University students' beliefs about learning and knowledge

Results of the empirical research of students' beliefs about the nature of learning and knowledge are presented. The research is based on conceptions on the multidimensional nature of these beliefs and on findings indicating that these beliefs influence learning behavior. Students from the University of Belgrade (N=560) answered Epistemological Questionnaire. Structure, developmental level, and relations of these beliefs to students' age, year of studies and indicators of academic success (grades and the number of passed exams) were investigated. Factor analysis confirmed the existence of four dimensions of these beliefs: 1) avoiding integration, avoiding ambiguity, and dependence on authority; 2) belief that learning cannot be learned and that success in learning does not depend on the effort invested; 3) belief that ability to learn is inborn and that learning is quick and 4) believing in absolutely certain and unquestionable nature of knowledge. Low positive correlations were obtained between dimensions. Developmental level of these beliefs is not related to students' age, but during studies at the University beliefs become more sophisticated. At beginning years of studying students’ express beliefs that concentrated effort is a waste of time, that learning ability is inborn and that learning is quick. Students who express sophisticated beliefs about learning had higher grades and passed more exams. Results indicate that development of students' beliefs about learning and knowledge should be longitudinally investigated. Development of these beliefs from naive to sophisticated can be influenced. Developing consciousness regarding one's own beliefs helps competences for living and working in contemporary society to develop. Encouraging a conceptual change − reorganization of knowledge structures − is the base for development of beliefs about learning and knowledge. Students should be included in different experiences during learning process.Improvement of learning process should be aimed to students' beliefs, not only to behavior.E-mail addresses: [email protected] (S. Mirkov), [email protected] (I. Jaksic

Helminth fauna of Mus musculus Linnaeus, 1758 from the suburban area of Belgrade, Serbia

The helminth fauna of the house mouse (Mus musculus Linnaeus, 1758) was studied on the basis of 429 host individuals from the suburban area of Belgrade. Eleven helminth species were recorded: three cestode species - Catenotaenia pusilla, Rodentolepis fraterna, and Cysticercus (= Strobilocercus) fasciolaris [larval stage of Taenia taeniaeformis (Batsch, 1821)]; and eight nematode species - Heligmosomoides polygyrus, Syphacia sp., Aspiculuris tetraptera, Syphacia obvelata, Heterakis spumosa, Trichuris muris, Mastophorus muris, and Gongylonema sp. Within the general helminth fauna, H. polygyrus was found to be the most prevalent species (39.2%) and caused the highest infection intensity. Prevalences of A. tetraptera, C. pusilla, and S. obvelata ranged from 12.8% to 6.1%, while the remaining species showed prevalences ranging from 4.9% (for Syphacia sp.) to 0.2% (for Gongylonema sp.). All the species found in males were also present in females, with the exceptions of M. muris and Gongylonema sp. No significant differences were found between males and females regarding prevalence (P%), mean infection intensity (MI), or mean abundance (MA).Helmintofauna kućnog miša (Mus musculus) istraživana je kod 429 jedinki izlovljenih sa suburbanog područja Beograda (selo Jabuka, 15 km severoistočno od Beograda), a prisustvo 3 vrste pantljičara (Cestoda) i 8 vrsta valjkastih crva (Nematoda) utvrđeno je u 262 jedinke (61.1%). Od pantljičara su bile prisutne Catenotaena pusilla, Rodentolepis fraterna i larveni stadijum Taenia taeniaeformis - Cysticercus (= Strobilocercus) fasciolaris, a od valjkastih crva Helygmosomoides polygirus, Syphacia sp., S. obvelata, Aspiculuris tetraptera, Heterakis spumosa, Trichuris muris, Mastophorus muris i Gongylonema sp. Dominantna vrsta bila je H. polygyrus sa prevalencom od 39,2% i prouzrokovala je najviši intenzitet infekcije. Za A. tetraptera, C. pusilla i S. obvelata prevalence su iznosile od 12,8 do 6,1%, a za ostale vrste helminata od 4,9 (za Syphacia sp.) do 0,2% (za Gongylonema sp.). Sve vrste nađene u mužjacima kućnog miša bile su nađene i u ženkama, izuzimajući M. muris i Gongylonema sp. Nisu nađene statistički značajne razlike između mužjaka i ženki kućnog miša u pogledu prevalence (P%) i srednjih vrednosti intenziteta infekcije (MI) i abundancije (MA).Projekat ministarstva br. 14303

Basic indices of spleen immune activity in natural populations of Norway rats (Rattus norvegicus berkenhout, 1769) in Serbia

Basic parameters of spleen immune activity (spleen weight, histomorphology of splenic compartments, and mitogen-induced splenocyte proliferative capacity in vitro) were evaluated in adult individuals of wild Norway rats from urban habitats and compared to the same data obtained in laboratory rat strains. A wider range of relative spleen mass and differential histomorphological characteristics, together with differences in the level and pattern of responsiveness of splenocytes to exogenous stimulation, were noted in spleens of wild Norway rats. Evidence of both enhanced and low-level immune-relevant spleen activity in wild rats demonstrates the complexity of changes in spleen immune activity in rats from natural populations.Ispitivani su osnovni parametri imunske aktivnosti u slezini (masa slezine, histomorfologija i sposobnost ćelija slezine da profilerišu u odgovoru na mitogen u in vitro uslovima) kod adultnih jedinki sivog pacova iz urbanih staništa i poređeni sa podacima dobijenim kod laboratorijskih sojeva pacova. Kod jedinki iz prirodnih populacija je zapažen veći opseg relativnih masa slezine, različite histomorfološke karakteristike i razlike u nivou i načinu odgovara ćelija slezine na egzogenu stimulaciju u poređenju sa jedinkama laboratorijskih sojeva. Ovi podaci ukazuju na kompleksne promene u imunskoj aktivnosti slezine kod jedinki iz prirodnih populacija.Projekat ministarstva br. 14303

Granulocyte-stimulating activity of the anticoagulant warfarin in rats

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Anthropometrische, kraft-, ausdauer-und flexibilitätsmerkmale männlicher elite-eiskletterer und sportkletterer

Objective: Purpose of this study was to compare elite male ice climbers and sport climbers for their anthropometry, muscular strength, endurance, and flexibility. Although there is a certain overlap between these two activities, sport climbing, which recently became an Olympic discipline, has been studied significantly more than the ice climbing. Hence, the second aim was to indirectly determine whether sport climbing training processes and nutrition can be beneficial for the ice climbing athletes. › Methods: 23 male ice climbers of the Ice Climbing World Cup 2010 in Saas Fee (Switzerland) who all reached the final round were compared to 23 elite male sport climbers, which refers to “on sight” climbing grade of VII+/6b (UIAA/French) or higher. Measurements included anthropometry, three different tests for flexibility, two for strength and two for endurance. › Results: Ice climbers have more fat in the trunk region (Fat%-T), have significantly less handgrip strength in both hands, as well as strength to mass ratio (SMR) of the dominant hand. In the test “foot raise”, ice climbers showed significantly less flexibility. › Conclusion: Results indicate that ice climbers have not only higher body fat percentage, probably as an adaption to cold environment but also lower strength and flexibility than sport climbers. With such data, we can conclude that sport climbing training protocols for development of strength, endurance and flexibility can be potentially beneficial to ice climbers.Ziel: Ziel dieser Studie war es, männliche Elite-Eisk letterer und Sportk letterer hinsichtlich ihrer Anthropometrie, Muskelkraft, Ausdauer und Flexibilität zu vergleichen. Das zweite Ziel war zu bestimmen, ob Trainingsprozesse und Ernährung auf der Grundlage von Untersuchungen an Sportk letterern auch für Eiskletterer von Vorteil sein können.›Methoden: 23 männliche Eisk letterer des Ice Climbing World Cup 2010 in Saas Fee (Schweiz), die alle in die Finalrunde kamen, w urden mit 23 männlichen Elite-Sportkletterern verglichen, die „on sight“ einen K lettergrad von V II+/6b (UIA A/French) oder hö-her aufw iesen. Die Messungen umfassten die Anthropometrie, drei verschiedene Tests für Flexibilität, zwei für K raft und zwei für Ausdauer.›Ergebnisse: Eisk letterer haben mehr Fett im Rumpf bereich (Fat%-T), signifikant weniger Handgriff kraft in beiden Händen sowie Kraft-zu-Masse-Verhältnis (SMR) der dominanten Hand. Eiskletterer zeigten deutlich weniger Flexibilität imHüftbereich.›Schlussfolgerung: Die Ergebnisse zeigen, dass Eisk letterer nicht nur einen höheren Körperfettanteil haben, wahrscheinlich als Anpassung an eine kalte Umgebung, sondern auch eine gerin-gere Kraft und Flexibilität als Sportkletterer. Sportkletter-Trai-ningsprotokolle können zur Entw ick lung von Kraft, Ausdauer und Flexibilität für Eisk letterer potenziell von Vorteil sein

Impact of gut microbiota on immune reactions relevant to lung pathologies

Bacterial microbiota of the gastrointestinal tract is known to prevent the invasion of pathogenic microorganisms and regulate intestinal permeability, digestion, metabolism, and immune response. It affects function, homeostasis, and disease outcomes in the gastrointestinal tract and extra-intestinal sites such as the lungs. This review summarizes the currently available knowledge regarding the gut-lung axis. The association of bacterial composition and/or dysbiosis in the gut with asthma, chronic obstructive lung disease, cystic fibrosis, recurrent respiratory tract infections, and lung cancer in humans is highlighted, as well as data obtained from animal models of pulmonary inflammation, which indicated that modulation of immune system activity lies at the base of this interaction. Additionally, the potential use of prebiotics, probiotics, and postbiotics in the treatment of lung inflammation is presented

Sojne razlike u toksičnosti antagoniste vitamina K varfarina kod pacova

Warfarin (3-(alpha-acetonylbenzy1)-4-hydroxy coumarin) is a vitamin K (VK) antagonist that inhibits vitamin K-dependent (VKD) processes, such as blood coagulation. It also exerts an influence on some non-VKD-related activities. In this study, the effect of sub-acute (30-day) oral warfarin (2 and 1 mg L-1) intake on hematological parameters was examined in two rat strains, Albino Oxford (AO) and Dark Agouti (DA), that differ in their sensitivity to certain chemicals. Greater susceptibility to the anticoagulant effect of 2 mg L-1 of warfarin was observed in AO rats and was associated with an increase in the relevant hematological parameters in this strain. Although both strains responded to 2 mg L-1 of warfarin with quantitative changes in the peripheral blood leukocytes, differential bone marrow and lung responses were observed. Strain-related differences in the pro-inflammatory activity of peripheral blood granulocytes and in mononuclear cell IFN-gamma production were observed. Recognition of differences in quantitative and qualitative effects of oral warfarin on processes other than hemostasis might be of relevance for those humans who are on warfarin therapy.Varfarin (3-α-acetonilbenzil)-4–hidroksikumarin) je antagonist vitamina K (VK) koji inhibira procese zavisne od ovog vitamina, uključujući koagulaciju krvi. Osim toga, on ispoljava i aktivnosti koje ne zavise od vitamina K kao što su anti-tumorska i imunomodulatorna aktivnost. U ovom radu je ispitan efekat subakutnog (30 dana) oralnog unosa varfarina na hematološke parametre i aktivnost leukocita periferne krvi kod dva soja pacova Albino Oxford (AO) i Dark Agouti (DA) koji se raz- likuju u osetljivosti na iste hemijske agense. Kod jedinki AO soja zapažena je veća smrtnost nakon konzumiranja doze od 4 mg L–1 kao i veća osetljivost na antikoagulantno dejstvo varfarina pri nižim dozama (2 mg L–1) koje je praćeno povećanjem nekih hematoloških parametara. Iako kod jedinki oba soja dolazi do povećanja broja neutrofilnih leukocita periferne krvi pri dozi od 2 mg L–1, promene u osnovnim proinflamatornim aktivnostima ovih ćelija su zapažene samo kod jedinki DA soja. Promene u broju neutrofilnih leukocita u krvi DA jedinki su praćene povećanjem broja granulocitnih prekursora u koštanoj srži, dok prisustvo neutrofila u plućima AO jedinki ukazuje na razmenu ćelija između periferne krvi i plućnog intravaskularnog pula ćelija. Diferencijalne sojno–zavisne promene u aktivnosti mononuklearnih ćelija periferne krvi su takođe zapažene. Razlike u efektu oralno unetog varfarina mogu da imaju implikacije za osobe na oralnoj varfarinskoj terapiji

Helminth fauna of Mus musculus Linnaeus, 1758 from the suburban area of Belgrade, Serbia

The helminth fauna of the house mouse (Mus musculus Linnaeus, 1758) was studied on the basis of 429 host individuals from the suburban area of Belgrade. Eleven helminth species were recorded: three cestode species - Catenotaenia pusilla, Rodentolepis fraterna, and Cysticercus (= Strobilocercus) fasciolaris [larval stage of Taenia taeniaeformis (Batsch, 1821)]; and eight nematode species - Heligmosomoides polygyrus, Syphacia sp., Aspiculuris tetraptera, Syphacia obvelata, Heterakis spumosa, Trichuris muris, Mastophorus muris, and Gongylonema sp. Within the general helminth fauna, H. polygyrus was found to be the most prevalent species (39.2%) and caused the highest infection intensity. Prevalences of A. tetraptera, C. pusilla, and S. obvelata ranged from 12.8% to 6.1%, while the remaining species showed prevalences ranging from 4.9% (for Syphacia sp.) to 0.2% (for Gongylonema sp.). All the species found in males were also present in females, with the exceptions of M. muris and Gongylonema sp. No significant differences were found between males and females regarding prevalence (P%), mean infection intensity (MI), or mean abundance (MA).Helmintofauna kućnog miša (Mus musculus) istraživana je kod 429 jedinki izlovljenih sa suburbanog područja Beograda (selo Jabuka, 15 km severoistočno od Beograda), a prisustvo 3 vrste pantljičara (Cestoda) i 8 vrsta valjkastih crva (Nematoda) utvrđeno je u 262 jedinke (61.1%). Od pantljičara su bile prisutne Catenotaena pusilla, Rodentolepis fraterna i larveni stadijum Taenia taeniaeformis - Cysticercus (= Strobilocercus) fasciolaris, a od valjkastih crva Helygmosomoides polygirus, Syphacia sp., S. obvelata, Aspiculuris tetraptera, Heterakis spumosa, Trichuris muris, Mastophorus muris i Gongylonema sp. Dominantna vrsta bila je H. polygyrus sa prevalencom od 39,2% i prouzrokovala je najviši intenzitet infekcije. Za A. tetraptera, C. pusilla i S. obvelata prevalence su iznosile od 12,8 do 6,1%, a za ostale vrste helminata od 4,9 (za Syphacia sp.) do 0,2% (za Gongylonema sp.). Sve vrste nađene u mužjacima kućnog miša bile su nađene i u ženkama, izuzimajući M. muris i Gongylonema sp. Nisu nađene statistički značajne razlike između mužjaka i ženki kućnog miša u pogledu prevalence (P%) i srednjih vrednosti intenziteta infekcije (MI) i abundancije (MA).Projekat ministarstva br. 14303

Strain differences in the toxicity of the vitamin K antagonist warfarin in rats

Warfarin (3-(α-acetonylbenzyl)-4-hydroxy coumarin) is a vitamin K (VK) antagonist that inhibits vitamin K-dependent (VKD) processes, such as blood coagulation. It also exerts an influence on some non-VKD-related activities. In this study, the effect of sub-acute (30-day) oral warfarin (2 and 1 mg L-1) intake on hematological parameters was examined in two rat strains, Albino Oxford (AO) and Dark Agouti (DA), that differ in their sensitivity to certain chemicals. Greater susceptibility to the anticoagulant effect of 2 mg L-1 of warfarin was observed in AO rats and was associated with an increase in the relevant hematological parameters in this strain. Although both strains responded to 2 mg L-1 of warfarin with quantitative changes in the peripheral blood leukocytes, differential bone marrow and lung responses were observed. Strain-related differences in the pro-inflammatory activity of peripheral blood granulocytes and in mononuclear cell IFN-γ production were observed. Recognition of differences in quantitative and qualitative effects of oral warfarin on processes other than hemostasis might be of relevance for those humans who are on warfarin therapy.Varfarin (3-α-acetonilbenzil)-4–hidroksikumarin) je antagonist vitamina K (VK) koji inhibira procese zavisne od ovog vitamina, uključujući koagulaciju krvi. Osim toga, on ispoljava i aktivnosti koje ne zavise od vitamina K kao što su anti-tumorska i imunomodulatorna aktivnost. U ovom radu je ispitan efekat subakutnog (30 dana) oralnog unosa varfarina na hematološke parametre i aktivnost leukocita periferne krvi kod dva soja pacova Albino Oxford (AO) i Dark Agouti (DA) koji se raz- likuju u osetljivosti na iste hemijske agense. Kod jedinki AO soja zapažena je veća smrtnost nakon konzumiranja doze od 4 mg L–1 kao i veća osetljivost na antikoagulantno dejstvo varfarina pri nižim dozama (2 mg L–1) koje je praćeno povećanjem nekih hematoloških parametara. Iako kod jedinki oba soja dolazi do povećanja broja neutrofilnih leukocita periferne krvi pri dozi od 2 mg L–1, promene u osnovnim proinflamatornim aktivnostima ovih ćelija su zapažene samo kod jedinki DA soja. Promene u broju neutrofilnih leukocita u krvi DA jedinki su praćene povećanjem broja granulocitnih prekursora u koštanoj srži, dok prisustvo neutrofila u plućima AO jedinki ukazuje na razmenu ćelija između periferne krvi i plućnog intravaskularnog pula ćelija. Diferencijalne sojno–zavisne promene u aktivnosti mononuklearnih ćelija periferne krvi su takođe zapažene. Razlike u efektu oralno unetog varfarina mogu da imaju implikacije za osobe na oralnoj varfarinskoj terapiji.Projekat ministarstva br. 17303

Gut microbial dysbiosis occurring during pulmonary fungal infection in rats is linked to inflammation and depends on healthy microbiota composition

While the effect of gut microbiota and/or inflammation on a distant body site, including the lungs (gut–lung axis), has been well characterized, data about the influence of lung microbiota and lung inflammation on gut homeostasis (lung–gut axis) are scarce. Using a well-characterized model of pulmonary infection with the fungus Aspergillus fumigatus, we investigated alterations in the lung and gut microbiota by next-generation sequencing of the V3–V4 regions of total bacterial DNA. Pulmo- nary inflammation due to the fungus A. fumigatus caused bacterial dysbiosis in both lungs and gut, but with different characteristics. While increased alpha diversity and unchanged bacterial composition were noted in the lungs, dysbiosis in the gut was characterized by decreased alpha diversity indices and modified bacterial composition. The altered homeostasis in the lungs allows the immigration of new bacterial species of which 41.8% were found in the feces, indicating that some degree of bacterial migration from the gut to the lungs occurs. On the contrary, the dysbiosis occurring in the gut during pulmonary infection was a consequence of the local activity of the immune system. In addition, the alteration of gut microbiota in response to pulmonary infection depends on the bacterial composition before infection, as no changes in gut bacterial microbiota were detected in a rat strain with diverse gut bacteria. The data presented support the existence of the lung–gut axis and provide additional insight into this mechanism. IMPORTANCE Data regarding the impact of lung inflammation and lung microbiota on GIT are scarce, and the mechanisms of this interaction are still unknown. Using a well-characterized model of pulmonary infection caused by the opportunistic fungus Aspergillus fumigatus, we observed bacterial dysbiosis in both the lungs and gut that supports the existence of the lung–gut axis. KEYWORDS fungal lung infection, gastrointestinal microbiota, lung microbiota, lung-gut axis, rats B acteria inhabit every part of the human body, but most of them are found in the gut. Gut microbiota are responsible for many functions, including nutrient metabolism, immunomodulation, maintenance of host physiology, and protection against pathogen overgrowth (1). To date, numerous scientific studies confirm the important role of gut bacteria in health and disease. This microbial community impacts not only local immunity but also a distant body site, such as the lungs. Disturbances in gut bacterial composition have been linked to asthma (2), chronic obstructive pulmonary disease (3), cystic fibrosis (4), and lung cancer (5). Furthermore, pulmonary involvement was noted in inflammatory gastrointestinal disease characterized by microbial dysbiosis (6), Month XXXX Volume 0 Issue 0 10.1128/spectrum.01990-23 1 Editor Agostinho Carvalho, University of Minho, Braga, Portugal Address correspondence to Maja Tolinacki, [email protected]. The authors declare no conflict of interest. See the funding table on p. 15. Received 11 May 2023 Accepted 25 July 2023 Published 25 August 2023 Copyright © 2023 Popovic et al. This is an open- access article distributed under the terms of the Creative Commons Attribution 4.0 International license. Downloaded from https://journals.asm.org/journal/spectrum on 09 October 2023 by 147.91.199.205. supporting the existence of a gut–lung axis. The gut bacterial microbiota or some of their constituents impact the immune response in the lungs against viruses (7–9), bacteria (10–13), fungi (14), and allergic airway inflammation (15) mainly through the effect of the gut microbiota (or their metabolites) on the immune cell activity. While the gut–lung axis is well characterized, the influence of the lung microbiota as well as lung inflammation on gut homeostasis has attracted much more attention in recent years. The first indication of the lung–gut axis was a higher prevalence (compared to healthy subjects) of gastrointestinal symptoms in patients with asthma (16) and chronic obstructive pulmonary disease (17). The existence of gastrointestinal symptoms in patients with pulmonary virus infection has also been documented (18). Gastrointesti- nal symptoms (abdominal pain, nausea, vomiting, and diarrhea) were noted in 11.6% of children with influenza infection (18), and a later study showed a decrease in alpha diversity in the feces of influenza-infected patients compared to healthy controls (19). Fecal bacterial samples from patients with COVID-19 infection were shown to cluster separately from those in healthy controls as well, but in the majority of these patients, SARS-Cov-2 could be detected in the feces (20). Experimental studies in mice confirmed the occurrence of gut dysbiosis following respiratory influenza virus infection (21–25) and respiratory syncytial virus infection (24), despite the fact that the virus has not been detected in the gut (21, 22, 24, 25). It has been shown that the alteration of gut microbiota is a consequence of infection with live virus particles, as administration of an attenuated influenza vaccine had no effect on the microbiota (24). Bacterial dysbiosis in the gut also occurs following pulmonary bacterial infection. A decrease in alpha diversity indices and differential relative abundance of fecal microbiota were noted in patients with pulmonary tuberculosis (26, 27) and in mice infected with Mycobacterium tuberculosis (28) and Klebsiella pneumoniae (29). Even administration of the major component of the outer membrane of Gram-negative bacteria, lipopolysac- charide, to the lungs caused gut bacteria dysbiosis (30). In addition to pulmonary infections caused by viruses or bacteria, alteration of the gut microbiota was noted in mice exposed to hyperoxia (31) and in patients with lung cancer (compared to healthy individuals) (32) indicating that pulmonary inflammation/injury affects the gut microbiota regardless of its origin. Despite a growing body of evidence for interaction between the lungs and gut, there is still a lot of work to be done to understand this crosstalk. There are virtually no data regarding gut microbiota changes during pulmonary infection caused by fungi. Our previous study showed an alteration in immune-mediated homeostasis of the gut in a rat model of sublethal pulmonary infection with A. fumigatus (33). Using the same experimental model of infection in Dark Agouti (DA) rat strain, we aimed to investigate changes in the lung and gut microbiota by next-generation sequencing of the V3–V4 regions of total bacterial DNA in these two organs. Possible mechanisms of lung–gut communication were also investigated. In addition, to examine whether gut dysbiosis is a general characteristic during pulmonary fungal infection, we analyzed feces from infected Albino Oxford (AO) rats, a strain that develop quantitatively different immune response to fungus A. fumigatus (34) and whose gut microbiota was previously shown to respond differently to oral cadmium administra- tion (35) compared to DA rats