The Influence of Interactive Learning Materials on Solving Tasks That Require Different Types of Mathematical Reasoning

The purpose of this study is to analyse the effects of the Interactive Learning Materials Triangle (iLMT) on the learning and knowledge retention of 12-year-old students. The iLMT is a digital version of the standard school learning materials in Serbia, and is characterized by a high degree of interactivity and immediate feedback during the learning process. We conducted an experiment to explore whether iLMT influences student success in solving mathematical tasks that require different types of mathematical reasoning. Based on previous extensive research by Lithner, 4 types of tasks are discussed: high relatedness answer, high relatedness algorithm, local low relatedness, and global low relatedness. The study involved 633 students and 13 teachers of mathematics, equally distributed in control and test groups. The main findings indicate that student success on a knowledge test for high relatedness answer and local low relatedness tasks for the test group was significantly higher than for the control group. On the knowledge retention test, students in the test group outperformed students in the control group at high relatedness algorithm and local low relatedness tasks. Our results also suggest that, even when learning materials are carefully digitalized with the use of available technological advantages, student success in global low relatedness tasks may still be lacking.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10763-021-10151-8.

Development of the automated software and device for determination of wicking in textiles using open-source tools

The development of automated software and the device for determination of wicking of textile materials, using open-source ImageJ libraries for image processing, and newly designed additional algorithm for the determination of threshold, is presented in this paper. The description of the device, design of the open-source software “Kapilarko”, as well as an explanation of the steps: image processing, threshold determination and reading of wicking height, are provided. We have also investigated the possibility of using the artificial neural networks for automatic recognition of the wicking height. The results showed that the recognition of the wet area of the sample, based on the application of artificial neural networks was in a very good agreement with the experimental data. The device's utility for the measurement of wicking ability of textile materials was proved by testing various knitted fabrics. The constructed device has the advantages of providing automated measurement and minimization of the subjective errors of the operators; extremely fast or long-term measurements; digital recording of results; consistency of experimental conditions; possibility of using water instead of colors and, last but not least, low cost of the device. Considering the importance and frequent measurements of wicking ability of textile materials, the advantages of the presented device, as well as the fact that commercial software without publishing the source-code, are used for most of the available devices, we believe that our idea to design the automated software and device by applying the "open-source" approach, will be of benefit to scientists and engineers in using or improving wicking experiments.

Latent structure of secondary traumatic stress, its precursors, and effects on people working with refugees

The study aims to examine the latent structure of secondary traumatic stress (STS), its precursors, and the psychological effects of it on the population of service providers working with refugees passing through the Balkan route. A total of 270 service providers (57% female) of different professional backgrounds working directly with refugees took part in the study. Participants were assessed for STS using the Secondary Traumatic Stress Scale, the extent of secondary exposure to trauma (i.e., clients’ traumatic experiences from the countries of origin and travel that were communicated to them directly), depression, anxiety, and quality of life. Comparisons of several confirmatory factor analyses following prominent PTSD conceptualizations showed that the model with three relatively distinct but highly correlated factors–intrusion, avoidance, and the blend of negative alterations in cognitions, mood, and reactivity (NACMR), had the best fit. STS has been shown to be positively correlated both with the amount of different traumatic experiences that were communicated to them as well as with the specific content of those experiences. Path analysis showed that the amount of secondary exposure to the clients’ traumatic experiences during travel, but not in the country of origin, had exclusive relationships with all three factors of STS. NACMR demonstrated direct effects on anxiety and depression symptoms, while intrusions exhibited a direct effect on anxiety-related symptomatology only. The avoidance factor did not have any independent direct effects on anxiety or depression. Finally, the effects of STS factors on quality of life were fully mediated by an increase of depression-related symptomatology. Results provide evidence on the latent structure of the STS which partially deviates from the prominent models of PTSD thus questioning the isomorphism of two constructs on the empirical level. Additionally, findings provide insights on the cascade of events that make professionals working with traumatized people especially vulnerable to STS and broader psychological distress.

Does age influence the quality of life in children with atopic dermatitis?

BACKGROUND

Atopic dermatitis (AD) is one of the most common childhood skin diseases that can affect the quality of life (QoL) of children. The QoL of Montenegrin children with AD has not been sufficiently explored. The aim of this study was to assess their QoL with special emphasize on age differences.

METHODS

This cross-sectional study included children with AD seen at the Clinic of Dermatology and Venereology, Clinical Center of Montenegro (CCM) in Podgorica between August 2017 and July 2018. The QoL was assessed with the Infants' Dermatitis Quality of Life Index (IDQOL) and the Children's Dermatology Life Quality Index (CDLQI). Disease severity was measured by the Three Item Severity (TIS) score.

RESULTS

A total of 386 children with AD aged from newborn to 16 years took part in this study. The mean total score of the QoL was 14.7 in infants (0-4 years old), 19.4 in younger children (5-9 years old), and 16.6 in older children (10-16 years old). Age was in negative correlation with the CDLQI score, leisure domain of the CDLQI and CDLQI sleep, and in positive correlation with the IDQOL child mood. TIS score was in positive correlation with both the IDQOL and CDLQI score.

CONCLUSIONS

The QoL measured by CDLQI was more impaired in younger children, whilst IDQOL child mood was more impaired in older infants. The most impaired QoL was seen in children in the age group 5-9 years. Regardless of disease severity, treatment and counseling of children suffering from AD should be tailored specifically to their age.

Strain differences in thymic atrophy in rats immunized for EAE correlate with the clinical outcome of immunization

An accumulating body of evidence suggests that development of autoimmune pathologies leads to thymic dysfunction and changes in peripheral T-cell compartment, which, in turn, perpetuate their pathogenesis. To test this hypothesis, thymocyte differentiation/maturation in rats susceptible (Dark Agouti, DA) and relatively resistant (Albino Oxford, AO) to experimental autoimmune encephalomyelitis (EAE) induction was examined. Irrespective of strain, immunization for EAE (i) increased the circulating levels of IL-6, a cytokine causally linked with thymic atrophy, and (ii) led to thymic atrophy reflecting partly enhanced thymocyte apoptosis associated with downregulated thymic IL-7 expression. Additionally, immunization diminished the expression of Thy-1, a negative regulator of TCRαβ-mediated signaling and activation thresholds, on CD4+CD8+ TCRαβ^lo/hi thymocytes undergoing selection and thereby impaired thymocyte selection/survival. This diminished the generation of mature CD4+ and CD8+ single positive TCRαβ^hi thymocytes and, consequently, CD4+ and CD8+ recent thymic emigrants. In immunized rats, thymic differentiation of natural regulatory CD4+Foxp3+CD25+ T cells (nTregs) was particularly affected reflecting a diminished expression of IL-7, IL-2 and IL-15. The decline in the overall thymic T-cell output and nTreg generation was more pronounced in DA than AO rats. Additionally, differently from immunized AO rats, in DA ones the frequency of CD28- cells secreting cytolytic enzymes within peripheral blood CD4+ T lymphocytes increased, as a consequence of thymic atrophy-related replicative stress (mirrored in CD4+ cell memory pool expansion and p16^INK4a accumulation). The higher circulating level of TNF-α in DA compared with AO rats could also contribute to this difference. Consistently, higher frequency of cytolytic CD4+ granzyme B+ cells (associated with greater tissue damage) was found in spinal cord of immunized DA rats compared with their AO counterparts. In conclusion, the study indicated that strain differences in immunization-induced changes in thymopoiesis and peripheral CD4+CD28- T-cell generation could contribute to rat strain-specific clinical outcomes of immunization for EAE.

Epigenetic regulation of human SOX3 gene expression during early phases of neural differentiation of NT2/D1 cells

Sox3/SOX3 is one of the earliest neural markers in vertebrates. Together with the Sox1/SOX1 and Sox2/SOX2 genes it is implicated in the regulation of stem cell identity. In the present study, we performed the first analysis of epigenetic mechanisms (DNA methylation and histone marks) involved in the regulation of the human SOX3 gene expression during RA-induced neural differentiation of NT2/D1 cells. We show that the promoter of the human SOX3 gene is extremely hypomethylated both in undifferentiated NT2/D1 cells and during the early phases of RA-induced neural differentiation. By employing chromatin immunoprecipitation, we analyze several histone modifications across different regions of the SOX3 gene and their dynamics following initiation of differentiation. In the same timeframe we investigate profiles of selected histone marks on the promoters of human SOX1 and SOX2 genes. We demonstrate differences in histone signatures of SOX1, SOX2 and SOX3 genes. Considering the importance of SOXB1 genes in the process of neural differentiation, the present study contributes to a better understanding of epigenetic mechanisms implicated in the regulation of pluripotency maintenance and commitment towards the neural lineage.

Stabilization of Human Serum Albumin by the Binding of Phycocyanobilin, a Bioactive Chromophore of Blue-Green Alga Spirulina: Molecular Dynamics and Experimental Study

Phycocyanobilin (PCB) binds with high affinity (2.2 x 106 M-1 at 25°C) to human serum albumin (HSA) at sites located in IB and IIA subdomains. The aim of this study was to examine effects of PCB binding on protein conformation and stability. Using 300 ns molecular dynamics (MD) simulations, UV-VIS spectrophotometry, CD, FT-IR, spectrofluorimetry, thermal denaturation and susceptibility to trypsin digestion, we studied the effects of PCB binding on the stability and rigidity of HSA, as well as the conformational changes in PCB itself upon binding to the protein. MD simulation results demonstrated that HSA with PCB bound at any of the two sites showed greater rigidity and lower overall and individual domain flexibility compared to free HSA. Experimental data demonstrated an increase in the α-helical content of the protein and thermal and proteolytic stability upon ligand binding. PCB bound to HSA undergoes a conformational change to a more elongated conformation in the binding pockets of HSA. PCB binding to HSA stabilizes the structure of this flexible transport protein, making it more thermostable and resistant to proteolysis. The results from this work explain at molecular level, conformational changes and stabilization of HSA structure upon ligand binding. The resultant increased thermal and proteolytic stability of HSA may provide greater longevity to HSA in plasma.

Mesoscale atmospheric transport of ragweed pollen allergens from infected to uninfected areas

Allergenic ragweed (Ambrosia spp.) pollen grains, after being released from anthers, can be dispersed by air masses far from their source. However, the action of air temperature, humidity and solar radiation on pollen grains in the atmosphere could impact on the ability of long distance transported (LDT) pollen to maintain allergenic potency. Here, we report that the major allergen of Ambrosia artemisiifolia pollen (Amb a 1) collected in ambient air during episodes of LDT still have immunoreactive properties. The amount of Amb a 1 found in LDT ragweed pollen grains was not constant and varied between episodes. In addition to allergens in pollen sized particles, we detected reactive Amb a 1 in subpollen sized respirable particles. These findings suggest that ragweed pollen grains have the potential to cause allergic reactions, not only in the heavily infested areas but, due to LDT episodes, also in the regions unaffected by ragweed populations.

Effects of pharmaceutical formulations containing thyme on carbon tetrachloride-induced liver injury in rats

BACKGROUND

Herbal supplements are widely used in the treatment of various liver disases, but some of them may also induce liver injuries. Regarding the infuence of thyme and its constituents on the liver, conflicting results have been reported in the literature. The objective of this study was to examine the influence of two commonly used pharmaceutical formulations containing thyme (Thymus vulgaris L.), tincture and syrup, on carbon tetrachloride-induced acute liver injury in rats.

METHODS

Chemical composition of investigated formulations of thyme was determined by gas chromatography and mass spectrometry. Activities of enzyme markers of hepatocellular damage in serum and antioxidant enzymes in the liver homogenates were measured using the kinetic spectrophotometric methods. Liver morphology was characterized by light microscopy using routine hematoxylin and eosin staining.

RESULTS

Thymol was found to be predominant active constituent in both tincture and syrup. Investigated thyme preparations exerted antioxidant effects in liver by preventing carbon tetrachloride-induced increase of lipid peroxidation. Furthermore, co-treatment with thyme preparations reversed the activities of oxidative stress-related enzymes xanthine oxidase, catalase, peroxidase, glutathione peroxidase and glutathione reductase, towards normal values in the liver. Hepatotoxicity induced by carbon tetrachloride was reflected by a marked elevation of AST and ALT activities, and histopathologic alterations. Co-administration of thyme tincture resulted in unexpected exacerbation of AST and ALT values in serum, while thyme syrup managed to reduce activites of aminotransferases, in comparison to carbon tetrachloride-treated animals.

CONCLUSIONS

Despite demonstrated antioxidant activity, mediated through both direct free radical scavenging and activation of antioxidant defense mechanisms, thyme preparations could not ameliorate liver injury in rats. Molecular mechanisms of diverse effects of thyme preparations on chemical-induced hepatotoxicity should be more in-depth investigated.