e-Learning in Higher Institutions and Secondary Schools during Covid-19: Crisis Solving and Future Perspectives

Background: The pandemic of Covid-19 brought significant changes to the education system and forcibly accelerated the process of digitizing teaching. Students and educators had to adapt to the new way of education, facing challenges such as technical problems and a lack of technical skills and social contact. Objectives: The purpose of the paper was to explore the attitudes of the university and high school educators and students towards the pandemic\u27s impact on digitization in teaching. Methods/Approach: Data were collected through a questionnaire distributed to university and high school educators and students in Croatia, Poland, Serbia and Germany in the field of accounting, finance, trade, tourism, and other areas of interest, resulting in 2,897 responses. The results were analyzed using descriptive statistics and non-parametric tests. Results: The research showed that: 1) high school students were less optimistic about the positive impact of the pandemic on applying digital tools in teaching than university students, 2) educators generally prefer traditional exams, while students generally prefer e-exams, 3) a higher proportion of university respondents believe that e-learning should be used as an important addition to traditional teaching when compared to high school respondents. Conclusions: The pandemic has changed how the teaching process will be performed, but we should learn from experience and address the issues with e-learning

Gain Mechanisms for Contextually Guided Visuomotor Transformations

A prevailing question in sensorimotor research is the integration of sensory signals with abstract behavioral rules (contexts) and how this results in decisions about motor actions. We used neural network models to study how context-specific visuomotor remapping may depend on the functional connectivity among multiple layers. Networks were trained to perform different rotational visuomotor associations, depending on the stimulus color (a nonspatial context signal). In network I, the context signal was propagated forward through the network (bottom-up), whereas in network II, it was propagated backwards (top-down). During the presentation of the visual cue stimulus, both networks integrate the context with the sensory information via a mechanism similar to the classic gain field. The recurrence in the networks hidden layers allowed a simulation of the multimodal integration over time. Network I learned to perform the proper visuomotor transformations based on a context-modulated memory of the visual cue in its hidden layer activity. In network II, a brief visual response, which was driven by the sensory input, is quickly replaced by a context-modulated motor-goal representation in the hidden layer. This happens because of a dominant feedback signal from the output layer that first conveys context information, and then, after the disappearance of the visual cue, conveys motor goal information. We also show that the origin of the context information is not necessarily closely tied to the top-down feedback. However, we suggest that the predominance of motor-goal representations found in the parietal cortex during context-specific movement planning might be the consequence of strong top-down feedback originating from within the parietal lobe or from the frontal lobe

Ortho-supstituirani PCB 153 – unutarstanični učinci u CHO-K1 staničnoj liniji

Non-planar di-ortho-substituted PCB 153 (2,2’,4,4’,5,5’-hexachlorobiphenyl), one of the most abundant PCB congeners in the environment and in biological and human tissues, has been identified as potential endocrine disruptor affecting the reproductive and endocrine systems in rodents, wildlife, and humans. The aim of this study was to gain a deeper insight into its mode/mechanism of action in Chinese hamster ovary K1 cells (CHO-K1). PCB 153 (10–100 µmol/L) inhibited CHO-K1 cell proliferation, which was confirmed with four bioassays (Trypan Blue, Neutral Red, Kenacid Blue, and MTT), of which the MTT assay proved the most sensitive. PCB 153 also induced ROS formation in a dose-dependent manner. Apoptosis was seen after 6 h of exposure to PCB 153 doses ≥50 µmol/L, while prolonged exposure resulted in the activation of the necrotic pathway. PCB153-induced disturbances in normal cell cycle progression were time-dependent, with the most significant effects occurring after 72 h.Neplanarni di-ortho-supstituirani PCB 153 (2,2’,4,4’,5,5’-heksaklorobifenil) jedan je od najčešćih PCB kongenera detektiranih u biološkim i u uzorcima iz okoliša. Identificiran je kao potencijalni endokrini modulator koji uzrokuje štetne učinke na reproduktivnom i endokrinom sustavu glodavaca, divljih životinja i ljudi. Ovo istraživanje pruža uvid u mehanizme djelovanja PCB 153 na stanicama ovarija. Primjenom četiriju metoda (Trypan Blue, Neutral Red, Kenacid Blue i MTT) utvrđeno je da PCB 153 (10–100 µmol/L) reducira proliferaciju CHO-K1 stanica, a od primijenjenih se metoda MTT test pokazao kao najosjetljiviji. PCB 153 inducirao je stvaranje ROS-a u stanicama ovarija, ovisno o primijenjenoj dozi. Citofluorimetrijska analiza upozorava na indukciju apoptoze nakon šest sati izloženosti stanica PCB-u 153 u dozama ≥50 µmol/L, a produljena izloženost rezultirala je aktivacijom nekroze. PCB 153 uzrokovao je poremećaje u progresiji staničnog ciklusa, s najznačajnijim promjenama uočenima nakon 72 sata izloženosti

Emerging Capabilities for Detection and Characterization of Near-Earth Objects (NEOs)

Here we describe the status for the detection and characterization of Near- Earth Objects (NEO) with current and future observatories. A summary of the capabilities, limitations, and obtainable NEO parameters is provided. <p/

Emerging Capabilities for Detection and Characterization of Near-Earth Objects (NEOs)

Here we describe the status for the detection and characterization of Near- Earth Objects (NEO) with current and future observatories. A summary of the capabilities, limitations, and obtainable NEO parameters is provided. <p/