Babeş-Bolyai University
  • Cluj-Napoca, Cluj, Romania
Recent publications
Background The extremely halophilic archaeon Haloferax (Hfx.) alexandrinus DSM 27206 T was previously documented for the ability to biosynthesize silver nanoparticles while mechanisms underlying its silver tolerance were overlooked. In the current study, we aimed to assess the transcriptional response of this haloarchaeon to varying concentrations of silver, seeking a comprehensive understanding of the molecular determinants underpinning its heavy metal tolerance. Results The growth curves confirmed the capacity of Hfx. alexandrinus to surmount silver stress, while the SEM–EDS analysis illustrated the presence of silver nanoparticles in cultures exposed to 0.5 mM silver nitrate. The RNA-Seq based transcriptomic analysis of Hfx. alexandrinus cells exposed to 0.1, 0.25, and 0.5 mM silver nitrate revealed the differential expression of multiple sets of genes potentially employed in heavy-metal stress response, genes mostly related to metal transporters, basic metabolism, oxidative stress response and cellular motility. The RT-qPCR analysis of selected transcripts was conducted to verify and validate the generated RNA-Seq data. Conclusions Our results indicated that copA, encoding the copper ATPase, is essential for the survival of Hfx. alexandrinus cells in silver-containing saline media. The silver-exposed cultures underwent several metabolic adjustments that enabled the activation of enzymes involved in the oxidative stress response and impairment of the cellular movement capacity. To our knowledge, this study represents the first comprehensive analysis of gene expression in halophillic archaea facing increased levels of heavy metals.
Mercury (Hg) is a toxic, non-essential element for living organisms, frequently present in high concentrations in soils from industrial areas. The total, dissolved, and labile Hg concentrations in garden soils and their accumulation in edible vegetables (onion, garlic, lettuce, and parsley) grown on contaminated soils in localities situated a former mining area were evaluated. The labile Hg fraction was estimated by diffusive gradient in thin films (DGT). The soil-to-vegetable transfer factors, as well as the health risk by exposure to Hg, were calculated based on the labile Hg concentration in soil. The total Hg concentration in soil varied widely (0.11–3.77 mg kg−1), Hg in soil solution ranged between 2.14 and 20.2 μg L−1 and labile Hg between 1.13 and 18.6 μg L−1. About 36–96% (84% on average) of the Hg concentration in soil solution was found in labile form. Multivariate analysis revealed significant correlations between the labile Hg concentration in soil and Hg accumulated in vegetables. The hazard indices showed that, although the study area is affected by legacy pollution, exposure to soil and consumption of locally grown vegetables do not pose health risks.
This paper explores the constitution of a moral economy of welfare through acts of benefit fraud. The structural conditions of contemporary labour, citizenship and migration regimes in Europe exclude large shares of workers from access to social citizenship and place them in a position of undeserving trespassers of the social contract. Drawing on the case of Bulgarian Roma engaged in precarious labour and short-term intensive mobility between Bulgaria and the Netherlands, I show how labour conditions in both countries and the structures of the welfare regimes effectively exclude them from access to social citizenship and confine them to the realms of informal work, thus putting them in a position of differential inclusion. The benefit fraud in this context has multiple interpretations—ranging from crime through a survival strategy to a claim to social justice. By mobilizing the idea of the moral economy of welfare, I seek to explain how migrants justify their actions not as a transgression, but as a claim to social citizenship and a critique of an unjust social and economic order. In a moral economy of welfare, the migrants see themselves as deserving state support both by virtue of being citizens and of being good workers. Being excluded from proper welfare support is interpreted as a failure of both states. In this context, the fraud is framed in moral terms as an act of citizenship aiming to restore justice.
The closed-form expression for pure R^2 vacuum solution obtained in Phys. Rev. D 107, 104008 (2023) lends itself to a generalization to axisymmetric setup via the modified Newman–Janis algorithm. We adopt the procedure put forth in Phys. Rev. D 90, 064041 (2014) bypassing the complexification of the radial coordinate. The procedure presumes the existence of Boyer-Lindquist coordinates. Using the Event Horizon Telescope Collaboration results, we model the central black hole M87* by the thus obtained exact rotating metric, depending on the mass, rotation parameter and a third dimensionless parameter. The latter is constrained upon investigating the shadow angular size assuming mass and rotation parameters are those of M87*. Stability is investigated.
To a strongly 𝐺-graded algebra 𝐴 with 1-component 𝐵, we associate the group Picent gr ⁢ ( A ) \mathrm{Picent}^{\mathrm{gr}}(A) of isomorphism classes of invertible 𝐺-graded ( A , A ) (A,A) -bimodules over the centralizer of 𝐵 in 𝐴. Our main result is a Picent \mathrm{Picent} version of the Beattie–del Río exact sequence, involving Dade’s group G ⁢ [ B ] G[B] , which relates Picent gr ⁢ ( A ) \mathrm{Picent}^{\mathrm{gr}}(A) , Picent ⁢ ( B ) \mathrm{Picent}(B) , and group cohomology.
Chronically high blood glucose levels (hyperglycaemia) can compromise healthy ageing and lifespan at the individual level. Elevated oxidative stress can play a central role in hyperglycaemia-induced pathologies. Nevertheless, the lifespan of birds shows no species-level association with blood glucose. This suggests that the potential pathologies of high blood glucose levels can be avoided by adaptations in oxidative physiology at the macroevolutionary scale. However, this hypothesis remains unexplored. Here, we examined this hypothesis using comparative analyses controlled for phylogeny, allometry and fecundity based on data from 51 songbird species (681 individuals with blood glucose and 1021 individuals with oxidative state data). We measured blood glucose at baseline and after stress stimulus and computed glucose stress reactivity as the magnitude of change between the two time points. We also measured three parameters of non-enzymatic antioxidants (uric acid, total antioxidants and glutathione) and a marker of oxidative lipid damage (malondialdehyde). We found no clear evidence for blood glucose concentration being correlated with either antioxidant or lipid damage levels at the macroevolutionary scale, as opposed to the hypothesis postulating that high blood glucose levels entail oxidative costs. The only exception was the moderate evidence for species with a stronger stress-induced increase in blood glucose concentration evolving moderately lower investment into antioxidant defence (uric acid and glutathione). Neither baseline nor stress-induced glucose levels were associated with oxidative physiology. Our findings support the hypothesis that birds evolved adaptations preventing the (glyc)oxidative costs of high blood glucose observed at the within-species level. Such adaptations may explain the decoupled evolution of glycaemia and lifespan in birds and possibly the paradoxical combination of long lifespan and high blood glucose levels relative to mammals.
One of the most difficult types of arithmetic word problems in primary school is compare problems. Among these problems, the most problematic are those in which the relational term is not consistent with the arithmetic operation required for the solution. This study investigates how 10–11-year-old primary school pupils’ read and interpret compare word problems. The consistency effect and the differences between successful and unsuccessful problem solvers are mainly studied using eye-tracking technology. The results show that students are more successful in solving consistent language (CL) problems than inconsistent language (IL) problems. Regarding eye movements during reading and solving the problems, fixation duration on the relational sentence and numbers is longer in the case of IL problems than in the case of CL problems. Compared to successful problem solvers, unsuccessful solvers fixate longer on the relational term, the pronominal reference word, and the statement and relational sentence of IL problems, but not on numbers.
We generalize to exact categories some new perspectives on projectivity, which allow us to unify a series of recent concepts from module categories or abelian categories and to obtain automatically dual results. We discuss objects having a minimal subprojectivity domain in exact categories, and we study properties of such domains, including several closure properties. We give applications to (possibly non-abelian) quasi-abelian categories, finitely accessible and exactly definable additive categories, and in particular, to module and comodule categories.
The Termini Online Hungarian–Hungarian Dictionary and Database describes the lexicon of the Hungarian language as spoken in the countries neighbouring Hungary. It is considered to be a general dictionary of present-day Hungarian. Each entry contains authentic example sentences to illustrate the use of the headword, making it possible to examine the special use of a word or construction in a grammatical and pragmatic context. The lexicographical database is edited online in eight countries. The editors of the dictionary are members of the Termini Hungarian Language Research Network. Online editing makes it possible for the dictionary to expand – even simultaneously – as a result of activity in eight countries. In the present study, the authors review the novelties and peculiarities of the dictionary in some detail, touching on the following topics: dictionary structure, IT support, database character, multimedia elements, and labelling system.
Analytical equations that describe the dynamic behavior of beams with a soft clamped end are very little treated in the literature. The paper aims to solve this problem by introducing a stiffness in the hinged end of the beam, respectively by comparing the bending moment in the clamped end with the slope in the hinge of the same end of the beam. The other end of the beam is permanently hinged. The characteristic equation for determining the eigenvalues and the modal function is deduced. The results show the first four vibration modes for seven stiffness values and the eigenvalues for eleven cases of soft clamped end.
In this paper, we determine properties of the coefficients of the integral operator G α 1, α 2 ,..., αn , β . We want to see if some results obtained on the interior unit disk can be extended on the exterior unit disk, so we make use of the usual transformation g ( z ) = 1 f ( 1 z ) g\left( z \right) = {1 \over {f\left( {{1 \over z}} \right)}} .
The advancements in digital technologies, especially for mobile apps, enabled simplified data collection methods. Consequently, through Citizen Science, numerous opportunities arose for citizens to become contributors and not just beneficiaries of scientific research. Furthermore, through such engagement, citizens can participate in decision-making processes at different spatial scales, getting closer to the civic aspiration of a digital agora. This paper offers a systematic review of 303 studies on such initiatives to outline the potential of mobile apps in Citizen Science. Based distinctly on their specificities and the needs they address, three content categories were highlighted: a) monitoring tools, b) validation of techniques and methods to improve mobile technologies for Citizen Science, and c) participatory approaches of citizens employing mobile apps. The review also showed a susceptibility of several domains of activity towards Citizen Science, such as monitoring biodiversity and reconnecting people with nature, environmental risk monitoring or improving well-being. The findings highlight future research potential in addressing topics such as new technologies to increase Citizen Science performance and its contributions to Open Science, as well as diversification and enhancement of citizen scientists’ contributions.
Background The use of patient‐reported outcomes (PRO) in clinical practice is gaining increasing attention. This study aimed to provide a critical assessment of the current state‐of‐the‐art and beliefs about the use of PRO in the management of people with epilepsy across some European countries. Methods Structured interviews were conducted with European experts to collect insights about (I) the personal experience with PRO; (II) the value and impact of PRO in the decision‐making process at the national level; and (III) the interest for and use of PRO by national health authorities. Results Nine neurologists (Austria, Belgium, Czechia, Denmark, France, Greece, Italy, Poland, and United Kingdom), three health economists (Portugal, Romania, and Sweden), and one epidemiologist (Slovakia) participated. They all stated that PRO are collected at their own countries in the context of clinical trials and/or specific projects. During everyday clinical practice, PRO are collected routinely/almost routinely in Austria and Sweden and only at the discretion of the treating physicians in Czechia, Denmark, France, Greece, and Portugal. There was complete consensus about the favorable impact that the PRO can have in terms of clinical outcomes, healthcare resources utilization, and general patient satisfaction. Only participants from Portugal and Sweden answered that the PRO are perceived as very important by the National Health Authorities of their respective countries. Conclusions Differences exist in attitudes and perspectives about PRO in epilepsy across Europe. An active plan is warranted to harmonize the measurement of PRO and ensure they can be relevant to people with epilepsy and health services.
The article examines how deindustrialization as economic restructuring and housing regime changes evolved interconnectedly in Romania during the Great Transformation from state socialism to neoliberal capitalism. This article also explores how they acted as conditions for the emergence of a real-estate-development-driven housing regime (REDD-HR) alongside other factors. The analysis is from the perspective of the geographical political economy on the variegated pathways of these phenomena across borders and secondary statistical data collected by two research projects conducted in Romania in the past two years. In the Eastern semiperiphery of global capitalism or a country of the Global Easts with a socialist legacy, after 1990, the state restructured the economy by privatizing industry and public housing. During state socialism, the housing regime supported industrialization-based urbanization, whereas deindustrialization-cumprivatization in emerging capitalism facilitated the appearance of real estate development. On the one hand, the article enriches studies on deindustrialization by highlighting the role of housing in the transformation of industrial relations; on the other hand, the paper revisits housing studies by analyzing deindustrialization as a process with an impact on the changing housing regime. Altogether, deindustrialization-cum-privatization and the changing housing sector are analyzed as prerequisites of the REDD-HR.
Sustainability is a key topic nowadays, mostly because in the last decade the pollution levels have reached an all-time high. National governments are searching for sustainable and environmentally friendly solutions to decrease the amount of pollution. This study is a cross-sectional study on 27 European countries, using data gathered in 2020. This study's main goal is to show the environmental sustainability of public transportation and its impact on country development in Europe. The methodology used in this study will consist of spatial econometrics methods with visual maps and graphs to help with a better visual representation of the phenomena presented. The empirical evidence will be confirmed by the spatial regression's results. Because the spatial diagnostic tests revealed that the spatial processes are present in terms of both spatial lag and spatial errors, the model that was used was a Spatial Autoregressive Moving Average Model (SARMA). Moreover, the environmental sustainability of public transport is also a significant factor. The expected results from which this study began – specifically, that the spatiality has a significant impact in modelling the relationship between public transportation and economic development – were confirmed.
In this paper, we use theoretical and computational tools to continue our investigation of ‐ hamiltonian graphs, that is, graphs in which the removal of any pair of adjacent vertices yields a hamiltonian graph, and their interplay with ‐ hamiltonian graphs, that is, graphs in which every vertex‐deleted subgraph is hamiltonian. Perhaps surprisingly, there exist graphs that are both ‐ and ‐hamiltonian, yet non‐hamiltonian, for example, the Petersen graph. Grünbaum conjectured that every planar ‐hamiltonian graph must itself be hamiltonian; Thomassen disproved this conjecture. Here we show that even planar graphs that are both ‐ and ‐hamiltonian need not be hamiltonian, and that the number of such graphs grows at least exponentially. Motivated by results of Aldred, McKay, and Wormald, we determine for every integer that is not 14 or 17 whether there exists a ‐ hypohamiltonian , that is non‐hamiltonian and ‐hamiltonian, graph of order , and characterise all orders for which such cubic graphs and such snarks exist. We also describe the smallest cubic planar graph which is ‐hypohamiltonian, as well as the smallest planar ‐hypohamiltonian graph of girth 5. We conclude with open problems and by correcting two inaccuracies from the first article.
In this paper, we review the concept of charge and chirality for particles and antiparticles. We point out that the commonly accepted equivalence of particles and antiparticles—with difference only in the opposite signs of their charges, which follows from the CPT invariance—is valid only for free non-chiral particles. We point out that the the equivalence of particles and antiparticles is violated if the weak interaction is turned on. We also discuss that within the standard model even free neutrinos are exceptions, as they can be produced only in chiral states. We conclude that in spite of a long history of antiparticles, interesting theoretical and experimental challenges remain in their complete understanding.
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9,336 members
Elisabeta Cristina Timis
  • Department of Chemical Engineering
  • Raluca Ripan Institute for Research in Chemistry, Department of Analytical Chemistry
Oana Alexandra David
  • Department of Clinical Psychology and Psychotherapy
Anca Farkas
  • Department of Molecular Biology and Biotechnology
Kogalniceanu Str. #1, 400084, Cluj-Napoca, Cluj, Romania
Head of institution
Prof. Dr. Daniel David
00 40 264 405300
00 40 264 591906