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Effect of 905 MHz microwave radiation on colony growth of the yeast Saccharomyces cerevisiae strains FF18733, FF1481 and D7

Effect of 905 MHz microwave radiation on colony growth of the yeast Saccharomyces cerevisiae strains FF18733, FF1481 and D7

Background. The aim of this study was to evaluate the effect of weak radiofrequency microwave (RF/MW) radiation emitted by mobile phones on colony growth of the yeast Saccharomyces cerevisiae.

Materials and methods. S. cerevisiae strains FF18733 (wild-type), FF1481 (rad1 mutant) and D7 (commonly used to detect reciprocal and nonreciprocal mitotic recombinations) were exposed to a 905 MHz electromagnetic field that closely matched the Global System for Mobile Communication (GSM) pulse modulation signals for mobile phones at a specific absorption rate (SAR) of 0.12 W/kg.

Results. Following 15-, 30- and 60-minutes exposure to RF/MW radiation, strain FF18733 did not show statistically significant changes in colony growth compared to the control sample. The irradiated strains FF1481 and D7 demonstrated statistically significant reduction of colony growth compared to non-irradiated strains after all exposure times. Furthermore, strain FF1481 was more sensitive to RF/MW radiation than strain D7.

Conclusions. The findings indicate that pulsed RF/MW radiation at a low SAR level can affect the rate of colony growth of different S. cerevisiae strains.

Open access
The comparative method for policy studies: the thorny aspects

Abstract

Over the past decades, the comparative method has attracted the attention of the theorists, and studies based on this approach have increased in applied policy research. In their daily and strategically policy decisions, the decision makers from local, regional and national levels use more and more the comparative research methods, especially due to interlinked relationship and the need for bench learning and benchmarking practices. The comparative method allows the actors to analyse other experiences, and thus to take decisions more efficient. This is a normal, an inevitable situation, when the unit of analysis is a country, a field of matters or a process where researchers compare cases from empirical or theoretical point of view. The purpose of this paper is to provide a critical view on the capacity of comparative method to foster knowledge in policy studies. The intention is to see and to explore the utility of comparative method for policy studies and policy analysis, since a new approach “evidence-based policymaking” arise, emphasising the importance of using evidence from other political and policy systems.

Open access
Indirect relationship between lipophilicity and maximum residue limit of drugs determined for fatty tissue

Abstract

The aim of this study was to determine the correlation between lipophilicity and maximum residue limit (MRL) value specified for veterinary drugs in the fatty tissue of various animal species. The analysis was performed on a group of 73 compounds with different modes of action and MRL values determined for the fatty tissue of animals. Additionally, the logarithm of water/organic phase partition ratio (LogP) and the ratio of ionised and unionised substance in buffer with pH 7.4 (LogD7.4) were calculated. The main analysis was performed after the division of the whole group into six fractions. The linear correlation and regression analysis were used to determine the indirect relationship between the mean arithmetic value of LogP or LogD7.4 in selected fractions and related LogMRL of the drugs tested. The calculations revealed a linear correlation between fractioned lipophilicity and LogMRL values for the analysed compounds. The existence of indirect relationship between lipophilicity and MRL values determined for fatty tissue was confirmed.

Open access
Corporate Governance and Financial Performance Nexus: Any Bidirectional Causality?

Abstract

Most studies on corporate governance recognize endogeneity in the nexus between corporate governance and financial performance. Little attention has, however, been paid to the direction of causality between the two phenomena, and hence the Vector Error Correction (VEC) model, which allows for endogenous determination of the direction of causality, has not been widely employed. This study fills that gap by estimating the nexus and the direction of causality using the VEC model to analyze panel data on selected listed firms in Nigeria. The results agree with the findings of most previous studies that corporate governance significantly affects financial performance. Board skills, board composition and management skills enhanced financial performance indicators – return on equity (ROE), return on asset (ROA) and net profit margin (NPM); in many occasions, significantly. Board size and audit committee size did not, and can actually undermine financial performance. More importantly, financial performance did not significantly affect corporate governance. On the basis of the lag structure of the VEC model, this study affirms unidirectional causality in the nexus, running from corporate governance to financial performance, nullifying the hypothesis of bidirectional causality in the nexus.

Open access
Cultural Leadership and Entrepreneurship As Antecedents of Estonia’s Singing Revolution and Post-Communist Success

Abstract

The Baltic people of Estonia, Lithuania, and Latvia gained recognition with their successful use of a cultural tool, singing folkloric songs, to protest collectively against their common Soviet oppressor in the summer of 1988, preceding the collapse of the Soviet Union. Rational-choice theorists have argued that large rebellious movements are paradoxical because the larger the number of potential revolutionaries, the greater the leadership, participation, and coordination problems they face (Olson, 1971; Tullock, 1974). This paper investigates Estonia’s Singing Revolution and illustrates how ethnic Estonians used their shared cultural beliefs and singing traditions as a tacit, informal institutional solution to overcome the collective-action problems with organizing and participating in mass singing protests against the Soviet regime. The paper goes further to extend the standard rational-choice framework and to include a more dynamic, entrepreneurial-institutional perspective on socio-cultural change by accounting for the role of cultural leaders as cultural entrepreneurs, a subset of institutional entrepreneurs. The success of Estonia’s Singing Revolution can be ultimately attributed to leadership in the form of cultural entrepreneurship going back to pre-Soviet Estonian times. The revived legacy of ancient shared beliefs, folkloric practices, and singing tradition represented the necessary social capital for the Estonian people to voice collectively shared preferences for political and economic governance during a window of constitutional opportunity. Mikhail Gorbachev’s Glasnost, a policy aimed to improve Soviet formal institutions by fostering freedom of speech and political transparency, also provided a context propitious for the Singing Revolution because it lowered the perceived costs of participation in the rebellious singing and opened a window of opportunity for political change.

Open access
Theory of Patronized Goods. Liberal Evolution of Paternalism

Abstract

The neo-classical principles of rational behavior are considered in the context of the nature of paternalism as the basis of the Theory of patronized goods. The formation of society’s normative interests is discussed in concern of political aspects. The article illustrates the theoretical and the practical aspects of the concept of consociation democracy, providing liberalization of the institutions for making political and economic decisions. The results of analysis reveal a pattern of paternalism drifting towards institutional liberalization. Proposed a hypothesis explaining why the economic policy in modern Russia still remains somewhere between archaic and merit paternalism.

Open access
Hybridizing ability and heterosis between Eucalyptus urophylla and E. tereticornis for growth and wood density over two environments

Abstract

Interspecific hybrids of Eucalyptus urophylla × E. tereticornis in a factorial-mating design were used to analyze general hybridizing ability (GHA), specific hybridizing ability (SHA) and heterosis for height (H; 0.5, 1.5, 2.5, 4 and 7.5 years in age), diameter at breast height (D; ages 1.5, 2.5, 4 and 7.5) and wood density (WD; age 7.5) across two environments. The GHA variances were significant for all traits, and those of the SHA were also significant for most of the traits but with less magnitude, indicating the greater importance of additive gene effects in explaining the phenotypic variation among hybrids. The narrow-sense heritability (h2) and dominance (d2) estimates with hybrid growth and wood density ranged between 0.02±0.05 (d2 in D7.5) and 0.23±0.10 (d2 in H1.5) over the different ages, suggesting weak additive and dominant effects on these traits. Additive genetic correlations of growth with wood density were weak at age 7.5. Female general combining ability (GCA) based on maternal open-pollinated families was not necessarily a good indicator of GHA as their correlations were 0.48 (P=0.17), 0.65 (P=0.04) and -0.56 (P=0.10) for H7.5, D7.5 and WD7.5, respectively. A great proportion of hybrids showed positive female-parent heterosis (FPH) at age 7.5, with the highest relative FPH of 47.2% in D7.5. This study demonstrates the heterosis between inter-sectional species and could have implications for E. urophylla × E. tereticornis hybrid breeding.

Open access
Mixed Symmetry-Tipe (k,1) Massless Tensor Fields. Consistent Interactions Of Dual Linearized Gravity

Abstract

A particular case of interactions of a single massless tensor field with the mixed symmetry corresponding to a two-column Young diagram (k,1) with k=4, dual to linearized gravity in D=7, is considered in the context of: self-couplings, cross-interactions with a Pauli-Fierz field, cross-couplings to purely matter theories, and interactions with an Abelian 1-form. The general approach relies on the deformation of the solution to the master equation from the antifield-BRST formalism by means of the local cohomology of the BRST differential.

Open access
Hydrazinyldiene-chroman-2,4-diones in inducing growth arrest and apoptosis in breast cancer cells: Synergism with doxorubicin and correlation with physicochemical properties

Abstract

This study evaluates the effects of previously synthesized hydrazinyldiene-chroman-2,4-diones on cell proliferation and apoptosis, cell cycle distribution and migration capacity of MCF-7 breast cancer cells in synergy with doxorubicin. Physicochemical properties of the synthesized compounds were correlated with their structure and activity. Significant cell viability decrease in comparison with the effect of doxorubicin alone and the reference 4-hydroxycoumarin was observed when combination treatment comprising doxorubicin and the title compounds was applied. Synergistic effect with doxorubicin was also observed in down-regulation of phospho-Thr308Akt levels, confirming reduced proliferation and increased apoptosis. Combined treatment increased the percentage of cells arrested at the G2/M stage. Additive inhibition of cell migration was also observed, pointing to the possibility of reducing the risk of metastases. With their solubility profile and log D7.4, all the synthesized compounds follow Lipinski’s rule of five for good permeability (absorption) potential.

Open access
Synthesis of certain pyrrole derivatives as antimicro-bial agents

Synthesis of certain pyrrole derivatives as antimicro-bial agents

In an effort to establish new pyrroles and pyrrolo[2,3-d] pyrimidines with improved antimicrobial activity we report here the synthesis and in vitro microbiological evaluation of a series of pyrrole derivatives. A series of new 2-aminopyrrole-3-carbonitriles (1a-d) were synthesized from the reaction of benzoin, primary aromatic amines and malononitrile, from which a number of pyrrole derivatives (2a-d to 5a-d) and pyrrolo[2,3-d]pyrimidines (6a-d to 10a, d) were synthesized. The in vitro antimicrobial testing of the synthesized compounds was carried out against Gram-positive, Gram-negative bacteria and fungi. Some of the prepared compounds, [2-amino-1-(2-methylphenyl)-4,5-diphenyl-1H-pyrrole-3-carbonitriles (1b), 2-amino-3-carbamoyl-1-(3-methylphenyl)-4,5-diphenyl-1H-pyrroles (2b), N-(3-cyano-1-(2-methylphenyl)-4,5-diphenyl-1H-pyrrol-2-yl)-acetamides (3b), N-(3-cyano-1-(3-methylphenyl)-4,5-diphenyl-1H-pyrrol-2-yl)-acetamides (3c), 2-amino-1-(4-methoxyphenyl)-4,5-diphenyl-3-tetrazolo-1H-pyrroles (5d), 7-(4-methoxyphenyl)-5,6-diphenyl-7H-pyrrolo [2,3-d]pyrimidin-4(3H)-ones (7d), 7-(3-methylphenyl)-5,6-diphenyl-7H-pyrrolo[2,3-d]pyrimidin-4(3H)-thione (9b) and N-(7-(2-methylphenyl)-5,6-diphenyl-7H-pyrrolo[2,3-d] pyrimidine)-N-aryl amines (10a)] showed potent antimicrobial activity.

Open access