The impact of local stellar radiation on the HI column density distribution

It is often assumed that local sources of ionizing radiation have little impact on the distribution of HI in the post-reionization Universe. While this is a good assumption for the IGM, analytic arguments suggest that local sources may typically be more important than the background radiation for high column density absorbers (N_HI > 10^17 /cm^2). We post-process cosmological simulations with accurate radiation transport to investigate the impact of local stellar sources on the HI distribution. We demonstrate that the limited numerical resolution and the simplified treatment of the ISM that are typical of current cosmological simulations provide significant challenges, but that many of the problems can be overcome by taking two steps. First, using ISM particles rather than stellar particles as sources results in a much better sampling of the source distribution. Second, by rescaling the source luminosities so that the amount of radiation escaping into the IGM agrees with that required to produce the observed background, many of the results become insensitive to errors in the predicted fraction of the radiation that escapes the immediate vicinity of the sources. By adopting this strategy and by varying the assumptions about the structure of the unresolved ISM, we conclude that we can robustly estimate the effect of local sources for column densities N_HI << 10^21 /cm^2. However, neither the escape fraction of ionizing radiation nor the effect of local sources on the abundance of N_HI >~ 10^21 systems can be predicted with confidence. We find that local stellar radiation is unimportant for N_HI << 10^17, but that it can affect Lyman Limit and DLA systems. For 10^18 < N_HI < 10^21 the impact of local sources increases with redshift. At z = 5 the abundance of absorbers with N_HI >> 10^17 is substantially reduced, but at z = 0 the reduction only becomes significant for N_HI >~ 10^21 /cm^2.Comment: 19 pages, 12 figures; Accepted for publication in MNRA

History dependent magnetoresistance in lightly doped La_{2-x}Sr_{x}CuO_{4} thin films

The in-plane magnetoresistance (MR) in atomically smooth La_{2-x}Sr_{x}CuO_{4} thin films grown by molecular-beam-epitaxy was measured in magnetic fields B up to 9 T over a wide range of temperatures T. The films, with x=0.03 and x=0.05, are insulating, and the positive MR emerges at T<4 K. The positive MR exhibits glassy features, including history dependence and memory, for all orientations of B. The results show that this behavior, which reflects the onset of glassiness in the dynamics of doped holes, is a robust feature of the insulating state.Comment: 4 pages, 4 figures, International School and Workshop on Electronic Crystals (ECRYS-2011); to appear in Physica

Are we reaching a turning point in Serbia with respect to Serbian Sign Language in deaf education?

This paper provides an overview of the challenges affecting deaf education in Serbia, as well as in Serbian Sign Language (SZJ) by probing important policy measures that have been introduced over the years. Furthermore, we provide a summary of sign language research and the beginning of deaf awareness in Serbia. Our discussion focuses on key changes in the education policy that took place in 2009 when inclusive education was introduced and when Serbia ratified the United Nation’s Convention on the Rights of Persons with Disabilities (UNCRPD). The ratification of UNCRPD and the subsequent empowerment of the Serbian deaf community paved the way for the legal recognition of Serbian Sign Language in 2015, along with the enactment/passing of the Law on the Use of Sign Language. We review the existing legal and policy documents concerning deaf education and Serbian Sign Language by providing an outline of the government’s latest Strategy on Education until 2030 and its accompanying Action Plan until 2023. In conclusion, by focusing on the major goals set by the Strategy and the Action plan, we consider the feasibility of the goals with respect to the time frame and situation in practice

The Relationship Between Organizational Culture and Employees’ Satisfaction Shown on the Example of Tourism Businesses in Montenegro

Organizational culture, as an area of management is a complex system of mutual values that creates an organization’s identity and makes it different from the competition. The aim of this paper is to create an adequate approach for improving competitive advantages and better performance of Montenegro’s tourism businesses through improving business environment as one of the competitiveness factors. Through this work, the relationship and influence between the type of organisational culture and employees’ satisfaction is being determined and analysed through different dimensions of the work they are doing. For the needs of this work a quantitative explorative research has been done, using the method of questionnaire. In the questionnaire, the Organizational Culture Assessment Instrument (OCAI) and the Test for measuring employees’ satisfaction have been used. The obtained results show us the type of organizational culture that is characteristic for tourism businesses in Montenegro, as well as the influence it has on the level of employees’ satisfaction, through different dimensions. Business environment that increases the level of job satisfaction of employees contributes to loyalty and achieving better results in tourism businesses. This work is licensed under a&nbsp;Creative Commons Attribution-NonCommercial 4.0 International License.</p

Credit Rating As a Factor of Stability in the Global Capital Market

Credit rating has an outstanding importance on the capital market. Opinions and assessments of rating agencies help us to improve growth, stability and efficiency of international and domestic markets, which now include over 80 trillion dollars of rated bonds and other securities with the fixed income. The contribution of the credit agencies to the market stability and efficiency is reflected in their ability to provide accurate, clear and reliable assessments of the solvency of participants on the financial markets. An adequate and proper risk assessment of securities contributes to stability. In order to achieve a given goal and to satisfy its purpose, the assessments should be based on a fundamental understanding of the key components of the credit risk. Also, in order to ensure a reliable framework for making investment decisions, the rating agencies are obliged to offer and to provide a wide range of securities, which are based on a global comparability of rating symbols and on the support given by the credit rating assignment committee and by the other relevant decision making bodies. Markets for structured products could not have developed without the quality assurance provided by CRAs. When analyzing a securitization program CRAs examine legal and structural protections provided to investors. Since the globalization is an inevitable phenomenon in today’s world the importance of the credit rating becomes more noticeable. On the other hand, the rating agencies have an obligation to reanalyze their decision making models in order to contribute to the reliability of the evaluation

Pseudomonas SP. in tomato rhizosphere (Lycopersicon esculentum Mill)

The aim of research is determining the presence and number of Pseudomonas sp in tomato rhizosphere. The tests were conducted on a tomato hybrid Big Beef grown on the soil type pseudoclay-hard. Bacteria isolation was conducted in the root zone 20-40 cm. Rhizosphere was separated mechanically on rhizospheral soil, root (unsterilized) and root (sterilized). Tripofan Medium was used for isolation of Pseudomonas sp. from the soil. In the obtained results biochemical and morphological characteristics were conducted. Results analysis was conducted with suitable statistical methods. Based on the results, we can conclude that the number of bacteria in different variants is statistically extremely significantly different on Tripofan Medium and statistically significantly different on Nutritious agar