69 research outputs found

    Spatial Econometrics – Usage in Transportation Sciences: A Review Article

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    Nowadays the spatial econometrics is became widely used in transportation sciences. In order to know which method can be used or how they should be used, the review articles give answers. In this recent paper the goal is to collect all of the methods in one article which can be used in further researches. The improvement in this article is that beside the spatial econometric methods, other necessary techniques are also introduced. With this fact a whole analysis can be applied

    Near surface mounted FRP reinforcement for strengthening of concrete structures

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    This paper is based on literature review regarding fibre reinforced polymers (FRP) used as near surface mounted (NSM) reinforcement for strengthening of concrete structures. Strengthening of structures is a complex task. Different systems can be used in order to utilize the fibre reinforced polymer in the most efficient way. Near surface mounted reinforcement is practical alternative to externally bounded reinforcement while it has many advantages

    Mitokondriális eredetű nitrogén szabadgyökök és ATP-függő K-csatornák szerepe az organellum működésében = The involvement of mitochondrial-derived nitrogen radicals and mitoK-ATP channels in the regulation of organelle function

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    Elsőként a mitoKATP csatornák alegységeit terveztük azonosítani humán szív mintákon. A kísérletek során megbizonyosodtunk afelől, hogy a korábban ilyen csatornáknak gondolt fehérjék nincsenek jelen megfelelő számban és formában a mitokondriális membránokban, ezért a nem valószínű hogy a mitokondirális ATP-függő kálium áramokat valós mitoKATP csatornák folytatnák. A mitokondriális NO szintáz (mtNOS) enzimrendszer vizsgálata azonban nem várt új felfedezésekhez vezetett. Az előkísérletekben is bemutatott, a pályázat során több fajra és szövetre (ember, egér, patkány, malac, szív, agy és máj) kiterjesztett, több párhuzamos módszerrel nyert eredményeink szerint bizonítottuk, hogy a feltételezett mtNOS nem azonos egyik ismert NOS variánssal sem. Megállapítottuk hogy a mitokondriális légzési lánc ubiquinon ciklusának működése mentén keletkező nitrogén gyökök azok, amelyeket korábban a mtNOS-nak tulajdonítottak. A reakcióút pontosabb tisztázása végett mitokondriumokat oxidatív stressznek vetettünk alá, ezzel fehérje modifikációt indukáltunk. Proteomikai módszerekkel (2D gélelektroforzis és tömegspektrometria) azonosítottuk nitrált és poly-ADP-rbozilált (PAR-ált) fehérjéket, köztük a mitokondirális dihidro-lipoamid dehidrogenázt amely a poliADP-riboziláció folyamatot is katalizálhatja. Kísérleteink ezzel egy teljesen új, független mitokondriális reakcióutat tártak fel. További kísérleteink a mitokondriális nitrogén monoxid metabolizmus és a cukorbetegség kapcsolatát vizsgálták. | Our experimental findings indicated that there previously suspected potential mitoKATP channel subunits are not present in the required format and amount in human heart mitochondria, therefore, they cannot play a role in K fluxes. We extended our preliminary results about the nature of the putative mitochondrial NO synthase (mtNOS) to several species and tissues (human, mouse, rat, pig, heart, brain and liver) and concluded that mtNOS is not a variant of any known NOS enzymes. Mitochondria are capable of producing significant amounts of nitrogen radicals through the catalyzation of nitrosothiol release by the ubiquinon cycle of the respiratory chain. Subjecting mitochondria to oxidative stress resulted in the nitration and poly-ADPribosylation (PARylation) of proteins. Proteomic identification of the affected molecules revealed that dihydrolipoamide-dehydrogenase is PARylated and may act as a polyADP-ribose-polymerase (PARP). Thus, we uncovered a completely new and independent mechanism of mitochondrial nitrosative stress, which is catalyzed by enzymes of the respiratory chain. Then, we concentrated our efforts on the potential role of mitochondrial oxidants in pathological reactions such as diabetes

    Spatial Econometric Cross-Border Traffic Analysis for Passenger Cars – Hungarian Experience

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    The role of cross-border commuting needs is remarkable, given that large cross-border cities tend to have high traffic attractiveness. Thus, agglomeration effects are strongly prevalent in populous settlements close to the border. This is due to the fact that both Hungary and the neighboring countries are burdened by spatial inequalities; therefore, the traffic at the individual border crossing points is unbalanced. Our aim is to show the extent to which the introduction of certain public transport modes contributes to the reduction of cross-border passenger car traffic. In order to do this, we have to set up a spatial econometric model that can simultaneously handle the parallel public transport infrastructure, the cross-border attractiveness of border cities, and the impact of spatial inequalities. The results of the research shed light on how the introduction of each means of transport contributes to increasing the competitiveness of border regions. This will demonstrate the effectiveness of policy tools that can improve the competitiveness of a given macroregion

    Order of the Cities: Usage as a Transportation Economic Parameter

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    On one hand, better and better databases occur through the world, however for cities a lot of important data is unavailable. On the other hand, the cities are one of the most important units, where transportation interactions ought to be analyzed. In this recent paper the order of the cities (based upon the NUTS – Nomenclature des unités territoriales statistiques classification) will be introduced, and an answer will be found for the question whether this parameter could be used as a substitution of an economic parameter

    Generalized Linear Modeling of Crashes on Urban Road Links

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    As crash data have distinctive behavior like over-dispersion, researchers have used statistical methods to deal with this unique behavior of crash data specifically. This study employed generalized linear modeling techniques to develop the model. It was assumed that the accident counts followed negative-binomial distribution, and the link function was chosen to be the log link function. Negative-binomial modeling technique was chosen over Poisson distribution because it is the most used technique by many researchers as crash data may encounter over-dispersion. The accident data set showed greater variability between its variance and mean. The accident frequency distribution is shown in this study that it is highly skewed, with a very high number of road segments registering zero accidents. Negative binomial distribution was chosen over Poisson distribution after comparing Akaike’s Information Criterion (AIC) and Bayesian Information Criteria (BIC). The method is widely applied to count data. Twenty-two parameters were estimated in the model. Since p < 0.05 in the omnibus test, the null hypothesis is rejected, which indicates that the model is reasonably fit. The strongest variables in the model were witnessed to be the length of the links, number of lanes, average daily traffic, bus lane, number of buses and trolleys, and HGVs

    Expenditure responses, policy interventions and heterogeneous welfare effects in Hungary during the 2000s

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    VAT rates have changed multiple times and to a relatively great extent in Hungary during the past years. We use the resulting price changes in estimating the price- and income-elasticity of households' expenditures. As a novelty, we introduce an interaction term in estimating the demand system and show that the own price elasticity of food is increasing with increasing production for own consumption. Based on the estimation results, we compute the average welfare effect of the changes and describe also its heterogeneity within the population. We find that the VAT-reforms in 2006 and 2009 have both decreased the welfare of those in the first income quintile. We also look at the welfare effect of multiple hypothetic reforms such as the decrease of the VAT rate of food and a decrease of utility prices as well as a subsidy to production for own consumption. We find that the best targeted measure is an income-transfer to the low-income unemployed either directly or through participation in the public works scheme

    Absorption and Tensility of Bioactive Sutures Prepared for Cell Transplantation

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    Biodegradable scaffolds are widely used to transplant stem cells into various tissues. Recent studies showed that living stem cells can be attached to the surface of absorbable sutures in vitro. Soaking the absorbable material polyglactin in a cell culture medium and thereby creating a stem cell biofilm on its surface may initiate the absorption process even before implantation; therefore, the physicochemical properties of the suture may be compromised in vivo. We found that pre-incubation of sutures in cell culture media in vitro results in tensile strength reduction and faster suture absorption in a rat model of muscle injury. Shorter incubation times of up to 48 h do not influence absorption or tensility; therefore, it is advisable to limit incubation times to two days for polyglactin-based cell delivery protocols

    Magyarország határátkelőinek térökonometriai elemzése

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