The role of development entrepreneurship and small and medium enterprises in managing structural changes

Small and medium-sized enterprises, under the direction of entrepreneurs, are considered to be the driving force of economic growth and development. Entrepreneurship is associated with job creation, innovation, welfare distribution, poverty reduction and an increase in economic performances of a country. In the last decade, there has been an increasing recognition of the role of entrepreneurs in economic development of Serbia. The main objective of the chapter is to analyse development of entrepreneurship and its contribution to economic development of Serbia over the 2006-2010 period of time by using the methodology initially developed by Venesaar and Loomets (2006), and adjusted to the objectives of this study and to the available data. The methodology assesses the development of entrepreneurship through SMEE sector development and new firm formation activity over the observed period. The measured firm formation rate indicated relatively strong but insufficient intensity of entrepreneurial activity. The empirical analysis shows a relatively stable activity in firm formation over time in terms of the average annual number of registrations per 1,000 active inhabitants and more significant variations in terms of the ratio of new firm registrations to the registered stock of businesses at the end of the year. The data also show a positive and significant relationship between firm formation rate and employment generation as an important indicator of economic development

Značaj ekoloških naknada za politiku zaštite životne sredine u Srbiji i Republici Češkoj

Ekološki porezi i naknade, kao izvori javnih prihoda, postaju sve prisutniji u naučnoj, političkoj i u široj javnosti. Upotrebom ekonomskih instrumenata za zaštitu životne sredine, kroz cene kao mehanizam stimulacija za promene ponašanja, može se uticati na preduzeća da smanje nivo štetnih emisija pri proizvodnim procesima, kao i na domaćinstva da smanje upotrebu proizvoda koji nisu ekološki prihvatljivi. U radu se analiziraju ekološke naknade i porezi koji se primenjuju u Srbiji i ČR. Procenjuje se njihova efikasnost kao i mogućnost budućeg razvoja

The Inhibitive effect of ethanolamine on corrosion behavior of aluminium in NaCl solution saturated with CO2

In this study, the inhibitive effect of ethanolamine on corrosion behavior of aluminium was investigated in 3 wt. % NaCl solution, saturated with CO2. All the experiments were carried out at 20 °C. Ethanolamine was added at different concentrations between 1 mM and 8 mM. In order to determine the corrosion inhibition efficiency of investigated inhibitor and the optimal concentration of inhibitor that provides the lowest corrosion of aluminium, the open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), linear sweep voltametry (LSV) measurements, weight loss measurements as well as scanning electron microscopy technique (SEM) were performed. The electrochemical study and weight loss measurements indicated that the minimum corrosion rate and maximum inhibition efficiency was detected for concentration of 5 mM of ethanolamine, as well as the ethanolamine did not change the mechanism of aluminium dissolution. The adsorption of ethanolamine was found to obey Frumkin adsorption isotherm at concentrations up to 5 mM, but further increase in concentration was found to deviate from Frumkin adsorption isotherm. The calculated value for interaction parameter a indicates attractive lateral interactions in the adsorbed inhibitor layer. The obtained value of standard free energy of adsorption, ∆Gads θ , confirms that the adsorption process is favorable, spontaneous physisorption process

PHYSICAL ACTIVITY AND HEALTH PROBLEMS OF STUDENTS IN SOUTHERN SERBIA DURING THE STATE OF EMERGENCY

The COVID-19 pandemic affected practically every country in the world and changed how people lead their daily lives. The purpose of research was to ascertain the relationship between physical activity levels and the incidence of health issues among pupils. This research was conducted using an anonymous online survey that contained selected questions from the World Health Organization's health behaviour in schoolchildren (HBSC questionnaire). The sample of participants consisted of 500 elementary and high school students from the territory of southern Serbia. It was observed that less than 1% of students reported having poor health, while 6% of participants said that they were dissatisfied with their health overall, compared to 94% of students who reported being satisfied with their health. Additionally, a total of 88% of students evaluated their lives with the highest marks, out of which 28% considered their lives to be the greatest they could possibly be. 90% of participants from this sample of students in southern Serbia reported engaging in physical activity three or more times per week, whereas only 3% of students reported engaging in physical activity only once a week or not at all. The key finding of this study proved that students who engaged in greater physical activity had fewer health issues than students who engaged in the least amount of physical activity. There are numerous benefits to being physically active, including how it influences the maintenance of human health and helps children grow and develop properly. Therefore, the importance of this work is reflected in the possibility of gaining knowledge about physical activity during the state of emergency and the connection between physical activity and health problems that emerged among students in southern Serbia during the COVID-19 pandemic

Influencers as a Segment of Digital Marketing Communication – Generation Y Attitudes

The aim of the research presented in this paper isto provide insights into marketing communication changes induced by digital transformation and social media use. Contemporary marketing communication strategies are observed in the context of dominant information sourcesshift, as well as demographic trendsthat have placed Generation Yin marketing theorists‘ and practitioners‘ focus of interest. This paper examinesthe role and significance of prominentsocial media users–influencersin creating contemporary marketing communication. Considering the fact that modern customers are characterized by a high degree of digitalsophistication, the research in this paper focused on the prominence ofsocial media as main sources of information sharing. This paper presentsthe results of an empirical research which aim was to examine the attitudes of Generation Y membersin Serbia regarding influencer marketing. The contribution of this paper isreflected in the critical analysis of obtained results, thusincreasing the corpus of relevant knowledge

Personalized Social Media Communication based on Millennials' Attitudes

As a result of intense and ever-growing technological development, as well as the increase of digital media usage in everyday life, communication strategies have undergone profound transformations in order to adapt to specific conditions of online environment. Due to the interactive essence of Internet communication, which is being realized on social media and other online platforms, the need for engaging social media users in creating communication strategies has emerged. Furthermore, demographic trends have resulted in the shift of target audience structure, since generation Y members (i.e. millennials) have growing importance within the structure of contemporary society. This generational cohort, among its other characteristics, can be depicted by its distinct sophistication in terms of communication preferences. To be more precise, this generation expects to be provided with interactive, real-time and personalized communication, which is adjusted to social media platforms they use and can be consumed on the go. Therefore, the aim of this paper is to observe and accentuate the changes in media communication strategies caused by millennials and their extensive use of technology. The results obtained from the research conducted in this paper can be useful for both communication researchers and practitioners, and can be used as guidelines for creating digital communication strategies for millennials

Supplementary information for: "Binding of metal ions and water molecules to nucleic acid bases: The influence of water molecule coordination to a metal ion on water–nucleic acid base hydrogen bonds"

Figure S1. Distance distribution for hydrogen bonds with coordinated and noncoordinated water, separately for different nucleic bases and positions; Table S1. The calculated interaction energies and distances between five nucleic bases and noncoordinated water molecules, at the B3LYP-D3/def2-TZVP (kcal/mol) and corrected for BSSE), MP2/def2-QZVP (kcal/mol) and noncorrected for BSSE) and CCSD(kcal/mol) and T)/CBS level; Table S2. The calculated interaction energies and distances at the B3LYP-D3/def2-TZVP level between five nucleic bases and water molecules coordinated to Zn2+ ion; Table S3. A number of hydrogen bonds between nucleic bases and coordinated water, and percentage of [M(H2O)n]x+ complexes, with different kinds of metals. Figure S2. Electrostatic potential maps for the nucleic bases. Figure S3. Distribution of the distance between water oxygen and nucleic base oxygen/nitrogen found in PDB structures for noncoordinated and coordinated water;Supplementary information for: Andrić, Jelena M., Stanković, Ivana, Zarić, Snežana D., "Binding of metal ions and water molecules to nucleic acid bases: The influence of water molecule coordination to a metal ion on water–nucleic acid base hydrogen bonds" in Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials, 75 (2019):301-309, [https://doi.org/10.1107/S2052520619001999]Published version of the article: [https://cer.ihtm.bg.ac.rs/handle/123456789/3521

Characterization of nanocomposite materials for optical aids

Испитивање утицаја светлости, како природне тако и вештачке, од изузетне је важности са аспекта здравља очног апарата и функционисањa људског организма генерално. Очне структуре поседују различит степен осетљивости на дејство електромагнетног зрачења, тако да неке таласне дужине могу проузроковати фотохемијска и фототермална оштећења. Зрачење у домену ултраљубичастог (УВ) и високо-енергетског плавог светла представља изузетну претњу очним ткивима, уз истовремен утицај и на мождане функције. Истраживање нових материјала који ће бити у могућности да филтрирају и потпуно елиминишу или трансформишу штетне таласне дужине зрачења је од савременог јавног значаја. Нови оптички материјали треба да поседују способност подешавања и прецизног дефинисања карактеристика таласних дужина трансмитованог зрачења. Многи фотофизички и фотохемијски процеси управо зависе од избора таласне дужине тако да оптички филтери, са различитим трансмисионим карактеристикама, омогућавају фотостимулацију истих и као такви потомажу развоју нових фотонских уређаја, фототерапијских апарата и заштитиних помагала. Уочено је да приликом затамњења оптичких помагала, стављања блокатора за УВ и плаву светлост, нису задовољени критеријуми осетљивости ока па долази до појаве нежељених ефеката, чије дејство изазива напрезање очних структура, а затим и њихово оштећење. Сагласно томе, основни циљ ове докторске дисертације је изналажење оптичког помагала које ће спречити штетан утицај УВ и високо-енергетског плавог светла, уз трансформацију упадног спектара светлости тако да буде што ближи спектру осетљивости ока. У сврху реализације постављених циљева истраживања, за израду оптичког помагала коришћени су нанокомпозитни материјали на бази полимера (поли (метил мeтакрилата), ПММА) и наноматеријала, фулерена (C60). Нанокомпозитни материјали израђени су са четири концентрације наноматеријала (0.025mas%, 0.050mas%, 0.075mas% и 0.100mas%.). За испитивање оптичких карактеристика нанокомпозитних материјала коришћени су УВ/ВИС спектрофотометар (ILT350 Spectroradiometer, International Light Technologies, САД), УВ/ВИС/НИР спектрометри (Lambda 950, Perkin Elmer, Италија и C10082CA, Mini-spectrometer, Hamamatsu, Јапан) и ФТИР микроспектроскопски систем (Spotlight 400 FT-IR Imaging System, Perkin Elmer, Италија). За нанокарактеризацију нових материјала коришћен је уређај за микроскопију атомских и магнетних сила (JSPM 5200, JEOL, Јапан). Истраживањем су дефинисане разлике дифузне светлости која улази у систем оптичког помагала и излазне светлости из оптичког помагала. Мултифакторска анализа снимљених карактеристика нанокомпозитних материјала за оптичка помагала, спектроскопским и нанотехнолошким методама и техникама, указује на значај концентрације молекула С60 у нанокомпозитном материјалу, односно утицају његове концентрације на оптичка и структурна својства новодобијеног материјала. Експериментално је утврђено која од наведене четири концентрације највише погодује изради оптичког помагала. Пробна сочива, са адекватном концентрацијом наноматеријала, тестирана су у оквиру прелиминарне офталмолошке студије, у две офталмолошке ординације, Laserfocus и Маcula, из Београда

Relationship between body condition and blood parameters in the peripartum period, production and reproductive results of Alpine goats

Radi ispitivanja odnosa telesne kondicije (OTK) i metaboličkih parametara krvi i proizvodnih i reproduktivnih rezultata u različitim fiziološkim fazama, izvedeno je istraživanje na dve grupe od ukupno 50 sjarenih primiparih i multiparih koza alpske rase. OTK je izvedena metodom Villaquiran-a i sar. (2004) četiri puta za svaku od grupa 10 do 15 dana pre, 10 do 15 dana i 30 dana po partusu i 10 do 15 dana pre zasušenja, a u prva tri termina je uzeta i krv iz v. jugularis za utvrđivanje koncentracija glukoze, ukupnih proteina (UP), albumina, uree, β-hidroksibuterne kiseline (BHBA), neesterifikovanih masnih kiselina (NEFA), kalcijuma i fosfora. Zabeleženi su ukupna količina (KM) i sastav mleka: udeo proteina (MP), masti (MM), laktoze (L) i suve materije (SM) u laktaciji, broj jaradi po kozi (BJ), telesna masa (TM) na rođenju i 30. dana, dužina servis perioda (SP) i težina porođaja. Značajnost postoji između UP 15 dana pre i 15 i 30 dana po jarenju (F=2,675, p<0,05; F=4,710 i F=3,834, p<0,01, redom), Ca 30 dana posle (F=2,925, p<0,05) i BHBA 15 dana posle (F=2,508, p<0,05). Ustanovljena je korelacija između OTK 30 dana posle i KM (r=0,302, p<0,05), 15 dana posle i SM (r=0,315, p<0,05) i 15 dana pred partus i BJ (r=0,282, p<0,05), kao i SP (r=0,460, p<0,01) i TM na rođenju (r=0,307, p<0,05). Paritet je u korelaciji s KM, BJ, TM i SP (r=0,774; r=0,610; r=0,588; r=0,833, p<0,01, redom), a u negativnoj s L (r=-0,297, p<0,05). BJ je u korelaciji s SP (r=0,630, p<0,01), KM (r=0,547, p<0,01) i MM (r=-0,294, p<0,05). SP je u korelaciji s TM (r=0,616, p<0,01) i KM (r=0,704, p<0,01), MM s L (r=0,316, p<0,05) i SM (r=0,592, p<0,01), a L s SM (r=0,386, p<0,01). Koncentracije parametara krvi variraju u peripartalnom periodu, uz značajne razlike između prvojarki i višejarki i imaju uticaj na proizvodnju i reprodukciju, i mogu biti korisni u prevenciji zdravstvenih, reproduktivnih i proizvodnih problema, iako je nađeno da OTK kod koza nije od značaja kao prediktor proizvodnje i kvaliteta mleka.In order to examine the relationship between body condition score (BCS) and metabolic parameters of blood and production and reproductive results in different physiological phases, a study was performed on two groups with 50 pregnant primiparous and multiparous Alpine goats. BCS was performed by the method of Villaquiran et al. (2004) four times for each of the groups 10 to 15 days before, 10 to 15 days and 30 days after parturition and 10 to 15 days before drying, when in the first three terms blood was taken from v. jugularis to determine glucose levels, total protein (TP), albumin, urea, β-hydroxybutyric acid (BHBA), non-esterified fatty acids (NEFA), calcium and phosphorus. Total amount (MY) and milk composition were recorded: protein content (MP), fat (MF), lactose (L) and dry matter (DM) during lactation, number of kids per goat (NK), body weight (BW) at birth and 30 days of age, length of service period (SP) and severity of birth giving. Significance was found between TP 15 days before and 15 and 30 days after kidding (F=2.675, p<0.05; F=4.710 and F=3.834, p<0.01, respectively), Ca 30 days after (F=2.925, p<0.05) and BHBA 15 days after (F=2.508, p<0.05). A correlation was found between BCS 30 days later and MY (r=0.302, p<0.05), 15 days after and DM (r=0.315, p<0.05), and 15 days before kidding and NK (r=0.282, p<0.05), as well as between BCS and SP (r=0.460, p<0.01) i BW at birth (r=0.307, p<0.05). The parity is correlated with MY, NK, BW and SP (r=0.774; r=0.610; r=0.588; r=0.833, p<0.01, respectively), and negatively with L (r=-0.297, p<0.05). NK is correlated with SP (r=0.630, p<0.01), MY (r=0.547, p<0.01) and MF (r=-0.294, p<0.05). SP is correlated with BW (r=0.616, p<0.01) and MY (r=0.704, p<0.01), MF with L (r=0.316, p<0.05) and DM (r=0.592, p<0.01), as well as L with DM (r=0.386, p<0.01). Blood parameter levels vary in the peripartum period, with significant differences between primiparous and multiparous goats and have an impact on production and reproduction, and therefore may be useful in preventing health, reproductive and production problems, although BCS in goats has not been found to be important as a predictor of milk production and quality

Construction of Amyloid PDB Files Database

Amyloids are insoluble proteins of a cross-_ structure found as deposits in many diseases. They are largely examined structurally, but there is a lack of a unique structural database for amyloid proteins resolved with atomic resolution. Here, we present a constructed amyloid database made based on keyword criterion as well as structural features of amyloids described in literature. The searching filter was performed by python programming. The total number of structures is 109. This database can help further structural general and statistical analysis of amyloids, as we know the molecular basis can lead to understanding of disease mechanisms related to amyloid proteins.Belgrade, Serbia, June 20-24, 201