Aging of the geiger-muller counter due to particle conductance in an insulating gas

In this paper, the aging effect of commercially available Geiger-Muller counters under working conditions is being considered from both theoretical and experimental point of view. In the experimental part lifetime curves for the commercial Geiger-Muller counter chamber are first recorded. After detection of the aging phenomena, the commercial chamber response to an impulse voltage is tested along with recording of the same response of the Geiger-Muller chamber model with conductive particles included. The law of similarity for the gaseous discharge is fulfilled both by the commercial Geiger-Muller chamber and by the chamber model with conductive particles. The results obtained from the U-test indicate that the aging of the Geiger-Muller chamber is mainly caused by the occurrence of a great number of conductive particles hovering inside the chamber. Some suggestions of how to reduce the aging effect due to conductive particles inside the Geiger-Muller chamber are given in the conclusion

Electrostatic and Topological Features as Predictors of Antifungal Potential of Oxazolo Derivatives as Promising Compounds in Treatment of Infections Caused by Candida albicans

The results presented in this study include the prediction of the antifungal activity of 24 oxazolo derivatives based on their topological and electrostatic molecular descriptors, derived from the 2D molecular structures. The artificial neural network (ANN) method was applied as a regression tool. The input data for ANN modeling were selected by stepwise selection (SS) procedure. The ANN modeling resulted in three networks with the outstanding statistical characteristics. High predictivity of the established networks was confirmed by comparisons of the predicted and experimental data and by the residuals analysis. The obtained results indicate the usefulness of the formed ANNs in precise prediction of minimum inhibitory concentrations of the analyzed compounds towards Candida albicans. The Sum of Ranking Differences (SRD) method was used in this study to reveal possible grouping of the compounds in the space of the variables used in ANN modeling. The obtained results can be considered to be a contribution to development of new antifungal drugs structurally based on oxazole core, particularly nowadays when there is a lack of highly efficient antimycotics

Uzroci izlučenja prvotelki na farmama sa različitim nivoom proizvodnje

It is general knowledge that management influences results in cattle production to the highest extent, and that the culling of cows is a very good indicator of the success of farm management. A comparison of results of culling for first calving cows on farms with various levels of production in 2011 established differences both for the number of culled animals and the reasons for culling. On farms with higher levels of production, the share of first calving cows in overall culling was 25.9% or 4.5% less than on farms with a lower level of production, i.e. 4.8% less died, and 0.7% first calving cows had to be slaughtered, while 5.6% more first calving cows were culled for economic reasons. At both levels of production, dominant reasons for culling were diseases of the legs and hoofs, which can be linked to the tie stall system (more pronounced on farms with higher production) and metabolic disorders (more dominant on farms with lower production). Reproduction was a more considerable problem on farms with higher milk production, while culling due to selection was more pronounced on farms with lower production. In early lactation of first calving cows, regardless of the level of production, dominant reasons for culling on farms are leg and hoof problems and metabolic disorders (total: 55% i.e. 55.9%). When reasons for culling of first calving cows after 100 days of lactation are investigated, on farms with high production the significance of diseases of legs and hoofs remains almost unchanged, but culling due to reproduction grows to 28%. On farms with lower production, culling due to leg and hoof diseases is considerably reduced after 100 days of lactation, however culling due to selection is tripled (62%).Opšte je poznato da menadžment u najvećoj meri utiče na rezultate u govedarskoj proizvodnji, a izlučenja krava su vrlo kvalitetan pokazatelj uspešnosti upravljanja farmama. Poredeći rezultate izlučenja prvotelki na farmama sa različitim nivoom proizvodnje u toku 2011. god. ustanovljene su razlike i u broju izlučenih grla, ali i u razlozima izlučenja. Na farmama sa višim nivoom proizvodnje učešće prvotelki u ukupnim izlučenjima bilo je 25.9% što je za 4.5% manje nego na farmama sa nižim nivoom proizvodnje, odnosno uginulo je za 4,8% manje i prinudno je zaklano za 0,7% manje prvotelki, a iz ekonomskih razloga izlučeno za 5.6% prvotelki više. Na oba nivoa proizvodnje dominantni razlozi izlučenja su bili oboljenja nogu i papaka što se može dovesti u vezu sa vezanim sistemom držanja (izraženije na farmama sa većom proizvodnjom) i metabolički poremećaji (dominantnije izraženi na farmama sa nižom proizvodnjom). Reprodukcija je bila znatniji problem na farmama sa većom proizvodnjom mleka, odnosno selekcijska izlučenja na farmama sa nižom proizvodnjom. U ranoj laktaciji prvotelki, bez obzira na nivo proizvodnje, na farmama kao razlozi izlučenja dominiraju problemi sa nogama i papcima i metabolički poremečaji (ukupno 55% tj. 55.9%). Kada se posmatraju razlozi izlučenja prvotelki nakon 100 dana laktacije, na farmama sa visokom proizvodnjom značaj obolenja nogu i papaka je gotovo nepromenjen, ali izlučenja usled reprodukcije rastu na 28%. Na farmama sa nižom proizvodnjom, izlučenja usled oboljenja nogu i papaka su znatno smanjena nakon 100 dana laktacije, ali je zato utrostručen broj izlučenih iz selekcijskih razloga (62%)

Deciphering nifedipine in vivo delivery from modified release dosage forms: Identification of food effect

With the increased reliance on in vitro dissolution testing as an indicator of in vivo drug behavior and the trend towards the in silico modeling of dosage form performance, the need for bioperformance dissolution methodology development has been enhanced. Determination of the in vivo drug delivery profile is essential for the bioperformance dissolution test development and in vitro/in vivo correlation modeling, as well as the understanding of absorption mechanisms. The aim of this study was to compare different methods in terms of their usefulness and applicability in deciphering in vivo delivery of nifedipine administered in modified release dosage forms. A detailed survey of publications on nifedipine pharmacokinetics was done and used to identify the magnitude of food effect. In vitro dissolution testing was performed under various experimental conditions. Obtained results indicate the potential for using the developed in silico model coupled with discriminative in vitro dissolution data for identification of the in vivo drug product behavior

Evaluation of toxicity and antioxidative effects of Tussilago farfara and Verbascum thapsus water extracts in zebrafish and in bronchial epithelial cells

Tussilago farfara (coltsfoot) and Verbascum thapsus (mullein) have been used as folk remedies for treating respiratory disorders. The aim of this study was to test the toxicity of the water extracts of T. farfara and V. thapsus in vivo in zebrafish and in vitro in BEAS 2B epithelial bronchial cells. To the best of our knowledge, this is the first study to investigate the antioxidative properties of T. farfara and V. thapsus extracts in cell culture. Our results show that the T. farfara leaf extract does not produce toxic effects on zebrafish embryos or BEAS 2B cells, and that it has a protective effect in BEAS 2B after induction of oxidative stress. The water extract from V. thapsus displayed pronounced toxic effects on zebrafish embryos and BEAS 2B cells and did not exhibit a significant antioxidative effect on BEAS 2B cells exposed to oxidative stress. Our results suggest that the use of T. farfara water leaf extract is potentially safe and effective in treating respiratory disorders, whereas the use of V. thapsus needs further investigation

Influence of ketoprofen application on lipid mobilization, ketogenesis and metabolic status in cows during early lactation

© 2016 Veteriner Fakultesi Dergisi. All rights reserved. Changes in metabolic functions in transition dairy cows represent a result of negative energy balance. This leads to increased lipid mobilization and ketogenesis, followed by increased concentrations of non-esterified fatty acids (NEFA) and beta-hydroxybutyrate (BHB). Hence, high lipid mobilization and ketogenesis modulate inflammation response and vice versa. The aim of this study was to investigate correlations between ketoprofen administration, high lipid mobilization, ketogenesis and characteristics of metabolic adaptation in cows. Ketoprofen was administered intramuscularly in the concentration of 3 mg/kg, during three consecutive days in 15 postpartum cows. The control group included 15 cows which were not treated with ketoprofen. Blood samples were taken from coccygeal vein, after calving, in the first and second week of the postpartum period. When compared with control, ketoprofen administration decrease the levels of NEFA, BHB and total bilirubin, increase levels of glucose, albumin and cholesterol. Our results showed decreased activity of AST in ketoprofen treated cows in comparison with control group. There was an increase in the intensity of lipolysis and ketogenesis in 66.7% of cows, with NEFA and BHB values over the optimal results, because ketoprofen was not applied to these animals. Cows in the control group were 2 or 2.4 times more likely to come to a state of increased lipid mobilization and ketogenesis. We have found high concordance between NEFA and BHB, and metabolic parameters. This correlation was lower in experimental group of cows hence we can conclude that the use of ketoprofen immediately after calving reduces lipid mobilization and ketogenesis during early lactation and the metabolic adaptation dependence on the intensity of these two processes

Long-term optical spectral monitoring of a changing-look active galactic nucleus NGC 3516 -- II. Broad-line profile variability

We analyze the broad H$\beta$ line profile variability of the "changing look" active galactic nucleus (CL-AGN) NGC 3516 over a long period of 25 years. The observed change in the broad line profile may indicate a change in the geometry of the broad line region (BLR). Using spectral line profiles, we aim to explore changes in the kinematics and dimensions of the BLR in NGC 3516. We consider two possible scenarios, i.e. changes in the broad-line emission are caused by a decrease of ionization continuum emission or by the BLR obscuration by outer dusty regions. With this investigation we aim to clarify the CL mechanism of this AGN. We analyze the spectral band around the H$\beta$ line as well as the broad H$\beta$ line parameters, and how they change in time. We model the broad-line profiles assuming that there is an emission from the accretion disc superposed with an emission from a surrounding region that is outside the disc. We find that in the Type 1 activity phase, the BLR is very complex. There is a clear disc-like BLR that contributes to the broad line wings and an additional intermediate line region (ILR) that contributes to the line core. In the high activity phase, the ILR emission is close to the center of the line (in some cases slightly shifted to the red), whereas in the low activity phase (i.e., Type 2 phase), the ILR component has a significant shift to the blue, indicating an outflow. We propose that the changing look mechanism in NGC 3516 is rather connected with the intrinsic effects than with an outer obscuring region. It may still be possible that the dust has an important role in the low activity phase when it is coming inside of the BLR, making a dusty BLR. In this way, it causes a decrease in the ionization and recombination rates.Comment: 16 pages, accepted in A&

Aging of the geiger-muller counter due to particle conductance in an insulating gas

In this paper, the aging effect of commercially available Geiger-Muller counters under working conditions is being considered from both theoretical and experimental point of view. In the experimental part lifetime curves for the commercial Geiger-Muller counter chamber are first recorded. After detection of the aging phenomena, the commercial chamber response to an impulse voltage is tested along with recording of the same response of the Geiger-Muller chamber model with conductive particles included. The law of similarity for the gaseous discharge is fulfilled both by the commercial Geiger-Muller chamber and by the chamber model with conductive particles. The results obtained from the U-test indicate that the aging of the Geiger-Muller chamber is mainly caused by the occurrence of a great number of conductive particles hovering inside the chamber. Some suggestions of how to reduce the aging effect due to conductive particles inside the Geiger-Muller chamber are given in the conclusion

A comparison of the concentrations of energy-balance-related variables in jugular and mammary vein blood of dairy cows with different milk yield

The aim of this study was to compare the concentrations of blood variables obtained simultaneously from the jugular and mammary veins of dairy cows. Eighty Holstein cows were divided into four equal groups: dry, low- (LY), medium- (MY) and high-yielding (HY). Blood insulin, glucose, non-esterified fatty acid (NEFA), beta-hydroxybutyrate (BHBA) and urea concentrations were measured. The jugular and mammary vein (J/M) ratio between concentrations of each variable was calculated. Differences between the groups of cows in concentrations of variables in the jugular vein were not in accordance with those obtained for the mammary vein. J/M values for insulin and glucose concentrations were above 1.0 in all groups of cows. The ratios for NEFA and BHBA concentrations were under or equal to 1.0 in dry and LY cows but above 1.0 in the MY and HY groups, indicating that in MY and HY cows those metabolites are apparently utilised by the mammary gland. J/M values for urea were above 1.0 in dry and LY cows but less than 1.0 in groups MY and HY, indicating that in the latter case urea is apparently released by the mammary gland. In conclusion, J/M for NEFA, BHBA and urea may be useful for estimation of the critical point when the mammary gland receives insufficient energy precursors for its current activity