Shape of an elastica under growth restricted by friction

We investigate the quasi-static growth of elastic fibers in the presence of dry or viscous friction. An unusual form of destabilization beyond a critical length is described. In order to characterize this phenomenon, a new definition of stability against infinitesimal perturbations over finite time intervals is proposed and a semi-analytical method for the determination of the critical length is developed. The post-critical behavior of the system is studied by using an appropriate numerical scheme based on variational methods. We find post-critical shapes for uniformly distributed as well as for concentrated growth and demonstrate convergence to a figure-8 shape for large lengths when self-crossing is allowed. Comparison with simple physical experiments yields reasonable accuracy of the theoretical predictions

Vasúti Új Selyemút, mint a 21. századi Eurázsia egyik meghatározó konnektivitása

A 21. században a konnektivitás a kor egyik megatrendjének tekinthető. A komplex infrastruktúra fejlesztésekkel megvalósítható összekapcsoltságért folyó verseny meghatározza a gazdasági és a geopolitikai kapcsolatok irányát is. Egy ilyen konnektivitást létrehozó hálózatnak tekinthető az Új Selyemút (BRI) is. Kína gazdaságélénkítő terve kiterjed a hagyományos infrastruktúra, így a vasúthálózat fejlesztésére is azzal a céllal, hogy létrejöjjön egy modern vasúti összeköttetés Kína, Ázsia és Európa között, amin keresztül növelhető a szállítás mértéke és a költségek csökkentése, és így ennek kereskedelmi kapcsolatok élénkítő szerepe lehet. Ennek fontos eleme a China Railway Express (CRE), amely Kínát köti össze Európával Közép-Ázsián keresztül, és teremti meg Eurázsiának a kínai állam által irányított vasúti összeköttetését

Video Gaming and mental health

Introduction: 61% of the total adult Hungarian population (3.8 million) played video games in 2020. Video Gaming is the most popular among the 18-25 age group (66%). Due to the increasing public health importance of game addictions, internet gaming disorder (IGD) has been included into Section III of DSM-5, moreover gaming disorder (GD) also appears in the ICD-11 list

Central Bank Digital Currency: the Next Money Revolution? : Central Bank Digital Currencies in the Dimension of Geopolitics

Throughout history, financial innovation was always interlinked with shifts in the word’s economic centre of gravity and the emergence of new power hubs. Nowadays, the huge interest in central bank digital currencies proves that we must have arrived at a new turning point in the development of money. Most studies, however, focus on financial issues related to CBDCs, and only few embark on discussing historical analogies and geopolitical consequences in a comprehensive way. Our study aims to deliver such an analysis. According to the results, the revolutionary effects of CBDCs might arise from re-modelling cross-border payments, i.e., achieving direct (atomic) transactions through multilateral platforms. The remarkable results of China in developing the digital yuan, and most importantly, acquiring a key role in international projects, reinforce the geopolitical trends of the last decade. Global or regional standard-setting will be a critical question, and in this regard, there is still some room for manoeuvre on the side of the U.S. which started its own CBDC development (Project Hamilton) belatedly. In the long run, it might be realistic to expect a scenario in which the global financial system is divided in two parts, a Western and an Eastern one

Eurázsia kora és a globális megatrendek szerepe az eurázsiai együttműködésben = The Age of Eurasia and Global Megatrends in the Context of Eurasian Cooperation

Az utóbbi évtizedek markáns folyamata a multipoláris világrend kialakulása. Az USA mellett hatalmi centrumként a Föld legnagyobb szárazföldje, az eurázsiai szuperkontinens és annak gazdaságai – mindenekelőtt Kína – jelennek meg kihívóként. Ám felmerül a kérdés: hogyan értelmezhető Eurázsia? A tanulmány elsőként ezt vizsgálja meg történelmi és geopolitikai szempontból. Az eurázsiai együttműködés mindig is érvényesült a történelem folyamán: az ősi kínai selyemút az áruk, a tudás, a kultúra és a technológiák cseréjével már időszámításunk előtt ösztönözte az ottani közösségek fejlődését. A különböző, ám rokon Eurázsia-felfogások között Oroszország, Kazahsztán és Törökország is kidolgozta a maga vízióját, Kína pedig – újraélesztve a selyemutat – elindította az Övezet és Út Kezdeményezést (BRI). Ehhez kapcsolódóan arra mutatunk rá, hogy a 21. század megatrendjei jó lehetőséget biztosítanak a BRI által is képviselt, széles értelemben vett eurázsiai együttműködés számára. A tanulmány a fenntarthatóság, a digitalizáció és a pénz jövőjét érintő trendek vizsgálata során arra a következtetésre jut, hogy Európa és Ázsia számára nagy potenciál rejlik a zöldstratégiák közötti szinergiák kiaknázásában. Szintén fontos érdekek fűződnek a technológiai kérdéseket érintő nemzetközi konszenzushoz; a digitális jegybankpénzek terén pedig már közvetlen európai–ázsiai együttműködésre is van példa. = Over the last decades, a multipolar world order has been on the rise. In addition to the USA as a power hub, the Eurasian supercontinent – the largest landmass on Earth – and its economies, especially China, are emerging as a challenger. But the question arises: how can Eurasia be defined? This paper examines this issue first from a historical and geopolitical perspective. Eurasian cooperation has always been present in history: the ancient Silk Road stimulated the development of the relevant communities through the exchange of goods, knowledge, culture and technology. Among the different, but interconnected concepts of Eurasia, several countries like Russia, Kazakhstan and Turkey have developed their own Eurasian visions, and China – reviving the old Silk Road – has launched the Belt and Road Initiative (BRI). In connection to this, we show that the 21-century megatrends provide a good opportunity for broad Eurasian cooperation. Examining the trends of sustainability, digitalization and money, the study concludes that there is great potential for Europe and Asia to exploit synergies between green strategies. There are also important interests in an international consensus on the issues of technological progress, and we can already see examples of Eurasian cooperation regarding central bank digital currencies

THE ROLE OF TOURISM MANAGEMENT FOR SUSTAINABLE TOURISM DEVELOPMENT IN NATURE RESERVES IN HUNGARY

The aim of the research is to reveal the opinion of regional professionals involved in the management of sustainable tourism and its three pillars. Through the results of 27 in-depth interviews with decision-makers and NGOs, we have explored the perceptions of the economic, environmental and social factors, both positive and negative, and the importance of each factor. The analysis of the results clearly shows a difference of opinion between decision-makers and NGOs. The negative impacts of tourism were highlighted by respondents, mainly in terms of the impact on the natural and economic environment, however, the positive impacts were more prominent. The research showed that the impacts on social environment were perceived more positively by respondents, and NGOs did not emphasise negative impacts in this category. The study shows that the role of tourism management in nature conservation areas is necessary and important for sustainable tourism development. The research clearly demonstrates that sustainability is an important issue in tourism. The results of the research also show that decisionmakers are not familiar with the concept of sustainability, its precise content and their preparation and knowledge are insufficient to make the right decisions on the subject. The research shows that there is a shortage of professionals with expertise in tourism management, which makes it difficult to implement coordinated tourism development in the area under study

Shape of an elastica under growth restricted by friction

We investigate the quasi-static growth of elastic fibers in the presence of isotropic dry or viscous friction. An unusual form of destabilization beyond a critical length is described. In order to characterize this phenomenon, a new definition of stability against infinitesimal perturbations over finite time intervals is proposed and a semi-analytical method for the determination of the critical length is developed. The post-critical behavior of the system is studied by using an appropriate numerical scheme based on variational methods. We find post-critical shapes for uniformly distributed as well as for concentrated growth and demonstrate convergence to a figure 8 shape for large lengths when self-crossing is allowed. Comparison with simple physical experiments yields reasonable accuracy of the theoretical predictions

Heterogén vastagbéldaganat: a fogazott útvonalon kialakuló, sporadikus laesiók jelentősége a klinikai gyakorlatban = Colorectal cancer heterogeneity: the clinical impact of sporadic lesions arising via the serrated pathway

Today, colorectal cancer is regarded as a heterogeneous disease. Its heterogeneity is caused by genetic alterations, molecular aberrations, different developing pathways as well as by micro- and macroenviromental agents. In the last decade, beside the classic genetic model for colorectal tumuorgenesis that follows the adenoma-carcinoma sequence, an alternative pathway has been identified. This pathway is called the serrated pathway and it is responsible for approximately one third of all colorectal lesions. Beyond their dissimilar molecular characteristics, these tumours also show different macroscopic and histologic appearance. Moreover, their malignant potency and progressive ability distinguish them from tumours of the classic genetic model. The aim of this review is to summarize the molecular and pathologic features of serrated lesions and the serrated pathway to colorectal cancer and to highlight their clinical impact