NOVE KOMUNIKATIVNE TEHNOLOGIJE POWERPOINT PREZENTACIJE U NASTAVI FIZIKE

In the frame of our national project “Development of Natural Science Competences” we have prepared physical educational materials, which main goal is to indicate better didactic strategies for the systematic development of pupils\u27 natural science competences, one of them being the digital competence. In this contribution we describe two sets of representative materials, one for primary and the other one for secondary school pupils. The first set of materials is dedicated to the realization of group experimental work on the subject of electric circuits and the second set is a text- and web-based learning materials about optical phenomena in the atmosphere. A common feature of both sets of materials is that pupils are requested to prepare PowerPoint presentations of their new findings and present them to their schoolfellows. Our materials are supplied with instructions about a proper creation of slides and a suitable realization of the oral presentation.U okviru našeg nacionalnog projekta „Razvoj prirodoslovnih kompetencija“ pripremili smo obrazovne materijale za nastavu fizike, kojima je glavni cilj što bolje prikazati didaktičke strategije za sustavni razvoj prirodoslovnih kompetencija učenika, a jedna od njih je digitalna kompetencija. U ovom radu opisujemo dva reprezentativna seta obrazovnih materijala, jedan za učenike osnovnih i drugi za učenike srednjih škola. Prvi set materijala je posvećen eksperimentalnom radu sa temom strujnih krugova, dok se drugi set temelji na učenju o optičkim pojavama u atmosferi putem teksta i Interneta. Zajednička značajka oba seta materijala je u tome, da učenici moraju o novo stečenim znanjima pripremiti PowerPoint prezentacije i potom ih prezentirati svojim kolegama u razredu. Materijali sadrže točne upute za izradu slajdova kao i upute za usmeno izlaganje

CHILDREN\u27S STRATEGIES OF ART DESIGN WITH VARIOUS DRAWING TECHNIQUES

Diplomsko delo z naslovom Likovno-oblikovne strategije otrok pri različnih risarskih tehnikah, je zgrajeno iz teoretičnega in empiričnega dela. V teoretičnem delu smo najprej z vidika risanja na kratko predstavili stopnje otrokovega likovnega izražanja na primeru človeške figure, ter različne likovne tipe otrok. Opisali smo pojme: risba, likovne tehnike, materiali, orodja in podloge. Nato smo predstavili likovna izrazila, ki jih uporabljamo pri risbi. Podrobneje smo opisali suhe in mokre risarske likovne tehnike ter govorili o računalniški risbi, računalniških orodjih in računalniku kot orodju za risanje. Empirični del vsebuje rezultate, ki smo jih pridobili z opazovanjem učencev med likovnim ustvarjanjem in primerjanjem njihovih izdelkov. Kot samostojno tehniko zbiranja podatkov smo izbrali analizo dokumentov, ki jih predstavljajo videoposnetki, posneti med likovnim ustvarjanjem otrok in analizo fotografij, posnetih med postopkom dela učencev. Pri empirični raziskavi smo uporabili deskriptivno, komparativno in kvalitativno metodo pedagoškega raziskovanja. Raziskovalni vzorec je predstavljalo šest osnovnošolskih otrok petega razreda devetletke — trije dečki in tri deklice, ki so bili naključno izbrani. Ugotovili smo, da se likovno-oblikovne strategije otrok spreminjajo glede na ponujeno risarsko tehniko — spreminjale so se tako pri tradicionalnih risarskih tehnikah (oglje in flomaster), kot tudi pri bolj nenavadni risarski tehniki (računalnik). Razlike so se pojavljale med dečki in deklicami, predvsem se je to pokazalo pri tradicionalnih risarskih tehnikah, z ogljem in s flomastrom in sicer pri začetni fazi ustvarjalnega dela učencev.This degree paper, titled Children\u27s Strategies of Art Design with Various Drawing Techniques, consists of a theoretical and an empirical part. At the beginning of the theoretical part the levels of a child\u27s ways of artistic expression on the example of a human figure, as well as different artistic types of children are shortly introduced. Terms such as drawing, art techniques, materials, tools and pads are described. Next the artistic ways of expression used at making a drawing are presented. The dry and wet drawing art techniques are described in more detail. Also the computer-made drawing, computer tools and the computer as a drawing tool are discussed. In the empirical part the results, obtained by observing the pupils during artistic activities and by comparing their works, are presented. As a method of gathering the results the document analysis method is used. The data to analyze consist of video data and photographs gathered during the children\u27s artistic activities. In this research the descriptive, comparative and qualitative methods of pedagogical research are used. Our sample consisted of six fifth-grade primary school pupils (aged around 10)three boys and three girls that were randomly selected. In the end we determine that the children\u27s strategies of art design vary according to the drawing technique used. In our case this was true both in the case of traditional techniques (charcoal and marker) as well as in the case of a more unusual technique (computer). There were differences between the genders. This was the most evident in the case of traditional drawing techniques, with charcoal and with a markerespecially in the initial phase

Both electrical and metabolic coupling shape the collective multimodal activity and functional connectivity patterns in beta cell collectives: A computational model perspective

Pancreatic beta cells are coupled excitable oscillators that synchronize their activity via different communication pathways. Their oscillatory activity manifests itself on multiple timescales and consists of bursting electrical activity, subsequent oscillations in the intracellular Ca2+, as well as oscillations in metabolism and exocytosis. The coordination of the intricate activity on the multicellular level plays a key role in the regulation of physiological pulsatile insulin secretion and is incompletely understood. In this contribution, we investigate theoretically the principles that give rise to the synchronized activity of beta cell populations by building up a phenomenological multicellular model that incorporates the basic features of beta cell dynamics. Specifically, the model is composed of coupled slow and fast oscillatory units that reflect metabolic processes and electrical activity, respectively. Using a realistic description of the intercellular interactions, we study how the combination of electrical and metabolic coupling generates collective rhythmicity and shapes functional beta cell networks. It turns out that while electrical coupling solely can synchronize the responses, the addition of metabolic interactions further enhances coordination, the spatial range of interactions, increases the number of connections in the functional beta cell networks, and ensures a better consistency with experimental findings. Moreover, our computational results provide additional insights into the relationship between beta cell heterogeneity, their activity profiles, and functional connectivity, supplementing thereby recent experimental results on endocrine networks

Endogenous social distancing and its underappreciated impact on the epidemic curve

Social distancing is an effective strategy to mitigate the impact of infectious diseases. If sick or healthy, or both, predominantly socially distance, the epidemic curve flattens. Contact reductions may occur for different reasons during a pandemic including health-related mobility loss (severity of symptoms), duty of care for a member of a high-risk group, and forced quarantine. Other decisions to reduce contacts are of a more voluntary nature. In particular, sick people reduce contacts consciously to avoid infecting others, and healthy individuals reduce contacts in order to stay healthy. We use game theory to formalize the interaction of voluntary social distancing in a partially infected population. This improves the behavioral micro-foundations of epidemiological models, and predicts differential social distancing rates dependent on health status. The model’s key predictions in terms of comparative statics are derived, which concern changes and interactions between social distancing behaviors of sick and healthy. We fit the relevant parameters for endogenous social distancing to an epidemiological model with evidence from influenza waves to provide a benchmark for an epidemic curve with endogenous social distancing. Our results suggest that spreading similar in peak and case numbers to what partial immobilization of the population produces, yet quicker to pass, could occur endogenously. Going forward, eventual social distancing orders and lockdown policies should be benchmarked against more realistic epidemic models that take endogenous social distancing into account, rather than be driven by static, and therefore unrealistic, estimates for social mixing that intrinsically overestimate spreading

Phase transitions induced by microscopic disorder: a study based on the order parameter expansion

Based on the order parameter expansion, we present an approximate method which allows us to reduce large systems of coupled differential equations with diverse parameters to three equations: one for the global, mean field, variable and two which describe the fluctuations around this mean value. With this tool we analyze phase-transitions induced by microscopic disorder in three prototypical models of phase-transitions which have been studied previously in the presence of thermal noise. We study how macroscopic order is induced or destroyed by time independent local disorder and analyze the limits of the approximation by comparing the results with the numerical solutions of the self-consistency equation which arises from the property of self-averaging. Finally, we carry on a finite-size analysis of the numerical results and calculate the corresponding critical exponents

Calcium imaging in intact mouse acinar cells in acute pancreas tissue slices.

The physiology and pathophysiology of the exocrine pancreas are in close connection to changes in intra-cellular Ca2+ concentration. Most of our knowledge is based on in vitro experiments on acinar cells or acini enzymatically isolated from their surroundings, which can alter their structure, physiology, and limit our understanding. Due to these limitations, the acute pancreas tissue slice technique was introduced almost two decades ago as a complementary approach to assess the morphology and physiology of both the endocrine and exocrine pancreas in a more conserved in situ setting. In this study, we extend previous work to functional multicellular calcium imaging on acinar cells in tissue slices. The viability and morphological characteristics of acinar cells within the tissue slice were assessed using the LIVE/DEAD assay, transmission electron microscopy, and immunofluorescence imaging. The main aim of our study was to characterize the responses of acinar cells to stimulation with acetylcholine and compare them with responses to cerulein in pancreatic tissue slices, with special emphasis on inter-cellular and inter-acinar heterogeneity and coupling. To this end, calcium imaging was performed employing confocal microscopy during stimulation with a wide range of acetylcholine concentrations and selected concentrations of cerulein. We show that various calcium oscillation parameters depend monotonically on the stimulus concentration and that the activity is rather well synchronized within acini, but not between acini. The acute pancreas tissue slice represents a viable and reliable experimental approach for the evaluation of both intra- and inter-cellular signaling characteristics of acinar cell calcium dynamics. It can be utilized to assess many cells simultaneously with a high spatiotemporal resolution, thus providing an efficient and high-yield platform for future studies of normal acinar cell biology, pathophysiology, and screening pharmacological substances

Stochastic resonance in soft matter systems: combined effects of static and dynamic disorder

We study the impact of static and dynamic disorder on the phenomenon of stochastic resonance (SR) in a representative soft matter system. Due to their extreme susceptibility to weak perturbations soft matter systems appear to be excellent candidates for the observation of SR. Indeed, we derive generic SR equations from a polymer stabilized ferroelectric liquid crystal (LC) cell, which is a typical soft matter representative constituting one of the basic components in several electro-optic applications. We generalize these equations further in order to study an even broader class of qualitatively different systems, especially disclosing the influence of different types of static disorder and interaction ranges amongst LC molecules on the SR response. We determine the required conditions for the observation of SR in the examined system, and moreover, reveal that a random field type static disorder yields qualitatively different responses with respect to random dilution, random bond and spin glass universality classes. In particular, while the latter three decrease the level of dynamic disorder (Gaussian noise) warranting the optimal response, the former evokes exactly the opposite effect, hence increasing the optimal noise level that is needed to resonantly fine-tune the system's response in accordance with the weak deterministic electric field. These observations are shown to be independent of the system size and range of interactions, thus implying their general validity and potentially wide applicability also within other similar settings. We argue that soft matter systems might be particularly adequate as a base for different SR-based sensitive detectors and thus potent candidates for additional theoretical as well as experimental research in the presently outlined direction.Comment: 11 two-column pages, 6 figures; accepted for publication in Soft Matte

Disrupted endothelial cell heterogeneity and network organization impair vascular function in prediabetic obesity

Background: Obesity is a major risk factor for diabetes and cardiovascular diseases such as hypertension, heart failure, and stroke. Impaired endothelial function occurs in the earliest stages of obesity and underlies vascular alterations that give rise to cardiovascular disease. However, the mechanisms that link weight gain to endothelial dysfunction are ill-defined. Increasing evidence suggests that endothelial cells are not a population of uniform cells but are highly heterogeneous and are organized as a communicating multicellular network that controls vascular function. Purpose: To investigate the hypothesis that disrupted endothelial heterogeneity and network-level organization contribute to impaired vascular reactivity in obesity. Methods and Results: To study obesity-related vascular function without complications associated with diabetes, a state of prediabetic obesity was induced in rats. Small artery diameter recordings confirmed nitric-oxide mediated vasodilator responses were dependent on increases in endothelial calcium levels and were impaired in obese animals. Single-photon imaging revealed a linear relationship between blood vessel relaxation and population-wide calcium responses. Obesity did not alter the slope of this relationship, but impaired calcium responses in the endothelial cell network. The network comprised structural and functional components. The structural architecture, a hexagonal lattice network of connected cells, was unchanged in obesity. The functional network contained sub-populations of clustered specialized agonist-sensing cells from which signals were communicated through the network. In obesity there were fewer but larger clusters of sensory cells and communication path lengths between clusters increased. Communication between neighboring cells was unaltered in obesity. Altered network organization resulted in impaired, population-level calcium signaling and deficient endothelial control of vascular tone. Conclusions: The distribution of cells in the endothelial network is critical in determining overall vascular response. Altered cell heterogeneity and arrangement in obesity decreases endothelial function and provides a novel framework for understanding compromised endothelial function in cardiovascular disease

Weak-periodic stochastic resonance in a parallel array of static nonlinearities

This paper studies the output-input signal-to-noise ratio (SNR) gain of an uncoupled parallel array of static, yet arbitrary, nonlinear elements for transmitting a weak periodic signal in additive white noise. In the small-signal limit, an explicit expression for the SNR gain is derived. It serves to prove that the SNR gain is always a monotonically increasing function of the array size for any given nonlinearity and noisy environment. It also determines the SNR gain maximized by the locally optimal nonlinearity as the upper bound of the SNR gain achieved by an array of static nonlinear elements. With locally optimal nonlinearity, it is demonstrated that stochastic resonance cannot occur, i.e. adding internal noise into the array never improves the SNR gain. However, in an array of suboptimal but easily implemented threshold nonlinearities, we show the feasibility of situations where stochastic resonance occurs, and also the possibility of the SNR gain exceeding unity for a wide range of input noise distributions.Yumei Ma, Fabing Duan, François Chapeau-Blondeau and Derek Abbot