Gravitational microlensing of AGN dusty tori

We investigated the gravitational microlensing of active galactic nucleus dusty tori in the case of lensed quasars in the infrared domain. The dusty torus is modeled as a clumpy two-phase medium. To obtain spectral energy distributions and images of tori at different wavelengths, we used the 3D Monte Carlo radiative transfer code SKIRT. A ray-shooting technique has been used to calculate microlensing magnification maps. We simulated microlensing by the stars in the lens galaxy for different configurations of the lensed system and different values of the torus parameters, in order to estimate (a) amplitudes and timescales of high magnification events, and (b) the influence of geometrical and physical properties of dusty tori on light curves in the infrared domain. We found that, despite their large size, dusty tori could be significantly affected by microlensing in some cases, especially in the near-infrared domain (rest-frame). The very long time-scales of such events, in the range from several decades to hundreds of years, are limiting the practical use of this method to study the properties of dusty tori. However, our results indicate that, when studying flux ratios between the images in different wavebands of lensed quasars, one should not disregard the possibility that the near and mid-infrared flux ratios could be under the influence of microlensing.Comment: 10 pages, 6 figures, 1 table, MNRAS accepted. V3: corrected values in Table

The shape of Fe Kα\alpha line emitted from relativistic accretion disc around AGN black holes

The relativistically broadened Fe K$\alpha$ line, originating from the accretion disc in a vicinity of a super massive black hole, is observed in only less than 50\% of type 1 Active Galactic Nuclei (AGN). In this study we investigate could this lack of detections be explained by the effects of certain parameters of the accretion disc and black hole, such as the inclination, the inner and outer radius of disc and emissivity index. In order to determine how these parameters affect the Fe K $\alpha$ line shape, we simulated about 60,000 Fe K $\alpha$ line profiles emitted from the relativistic disc. Based on simulated line profiles, we conclude that the lack of the Fe K$\alpha$ line detection in type 1 AGN could, be caused by the specific emitting disc parameters, but also by the limits in the spectral resolution and sensitivity of the X-ray detectors.Comment: Based on the talk presented Balkan Workshop BW2018 (10-14 June 2018, Ni\v{s}, Serbia), accepted for publishing in International Journal of Modern Physics A, 8 figures, 1 table, 15 page

The influence of type 2 diabetes on cardiovascular functional capacity

Introduction: Diabetes mellitus type 2 (DM2) is a heterogeneous group of disorders, characterized by varying degrees of insulin resistance, impaired insulin secretion and an increased concentration of glucose in the blood. DM2 is responsible for the structural and functional alterations of the cardiac muscle in the presence or absence of coronary artery disease (diabetic cardiomyopathy). Modern diagnostic testing of people with diabetes includes echocardiography and ergospirometry, which is important in the diagnosis of diabetic cardiomyopathy, as well as in the evaluation and treatment of this disease. Aim: To assess the functional capacity of patients with DM2, who have good glycemic regulation and preserved systolic function and to compare the value of the maximum (peak) oxygen uptake (peakVO2) with the values measured in the control group of healthy subjects. Material and methods: The prospective study included 30 patients (15 with and 15 without DM2), of both sexes, under the age of 55, with preserved systolic function, in whom anthropometric parameters, laboratory analysis, echocardiographic and cardiopulmonary exercise testing parameters were measured. The obtained data were processed statistically, and Pearson's correlation coefficient were used for determining the correlation. Results: Statistically significantly higher mean values of peak oxygen uptake and maximal oxygen pulse were found in the control group, while blood glucose levels and systolic blood pressure at rest were significantly lower. The slope of carbon dioxide equivalent was steeper in the group of patients with DM2. There were no significant differences in the structural and functional echocardiographic parameters between the groups. Conclusion: Patients with type 2 diabetes mellitus have lower functional capacity, expressed by peak oxygen uptake during exercise, even with good glycemic control. These changes in the functional capacity precede manifest complications, regarding structural and functional changes in the myocardium

SUPERMASSIVE BINARY BLACK HOLES - POSSIBLE OBSERVATIONAL EFFECTS IN THE X-RAY EMISSION

Here we discuss the possible observational effects in the X-ray emission from two relativistic accretion disks in a supermassive binary black hole system. For that purpose we developed a model and performed numerical simulations of the X-ray radiation from a relativistic accretion disk around a supermassive black hole, based on the ray-tracing method in the Kerr metric, and applied it to the case of the close binary supermassive black holes. Our results indicate that the broad Fe K line is a powerful tool for detecting such systems and studying their properties. The most favorable candidates for observational studies are the supermassive binary black holesin the galactic mergers during the phase when the orbital velocities of their components are very large and exceed several thousand kms-1

Key challenges in the status analysis for the sustainable urban mobility plan in Podgorica, Montenegro

The paper presents the results of the application of a practical approach for collecting data, which provides a simple, cost efficient, and easily reproducible method that was applied to obtain the necessary data for the status analysis of the Sustainable Urban Mobility Plan (SUMP) for Podgorica, the capital of Montenegro. Important data for the estimation of the existing condition of the traffic system were collected through desk research from the appropriate institutions and organizations. Several surveys and focus group interviews were conducted, in which about 5000 residents of Podgorica participated. In addition to answering questions, residents made numerous suggestions, confirming the correctness of a participatory approach in the new traffic planning paradigm that provides the SUMP with crucial advantages. A manual cordon count of traffic on five bridges for the traffic of the motor vehicles, as well as on two pedestrian-only bridges, was performed by students from the study program Road Traffic, and there are plans to repeat this in the coming years in order to enable more reliable monitoring and evaluation of the obtained data. Contemporary quality management tools such as BYPAD and ParkPAD were also used to assess the status of cycling and parking policy, respectively. It is especially important to emphasize that Podgorica is the first city in the West Balkans, and the fourth city in Europe, in which the ParkPAD tool was applied. A wide range of negative phenomena and trends was identified, like a rapid increase in the number of registered vehicles, an increase in the motorization rate and the number of traffic accidents, increased non-compliance with traffic rules, excessive use of passenger cars and auto-taxi vehicles, insufficient use of unattractive public transport, walking and cycling, etc. Based on the data collected, key challenges in status analysis in Podgorica were identified, which the SUMP should try to overcome. View Full-Text Keywords: sustainability urban mobility plan (SUMP), urban planning, vehicles, parking, public transportation, walking, cyclingpublishedVersio

Testing of correlation between amounts of visceral and subcutaneous abdominal adipose tissue in obese people measured by ultrasound and biochemical indicators of glycolipid status

Introduction: Obesity is a growing health problem in economically developed countries. Abdominal fat is distributed in two large compartments: visceral fat is localized in the abdominal cavity (around the abdominal organs) and subcutaneous fat (between the skin and muscle layers of the abdominal wall). Ultrasonography is the most appropriate imaging method for estimating the amount of visceral and subcutaneous abdominal fat in obese patients. Aim: The aim is to assess the correlation between the amount of visceral and subcutaneous abdominal adipose tissue, estimated by ultrasound in obese individuals, and biochemical indicators of their glycolipid status. Material and Methods: Retrospective study included 183 adult obese patients (131 women and 52 men, mean age 42.6 ± 12.2, mean weight 123.4 ± 26.7 kg, mean BMI 43.5 ± 7.6kg/m2), in whom diameters of visceral (dVAFT) and subcutaneous abdominal fat (dSCAFT) were measured by ultrasonography. Following anthropometric parameters, height, weight, waist circumference (WC) and hip cimrcumference (HC) were also measured. Also, biochemical analysis of the concentration of glucose, insulin, HbA1c, triglycerides and cholesterol (parameters of the glycolipid status) was done. Correlation among these parameters was tested using Pearson's test of linear correlation (r). Results: Positive correlation was found between the dVAFT and all analyzed biochemical parameters of the glycolipid status (p < 0.001). The exceptions were total cholesterol (p = 0.158), negative correlation between the dSCAFT and concentrations of serum glucose, HbA1c and triglycerides (p < 0.01), dVAFT/dSCAFT index most strongly positively correlated with the glucose concentration (r = 0.534), HbA1c (r = 0.456) and triglyceride levels (r = 0.443). WC and WC/HC index significantly correlated with the concentration of all biochemical parameters of glycolipid status, except total cholesterol, but less strongly than dVAFT and dVAFT/dSCAFT index. Conclusion: Visceral and subcutaneous abdominal fat diameters were measured by ultrasound, and especially dVAFT/dSCAFT index, express stronger correlation with the biochemical parameters of glycolipid status, than the anthropometric parameters, in adult obese people

Examination of C-phycocyanin interactions with selected vitamins

C-phycocyanin (C-PC) is a photosynthetic protein from Arthrospira platensis (cyanobacteria). Due to its intense blue colour, which is very rare in nature, C-PC has industrial applications as a food colourant as a substitute for synthetic food colourants. Disadvantages of C-PC as a food colourant are its poor stability at high temperatures (during thermal treatment of the food) and its sensibility to change pH value. The binding of food-derived small molecules, such as vitamins, could stabilize the structure of C-PC at high temperatures and wide pH ranges. In this study, we characterized the binding of selected vitamins to C-PC, purified from the commercial powder of Arthrospira platensis. We used hydrophilic vitamins (B1, B2, B7, B9, B12), lipophilic vitamins (A, D3) and provitamin (β-carotene). Fluorescent spectroscopy showed a decrease in fluorescence of CPC i n t he p resence o f v itamin A, v itamin D3 a nd β -carotene (lipophilic molecules) compared to the control. In contrast, the fluorescence of C-PC in the presence of hydrophilic vitamins showed minimal change. The protein fluorescence quenching approach demonstrated hydrophobic (pro)vitamins binding affinities ranging from 0.02 to 5.9 x 105 M-1, with the ability of hydrophobic (pro)vitamins to bind at the different sites on C-PC. UV-VIS spectrophotometry showed that the binding of hydrophobic (pro)vitamins does not affect the protein colour, while CD spectroscopy revealed that the binding of chosen molecules does not significantly influence the secondary structure of C-PC. Overall, this study demonstrated C-PC's significant potential in binding hydrophobic (pro)vitamins, while further research is required to test if these ligands could improve CPC stability

Stabilization of C-phycocyanin by immobilization in alginate beads

C-Phycocyanin (C-PC), the major protein of cyanobacteria Arthrospira platensis, is a phycobiliprotein with potent biological activity. It has several beneficial effects, including anti-oxidant, anti-inflammatory, immunomodulatory, and anti-cancer. A significant challenge for the broader application of C-PC in the food industry is its stability in food processing conditions, such as increased light exposure, temperature, and high pressure and drying. This work aimed to investigate if the immobilization of C-PC onto alginate beads could improve its stability. C-PC was immobilized by dropping the solution of C-PC and 1% alginate (final concentration) in the solution of 2% CaCl2. Both protein/alginate mixture and CaCl2 were kept at pH 4. Immobilized CPC was treated for 30 min at 65°C, by high pressure up to 4500 bar, and incubated under light exposure for a month. Alginate beads with immobilized C-PC were also left to dry in the fridge and kept for a month. C-PC was extracted from alginate beads by immersing them in 20 mM phosphate buffer, pH 7. The stability of C-PC was assessed by a color change and UV-VIS spectroscopy. Immobilized C-PC was stable under all tested conditions, with only small aggregation and color change appearing after high-pressure treatment. Immobilization of C-PC by alginate thus shows promise for its efficient stabilization under food processing conditions

Efficacy of Healthy Weight Loss Program in Obesity Treatment: Croatian Experience

We evaluated the efficiency of a six-month outpatient weight loss treatment program combining healthy diet, fat reduction, psychological counseling, exercise, and orlistat treatment, by measuring body weight and levels of cardiovascular risk factors in 476 subjects with BMI over 30 or 28 with increased blood pressure, cholesterol, and sugar at the baseline and at the end of program. After four weeks of adjustment to a mild low-calorie diet (1600 kcal/day) and counseling, subjects started receiving orlistat (120 mg TID). The mean weight loss after 6 months was 10.9%. Systolic pressure dropped by 6.7%, diastolic by 4.2%, fasting blood glucose by 10.1%, and total cholesterol by 9.8%. Only 9 subjects (7.8%) poorly tolerated the treatment. More men than women were able to maintain the achieved weight loss six months after the program (70.6% vs. 58.3%, respectively). The healthy weight loss program was an efficient approach to obesity treatment