The task complexity and Extraversion: an ERP study

Trying to prove the validity of Eysenck’s theories for the biological basis of personality many data for the differences between extraverts and introverts were collected. It was obtained, that the ERP differences between extraverts and introverts depend on the intensity and frequency of stimulation, but the papers concerning task difficulty dependence are very limited. The purpose of this work was to investigate how the task complexity affects ERP differences between extraverts and introverts. For testing the extraversion we used Eysenck Personality Questionary (EPQ). We recorded EEG under four equal audio series of pseudo-randomized low and high tones. We changed the level of task complexity by different instructions: 1 - passive listening; 2 – answering with the right index finger to the low tone and the left index finger to the high tone; 3 – counting the low tones; 4 – answering with the right index finger to low tones; We averaged stimulus locked ERP across each series and tones for extraverts and introverts separately. It was evident that the ERP differences between extraverts and introverts depend on the task complexity. We found P2, N2 and P3 latency differences and N1, P2, N2 and P3 amplitude differences. As whole extraverts showed larger N2 amplitudes and shorter N2 latencies. The differences were more pronounced in the task supposed less complexity and decreased with the increase of task complexity

UNEMPLOYMENT BENEFITS IN BULGARIA AND THEIR POTENTIAL FOR PREVENTION OF POVERTY

Prevention of poverty and social exclusion is a process directly related to public incentives for vulnerable groups aiming to achieve a decent and independent life. Labour income is one of the main prerequisites for overcoming the problem. However, a large number of the working population is economically inactive and do not even look for forms of employment. Low education levels, the lack of working habits and the limited demand for skilled labour are objective factors for this. The characteristics of the tax and social security system as well as the state policy with regard to income and the labour market towards vulnerable groups also affect the desire to work and employment opportunities

EEG Fractal Dimension Measurement before and after Human Auditory Stimulation

The aim of this work is to investigate the change of fractal dimension Df with the help of Higuchi Fractal Dimension measure (HFD) in Event-Related Potentials (ERP) of human EEG time series, obtained as a result of oddball paradigm usage and auditory stimulation with instruction for passive listening and counting tasks, depending on gender, personality type and task condition. In our study 77 healthy volunteers have been participated and 38 of them have been selected after a personality classification with Eysenck’s personality questionnaire (EPQ).The achieved results showed specific functional meaning of ERP HFD change depending on the individual personality type and gender

The Case For Emerging Market Funds

This study investigates the performance of open-end actively managed emerging market mutual funds during the time period 1999 to 2005. Our analysis is cross-sectional and time series across a wide range of emerging markets. Previous research includes performance studies of international mutual funds and emerging market funds, but none of the previous studies were as broad nor as specific as the current study. Monthly fund returns are compared to three indices (emerging markets, MSCI, and S&P 500 Index), using annualized returns, Sharpe ratio and Treynor ratio. The results show that the emerging market funds outperform the MSCI Index and the S&P 500 Index, but not the emerging market index. During the study period, an investor would have benefited by either investing in emerging market funds or the emerging market index. There is also a negative relationship between emerging market fund returns and turnover, and a positive relationship between fund returns and size

Infrared ellipsometric study of hydrogen-bonded long-chain thiolates on gold: Towards resolving structural details

A set of newly synthesized aryl-substituted amides of 16-mercaptohexadecanoic acid (R = 4-OH; 3,5-di-OH) are self-assembled on Au(111) substrate. Self assembled monolayers (SAMs) formed by these molecules are studied by ellipsometry from infrared to visible spectral range. Best fit calculations based on the three-phase optical model are employed in order to determine the average tilt angle of the hydrocarbon chains. The data revealed that the SAMs reside in a crystalline-like environment as the long methylene chains predominantly exist in all-trans conformation. The calculated tilt angle of the hydrocarbon chain is decreased by approximately 12° in comparison with the one for the correspondent long-chain n-alkyl thiols. Strong hydrogen bonded networks were detected between the amide proton and the carbonyl oxygen as well as between hydroxyl groups in the end aryl substituents. The transition dipole moments of the C=O, N-H and O-H modes are oriented almost parallel to the gold surface

Infrared ellipsometric study of hydrogen-bonded long-chain thiolates on gold: Towards resolving structural details

A set of newly synthesized aryl-substituted amides of 16-mercaptohexadecanoic acid (R = 4-OH; 3,5-di-OH) are self-assembled on Au(111) substrate. Self assembled monolayers (SAMs) formed by these molecules are studied by ellipsometry from infrared to visible spectral range. Best fit calculations based on the three-phase optical model are employed in order to determine the average tilt angle of the hydrocarbon chains. The data revealed that the SAMs reside in a crystalline-like environment as the long methylene chains predominantly exist in all-trans conformation. The calculated tilt angle of the hydrocarbon chain is decreased by approximately 12° in comparison with the one for the correspondent long-chain n-alkyl thiols. Strong hydrogen bonded networks were detected between the amide proton and the carbonyl oxygen as well as between hydroxyl groups in the end aryl substituents. The transition dipole moments of the C=O, N-H and O-H modes are oriented almost parallel to the gold surface

Synthesis of some 1,8-naphthalic anhydride derivatives as dyes for polymeric materials

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Bio-inspired antibacterial polymer coatings with included silver nanoparticles and porphyrin-based photosensitizer

peer reviewedIn this work, we have prepared novel bio-inspired photoactive antibacterial polymer coatings on stainless steel (SS), which possess good mechanical and antibacterial properties. The formation of the photoactive antibacterial polymer coatings consists of the sequential deposition of three components on SS substrate (1) a catechol-based cationic glue P(mDOPA)-co-P(DMAEMA+) used as a universal primer, which facilitates the strong anchoring to SS; (2) a silver loaded (Pox(mDOPA)-Ag0/PAH) nanogel decorated with o-quinones applied to enhance the antibacterial properties of the coating and to permit the covalent grafting of the photosensitizer, and (3) an ethylene diamine derivative of protoporphyrin IX (PPIX-ED). Porphyrins are widely recognized for their antibacterial activity by producing reactive oxygen species when exposed to visible light. To estimate the deposition of the components on the SS substrate, SEM-EDX elemental mapping analysis was applied. Scratch test, nanoindentation, and accelerated property mapping (XPM) analysis were used to assess the mechanical properties of the coatings. The established antibacterial activity of the prepared photoactive polymer coatings on SS against Gram-positive B. subtilis and Gram-negative E. coli strains demonstrates their potential applications in medical and biomedical fields

Design and Photophysics of 2-Vinyl Quinazolin-4-ones

The reported work has been carried out under Contract DN 19/11, 10.12.2017, with the National Science Fund of Bulgaria