Comment on "Spatial optical solitons in highly nonlocal media" and related papers

In a recent paper [A. Alberucci, C. Jisha, N. Smyth, and G. Assanto, Phys. Rev. A 91, 013841 (2015)], Alberucci et al. have studied the propagation of bright spatial solitary waves in highly nonlocal media. We find that the main results in that and related papers, concerning soliton shape and dynamics, based on the accessible soliton (AS) approximation, are incorrect; the correct results have already been published by others. These and other inconsistencies in the paper follow from the problems in applying the AS approximation in earlier papers by the group that propagated to the later papers. The accessible soliton theory cannot describe accurately the features and dynamics of solitons in highly nonlocal media.Comment: 2 page

Strategy for Sustainable Development and Utilization of Sheep and Goat Resources in Serbia

The aims of this study were to determine the status of small ruminant production in Serbia and to provide projections for their sustainable use with optimal strategy of genetic improvement of sheep and goats in the future. For sustainable sheep and goat production, it is necessary to know a number of biological, technological, organizational and market factors. Number of sheep in Serbia during the past two decades fell by about 20%.  This  country grows more than 1.7 million sheep. In terms of breed structures, most of the populations are indigenous Pramenka sheep (80%), while the remaining 20% are Tsigai, Merinolandschaf, Ile de France, Pirot improved, Mis sheep, and other less important populations, as well as the crossbreed with foreign and domestic sheep. Interest of goat rearing is constantly increasing in last years for 20-30%.  In regard to the breed structure, the least represented are goats of Alpine breed – approx. 2- 3%, White Serbian goat - 15%, different types of crosses – approx. 35% same as goats of low land Balkan type, and approx. 12% of high land Balkan type. Strategy of sheep and goat breeding programs in Serbia is focused on the improvement of indigenous breeds, because they are less demanding, and most importantly, the input is lower and their products have higher quality. Keywords: sheep; goat; sustainable; resources; meat; mil

Correlation analysis of milk production traits across three generations of Simmental cows

The relationship between milk production traits over whole lactations was evaluated across three generations of Simmental cows (between daughters, dams and granddams) by a corelation analysis with whole lactation traits in the daughter generation being used as the dependent variables (x<sub>1</sub>), and those in the dam and granddam generations being used as the independent variables (x<sub>2</sub> and  x<sub>3</sub>). The results were obtained from a sample of 1170 daughters and as many dams and  granddams. The correlation of whole lactation milk production traits between daughters, dams and  granddams, as calculated by simple, partial and multiple correlation coefficients was very weak or  non-existent. All of the calculated simple and partial correlation coefficients were positive and mostly  statistically very significant (P<0.01). The calculated coefficients of multiple correlation (R1.23) between  lactation length, milk fat content, milk yield, milk fat yield and 4% FCM yield with the expression of the traits in the daughters being used as the dependent variable and that in the dams and granddams as the independent variable were statistically very significant (P<0.01), amounting to 0.091, 0.251, 0.180, 0.133 and 0.153, respectively.Key words: Simmental breed, production traits, generation, coefficient of partial correlation, coefficient of multiple correlation

Influence of initial operating conditions on technological function parameters of servicing systems - machines and devices

U skladišnim i proizvodnim sustavima, svaki novi početak rada uređaja ili stroja poslije otkaza ili na početku nove smjene, dovodi do njihovog nestacionarnog režima rada izazvanog određenim brojem zaostalih neopsluženih jedinica. U skladišnim sustavima nestacionarni režim rada je uobičajena situacija kada je skladištenje paletizirane robe moguće u jednoj ili dvije smjene dok se proizvodnja odvija u dvije ili tri smjene. Opisane situacije utječu na parametre tehnološke funkcije (TFP) skladišnih ili proizvodnih sustava. Nestacionarni režim rada pojedinačnih uređaja ili strojeva može se modelirati kao jednokanalni sustav opsluživanja s ograničenim redom – M/M/1/K. Stoga je opći analitički izraz za integracijske konstante izveden na osnovu proizvoljnih početnih vrijednosti vjerojatnoća stanja sustava. Utjecaj početnog nestacionarnog režima, kao i njegovo trajanje, na TFP skladišnog sustava je kvantificiran uzimajući u obzir radne uvjete u postojećem paletnom visokoregalnom skladištu.In warehousing and production systems, every device or machine re-commissioning after malfunction or at the start of a new shift, leads to their non-stationary operating regime caused by a certain number of residual unprocessed units. In warehouse systems, non-stationary operating regime is common when palletized goods are stored in one (two) shifts while their production runs in two (three) shifts. Such situations influence technological function parameters (TFPs) of production or warehousing systems. On the other hand, non-stationary operating regime of a single device or machine may be modelled as a single server servicing system with a finite waiting room – M/M/1/K. As a result, general analytical integration constants expression was derived based on initial arbitrary system state probability values. Influence of initial non-stationary operating regime and its duration on warehousing system TFPs is evaluated in view of the operating conditions of an existing high bay pallet warehouse

Uticaj hodnog sistema na neke eksploatacione karakteristike traktora

Basic types of tractor locomotion systems and their main characteristics are presented in the paper. Pull and steering properties of the tractor are realized through a contact surface between the locomotion system and soil. Therefore, the most influencing parameters, like athesion (ϕ), locomotion resistance factor (f ) and slipping factor of the locomotion system (λ), are analyzed. Together with the comparison of pull and steering properties of different tractors, this analysis refined basic advantages and disadvantages of different locomotion systems based on wheels, metal and rubber crawlers.U radu su prikazani osnovni tipovi hodnih sistema traktora i njihove najvažnije karakteristike. Vučna i upravljačka svojstva traktora ostvaruju se preko adhezije hodnog sistema i podloge na dodirnoj površi/sloju. Stoga su analizirani najuticajniji pripadajući faktori kao što su: adhezija φ, odnosno efikasnost prianjanja hodnog sistema na podlogu, koeficijent otpora (trenja) kotrljanja f i klizanje hodnog sistema λ. Kao rezultat poređenja vučnih i upravljačkih svojstava različitih traktora i analize navedenih relevantnih parametara, utvrđene su međusobne prednosti i nedostaci pripadajućih hodnih sistema i predložene oblasti njihove optimalne primene

Influence of dialysis modality on the treatment of anemia in patients with end-stage kidney disease

© 2020, University of Kragujevac, Faculty of Science. All rights reserved. Anemia is a common complication among the patients with end-stage kidney disease. Management of anemia is influenced by several factors: iron deficiency, subtherapeutic dosage of erythropoietin, microinflammation, vitamin D de-ficiency, increased iPTH levels and inadequate hemodialysis. The aim of the study was to examine impact of dialysis mo-dality on blood hemoglobin level as well as status of iron, status of vitamin D, hemodialysis adequacy and erythropoietin dose. The study included 120 patients which were divided into two groups: the group of patients treated with hemodiafiltra-tion and the group of patients treated with standard hemo-dialysis. For statistical analysis Kolmogorov-Smirnov test, Student’s t-test and Mann-Whitney U-test were used. Blood hemoglobin level and parameters of hemodialysis adequacy (Kt/V index, spKt/V index, URR index), hemato-crit ad protein catabolic rate (nPCR) were statisticaly significant lower in patients treated with regular hemodialysis compared to patients treated with regular hemodiafiltra-tion. Serum ferritin level, C-reactive protein level and av-erage monthly dose of intravenous iron were higher in the patients treated with regular hemodialysis compared to patients treated with hemodiafiltration. Patients treated with hemodiafiltration have lower grade of microinflammation, better iron status and better control of anemia compared to the patients treated with regular hemodialysis. Dialysis modality is an important factor that influences management of anemia in the patients with end-stage kidney disease

Uticaj termičkog tretmana na higijenski kvalitet mleka

In the conducted study, the influence of the pasteurization and sterilization regime on the hygienic quality of raw and thermally treated milk was analyzed. Tests were conducted in the dairy "MEGGLE Srbija, doo" in Kragujevac. The following methods of thermal treatment were applied: short-term HTST pasteurization of raw milk at 75ºC, high HTST pasteurization of raw milk at 95ºC and flow-through UHT sterilization at 139ºC of previously pasteurized milk at 75ºC. The efficiency of thermal treatments on the hygienic quality of milk was determined by the following microbiological analyzes: by determining the total number of bacteria by the indirect method by Koch and by the internal analysis method applied in the dairy "MEGGLE Srbija, doo". Based on the tests carried out, a significant reduction in the number of bacteria after the pasteurization process of milk samples and their complete inhibition after the sterilization process was determined.U sprovedenom ispitivanju analiziran je uticaj režima pasterizacije i sterilizacije na higijenski kvalitetet sirovog i termički tretiranog mleka. Ispitivanja su obavljena u mlekari „MEGGLE Srbija, d.o.o.“ u Kragujevcu. Primenjene su sledeće metode termičke obrade: kratkotrajna HTST pasterizacija sirovog mleka na 75ºC, visoka HTST pasterizacija sirovog mleka na 95ºC i protočna UHT sterilizacija na 139ºC prethodno pasterizovanog mleka na 75ºC. Efikasnost termičkih tretmana na higijenski kvalitet mleka utvrđivana je sledećim mikrobiološkim analizama: određivanjem ukupnog broja bakterija indirektnom metodom po Koch-u i metodom interne analize koja se primenjuje u mlekari „MEGGLE Srbija, d.o.o.“. Na osnovu obavljenih ispitivanja ustanovljena je značajna redukcija broja bakterija nakon procesa pasterizacije uzoraka mleka i njihova potpuna inhibicija nakon procesa sterilizacije