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Simple Summary Reported clinical data on high dose rate mono brachytherapy of prostate cancer carried out using two different treatment regimens are analyzed in this study. The analysis is based on a mechanistic tumor control probability model, which accounts for a possible increase in the tumor radio-sensitivity during treatment. The aim of the study was to verify a hypothesis that the clinically observed better performance of the longer treatment regimen (28 days vs. 14 days) might be due to a state of initial hypoxia and its ensued overcoming by re-oxygenation and, hence, re-sensitization of the prostate cancer. The performed investigation confirmed the assumption of initially hypoxic stage of the tumor followed by its re-sensitization, thus providing a foundation for the use of prolonged schedules for low- to intermediate-risk prostate cancer treatment. Abstract Background: Mechanistic TCP (tumor control probability) models exist that account for possible re-sensitization of an initially hypoxic tumor during treatment. This phenomenon potentially explains the better outcome of a 28-day vs 14-day treatment schedule of HDR (high dose rate) brachytherapy of low- to intermediate-risk prostate cancer as recently reported. Methods: A TCP model accounting for tumor re-sensitization developed earlier is used to analyze the reported clinical data. In order to analyze clinical data using individual TCP model, TCP distributions are constructed assuming inter-individual spread in radio-sensitivity. Results: Population radio-sensitivity parameter values are found that result in TCP population values which are close to the reported ones. Using the estimated population parameters, two hypothetical regimens are investigated that are shorter than the ones used clinically. The impact of the re-sensitization rate on the calculated treatment outcome is also investigated as is the anti-hypothesis that there is no re-sensitization during treatment. Conclusions: The carried out investigation shows that the observed clinical data cannot be described without assuming an initially hypoxic state of the tumor followed by re-oxygenation and, hence, re-sensitization. This phenomenon explains the better outcome of the prolonged treatment schedule compared to shorter regimens based on the fact that prostate cancer is a slowly repopulating tumor.

The study presents first Re-Os age data of molybdenite from the region at Babyak Mo-Ag-Au-W-Bi-base metal deposit, in combination with electron microprobe and laser ablation inductively coupled plasma mass spectrometry results for molybdenite aggregates. The Re-Os geochronology of the analyzed samples defines age at 52.6 ± 0.2 to 53 ± 0.2 Ma of the ore-forming process in the Babyak area. It marks a distinct fertile Early Eocene event in the Cretaceous-Paleogene evolution of the Rila-West Rhodopes batholith.

Samples of water flowing from the abandoned prospecting gallery at the Grantcharitsa tungsten deposit and the accompanying ocherous iron oxide precipitates taken in different seasons are the subject of the study aimed at establishing the chemical and phase composition of ocher iron oxide materials and its relationship with water composition. The studied drainage waters are low-mineralized, with a pronounced seasonally dependent pH parameter. Water acquires the features characteristic of acid mine drainage only during the season of high waters, while at other time it is gradually neutralized. The low-crystalline (ferrihydrite+schwertmannite) precipitates formed in the place of water discharge are inhomogeneous with a variable content of Si, Fe, and W. It was found that the W content in them correlates with the Fe content.

In this paper, we present the usability evolution of human-computer interactions. In addition, we group the various user interfaces of human-computer interaction into two generations with three classes each. The most user interfaces for human-computer interaction are assigned into a class depending on objective criteria scores, such as technical literacy level, level of natural interactions, user learning curve and UI’s ability to adapt. In addition, current tendencies for HCI are presented and future perspectives are discussed. Finally, we summarize the achieved results and draw conclusions.

The economic significance of pegmatites as a source of strategic rare metals for high-tech products and green energy motivated the present study on Ta–Nb oxides from Vishteritsa rare-element beryl–columbite LCT pegmatites of the Rila–West Rhodopes Batholith in the Western Rhodopes, Bulgaria. Here, we present the first U/Pb age data from columbite with application of the LA–ICP–MS U–Pb technique and a new X36 columbite standard reference material. The obtained Concordia age of 47.57 ± 0.32 Ma with a small spread of the individual 206Pb/238U ages between 45 and 51.3 Ma argues for Early Eocene magmatism and pegmatite formation. The host granite of the rare-element pegmatites is dated 51.94 ± 0.61 Ma with LA–ICP–MS U–Pb technique on zircon and suggests a fertile Early Eocene magmatic period in the Western Rhodopes. EPMA data for the composition of the columbite is used to refine the formula of the mineral (Mn0.554Fe0.427U0.006)0.987(Nb1.826Ta0.085Ti0.116)2.03O6 and define it as columbite-(Mn). Application of the in-situ LA–ICP–MS data technique establishes a series of typical trace elements (Ti, U, Zr, Hf, Y, W, and Zn) that are usually found in content above 500 ppm. The studied columbite is enriched in heavy rare earth elements (HREE sum: 306–697 ppm) and depleted in light REE and Eu. These geochemical characteristics are collectively interpreted as evidence for crystallization from highly fractionated fluid-rich magma. High UO2 content reaching 0.89 wt. % is characteristic for the Vishteritsa columbite. The decrease of U proximal to cracks and in outer crystal zones documents U-mobility during overprinting hydrothermal processes.

In this paper we present a novel approach for building a common software platform for simulating armored combat vehicles. We use Unreal Engine 4 as our simulation software. The presented approach is an attempt towards integrating different combat vehicle modules into a simulated environment. The presented simulator architecture can be used in various training combat scenarios, such as reconnaissance, coordinated firing on targets, different cooperation scenarios, etc.

Age-related macular degeneration is a leading cause of irreversible vision loss in individuals over 55 years of age worldwide. Conventionally, it is divided into two subtypes – dry (non-neovascular) and wet (neovascular) form. Neovascular age-related macular degeneration comprises only 10-15% of all patients but is responsible for more than 80% of blindness related to the disease. It requires early diagnosis and timely treatment. Fluorescein angiography is the current ‘gold standard’ for diagnosing neovascular forms. However, as an invasive procedure, it may be contraindicated in some circumstances and cause serious adverse effects. Optical coherence tomography-angiography is a relatively new, non-invasive and fast imaging modality gaining popularity in the diagnosis of age-related macular degeneration, especially for the neovascular form of the disease. It enables structural and functional information of blood vessels in the retina and choroid, without the need of an intravenous dye. In this study we present and discuss 3 cases of different subtypes of choroidal neovascularization secondary to neovascular age-related macular degeneration. All of them were examined by fluorescein angiography and optical coherence tomography-angiography. The results were qualitatively analyzed.

Objectives: Frailty is a geriatric syndrome associated with increased vulnerability of older adults. Knee osteoarthritis (OA) is the most prevalent joint disease and one of the leading causes of disability and poor physical activity (PA) of elderly individuals worldwide. Total knee arthroplasty TKA has been recognized as an effective surgical treatment in end-stage of knee OA. There is a lack of consensus regarding the universally accepted rehabilitation protocol for frail elderly subjects after TKA. Aim: to evaluate the potential benefits in functional ambulation (FA) and PA among frail elderly Bulgarian subjects underwent TKA, a novel group-based rehabilitation protocol was performed from the subjects. Materials and methods: A total of 130 frail elderly Bulgarian TKA recipients (67 women and 63 men aged 72, 69 ± 0.44,) were included. FA was assessed by the six-minute walking distance (6MWD). PA was evaluated by the PASE questionnaire. Participants were evaluated one week before TKA, as well as 3 and 6 months after the group-based rehabilitation. Results: Significant increase in FA was observed at the third and sixth month after the group-based intervention (p< 0.001). PASE score, was increased at the third and sixth month after the group-based intervention (p

Probabilistic seismic hazard assessment (PSHA) takes into account as much data as possible for defining the initial seismic source zone model. In response to this, an algorithm has been developed for integration of geological, geophysical and seismological data through a spatial index showing the presence or absence of a potential seismic source feature in the input data. The spatial matching index (SMI) is calculated to define the coincidence of independent data showing any indications for existence of a fault structure. It is applied for hazard assessment of Bulgaria through quantification of the seismic potential of 416 square blocks, 20 × 20 km in size covering the entire territory of Bulgaria and extended by 20 km outside of the country borders. All operations are carried out in GIS environment using its capabilities to work with different types of georeferenced spatial data. Results show that the highest seismic potential (largest SMI) is observed in 56 block elements (13% of the territory) clearly delineating cores of the source zones. Partial match is registered in 98 block elements when one of the features is missing. Not any evidence for earthquake occurrence is predicted by our calculation in 117 elements, comprising 28% of the examined area. The quantitative parameter for spatial data integration which is obtained in the present research may be used to analyze information regardless of its type and purpose.

Intellectual qualities of the university students are important factors for the successful participation in different academic activities. In view of this it is important to evaluate the initial level of intellectual development by applying a group of specific tests. In this paper we propose the application of the approach of InterCriteria Analysis to data of intellectual status parameters, obtained from university students practicing sports activities in order to evaluate the appropriateness of the used tests.

Along with acquiring of knowledge in the universities for a certain type of activities, the availability of qualities of each individual is of importance too – motor, psychic and personal. They are in the base for the successful sport career and professional realization. The significance of personal qualities has been established, both for sport and professional career of human being. For the labour activity, they are professionally significant. Such are the volitional qualities and the personal anxiety. We have directed to compare the level of development with students, dealing with basketball, in educational groups of the discipline „Physical education“ and in the representative basketball team at the UNWE, in the beginning of the educational year. As regards the variability with both indices (volitional qualities and personal anxiety), the coefficients of variation define the groups of students as comparatively homogeneous. The average values for both indices define the students as individuals of “strong will”. Statistically, reliable differences with comparison of the results have not been established and with both signs investigated. For establishing the influence of basketball game on these personal characteristics on both aggregates, it is recommended to repeat the study in the end of the educational year.

Luxembourg receives ample investment from multinational corporations, in part due to some attractive features in its international tax rules. Around 95 percent of these foreign investments pass through Luxembourg via companies performing holding and/or intra-group financing activities. While their contribution to Luxembourg’s economy is modest relative to their large overall balance sheets, they still generate around 3 percent of GDP in tax revenue, create almost 4500 direct jobs, and spend almost 3 percent of GDP on salaries and purchases of business services. Ongoing changes in the international corporate tax framework pose risks to these economic contributions, which this paper attempts to quantify. It also discusses options for reforms in Luxembourg’s tax system that could help offset adverse revenue and economic effects.

Макулната дегенерация, свързана с възрастта (МДСВ) представлява хронично, придобито, мултифакторно, дегенеративно заболяване на макулата, характеризиращо се с прогресивно увреждане на зрителната функция в резултат от невродегенеративни процеси в комплекса фоторецепторни клетки-ретинен пигментен епител (РПЕ)-хориокапиларис. МДСВ е водеща причина за необратима загуба на централното зрение в развитите страни. Засяга около 10% от хората над 65 години и повече от 25% над 75-годишна възраст. Очаква се броят на засегнатите от МДСВ индивиди да достигне 196 милиона души през 2020 година и 288 милиона през 2040 година поради удължената продължителност на живот и увеличаване на застаряващото население в световен мащаб. Заболяванията на макулата, главно МДСВ, са причина за слепота (дефиниция: зрителна острота, Age-related macular degeneration (AMD) is a chronic, acquired, multifactorial, degenerative macular disease characterized by progressive impairment of visual function as a result of neurodegenerative processes in the photoreceptors-retinal pigment epithelium (RPE)-choriocapillaris complex. AMD is the leading cause of irreversible loss of central vision in developed countries. It affects about 10% of people over 65 and more than 25% over 75 years old. The number of AMD patients is expected to reach 196 million in 2020 and 288 million in 2040, due to the prolonged life expectancy and increasing aging population worldwide. Macular diseases, mainly AMD, are a cause of blindness (definition: visual acuity

In this paper we present a cost-effective approach of building a hardware microcontroller for simulating the M1A2 Abrams battle tank. We have focused on modeling the battle tank gunner station controls, as well as a virtual representation of the tank itself. We have additionally simulated the flight paths of the four main cannon rounds. Finally, we have conducted several experiments on firing at targets, compared the results with actual data sheets and draw conclusions.

In the hasty and strained contemporary life rhythm, requirements to human being become still bigger. It is particularly valid for a number of professions, in which apart from excellent knowledge, required are also various motor, psychic and personal qualities. In our development we focus our attention on the professionally significant motor qualities for the profession engineer in the mining sector. The aim is to investigate the level of development of these qualities with students, educated for the profession at the University of Mining and Geology “St. Ivan Rilski” – Sofia, establishing the homogeneity of educational groups on the subject “Physical education”. It is an important step for future updating of educational programmers in the investigated four sports. From the investigated four professionally significant motor qualities, the results in three of them define the groups as comparatively homogenous – general physical endurance, quickness and flexibility. As for the strength, the four investigated groups are quite heterogeneous. In conclusion, it is recommended to include additional methods in all educational groups per sport type for development of the quality strength.

MASRI – Infrastructure for Sustainable Development of Marine Research Including the Participation of Bulgaria in the European Infrastructure Euro-Argo is a project of the National roadmap for scientific Infrastructure (2017-2023) of Bulgaria. The mission of MASRI is to build and utilize a modern research infrastructure which will provide the basis for highly efficient marine and maritime research to expand our knowledge of the marine environment and to support blue growth and implementation of marine policy and maritime spatial planning in order to achieve UN Sustainable Development Goal 14: Conservation and sustainable use of oceans, seas and marine resources for sustainable development.MASRI activities include the modernization of existing unique resources and equipment and the establishment of new facilities. The research infrastructure consists of four main modules: Research fleet; National Operational Marine Observing System – NOMOS; Data and information center and Research laboratory complex, each representing a distinct on functional basis part of the scientific infrastructure, and consists of separate components distributed physically in different scientific organizations, in the city of Varna. Thus, MASRI is intended to be a large-scale, interdisciplinary multifunctional (physics, chemistry, biology, geology, aquacultures, medicine, energy, underwater, and offshore technologies) marine research infrastructure of scientific significance and will provide unique facilities (including databases and computer network) which will be widely accessible on national, regional and international level for multidisciplinary researches.Research vessels are intended to provide access to the investigated medium – the sea and they are providing a working platform for conducting research. NOMOS is a system of systems to measure in situ parameters of the marine environment and the surrounding atmosphere. It is designed to provide information on the state of the marine environment for scientific research, forecasting and marine industry. Data and information center provide a computing environment, communication environment and environment for quality control and reliable storage of data and information within the scientific infrastructure. Research laboratory Complex represents a system of research laboratories for chemical, biological and geological analyzes and for relevant research on marine medicine as well as of laboratories for marine resources and technologies research.As an important module of MASRI, NOMOS includes several components: BulArgo – a system of profiling floats to measure the profiles of the characteristics of the marine environment in the depth up to 2000m; waves and currents monitoring system; national sea level observing system; moorings network; coast research bases and metrological control laboratory.MASRI is also intended to support the participation of Bulgaria in European research infrastructure consortia Euro-Argo ERIC. Al least three floats are provided and launched in the Black sea every year in the frame of the BulArgo project. Thus, BulArgo gives an important contribution to the Argo program in particular in the Black sea, providing a significant volume of very important in-situ data both for climatic research, for assimilation into the models and verification of the forecasts.

The accuracy of numerical simulations of free‐surface flows depends strongly on the computation of geometric quantities like normal vectors and curvatures. This geometrical information is additional to the actual degrees of freedom and usually requires a much finer discretization of the computational domain than the flow solution itself. Therefore, the utilization of a numerical method, which uses standard functions to discretize the unknown function in combination with an enhanced geometry representation is a natural step to improve the simulation efficiency. An example of such method is the NURBS‐enhanced finite element method (NEFEM), recently proposed by Sevillaet al. The current paper discusses the extension of the spatial NEFEM to space‐time methods and investigates the application of space‐time NURBS‐enhanced elements to free‐surface flows. Derived is also a kinematic rule for the NURBS motion in time, which is able to preserve mass conservation over time. Numerical examples show the ability of the space‐time NEFEM to account for both pressure discontinuities and surface tension effects and compute smooth free‐surface forms. For these examples, the advantages of the NEFEM compared with the classical FEM are shown.&nbsp