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Search Results: 1 - 10 of 401245 matches for " M. Todorova "
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World Demand as a Determinant of Immiserizing Growth  [PDF]
Tamara Todorova
iBusiness (IB) , 2010, DOI: 10.4236/ib.2010.23033
Abstract: Theoretically economic growth could have negative effects over the growing economy when production expands for products the world demand for which is inelastic. If growth occurs in sectors and for products the world demand for which is elastic it could be expected that total revenues to domestic producers and exporters increase. Our goal is to prove that growth would be immiserizing only for products for which world demand is inelastic and expansion leads to a sizable worsening of the terms of trade. We show that there are few such commodities, namely food products and natural resources such as oil. Studying econometrically the demand function for Brazilian coffee as an example, we compare our estimation of the elasticity of demand for Brazil’s exports of green coffee with other research on the world elasticity of demand for green coffee. We conclude that for manufactured products the demand for which is highly elastic it is unlikely that exporting countries fall into immiserization, therefore, growth and further participation in global trade turn out to be quite beneficial. Our conclusion is that too much emphasis is put in economic theory and trade policy on the concept of immiserizing growth which is more of a theoretical possibility than a real-life problem.
Cloning, purification and characterization of the ribosomal protein L11 from E. coli  [PDF]
Roumiana Todorova
American Journal of Molecular Biology (AJMB) , 2011, DOI: 10.4236/ajmb.2011.11005
Abstract: A high-expression system of L11 was constructed and investigated its interaction with other elements of the ribosome using physicochemical methods. The gene rplK, coding for the protein L11 from the E. coli 50S ribosomal subunit was amplifyied, cloned and over-expressed. The protein L11 was purified under native and denaturing conditions, refolded and the structure of both proteins was compared. The protein L11 properly refolded from 6M urea after dialysis. Experiments on binding of proteins L11, RRF and EF-G from Escherichia coli were performed by ana-lytical centrifugation and Biacore. Specific binding between protein L11 and RRF by analytical cen-trifugation was not detected probably due to struc-tural reasons. These findings may be helpful in the design of new antibiotics that specifically disrupt the interactions in the “GTP-associated site” of the bac-terial ribosome, as many of them are not effective anymore. A common intrinsically disordered region of protein L11 was found to be the amino acid se-quence 86-97, while the residues 67-74, containing the linker region, are predicted to be disordered by DisEMBL.
Disorder structural predictions of the native EWS and its oncogenic fusion proteins in rapport with the function  [PDF]
Roumiana Todorova
Advances in Bioscience and Biotechnology (ABB) , 2012, DOI: 10.4236/abb.2012.31005
Abstract: The Intrinsic structural disorder (ISD) of native EWS and its fusion oncogenic proteins, including EWS/FliI, EWS/ATF1 and EWS/ZSG, was estimated by different Predictors. The ISD difference between the wild type and the oncogenic fusions found in the CTD is due to the fusion partner, usually a transcription factor (TF). A disordered region was found in the sequence (AA 132 - 156) of the NTD (EAD) of EWS, consisting of the longest region free of Y motifs. The IQ domain (AA 258 - 280), a Y-free region, flanked by two Y-boxes, is also disordered by all used Predictors. The EWS functional regions RGG1, RGG2 and RGG3 are predominantly disordered. A strong dependence was found between the structure of EWS protein and its oncogenic fusions, and their estimated ISD. The oncogenic function of the fusions is related to a decreased ISD in the CTD, due to the fused TF. The Predictors shown that the different isoforms have similar profiles, shifted with some amino acids, due to the translocations. On the bases of the prediction results, an analysis was made of the EWS sequence and its functional regions with increased ISD to make a relationship sequence-disorder-function that could be helpful in the design of antitumor agents against the corresponding malignances.
The Economic Dynamics of Inflation and Unemployment  [PDF]
Tamara Todorova
Theoretical Economics Letters (TEL) , 2012, DOI: 10.4236/tel.2012.22025
Abstract: We study the time path of inflation and unemployment using the Blanchard treatment of the relationship between the two and taking the monetary policy condition into account. We solve the model both in continuous and discrete time and compare the results. The economic dynamics of inflation and unemployment shows that they fluctuate around their intertemporal equilibria, inflation around the growth rate of nominal money supply, respectively, and unemployment around the natural rate of unemployment. However, while the continuous-time case shows uniform and smooth fluctuation for both economic variables, in discrete time their time path is explosive and nonoscillatory. The hysteresis case shows dynamic stability and convergence for inflation and unemployment to their intertemporal equilibria both in discrete and continuous time. When inflation affects unemployment adversely the time paths of the two, both in discrete and continuous time, are dynamically unstable.
The 22-year cycle in the geomagnetic 27-day recurrences reflecting on the F2-layer ionization
E. M. Apostolov, D. Altadill,M. Todorova
Annales Geophysicae (ANGEO) , 2004,
Abstract: Solar cycle variations of the amplitudes of the 27-day solar rotation period reflected in the geomagnetic activity index Ap, solar radio flux F10.7cm and critical frequency foF2 for mid-latitude ionosonde station Moscow from the maximum of sunspot cycle 18 to the maximum of cycle 23 are examined. The analysis shows that there are distinct enhancements of the 27-day amplitudes for foF2 and Ap in the late declining phase of each solar cycle while the amplitudes for F10.7cm decrease gradually, and the foF2 and Ap amplitude peaks are much larger for even-numbered solar cycles than for the odd ones. Additionally, we found the same even-high and odd-low pattern of foF2 for other mid-latitude ionosonde stations in Northern and Southern Hemispheres. This property suggests that there exists a 22-year cycle in the F2-layer variability coupled with the 22-year cycle in the 27-day recurrence of geomagnetic activity. Key words. Ionosphere (mid-latitude ionosphere; ionosphere- magnetosphere interactions) – Magnetospheric physics (solar wind-magnetosphere interactions)
The relation of steady evaporating drops fed by an influx and freely evaporating drops
Desislava Todorova,Uwe Thiele,Len M. Pismen
Physics , 2010, DOI: 10.1007/s10665-011-9485-1
Abstract: We discuss a thin film evolution equation for a wetting evaporating liquid on a smooth solid substrate. The model is valid for slowly evaporating small sessile droplets when thermal effects are insignificant, while wettability and capillarity play a major role. The model is first employed to study steady evaporating drops that are fed locally through the substrate. An asymptotic analysis focuses on the precursor film and the transition region towards the bulk drop and a numerical continuation of steady drops determines their fully non-linear profiles. Following this, we study the time evolution of freely evaporating drops without influx for several initial drop shapes. As a result we find that drops initially spread if their initial contact angle is larger than the apparent contact angle of large steady evaporating drops with influx. Otherwise they recede right from the beginning.
Optimal Time and Opportunity Cost of Job Search in Low-Income Groups: An Out-of-the-Job Search Model  [PDF]
Tamara Todorova, Veselina Dzharova
Modern Economy (ME) , 2010, DOI: 10.4236/me.2010.13022
Abstract: Our paper studies the causes of poverty from the perspective of job search. We show that poor people remain poor because they have less time and initial endowment to search for a better job. Initial endowment is key to successful job search, as one can afford not to work and search longer for a better job. Having an initial endowment, a worker is able to educate or re-qualify himself. Working long hours and obtaining low pay, poor people have little time to look for a better job. Low-paid, low-skilled jobs rarely allow on-the-job search like high-paid positions where with the help of contacts and a lot of idle time professionals seek better jobs. Quitting in order to find a better job increases the opportunity cost of search for poorer people. Since they do not have any accumulated income, they can only live off their salary. With less income and time, poorer people are less likely to get educated since education requires both wealth and free time. But being less educated, they are likely to remain poor as education is a promise for success in contemporary society. Thus, they remain in the vicious circle of poverty. In order to prove this hypothesis we investigate optimal search time for a better job as dependent on factors such as wage rate, individual’s income, education, and skills.
Generalized Option Betas  [PDF]
Sven Husmann, Neda Todorova
Journal of Mathematical Finance (JMF) , 2013, DOI: 10.4236/jmf.2013.33035

This paper extends the option betas presented by Cox and Rubinstein (1985) and Branger and Schlag (2007). In particular, we show how the beta of the underlying asset affects both an option’s covariance beta and its asset pricing beta. In contrast to Branger and Schlag (2007), the generalized option betas coincide if the options are evaluated according to the CAPM option pricing model of Husmann and Todorova (2011). The option betas are presented in terms of Black-Scholes option prices and are therefore easy to use in practice.

Gram-positive nosocomial infections in a general ICU: searching for a clue
G Georgiev, S Milanov, V Todorova, M Milanov
Critical Care , 2008, DOI: 10.1186/cc6225
Abstract: A historical cohort study was conducted and included all cases of documented nosocomial infections in our general ICU for a 1-year period (November 2006–November 2007). Data on demographic characteristics, primary diagnosis, comorbidity, number of indwelling devices, previous microbial isolates and current antibiotics were cross-tabulated according to the presence and type of Gram(+) pathogens isolated. For the identified most likely risk factors, separate contingency tables were constructed and analyzed.Sixty-six patients (39.05% of 169 with documented nosocomial infections) with Gram(+) isolates were identified. Methicillin-resistant Staphylococcus epidermidis (MRSE) (34.85%) and Enterococci (25.76%) were most commonly isolated, followed by methicillin-resistant Staphylococcus aureus (MRSA), methicillin-susceptible S. epidermidis (MSSE), Streptococci, and methicillin-susceptible S. aureus (MSSA). In eight (12.12%) of these 66 patients the same pathogen was isolated more than once and in 14 patients (21.21%) more than one Gram(+) pathogen was present during his/her ICU stay. There were no significant differences between the groups according to demographic characteristics. The following independent risk factors for Gram(+) nosocomial infection were identified – for MRSE, gunshot wound, chronic obstructive pulmonary disease comorbidity, previous isolation of both Acinetobacter spp. and Pseudomonas spp, previous/current treatment with carbapenem; for Enterococcus spp., billiary peritonitis, previous/current treatment with the combination cefoperazone–sulbactam; for MRSA, clinical uroinfection; for MSSE, previous/current treatment with combination first/second-generation cephalosporin–metronidazole; for MSSA, neurologic injury. Surprisingly the number of indwelling devices was not linked with increased risk of coagulase-negative staphylococcal infections, nor there was found a long latent period for their clinical manifestation.Exploratory hypotheses for further larger
Parameter passing between Molecular Dynamics and continuum models for droplets on solid substrates - The static case
Nikita Tretyakov,Marcus Müller,Desislava Todorova,Uwe Thiele
Physics , 2012, DOI: 10.1063/1.4790581
Abstract: We study equilibrium properties of polymer films and droplets on a solid substrate employing particle-based simulation techniques (Molecular Dynamics) and a continuum description. Parameter-passing techniques are explored that facilitate a detailed comparison of the two models. In particular, the liquid-vapor, solid-liquid and solid-vapor interface tensions, and the Derjaguin or disjoining pressure are determined by Molecular Dynamics simulations. This information is then introduced into continuum descriptions accounting for (i) the full curvature and (ii) a long-wave approximation of the curvature (thin film model). A comparison of the dependence of the contact angle on droplet size indicates that the theories agree well if the contact angles are defined in a compatible manner.
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