Modular design of ionotropic glutamate receptors: Coupling of a viral K+-channel with a glutamate-binding domain

Ionotropic glutamate receptors form the basic structures for rapid excitatory signal transmission in the central nervous system. After the binding of a ligand and the resulting pore opening, they allow an ion flow across the membrane. From an evolutionary point of view, these are highly developed and highly complex structures composed of different domains. There is a ligand binding domain necessary for ligand recognition coupled to the pore which is responsible for the real ion conduction. Extracellular additionally the n-terminal domain and intracellular the c-terminal is located both involved in modulational tasks where the n-terminus should also be responsible for the assembly. Due to the structural similarity and overlaps in the sequence, it has been assumed for years that these highly engineered receptors originally evolved through a fusion of substrate binding proteins and upturned potassium channels. However, attempting to rebuild a glutamate receptor to a potassium selective one or even to install a potassium channel failed. GluR0, a bacterial glutamate receptor, shows an increased potassium selectivity what is a further indication for this theory but could not be merged with mammalian receptor so far. In the first chapter I can show that it is possible to insert a rudimentary potassium channel (KcvATCV-1) in an inverted orientation into the cell membrane. This property fits perfect to the idea to exchange the pore of a glutamate receptor to make it potassium selective. In the second chapter I designed a chimera out of a KcvATCV-1 and a highly developed glutamate receptor (GluA1). Using this chimera, I demonstrated that it is possible to gate a potassium channel by the gating machinery of a glutamate receptor. In this chimeric receptor the most important pharmacological parameters of the GluA1 are obtained even though the selectivity of the KcvATCV-1 is transferred. The studied main characteristics of the potassium channel, the barium block and also the selectivity are still present as well as the effects of certain mutations on channel behavior. In turn, the chimera still reacts to the same agonists and antagonists as the origin receptor. Interestingly, not even the apparent affinity for the tested agonists and antagonists was affected in the chimeric receptor. In the third chapter, a connection to the bacterial GluR0 could be opened. Mammalian wild-type receptors, unlike GluR0, possess an essential extra transmembrane domain. Removing of this extra transmembrane domain in mammalian receptors makes them unfunctional. Interestingly this third TM can be removed in the chimera. A function, albeit with a reduced affinity for glutamate, is still present

Development and evaluation of the Measure of the International Learning Environment Status (MILES) in international higher education

The aim of this study was to develop and evaluate an instrument to assess international students' perceptions of the international learning environment called 'Measure of the International Learning Environment Status' (MILES). We based the development of the MILES on a solid theoretical framework from Moos by addressing three domains to measure the quality of the international learning environment, namely goal direction, relationships, and system change and system maintenance. We have designed and constructed the instrument in three steps. Firstly, we have collected items from relevant existing instruments and grouped them into the three domains via content analysis. Secondly, we applied a Delphi procedure involving international higher education experts from different stakeholder groups and from different cultural backgrounds to identify and reach consensus on the items comprehensively covering important elements of the international learning environment. Thirdly, we carried out an initial questionnaire evaluation. The final MILES consisted of 47 items with 13 in the first domain, 17 in the second and 17 in the third domain. The content of the domains was clearly in line with Moos theoretical framework and we interpreted the sets of items as goal direction, relationships, and supporting services, respectively. This study provides a comprehensive and systematically developed instrument for future research to better understand international students' perspectives towards the international learning environment that are supported by stakeholders from a range of cultures.</p

Reinserción de ex-combatientes y cooperación internacional en Colombia

No present

Influence of online collaborative learning on social network and academic performance of medical students: lessons learned from the COVID-19 pandemic

INTRODUCTION: The social distancing restrictions due to the COVID-19 pandemic have changed students' learning environment and limited their social interactions. Therefore, the objective of this study was to investigate the influence of the social distancing restrictions on students' social networks, wellbeing, and academic performance.METHODS: We performed a questionnaire study in which 102 students participated before and 167 students during the pandemic. They completed an online questionnaire about how they formed their five peer social networks (study-related support, collaboration, friendship, share information, and learn-from) out-of-class. We performed social network analysis to compare the sizes, structures, and compositions of students' five social networks before and during the pandemic, between first- and second-year students, and between international and domestic students. Additionally, we performed Kruskal-Wallis H test to compare students' academic performance before and during the pandemic. We performed thematic analysis to answers for two open-end questions in the online questionnaire to explore what difficulties students encountered during the COVID-19 pandemic and what support they needed. RESULTS: The results showed that the size of students' social networks during the pandemic was significantly smaller than before the pandemic. Besides, the formation of social networks differed between first- and second-year students, and between domestic and international students. However, academic performance did not decline during the COVID-19 pandemic. Furthermore, we identified three key areas in which students experienced difficulties and needed support by thematic analysis: social connections and interactions, learning and studying, and physical and mental wellbeing.CONCLUSION: When institutions implement learning with social distancing, such as online learning, they need to consider changes in students' social networks and provide appropriate support.</p

Stimulating undergraduate medical students’ scientific careers: the Groningen concept

For many medical students entering medical school, becoming a physician-scientist is not the first career opportunity they depicted for themselves. Most students start medical school with the idea of becoming a professional medical doctor using scientific knowledge in direct patient care and in the development of protocols and guidelines. With the rapid growth of scientific knowledge and the fast development of new medical techniques and treatment options, the need for more physician-scientists is more urging then ever.[...

How students and specialists appreciate the mini-clinical evaluation exercise (mini-CEX) in Indonesian clerkships

Background Cultural differences might challenge the acceptance of the implementation of assessment formats that are developed in other countries. Acceptance of assessment formats is essential for its effectiveness; therefore, we explored the views of students and specialists on the practicality and impact on learning of these formats. This study was conducted to explore Indonesian students' and specialists' appreciation of the implementation of the Mini-Clinical Evaluation Exercise (Mini-CEX) in Indonesian clerkships. Methods This study was conducted at the Universitas Gadjah Mada, Indonesia. Participants were 52 students and 21 specialists in neurology and 78 students and 50 specialists in internal medicine. They were asked to complete a 19-item questionnaire that covered the characteristics of the mini-CEX such as its practicality, and the impact on learning and professional development. We used a Mann-Whitney U test to analyse the data. Results In total, 124 students (46 from neurology and 78 from internal medicine) and 38 specialists (13 from neurology and 25 from internal medicine) participated in this study. Students and specialists were positive about the practicality of the mini-CEX and the impact of this assessment format on learning and on professional development. The Mann-Whitney U test showed that there were no significant differences between students' and specialists' opinions on the mini-CEX, except for 2 items: specialists' appreciation of direct observation (mean rank = 93.16) was statistically significantly higher than students' appreciation of it (mean rank = 77.93; z = 2.065; p <0.05), but students' appreciation of the item that students' past mini-CEX results affected their recent mini-CEX outcomes (mean rank = 85.29) was significantly higher than specialists' appreciation of it (mean rank = 69.12; z = 2140; p <0.05). Conclusion Students and specialists were positive about the mini-CEX in Indonesian clerkships, although it was developed and validated in another culture. We found only small differences between their appreciations, which could be explained by the patterns of specialist-student interaction in Indonesian culture as large power distance and low individualism country

A conducive learning environment in international higher education:A systematic review of research on students’ perspectives

Higher education institutions (HEIs) strive to meet international students' needs and expectations regarding their learning environments. Current literature covers a wide range of needs, expectations, and HEIs' responses. However, there doesn't seem to be a consensus about the needs and expectations to be addressed. A coherent theoretical framework may help HEIs identify areas of need and provide additional resources and comprehensive services. We performed a systematic review to obtain an overview of international students' needs, expectations, and experiences regarding their learning environments as described in the literature. We categorized students' perspectives into dimensions. Subsequently, we investigated whether these dimensions related to the three key domains outlined in the theoretical framework and the coverage of these key domains by HEIs. Sixty-three studies were eligible for inclusion. We identified 18 dimensions of international students' needs, expectations, and experiences that could be mapped onto the framework. Based on these results, the content of the three domains could be summarized as goal direction, relationships, and supporting services. Thirteen studies covered one domain, 14 covered two domains, and 36 covered three domains. To provide optimal support, HEIs should cover all three domains. Our study may help to better understand and optimize learning environments for international students

Influence of feedback characteristics on perceived learning value of feedback in clerkships: does culture matter?

Background: Various feedback characteristics have been suggested to positively influence student learning. It is not clear how these feedback characteristics contribute to students' perceived learning value of feedback in cultures classified low on the cultural dimension of individualism and high on power distance. This study was conducted to validate the influence of five feedback characteristics on students' perceived learning value of feedback in an Indonesian clerkship context. Methods: We asked clerks in Neurology (n = 169) and Internal Medicine (n = 132) to assess on a 5-point Likert scale the learning value of the feedback they received. We asked them to record whether the feedback provider (1) informed the student what went well, (2) mentioned which aspects of performance needed improvement, (3) compared the student's performance to a standard, (4) further explained or demonstrated the correct performance, and (5) prepared an action plan with the student to improve performance. Data were analyzed using multilevel regression. Results: A total of 250 students participated in this study, 131 from Internal Medicine (response rate 99%) and 119 from Neurology (response rate 70%). Of these participants, 225 respondents (44% males, 56% females) completed the form and reported 889 feedback moments. Students perceived feedback as more valuable when the feedback provider mentioned their weaknesses (beta = 0.153, p <0.01), compared their performance to a standard (beta = 0.159, p <0.01), explained or demonstrated the correct performance (beta = 0.324, p <0.001) and prepared an action plan with the student (beta = 0.496, p <0.001). Appraisal of good performance did not influence the perceived learning value of feedback. No gender differences were found for perceived learning value. Conclusions: In Indonesia, we could validate four out of the five characteristics for effective feedback. We argue that our findings relate to culture, in particular to the levels of individualism and power distance. The recognized characteristics of what constitutes effective feedback should be validated across cultures