Sustainable Tourism in the Context of Environmental Economics

Increasing international focus on sustainable development have highlighted the need for a new paradigm of sustainable development in the tourism industry. Tourism, more than any other activity, depends on the quality of natural and social resources. The rapid spread of Covid-19 and its already palpable impact on the travel and tourism industry has highlighted the increasing complexity of the interconnections in the world. Sustainable tourism takes full account of its current and future economic, social and environmental impacts, addressing the needs of visitors and the industry. The subject of this paper was the sustainable development of tourism in the context of environmental economics. The main goal of this research was to examine the interplay between tourism and the environment within the context of the pandemic. The methodological basis was the Travel and Tourism Competitiveness Index (TTCI), with a particular focus on environmental sustainability. The paper included an impact assessment of Covid-19 on sustainable tourism and forward-looking scenarios for 2021-2024. One of the key considerations was a SWOT analysis of the tourism industry within the pandemic conditions. Global recovery scenarios were discussed, as was the economic impact of Covid-19 on tourism in the European Union. Finally, this research put forward policy recommendations for governments to avert the worst effects and facilitate recovery in this field. Keywords: tourism economics, environmental sustainability, Travel and Tourism Competitiveness Index (TTCI), European Union, Covid-19, crisis managemen

Cki-1 links cell division and cell fate acquisition in the C. elegans somatic gonad

AbstractThe formation of a complex multicellular organism requires the precise specification of many diverse cell types at the correct time and position throughout development. This may be achieved by coordinating cell fate specification processes with progression through the cell cycle. Here, we show that the extra distal tip cells (DTCs) associated with the loss of cki-1, a Caenorhabditis elegans homologue of the cyclin-dependent kinase inhibitor p27, do not arise from duplications of pre-existing DTCs, but that they are formed from another cell type within the somatic gonad. Results from our laser microsurgery experiments suggest that the extra DTCs are caused by aberrant somatic gonadal precursor cell divisions in the absence of cki-1, resulting in abnormal daughter cell fates. cki-1(RNAi) animals also possess extra anchor cells and ectopic gonad arms with variable sheath cell numbers and positioning. In addition, cki-1(RNAi) animals display an endomitotic oocyte (Emo) phenotype. Our results uncover a novel role of this CKI in cell fate acquisition, either by directly influencing specification, or through a more conventional role in appropriately linking cell cycle phase with this process

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

Preserved erythrocyte membranes produced from slaughterhouse blood as systems for prolonged delivery of active substances

У овој докторској дисертацији развијен је процес за изоловање говеђих и свињских еритроцитних мембрана („духова”) из отпадне кланичне крви. Поред тога, развијени су и детаљно in vitro окарактерисани системи за продужено ослобађање активних супстанци на бази добијених еритроцитних мембрана. У циљу пројектовања процеса којим би се добиле говеђе и свињске еритроцитне мембране које су структурно очуване, а пореклом из отпадне кланичне крви, дефинисане су специфичне осмотске карактеристике ових еритроцита. Показано је да су свињски еритроци осмотски осетљивији и да еритроцити ниједне од испитиваних врста нису осмотски хомогени. Ова хетерогеност је детектована између еритроцита различитих узорака исте врсте, али и еритроцита једног узорка. Као оптимални пуфер за извођење хемолизе говеђих и свињских еритроцита одређен је 35 mМ натријум фосфатни/NaCl пуфер чијом применом се у процесу градуалне хипотоничне хемолизе, при протоку пуфера од 300 ml/h, током 30 min, ослобађа >90% хемоглобина из велике запремине (100 ml) обе врсте еритроцита. Биохемијска анализа добијених мембрана еритроцита је показала да се садржај протеина и холестерола није битно разликовао у односу на мембране интактних еритроцита. Такође, пречник еритроцитних мембрана обе врсте био је за само 10% мањи од интактних еритроцита, а расподела величине униформна. Ови резултати су показали да духови кланичних еритроцита обе врсте животиња имају способност да „имитирају" хемијско и структурно анизотропно окружење ћелијских мембрана in vivo, што је од значаја за дифузију и партициони коефицијет активних супстанци при њиховој инкапсулацији. У следећој фази истраживања испитана је могућности примене процеса градуалне хипотоничне хемолизе за инкапсулацију модел супстанце, синтетског глукокортикоида и најшире коришћеног антиинфламаторног лека, дексаметазон-натријум-фосфата (DexP)...In this doctoral dissertation, а process for production of empty erythrocyte membranes („ghosts“) originating from bovine and porcine wasted slaughterhouse blood was developed. In addition, with an aim of designing prolonged drug delivery vehicles, ghost-based drug delivery systems were formulated and in vitro characterized. In order to design the process by which hemoglobin would be released from erythrocytes, leaving preserved cell membranes, the first step was to define specific osmotic properties of bovine and porcine erythrocytes derived from slaughterhouse blood. The results showed that porcine erythrocytes were more osmotically susceptible compared to bovine ones, but neither of the two examined types of erythrocytes was homogeneous regarding their osmotic properties. This heterogeneity was detected among erythrocytes from different samples of one species, as well as among erythrocytes in one sample. The hypotonic sodiumphosphate/ NaCl buffer of 35 mM concentration circulating with a flow rate of 300 ml/h during 30 min was optimal for conducting gradual hypotonic hemolysis. Under these conditions the process of gradual hemolysis resulted with a high hemolysis extent (>90%). Biochemical analysis revealed that protein and cholesterol content of isolated ghosts were nearly the same as in intact erythrocytes. Compared to starting erythrocytes, average diameter of the ghosts from both type of erythrocytes decreased for only 10%. These results indicate that isolated membranes have possibility to mimic the chemical and structural anisotropic environment of in vivo cell membranes, and this fact is of significance for drug diffusion and partition coefficients during encapsulation procedure. In the next step, the gradual hypotonic hemolysis was evaluated as an encapsulation procedure for a model drug into the ghosts which were obtained in the previous experimental stage. A synthetic glucocorticoid, widely used antiinflammatory drug, dexamethasone sodium phosphate (DexP), was selected as a model compound. The processing parameters of DexP encapsulation into the ghosts-temperature, initial drug concentration, and cross-linker addition- were optimized..

Use of internal reports at Croatian higher education institutions

This paper explores the use of internal reports at higher education institutions (hereinafter HEIs) in Croatia. It also highlights the importance of internal reports for the decision – making process. In that context, the survey research based on two questionnaires was conducted in the year 2014. The questionnaires were sent to all higher education institutions in Croatia, more precisely to the Deans and to the Heads of Accounting. The authors have set three hypotheses. Statistical analysis of conducted empirical research shows that internal reports are insufficiently developed at HEIs in Croatia. At the end of the paper, authors provide some recommendations regarding future development and usage of internal reports at HEIs

COMPETITIVENESS AND DEVELOPMENTAL TRENDS OF THE NEW INDUSTRIAL POLICY OF THE REPUBLIC OF SERBIA

The achieved level of economic development determines the degree of industrial development in one country. The aim of this paper is to identify the key determinants of the new industrial policy of Serbia, in the context of European integration processes. The same is based on the analysis of strategic documents of Serbia and the European Union, governing the industrial development for the period up to 2020. Particular attention is paid to the monitoring of developmental dynamics and trends in improving industrial competitiveness. It has been noted that the achieved level of industrialization defines the industrial competitiveness of a national economy. Serbia needs an efficient, industrially competitive economic structure that will be able to meet the growing demands and challenges of the market. Only a properly designed and consistently applied industrial policy can follow the European developments in the future.Key words: new industrial policy, the European integration process, The Competitive Industrial Performance Index (CIP), the development and competitiveness of the industry

Transport of silver nanoparticles from nanocomposite Ag/alginate hydrogels under conditions mimicking tissue implantation

The aim of this work was to assess phenomena occurring during AgNP transport from nanocomposite Ag/alginate hydrogels under conditions relevant for potential biomedical applications as antimicrobial soft tissue implants. First, we have studied AgNP migration from the nanocomposite to the adjacent alginate hydrogel mimicking soft tissue next to the implant. AgNP deposition was carried out by the initial burst release lasting for similar to 24 h yielding large aggregates on hydrogel surfaces and smaller clusters (similar to 400 nm in size) inside. However, the overall released content was low (0.67%) indicating high nanocomposite stability. In the next experimental series, release of AgNPs, 10-30 nm in size, from Ag/alginate microbeads in water was investigated under static conditions as well as under continuous perfusion mimicking vascularized tissues. Mathematical modeling has revealed AgNP release by diffusion under static conditions with the diffusion coefficient within the Ag/alginate hydrogel of 6.9x10(-19) m(2) s(-1). Conversely, continuous perfusion induced increased AgNP release by convection with the interstitial fluid velocity estimated as 4.6 nm s(-1). Overall, the obtained results indicated the influence of hydrodynamic conditions at the implantation site on silver release and potential implant functionality, which should be investigated at the experimentation beginning using appropriate in vitro systems

DESIGN OF FIRST ORDER DIFFERENTIATOR WITH PARALLEL ALL-PASS STRUCTURE

In this paper a new method for design of the first order differentiator is presented. The proposed differentiator consists of two parallel branches, i.e. direct path and IIR all-pass filter. The described design method allows one to obtain solution with minimum mean relative error at the desired region by controlling the ratio of phase response extremes. A small relative magnitude error, as well as a low phase error, at low frequencies is condition for good time domain behaviour. The obtained differentiator can be realized by means of only two multipliers, hence being a good choice for real time applications. The proposed solution provides a lower magnitude error than several known differentiators with similar phase error

Синтетски пут за добијање 1,2,3,4-тетрахидрохиноксалинскo/пиперидинског трицикличног система

The synthetic route toward novel tricyclic, nitrogen-containing system is disclosed. Three novel compounds possessing structural features of 1,2,3,4-tetrahydroquinoxaline and decahydropyrido[3,4-b]pyrazine are synthesized starting from readily available precursors in six or seven steps, of which the last three or four steps respectively are diastereoselective. Key reaction steps include N-acylation, Hofmann rearrangement and ring-closing Buchwald– Hartwig reaction. Compounds trans-8, cis-12 and trans-12 are synthesized in order to prove that this novel, tricyclic system can be functionalized with various groups. Synthetic significance of this heterocyclic system lies in the possibility for the orthogonal functionalization of three different amino groups, allowing fine structural tuning.У овом раду представљена је синтеза новог трицикличног система који садржи азот. Три нова једињења код којих су комбиноване структурне карактеристике 1,2,3,4-тетрахидрохиноксалина и декахидропиридо[3,4-b]пиразина, добијена су полазећи од лако доступних прекурсора, у шест или седам фаза од којих су последње три или четири, редом, диастереоселективне. Кључне синтетичке трансформације укључују N-ациловање, Hofmann премештање и интрамолекулску Buchwald–Hartwig реакцију, као фазу у којој долази до циклизације. Једињења trans-8, cis-12 и trans-12 су синтетисана како би се представила могућност функционализације новог трицикличног система. Синтетички значај новог хетероцикличног система представљен је у могућности ортогоналне функционализације три различите амино групе, чиме се може постићи фино подешавање структуре