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Acta Veterinaria Hungarica
Authors:
Dominik Gulyás
,
Gábor Kovács
,
István Jankovics
,
Máté Hidvégi
,
Béla Dénes
,
Lilla Kálfalvy-Molnár
,
Rebeka Nagypál
, and
Márta Lőrincz

Abstract

The interplay of regulatory T cells (Tregs) within the tumour microenvironment presents a significant challenge in anticancer immunotherapy. This study investigates the potential of Treg blockade to enhance the efficiency of effector T cells. Two distinct treatment cocktails were examined: 3p-hpRNA (5′ triphosphate hairpin RNA) combined with unmethylated CpG oligonucleotide (CpG); CpG in combination with OX40 receptor-specific monoclonal antibody (anti-OX40). Treatment efficacy was assessed using a murine model of kidney adenocarcinoma.

Renca cells (renal cortical cells with adenocarcinoma) were subcutaneously engrafted in 30 BALB/c mice, then animals were allocated into three treatment groups: Group 1: CpG+anti-OX40, Group 2: CpG+3p-hpRNA, Group 3: untreated control. Treatment efficacy was evaluated based on tumour growth, the occurrence of metastases and overall survival.

On day 28 post-implantation, experiments had to be terminated due to tumour progression. Although comparisons of survival times and primary tumour sizes thus became inconsequential, histological examinations provided valuable insights. We observed distinct variations in primary tumour characteristics among the different groups: Groups 1 and 2 displayed demarcations, while Group 3 exhibited diffuse tumours with necrosis. Lung metastases were evident in 70% of untreated mice, whereas none were observed in either of the treated groups.

Our findings instil confidence in the potential efficacy of the treatments, thereby laying a solid foundation for future investigations.

Open access

Abstract

This study examines the complexity in the Eastern European economies, with a focus on the role of foreign direct investment (FDI). Despite transitioning to market economies, these countries remain economically fragile and dependent. Their lower technological complexity and reliance on foreign capacity make them vulnerable. However, some countries like Austria and Poland demonstrate successful integration of production and innovation. The analysis shows FDI has a limited impact on developing complex knowledge but contributes positively to economic complexity. Results also indicate that in the long-term, economic and technological complexity does not lead to accelerated total factor productivity growth, contrary to complexity literature. Combining labour with innovation, safeguarding local industries, and prioritizing education and research are more effective approaches. The study clearly shows how Hungary is stuck in an “assembler trap.” It also finds that the gap between economic and technological complexity negatively affects liberal democracies.

Open access
Acta Oeconomica
Authors:
José Antonio Clemente-Almendros
,
Florin Teodor Boldeanu
,
Cristina Drumea
, and
Samer Ajour El Zein

Abstract

This paper investigates the use of redundancy procedures (RPs) by small and medium-sized enterprises (SMEs) in Spain during the COVID-19 pandemic. The novelty of this study is that it goes beyond the direct influence of the determinants of RPs on RP use, and analyses how the interactions among them moderate the direct effect. In contexts of rising uncertainty, businesses need to adapt their operations and fixed costs, including staffing. While teleworking is an alternative to RPs, our results show that it was not enough to deal with the negative impact of a worsening crisis. Moreover, when the survival of the business is at stake, the use of RPs increases further when the company is simultaneously affected by changes in demand and liquidity issues. We argue that our results reveal the need for flexible tools along with the policies that take into account the fact that businesses' reactions are contingent on their exposure to risk.

Full access

Abstract

The dividend puzzle for private corporations has a long-lasting history. Six theories provide explanations to this puzzle. However, the dividend puzzle has not yet been discussed as an economic problem for state-owned enterprises (SOEs). The article addresses this issue based mainly on the experience of the Bulgarian SOEs.

In the paper all well-known six theoretical concepts of the dividend puzzle are presented and their strengths and weaknesses are analysed. Furthermore, the specific features of SOEs are brought out and the dividend puzzle for them is formulated. Presenting the experience of the dividend policy of SOEs, a confrontation with the theories is made. It is proved that only the theory of dividend payment preference is relevant to SOEs.

Restricted access

Ellátásbiztonság az energiaátmenet időszakában

Security of supply in times of energy transition

Scientia et Securitas
Authors:
Ágnes Csermely
,
Péter Kaderják
,
Balázs Lengyel
,
Anna Mészégető
, and
Pálma Szolnoki

Összefoglalás.

A zöld energetikai átállás folyamatát leggyakrabban klímavédelmi szempontok alapján elemzik. Ebben a cikkben az energiabiztonságra gyakorolt hatását vizsgáljuk a megújuló energiahordozók térnyerésének. A mérleg pozitív serpenyőjében szerepel az energiafüggetlenséghez való hozzájárulás, a széles körben elérhető technológia és a fosszilis energiahordozókhoz képest kiszámítható árazás. A folyamat ugyanakkor számos kihívással is együtt jár, melyek közül kiemeljük a szezonális tárolás lehetőségének korlátosságát, az ellátásbiztonsághoz szükséges nem időjárásfüggő tartalékkapacitások fenntartásának nehézségeit, a hálózatüzemeltetéssel kapcsolatos problémákat, a digitalizációval együtt növekvő kiberbiztonsági kockázatokat és a kritikus alapanyagok koncentrációjából fakadó kihívásokat. E kihívásokra költséghatékony megoldásokat kell kialakítani, így a zöldenergia térnyerése komplex, a szakpolitika koordinációját igénylő, több évtizeden áthúzódó folyamat lesz.

Summary.

The green energy transition process is most often analysed from a climate protection perspective. In this article, we look at the impact of rising renewable generation on the security of energy supply. On the positive side there is renewables’ contribution to energy independence, their widespread availability, and their predictable pricing compared to fossil fuels. However, the process of increasing the share of renewables also carries several challenges, including the limitations of seasonal storage, the difficulties of maintaining non-weather-dependent reserve capacity for security of supply, grid management issues, the growing cyber security risks associated with digitalisation and the concentration of the availability of critical minerals. Cost-effective solutions to these challenges need to be developed, making the take-up of green energy a complex process that requires policy coordination over the next several decades.

Open access

Előszó

Foreword

Scientia et Securitas
Authors:
Marcell Gáspár
and
Attila Aszódi
Open access

Energetikai szektorban előforduló por közegek robbanási és gyulladási tulajdonságainak vizsgálata

Investigation of the explosion and ignition properties of dust media occurring in energy sector

Scientia et Securitas
Authors:
Zoltán Siménfalvi
,
Viktória Kállai
,
Viktória Mikáczó
,
Máté Petrik
,
Tamás Pusztai
,
Bernadett Pusztai-Spisák
,
Zoltán Szamosi
,
Levente Tugyi
, and
L. Gábor Szepesi

Összefoglalás.

Ipari környezetben, ahol az alapanyagok között por alapanyagú termékek találhatóak, felmerül a porrobbanás lehetősége, ez alól az energiaszektor sem kivétel. Ebben az iparágban is megjelentek a biomasszák mint energiahordozók, amely termékekről számos esetben bebizonyosodott, hogy porrobbanás-veszélyesek, ezért szükséges védelmi intézkedéseket tenni. Jelen közleményünkben összefoglaljuk azon vizsgálati eljárásokat, amelyekkel meghatározhatóak a későbbi védelmi intézkedések alapadatául szolgáló paraméterek. Ismertetjük a vizsgálati eljárásokat, berendezéseket, valamint néhány konkrét vizsgálati eredményt is bemutatunk.

Summary.

In an industrial environment where dust-based products are among the raw materials, the potential for dust explosion arises, and the energy sector is no exception. This industry has also started to use biomass as a source of energy, which has been shown in many cases to be explosive and therefore requires protective measures. In this article, we have presented the distribution of dust explosion accidents in the US in 2021, which shows that 4% of the accidents directly related to the energy industry are much higher than the direct proportion. The set of conditions required for such accidents to occur is described and the investigation procedures that can be used to determine the parameters that will form the basis for future protection measurements are summarized. These parameters include the maximum explosion overpressure (Pmax), the explosion constant (Kst), the lower explosibility rate (LEL), the limiting oxygen concentration (LOC), the minimum ignition temperature of dust clouds (MIT), the layer ignition temperature (LIT), and finally the minimum ignition energy (MIE). The test procedures and equipment are described, and some concrete test results are presented. Determining these variables is essential for the design of explosion protection for a dust explosion hazardous technology or area. The description of the test procedures is based mainly on the standard specifications applicable in the European Union. The structure of the measurements and the interpretation of the results obtained are described through the analysis of a fermentation residual solid.

Open access

Felügyelt gépi tanulási módszerek alkalmazása a pszichológiai kutatásokban

Using supervised machine learning methods in psychological research

Magyar Pszichológiai Szemle
Authors:
Nándor Hajdú
,
Barnabás Szászi
,
Balázs Aczél
, and
Tamás Nagy

A pszichológiai kutatások számos területén hasznosítható a felügyelt gépi tanulás, amelynek alkalmazásával összetettebb adatok elemzése válik lehetségessé. Célunk, hogy bemutassuk a felügyelt gépi tanulás fajtáit, működését és használatát a pszichológiai kutatásokban. Áttekintjük a gépi tanulás előnyeit, valamint a túlillesztés, torzítási hiba és adatvariabilitás fogalmait, amelyek segítenek a modellválasztásban, és az eredmények robusztusságának biztosításában. Röviden bemutatjuk továbbá a legfontosabb felügyelt gépi tanulási algoritmusokat, és leírjuk a változók és adatok előkészítésének legfontosabb lépéseit. Egy példaelemzés keretében bemutatjuk, hogyan modellezhető egyetemi hallgatók lépcső és lift közötti választása felügyelt gépi tanulással. A cikk végén kitérünk a gépi tanulás korlátaira és annak helyére a pszichológusok oktatásában. Reméljük, hogy a bemutatott ismeretek segítenek a pszichológusoknak a gépi tanulás hatékonyabb és kreatívabb használatában.

Open access

A hűtési és fűtési időszakot jellemző éghajlati klímaindexek változása Magyarországon

Observed changes in weather-dependent heating and cooling energy demand in Hungary

Scientia et Securitas
Authors:
Mónika Lakatos
and
Kinga Bokros

Összefoglalás.

Az elmúlt évtizedekben a globális felmelegedés hatásai Európában, azon belül a Kárpát-medencében is nyilvánvalóvá váltak, s ez a hatás jelentős mértékű az energiaszektorra is. A kizárólag az időjárás által befolyásolt függő fűtési és hűtési energiaigényt leíró technikai klímaindexek alakulását mutatjuk be Magyarországon, nevezetesen a fűtési foknap (Heating Degree Days) és a hűtési foknap (Cooling Degree Days) paramétereket vizsgáljuk. A jelen klímát leginkább jellemző éves és havi normálértékek mellett a változásokat is elemezzük. A múlt század elejétől a fűtési foknapok egyértelmű csökkenése, míg a hűtési foknapok egyértelmű emelkedése figyelhető meg. Országos átlagban 314,6 foknappal [°C nap] csökkent a fűtési foknapok éves összege a lineáris trendmodell szerint 1901-től, míg ugyanerre az időszakra 79,4 ℃ nappal nőtt a hűtési foknap értéke. A legutóbbi három évtizedben, a legintenzívebb melegedés időszakában igen markánsak a változások, s ez a folyamat minden bizonnyal folytatódik a század végéig és azon túl is.

Summary.

In recent decades, the effects of global warming have become evident in Europe, including the Carpathian Basin, and this impact is significant for the energy sector. The most obvious impact of climate change in Hungary is the increase in extremes associated with high temperatures. Not only summer, but also winter and transition seasons show a warming trend, affecting all productive and service sectors. Rising temperatures could lead to shorter heating seasons and milder cold months, potentially reducing heating energy demand. However the heat waves have become more frequent and intense due to warming, leading to an increase in cooling energy demand. In the first part of this article, we present the evolution of heating degree-days from the beginning of the last century to the present day for the whole area of Hungary. The heating degree day is an indicator of the energy consumption for heating of buildings, which depends only on the weather. That is a temperature value, expressed in °Cday, which is proportional to the amount of energy required to heat the indoor environment to a given temperature on a given day, taking into account the daily minimum, maximum and mean temperature for a specific base temperature (15.5°Cday). Importantly, its value does not depend on the insulation of the buildings, economic indicators or the type of energy sources. Essentially, the colder the weather, the more the air temperature deviates from the base temperature of 15.5 degrees Celsius, the more energy is needed to heat the indoor environment and the higher the heating degree day value will be. In addition, we present the analysis of cooling degree days. The cooling degree day is derived in a similar way, following the logic of the heating degree day derivation. Therefore, the warmer the weather and the higher the air temperature is above the base temperature of 22°C, the more energy is needed to cool the indoor environment.

Based on the results presented in the article, we can conclude that the annual as well as the monthly amounts of heating degree-days have decreased since the beginning of the last century, with the greatest decrease in mountainous areas and in Western Hungary. One of the few benefits of climate change is that less energy is needed to heat interiors, and this is particularly true for the last decades, when annual heating degree-day amounts were usually lower than normal. At the same time, as heating degree-days have decreased, as the heat waves have become more frequent and intense with warming, resulting in an increase in cooling degree-days. In Hungary, on average, the last 30 years have been characterised by the highest cooling degree-day values over the last century’s climate normal periods. On a national average, the annual amount of heating degree-days has decreased by 314.6°Cday according to the linear trend model since 1901, while the cooling degree-day value has increased by 79.4°Cday over the same period. During the period of most intense warming, the August weather-dependent cooling energy demand increased the most. Due to the urban heat island effect in the inner-city environment, cooling of buildings requires additional energy. The recent trends is likely to continue until the end of the century and beyond. Therefore important to monitor changes in climate parameters affecting energy security and to develop an effective strategy and action plans to address the climate risks for the energy sector.

Open access

Abstract

This research investigates the causal relationship between innovation, financial development and economic growth in Brazil, Chile, Colombia, Mexico and Peru between 2000 and 2019. Based on quantitative analysis, including vector autoregressive (VAR) models, it can be concluded that bidirectional Granger-causalities are present in the trivariate nexus in the five Latin American countries over the investigated times. Consequently, the three variables support forecasting and policy implications focusing on one of the three sectors that impacts the other two in the future. The paper concludes that imitation and innovation policies focusing on intellectual property rights protection, education, knowledge, institutional change and technological catch-up are necessary to foster economic growth and financial development.

Restricted access