibility to perform practical trainings. After the normalization of the pandemic situation, on-site teaching should be supplemented with blended learning concepts such as the inverted classroom model. GRAPHICAL ABSTRACT: Percentages of results are rounded averages from summer and winter semesters. [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12909-022-03480-x

From modular to centralized organization of synchronization in functional areas of the cat cerebral cortex

Recent studies have pointed out the importance of transient synchronization between widely distributed neural assemblies to understand conscious perception. These neural assemblies form intricate networks of neurons and synapses whose detailed map for mammals is still unknown and far from our experimental capabilities. Only in a few cases, for example the C. elegans, we know the complete mapping of the neuronal tissue or its mesoscopic level of description provided by cortical areas. Here we study the process of transient and global synchronization using a simple model of phase-coupled oscillators assigned to cortical areas in the cerebral cat cortex. Our results highlight the impact of the topological connectivity in the developing of synchronization, revealing a transition in the synchronization organization that goes from a modular decentralized coherence to a centralized synchronized regime controlled by a few cortical areas forming a Rich-Club connectivity pattern.Comment: 24 pages, 8 figures. Final version published in PLoS On

Emergence of structural patterns out of synchronization in networks with competitive interactions

Synchronization is a collective phenomenon occurring in systems of interacting units, and is ubiquitous in nature, society and technology. Recent studies have enlightened the important role played by the interaction topology on the emergence of synchronized states. However, most of these studies neglect that real world systems change their interaction patterns in time. Here, we analyze synchronization features in networks in which structural and dynamical features co-evolve. The feedback of the node dynamics on the interaction pattern is ruled by the competition of two mechanisms: homophily (reinforcing those interactions with other correlated units in the graph) and homeostasis (preserving the value of the input strength received by each unit). The competition between these two adaptive principles leads to the emergence of key structural properties observed in real world networks, such as modular and scale–free structures, together with a striking enhancement of local synchronization in systems with no global order

To meat or not to meat? New perspectives on Neanderthal ecology.

Neanderthals have been commonly depicted as top predators who met their nutritional needs by focusing entirely on meat. This information mostly derives from faunal assemblage analyses and stable isotope studies: methods that tend to underestimate plant consumption and overestimate the intake of animal proteins. Several studies in fact demonstrate that there is a physiological limit to the amount of animal proteins that can be consumed: exceeding these values causes protein toxicity that can be particularly dangerous to pregnant women and newborns. Consequently, to avoid food poisoning from meat-based diets, Neanderthals must have incorporated alternative food sources in their daily diets, including plant materials as well

Robust Optical User Motion Tracking Using a Kalman Filter

Optical tracking has a great future in applications of virtual and augmented reality. It will assist to enhance the acceptance of virtual reality user interfaces, since optical tracking allows wireless interaction and precise tracking. Existing commercial motion capture systems are neither working reliably in real-time. Additionally, only few optical trackers can smooth and predict motion and include a motion estimator supplying similar results to the presented approach. A Kalman filter formulation is proposed, providing the robustness required by most virtual reality applications. The filter is evaluated with respect to different rigid body motions and provides precise prediction. Thereby, the frequency and reliability of the optical tracker is enhanced. Predicted motion can be used to cope with display lags of complex virtual scenes or with acquisition or communication delays. The proposed filter may also be used with nonoptical based trackers providing the pose of an object with six degrees of freedom

Vergleichende computergestützte funktionsmorphologische Analyse an Molaren cercopithecoider Primaten

Die Analyse funktioneller Zusammenhänge zwischen Ernährung und Zahnmorphologie ist ein wichtiger Aspekt primatologischer und paläontologischer Forschung. Als überdauernder Teil des Verdauungssystems geben Zähne die bestmöglichen Hinweise auf die Ernährungsstrategien (ausgestorbener) Arten und eine Fülle weiterer Informationen. Aufgrund dessen ist es für die wissenschaftliche Arbeit von größter Bedeutung, die Zähne so detailliert und exakt wie möglich in ihrer gesamten Struktur zu erfassen. Bisher wurden zumeist zweidimensionale Parameter verwendet, um die komplexe Kronenmorphologie von Primatenmolaren vergleichend zu untersuchen. Die vorliegende Arbeit hatte das Ziel, Zähne verschiedener Arten von Altweltaffen mittels computerbasierter Methoden dreidimensional zu erfassen und neue Parameter zu definieren, mit denen die Form dieser Zähne objektiv erfasst und funktionell interpretiert werden kann. Mit einem Oberflächen-Scanner wurden die Gebisse einer Stichprobe von insgesamt 48 Primaten von fünf verschiedenen Arten eingescannt und mit Bildverarbeitungsmethoden so bearbeitet, dass dreidimensionale digitale Modelle einzelner Backenzähne zur Analyse vorlagen. Es wurden dabei sowohl Arten ausgewählt, die eine für ihre Gattung typische Ernährungsweise besitzen - also Frugivorie bei den Cercopithecinen und Folivorie bei den Colobinen - als auch solche, die eine davon abweichende Alimentation bevorzugen. Alle Altweltaffen haben sehr ähnliche Molaren. Colobinen haben jedoch höhere und spitzere Zahnhöcker, dünneren Zahnschmelz und scheinen ihre Zähne weniger stark abzukauen als die Meerkatzen. Diese Beobachtungen konnten mit Hilfe der neuen Parameter quantifiziert werden. Aus der 3D-Oberfläche und der Grundfläche der Zähne wurde ein Index gebildet, der die Stärke des Oberflächenreliefs angibt. Dieser Index hat bei Colobinen deutlich höhere Werte als bei Cercopithecinen, auch bei Zähnen, die schon stark abgekaut sind. Die Steilheit der Höcker und ihre Ausrichtung wurden außerdem gemessen. Auch diese Winkelmessungen bestätigten das Bild. Je höher der Blätteranteil an der Ernährung ist, desto höher sind die Indexwerte und umso steiler sind die Höcker. Besonders wichtig war es, dies auch für abgekaute Zähne zu bestätigen, die bisher nicht in funktionelle Analysen miteinbezogen wurden. Die Ausrichtung der Höckerseiten gibt Hinweise auf die Kaubewegung, die zum effizienten Zerkleinern der Nahrung notwendig ist. Die Ausrichtung der Höcker der Colobinen deutet darauf hin, dass diese Primaten flache, gleitende Kaubewegungen machen, bei denen die hohen Höcker aneinander vorbei scheren. Dies ist sinnvoll zum Zerschneiden von faserreicher Nahrung wie Blättern. Cercopithecinen scheinen ihre Backenzähne eher wie Mörser und Stößel zu verwenden, um Früchte und Samen zu zerquetschen und zu zermahlen. Je nachdem, was neben der hauptsächlichen Nahrung noch gekaut wird, unterscheiden sich die Arten graduell. Anders als bisher vermutet wurde, konnte gezeigt werden, dass Colobinen trotz des dünnen Zahnschmelzes ihre Zähne weniger stark abkauen und weniger Dentin freigelegt wird. Dies gibt eindeutige Hinweise auf die Unterschiede in der mechanischen Belastung, die während des Kauvorgangs auf die Zähne wirkt, und lässt sich gut mit der Ernährung der Arten in Zusammenhang bringen. Anhand dieser modellhaften Beobachtungen können in Zukunft ausgestorbene Arten hinsichtlich ihrer Ernährungsweise mit 3D-Techniken untersucht werden.Analysing functional interrelation between diet and tooth morphology is a crucial aspect of primatology and paleontology. As remaining structure of the digestive system, teeth give insight into the dietary regime of extant and extinct species and a plethora of further information. Therefore, it is crucial for scientific work to describe the teeth as exact and in as much detail as possible. To date, mostly two dimensional parameters have been used to examine the complex crown morphology of primate molars. The aim of the present work was to capture teeth from different cercopithecoid species three-dimensionally with computer based methods and to define new parameters that allow objective measuring of the form and functional interpretation of these teeth. The dentition of 48 primates, representing 5 different species, were scanned with a surface scanner and edited with image processing tools so that three dimensional digital models of single molars were ready for analysis. Species were chosen according to either have a diet typical for its genus – i.e., frugivory in cercopithecines and folivory in colobines – or having a diet different from that. As a result, the sample comprised a specialized folivore: Piliocolobus badius badius, one leaf and seed-eater: Procolobus verus verus, a specialized frugivore: Cercopithecus nictitans nictitans, a generalized frugivore that eats also a lot of leaves: Cercopithecus l’hoesti, and a generalized frugivore: Chlorocebus aethiops aethiops. All cercopithecoids have very similar molars. Nontheless, Colobines have higher and more pointed cusps, relatively thinner tooth enamel, and seem to wear down their teeth less severely than cercopithecines. With the help of new parameters, these observations were able to be quantified. An index was calculated from the 3d surface and the tooth base that expresses the magnitude of the surface relief. This index has considerably higher values in colobines, also in teeth that are worn down. The steepness of the cusps slopes and their orientation were also measured. These measurements confirm this picture. The higher the amount of leaves in the diet, the higher are the index values and the steeper are the cusp slopes. It was especially important to show this to be the case also in worn teeth that so far have not been included in functional analyses. The orientation of the cusp slopes give insight into chewing movents that are needed to efficiently process the diet. The orientation of colobine cusp slopes points to flat, gliding chewing movements during which the cusps glide past one another. This is efficient in slicing fibrous diet like leaves. Cercopithecines seem to use their molars more in a mortar-and-pestle-kind of way in order to crush and grind fruits and seeds. According to what else is eaten in addition to the main alimentation, the species differ gradually. Unlike it has widely been postulated so far, colobines do wear down their teeth less and expose less dentine, despite their thin enamel. This gives clear evidence of the different mechanical load that is put onto the molars during mastication and can be well connected with the species’ alimentation. With the help of these exemplary observations, extinct species can now be examined regarding their dietary regime with the help of 3d techniques

Optical tracking : from user motion to 3D interaction

Zsfassung in dt. Sprache17