Mechanisms of cell proliferation in the uterus

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A városi területhasználat monocentrikus modelljéről

A városokban a területhasználatot, ehhez kapcsolódva a településszerkezetet, valamint az ingatlanok kínálatának és keresletének jellemzőit többféle módon és különböző modellekkel lehet vizsgálni. A városgazdaságtanban közismert a monocentrikus városmodell, amelyet Alonso dolgozott ki 1964-ben, továbbfejlesztve Thünen mezőgazdasági földhasználatra vonatkozó elméletét. Alonso a bérleti díj függvény bevezetésével a neoklasszikus közgazdaságtan alapgondolatait, fogalmait és módszereit alkalmazta a városszerkezet vizsgálatára, arra törekedett, hogy a városi földterület kínálata és kereslete közötti térbeli egyensúly jellemzőit kimutassa. Tanulmányunkban a legfontosabb fogalmak bevezetése után ismertetjük a monocentrikus városmodell alapgondolatait. Részletesen levezetjük a területhasználat intenzitását megadó kifejezéseket, amelyekkel a vállalatok bérleti díjait leíró függvények jellemezhetők, valamint elemezzük a háztartásoknak a lakásválasztáshoz kapcsolódó döntéseit. A kétféle mikroszervezet, a vállalatok és háztartások ajánlati bérleti díj függvényei alapján bemutatjuk a monocentrikus modellt és napjainkban érvényesnek tekinthető policentrikus kiterjesztését. A dolgozatban a nemzetközi szakirodalom azon legújabb alapvető elméleti eredményeit tekintjük át és értelmezzük, amelyek széles körben elfogadottak

The effect of forest stand characteristics on spider diversity and species composition in deciduous-coniferous mixed forests

We studied how forest stand characteristics influence spider assemblage richness and composition in a forested region of Hungary. Deciduous-coniferous mixed forests dominate in the O˝rse´g National Park. Thirty-five plots were established and sampled for spiders for three years in 70–110 year-old stands with a continuum of tree species composition. Detailed background information was acquired for stand structure, tree species composition, forest-floor-related variables and spatial position of the plots. The effect of variables was analyzed by nonparametric multiplicative regression on rarefied spider species richness and by redundancy analysis on species composition. The relative importance of variable groups was assessed by variation partitioning. Spider species richness was positively and strongly affected by tree species richness, and the species composition of the spider assemblage was influenced by the proportion of the most important tree species. This study established the importance of tree species composition, but variance partitioning analysis also showed that tree species identity and forest floor variables together explain much of the variation. These findings may guide management and conservation efforts to maintain regional diversity of the spider fauna

Spatial Aspects of the Restructuring of the Hungarian Economy Between 2000 and 2019

In the years following the regime change of 1989-90, Hungary faced numerous economic and political challenges. Apart from the dominance of privatisation, the ‘90s can definitely be described as a decade of transition. The performance of the Hungarian economy had reached the pre-transition level by the turn of the millennium, while the labour market and the structure of economic sectors had undergone substantial changes. In the present paper, we investigate how stable the developed sectoral structure proved to be in the two decades that followed and what territorial specificities the changes were characterised by. Our main question is how further structural changes – besides the sectors’ performance (productivity) growth – contributed to the changing economic performance of territorial units in the period of 2000-2019. In our study, we divide productivity change into a “between-sector” and a “within-sector” element. We regard the analysis as a relevant research question in general as well. However, the global financial crisis occurring at the “mid-term” of the studied period (2008) represents a special rupture. The analysis framework is provided by the counties (NUTS3 regions), we conduct our analysis in this context. It can be established that the primary factor of productivity growth is the increase of performance within sector groups and not the change in the economic structure of counties. The impact of structural changes is smaller in magnitude and may even have a negative value in several cases, i.e., the economic structure of counties has shifted from higher-productivity sectors towards those with lower productivity

Energy Saving Potential of Traffic-Regulated Street Lighting

Some municipalities switch off street lights for several hours at night to save energy and reduce operating costs as a consequence of soaring electricity prices in Europe. Complete darkness in the streets raises public concern about safety and security. The current street lighting standard EN 13201 enables the road luminance to be reduced in parallel with diminishing traffic volume offering a viable tradeoff between energy saving and road safety. This paper presents a methodology to estimate the energy-saving potential of traffic-regulated street lighting based on traffic counting data. By analyzing traffic volume and composition collected from an urban street over the one-year period, we found that traffic sensor-regulated street lighting can deliver up to 55% reduction in electricity costs while maintaining road luminance in line with the recommendations of EN 13201-2. In the presented case, the daily traffic volume profiles were remarkably stable following either a workday or a holiday pattern. Statistical analysis showed that 45% energy saving could be achieved by the pre-programmed dimming schedule of the luminaires while remaining compliant with the standard. The effect of daylight-saving time on the energy consumption of adaptive street lighting was also analyzed

EFFECT OF SOME ENVIRONMENTAL FACTORS ON WEANING PERFORMANCE OF HUNGARIAN GREY CATTLE POPULATIONS

Weaning performance of 2857 purebred calves (660 male and 2197 female) born from 1498 cows mated with 78 sire were analised in seven farms. Genetic- and environmental variance and heritability, breeding value of weaning weight (VS), preweaning daily gain (SGY) and 205-day weight (KVS) were calculated. Farm, year of birth, season of birth, sex, number of calving as fixed, while sire as a random effect was treated. Data were analyzed with SPSS 9.0 and Harvey’s (1990) Least Square Maximum Likelihood Computer Program. The environmental factors examined had an effect on all traits. The overall mean value and standard error (SE) of VS, SGY and KVS were 208±3.31 kg, 887±15.66 g/day and 199±14.774 kg, respectively. The heritability of the investigated traits was 0.24, 0.25 and 0.25. The results of the examination show that the 205-day weight was increased to seventh calving. The male calves were hevier than females, the difference was 22 kg (10,5%)