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

ORGANIZATIONAL CHANGE RESISTANCE: EXPERIENCE FROM PUBLIC SECTOR

The study described in the paper aimed to measure the level of resistance of public sector employees to organizational changes, in order to draw a conclusion on whether the level of resistance is a risk to the successful implementation of change or not. The differences between the resistance of several categories of employees were observed, depending on age, education and satisfaction with personal monthly income. In addition, the most important causes of resistance to change within the sample were determined, such as: lack of involvement of employees in the process of planning change, conviction of employees about non-existence of adequate rewards for the accomplishment of change and high levels of stress at work. The findings indicate that the level of change resistance in public sector is within moderate limits, which means that this issue needs further attention in planning and management of organizational change, but, on the other hand, the situation can not be characterized as highly risky for the process of change implementation. The paper also provides a brief theoretical overview of the most important findings in the field of organizational changes in the public sector

Uticaj đubrenja na broj, masu i prečnik cvjetova nevena

The goal of this research was to determine how different dosage use of nitrogen (N) affects the overall number, mass and diameter of Marigold flowers. According to the primary hypothesis, increased amounts of mineral fertilizers have negative effects on Marigold flower production. Monofactorial experiment was executed using the random block system with four repetitions, at the 2m2 experimental parcel site. In this experiment we used the NPK fertilizer with formulation (7:20:30) and nitrogen fertilizer KAN. Based on the sample of 10 flowers we applied and tested the both types of fertilizers and analyzed the : whole-plant mass, height of plant, number of flowers per plant and diameter of inflorescence.Cilj ovih istraživanja bio je da se utvrdi efekat djelovanja različitih doza azota na broj, masu i prečnik cvjetova nevena. Osnovna hipoteza od koje se polazi jeste da povećana količina mineralnih đubriva utiče negativno na produkciju cvjetova nevena. Monofaktorijalni ogled postavljen je po slučajnom blok sistemu u 4 ponavljanja sa veličinom obračunske parcele od 2m2. U ogledu smo koristili NPK đubrivo formulacije (7:20:30) i azotno đubrivo KAN. Na uzorku od 10 biljaka svake varijante đubriva analizirali smo : masu cijele biljke , visinu biljke , broj cvjetova po biljci i prečnik cvasti

The influence of pyrolysis type on shale oil generation and its composition (Upper layer of Aleksinac oil shale, Serbia)

The influence of pyrolysis type on shale oil generation and its composition was studied. Different methods such as Rock-Eval pyrolysis, thermogravimetric analysis (TGA) and pyrolysis in the open and closed systems were applied. Samples from the Upper layer of Aleksinac oil shale (Serbia) were used as a substrate and first time characterized in detail. The impact of kerogen content and type on the shale oil generation in different pyrolysis systems was also estimated. Majority of the analysed samples have total organic carbon content > 5 wt. % and contain oil prone kerogen types I and/or II. Therefore, they can be of particular interest for the pyrolytic processing. Thermal behavior of analysed samples obtained by TGA is in agreement with Rock-Eval parameters. Pyrolysis of oil shale in the open system gives higher yield of shale oil than pyrolysis in the closed system. The yield of hydrocarbons (HCs) in shale oil produced by open pyrolysis system corresponds to an excellent source rock potential, while HCs yield from the closed system indicates a very good source rock potential. The kerogen content has a greater impact on the shale oil generation than kerogen type in the open pyrolysis system, while kerogen type plays a more important role on generation of shale oil than the kerogen content in the closed system. The composition of obtained shale oil showed certain undesirable features, due to the relatively high contents of olefinic HCs (open system) and polar compounds (closed system), which may require further treatment to be used

Randman trogodišnjeg šarana iz kaveznog sistema uzgoja

Uzgoj šarana (Cyprinus carpio L.) u kaveznom sistemu predstavlja posebnu vrstu intenzivne proizvodnje. Odlikuje se malim početnim ulaganjima u izgradnju kaveznog ribnjaka, ne zahteva značajno angažovanje radne snage i obezbeđuje veliku proizvodnju po jedinici zapremine. Izbor lokacije je od velikog značaja jer utiče na ekonomsku održivost, proizvodnju i mortalitet šarana. U odnosu na druge uzgojne sisteme, utvrđeno je da u kaveznom sistemu morbiditet i mortalitet mogu značajno varirati i u slučaju odstupanja vrednosti parametara kvaliteta vode od optimalnih, gubici mogu nastupiti brzo i biti dramatični. Nedostatak kaveznog sistema gajenja ogleda se u olakšanoj transmisiji bolesti i zagađenju vodenog ekosistema u kome je kavezni sistem postavljen, što se može sprečiti uvođenjem zaštitnih sistema. Uz poštovanje načela dobre proizvođačke prakse, održavanjem dobrog kvaliteta vode i optimalno izbalansiranu hranu primerenu starosnoj kategoriji uzgajanog šarana, očekivan mortalitet je 1-5%. Zahtevi savremenog tržišta su sve više usmereni ka obrađenoj ribi, posebno filetima. Uklanjanjem kože i odstranjivanjem unutrašnjih organa i intramuskularnih kostiju, fileti šarana i ostalih ciprinida koje se gaje u polikulturi sa šaranom, postaju visokovredni obroci, koji se lako i brzo spremaju. Randman riba je ekonomski parametar čija je vrednost značajna pri svim tehnološkim operacijama vezanim za preradu ribe. Iskazuje se kao odnos primarno obrađenog trupa u odnosu na masu trupa žive ribe. Odnos jestivog i nejestivog dela trupa ribe može značajno da varira u zavisnosti od vrste, mase i veličine ribe i sezone ulova). Od njega direktno zavisi ekonomičnost proizvodnje i neopravdano je zanemaren kao parameter u istraživanjima. Razlika u randmanu između različitih linija i njihovih hibrida javlja se zbog različitog oblika, dužine glave, debljine i širine tela. Randman riba značajno je povoljniji od randmana kod ostalih vrsta životinja. Delovi koji se odbacuju mogu sadržati sve ili samo neke delove glave, krljušti, kože, creva, gonada i peraja. Cilj istraživanja bio je određivanje randmana kod trogodišnjeg šarana poreklom iz kaveznog sistema uzgoja. Uzorkovanje je obavljeno iz dva kavezna sistema na Tikveškom jezeru (Makedonija) (41°20′51″N 21°57′58″E) i iz jednog na Bilećkom jezeru (Bosna i Hercegovina) (42°49′31″N 18°26′17″E). Ishrana riba vršena je kompletnim krmnim smešama različitih proizvođača. Iz svakog kaveznog sistema uzorkovano je po 8 jedinki muškog i 8 jedinki ženskog pola (ukupno po 24 jedinke svakog pola). Morfometrijske osobine riba utvrđene su sa ciljem da se ispita uticaj pola na randman trogodišnjeg šarana gajenog u kaveznom sistemu. Nakon što su izlovljeni, šarani su držani na ledu. Krljušt je skinuta ručno nazubljenim nožem. Glava je odsečena cirkularnim rezom ispred pojasa pektoralnog peraja tako da je peraje ostalo na trupu. Peraja su odsečena na početku perajnih žbica. Egzenteracija organa zajedno sa gonadama obavljena je ručno. Dobijeni su obrađen trup, koji podrazumeva trup ribe bez krljušti, peraja, unutrašnjih organa i glave. Posle odstranjivanja krljušti, unutrašnji oragni, gonade, glava, peraja i obrađen trup su izmereni. Rezultati su obrađeni t-testom kako bi se utvrdio uticaj pola na randman trogodišnjeg šarana gajenog u kaveznom sistemu proizvodnje. U odnosu na pol (ženke naspram mužjaka šarana) pažnja je usmerena na parametre koji su važni sa aspekta gajenja i što povoljnijeg randmana. U našem istraživanju randman je određen kao odnos mase cele ribe i mase trupa bez glave, krljušti, peraja i unutrašnjih organa. Rezultati dobijeni u našem istraživanju pokazuju veću težinu ženskih u odnosu na muške jedinke (FW), ali nemaju statističku značajnost. Ukupna dužina (TL), standardna dužina (SL) i dužina trupa (CL) ženki u odnosu na mužjake imaju statistički značajnu razliku (p < 0,01), dok razlike u telesnoj masi ženki i mužjaka nisu statistički značajne. Rezultati dobijeni merenjem težine trupa (CW) i težine unutrašnjih organa (VW) ženki u odnosu na iste parametre kod mužjaka imaju statistički značajnu razliku (p < 0,01). Vrednosti dobijene merenjem težine glave (HW), težine gonada (GW) mužjaka, kao i vrednosti gonadosomatskog indeksa (GSI) u odnosu na vrednosti istih parametara kod ženki imaju statistički značaj (p < 0,01). Razlike u dužini glave (HL), visini tela (BH), masi peraja (FW), masi jedinki (FW) i obrađenih fileta (FilletW) mužjaka i ženki, nemaju statistički značaj. Vrednosti dobijene izračunavanjem relativne težine fileta i randmana uzorkovanih trogodišnjih jedinki šarana muškog i ženskog pola nemaju statistički značajnu razliku

Hepatic Macrosteatosis Is Partially Converted to Microsteatosis by Melatonin Supplementation in ob/ob Mice Non-Alcoholic Fatty Liver Disease

Obesity is a common risk factor for non-alcoholic fatty liver disease (NAFLD). Currently, there are no specific treatments against NAFLD. Thus, examining any molecule with potential benefits against this condition emerged melatonin as a molecule that influences metabolic dysfunctions. The aim of this study was to determine whether melatonin would function against NAFDL, studying morphological, ultrastuctural and metabolic markers that characterize the liver of ob/ob mice

Risk factors for severe dental anxiety among medical students

Background/Aim. Severe dental anxiety (SDA) is the most severe form of dental anxiety, thus the aim of this study was to determine the factors associated with SDA in students of health-related disciplines. Methods. In this case-control study the cases were students with severe dental anxiety. The study was conducted at the Faculty of Medical Sciences, University of Kragujevac, Serbia. The participants were undergraduate students attending lectures during spring semester 2010/2011 (n = 1,812). A random sample of 800 students was assessed for the association between various risk factors and the severe dental anxiety. The main outcome measures were the data on demographics, dental anxiety, habits concerning oral hygiene, nutrition, general anxiety and (co)morbidity which were collected from the study participants by semi-structured question questionnaire. Results. Less frequent visits to the dentist (OR adjusted = 7.02 [2.65; 18.60]) and visiting the dentist only when there is a dental problem (OR adjusted = 8.08 [1.28; 50.93]) were associated with severe dental anxiety. The same was true for improper oral hygiene (OR adjusted = 4.25 [1.16; 15.60]). Factors as changing toothbrush more frequently (OR adjusted = 0.33 [0.14; 0.76]) and having chronic disease (OR adjusted = 0.01 [0.00; 0.09]) were inversely associated with severe dental anxiety. The level of education of students was not associated with severe dental anxiety. Conclusion. Inappropriate oral hygiene, less frequent changes of a toothbrush and less frequent visits to the dentist are important risk factors for severe dental anxiety

BALANCE IN YOUNG GYMNASTS: AGE-GROUP DIFFERENCES

The aim of this study was to investigate difference in balance test scores and success on the balance beam of young gymnasts, international level of competition. Forty eight young gymnasts divided into two age groups participated in the study (Group 1: n=22, age 9.0 ± 1.1 years, 136.0 ± 7.6 cm, 30.8 ± 4.3 kg; Group 2: n=26, 12.1 ± 0.6 years, 146.0 ± 7.0 cm, 36.9 ± 6.6 kg;). To assess static balance, participants performed 3 stance variations (double leg, single leg, and tandem leg) on stiff surfaces and 3 specific static-balance tests consist of gymnastics elements on the balance beam (Scale, handstand and side handstand). For assessment of dynamic balance, participants performed multidirectional maximal single-leg reaches from a unilateral base of support (Y - balance test) and 3 specific dynamic-balance tests consisted of two connected gymnastics elements (Turns for 360°, jumps with 180º  and cartwheels). In the static balance test there is a significant difference only in one-leg stance (SRJN, .021) and specific static balance test SSSU (.000). In the dynamic balance tests, there was a significant difference in performing SD2Z test between the two groups (p=.043). These results suggests that the older gymnasts had better results in demanding tests such as one-leg stance, handstand and cartwheels on the balance beam. To achieve top results in the Women's Artistic gymnastics it is necessary to achieve good results on the balance beam and monitoring of balance ability for future success