757 research outputs found

    CROWN-TO-ROOT RATIO IN ENDODONTIC SURGERY: A SURVIVAL STUDY

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    Aim: to assess the influence of the crown height (CH), root length (RL) and crown-to-root ratio (CRR) on the survival of te- eth subjected to surgical endodontic retreatment and classi- fied as periapically healed. Methods: a single operator performed all the endodontic mi- crosurgery interventions. The present analysis selected the te- eth classified as ‘‘complete periapical healing’’ according to the Molven-Halse-Grung scale. The periapical radiographs were analyzed by two independent calibrated examiners, who measured CH and RL in a blind manner. The CRR was calcula- ted as the ratio of the two variables CH and RL. The measure- ments were performed by comparing the post-operative radio- graphs (t0) with those taken for a previous retrospective analysis (t1) and the most recent available (t2). An independent statistician conducted a survival analysis using Kaplan-Meier plots and a log-rank test (a = 0.05). Results: thirty-eight patients were evaluated, each one contri- buting to the study with a single tooth. The mean follow-up pe- riod was 5,96 ± 3,36 years. Comparing the CRR and RL values between t1 and t2, the difference was found statistically signifi- cant (p = 0.03). Survival was improved for the teeth with roots longer than 7 mm. There were no statistically significant diffe- rences among the remaining comparisons. Conclusions: root length ≥ 7mm exhibited better chances of long-term survival. Over time, a risk of further decrease of cli- nical RL due to periodontal disease and consequent increase of CRR could be critical by a mechanical point of view. Other studies are needed

    Fluktuacije ulova nekih pelagičnih vrsta riba u Mediteranu

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    U radu su analizirani 63 godine dugački podaci o ulovu tune (Thunnus thynnus) i srdele (Sardina pilchardus) u Mediteranu, metodom spektralne (Fourierove) analize i kros korelacjom. Analiza je pokazala da ulov tune sadrži ciklične komponente od 2.6, 3.65, 5.64, 7.75, 10.34 and 15.5 i verovatno 31 godinu, dok su u ulovu srdele najizraženije bile amplitude od 2.44, 3.65, 6.2, 7.75 i 10.34 godina. Prema tome, oba su vremenska niza bila koherentna u ciklusima od 3.65, 7.75 i 10.34 godina. Takođe je ustanovljeno da je ulov tune koherentan sa indeksom severoatlantske oscilacije (NAO) i to u periodima od 2, 3.35, 4.43, 6.89, 10.34 i verovtno 31 godina. Ovo ukazuje da klimatski ciklusi utiču na fluktuacije populacije ove ribe. Nadalje, upoređenje fluktuacija ulova tune u zapadnom i istočnom Mediteranu je pokazalo da su one potpuno sinhrone

    Homological Localisation of Model Categories

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    One of the most useful methods for studying the stable homotopy category is localising at some spectrum E. For an arbitrary stable model category we introduce a candidate for the E–localisation of this model category. We study the properties of this new construction and relate it to some well–known categories

    Privredni ribolov na Dunavu u Srbiji

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    U radu se daje pregled slatkovodnog ribarstva sa aspekta upravljanja, ekspolatacije ribljih resursa, tržišta ribom, legislative koja uređuje delatnost ribarstva, kao i problemi sektora ribarstva u Srbiji. Istraživanje i analiza privrednog ribolova na Dunavu kroz Srbiju (588 km toka) sprovedeno je prikupljanjem podataka ribarske statistike za period od 1948. do 2010. godine, njihovim unošenjem u elektronsku bazu i analiziranjem uz korišćenje različitih metoda. Statistički podaci uključuju ukupan ulov, ulov rekreativnog i privrednog ribolova, ulov privredno značajnih vrsta i alohtonih vrsta. Korišćenjem anketnog upitnika za ribare dobijeni su podaci o demografskoj strukturi ribara koji se bave ribarenjem kao osnovnom delatnošću, o sastavu ulova, koliko je ribarstvo perspektivna privredna grana i koji su problemi i potencijalna rešenja. Većina ribara pripada starosnoj grupi koja je u opsegu od 45 do 50 godina. Privredni ribolov je važna ekonomska delatnost i predstavlja osnovni izvor prihoda za većinu ribara. Tržište slatkovodnom ribom je neuređena oblast koja zavisi od ličnog zalaganja i odgovornosti pojedinca koji ima interes u prodaji ribe. Ribarstvo na Dunavu u Srbiji je već dugi niz godina u procesu tranzicije ka tržišnoj ekonomiji. Dugoročne fluktuacije hidroloških podataka (vodostaj) upoređivane su sa fluktuacijama godišnjeg ulova ribe iz Dunava kako bi se uočila eventualna međusobna zavisnost i uporedili njihovi trendovi. Rezultati ovog istraživanja treba da posluže kao pregled stanja sektora sa svim postojećim nedostacima koje treba ispraviti u cilju što uspešnijeg upravljanja ribarstvom na Dunavu i ostalim rekama u Srbiji gde je zastupljen privredni ribolov

    Usporedba kakvoće strojno otkoštenog mesa peradi upotrebom različitih postupaka separacije

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    Selected parameters of quality (hydroxyproline, calcium, bone particles content, and histological determination of bone particles) of mechanically deboned poultry meat (MDPM - „firmseparation“ and soft separation „Baadermeat“) were compared. Comparison of results with composition (except bone particles) of fresh poultry meat (breast and thigh muscles) was performed. Hydroxyproline content was significantly different and the mean value of hydroxyproline content was in mechanically deboned meat more than two-fold higher in comparison with Baader meat (333.17 mg.100g-1, 152.90 mg.100g-1 respectively). Similar results were achieved in calcium content (1.94g.kg-1, 1.05 g.kg-1 respectively). The mean content of bone particles was 0.27 % (MDPM) and 0.034 % (Baader). Finally, histological determination of bone particles in MDPM and Baader meat was carried out.U radu su uspoređeni odabrani parametri kakvoće (hidroksiprolin, kalcij, sadržaj čestica kostiju i histološko određivanje čestica kostiju) strojno otkošteog mesa peradi (engl. mechanically deboned poultry meat; MDPM -„čvrsta separacija“ i „meka separacija“ „Baader meso“). Rezultati su uspoređeni sa sastavom (izuzev koštanih čestica) svje žeg pilećeg mesa (mišići prsiju i bataka). Sadržaj hidroksi prolina pokazivao je značajne razlike, a srednja vrijednost sadržaja hidroksiprolina u strojno otkoštenom mesu bila je dvostruko veća u odnosu na „Baader meso“ (333,17 mg.100g-1, odnosno 152,90 mg.100g-1). Analiza sadržaja kalcija dala je slične rezultate (1,94g.kg-1, odnosno 1,05 g.kg-1). Srednji sadržaj čestica kostiju iznosio je 0,27 % (MDPM) i 0,034 % („Baader“). Provedeno je histološko određivanje čestica kostiju u MDPM i „Baader“ mesu

    Comparison of comet assay parameters for estimation of genotoxicity by sum of ranking differences

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    Genotoxic potential of waters in six rivers and reservoirs from Serbia was monitored in different tissues of chub (Squalius cephalus L. 1758) with the alkaline comet assay. The comet assay, or a single cell gel electrophoresis, has a wide application as a simple and sensitive method for evaluating DNA damage in fish exposed to various xenobiotics in the aquatic environment. Three types of cells, erythrocytes, gills and liver cells were used for assessing of DNA damage. Images of randomly selected cells were analyzed with a fluorescence microscope Leica and image analysis by software (Comet Assay IV Image analysis system, PI, UK). Three parameters (tail length - l, tail intensity - i and Olive tail moment – m) were analyzed on 1750 nuclei per cell type. The procedure for sum of ranking differences (SRD) was implemented to compare different types of cells and different parameters for estimation of DNA damage. Regarding our nine different estimations of genotoxicity: tail length, intensity and moment in erythrocytes (rel, rei, rem), liver cells (rll, rli, rlm) and gill cells (rgl, rgi, rgm) SRD procedure has shown that the Olive tail moment and tail intensity are (almost) equally good parameters; the SRD value was lower for the tail moment and tail intensity than for tail length in case of all types of cells. The least reliable parameter was rel; close to the borderline case were rei, rll, and rgl (~5% probability of random ranking)

    A Survey of Women in Academia and the role of a Multidisciplinary Professional Society

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    The Society of Women Engineers (SWE) is a global professional society of over 30,000 members with a mission to “Stimulate women to achieve full potential in careers as engineers and leaders, expand the image of the engineering profession as a positive force in improving the quality of life, and demonstrate the value of diversity”1. SWE is an organization that is deeply rooted in industry. The founding members were employed by firms that are a result of the industrial revolution, and thus the focus of its membership is on those that work for industry, consultants, and often themselves. This focus has unintentionally left a large population of its membership, the academic population, underrepresented and misunderstood. Early discussion at the board level in the mid 2000’s indicated a willingness for a paradigm shift. However, the representation of academics on the board and other leadership roles has been lacking. This can be attributed to the lower numbers of this group relative to the whole, as well as the requirements of tenure that do not support the time and dedication to such an endeavor. A small but influential group of members, including a former board member, and a few involved at various levels of the society have been working toward increasing opportunities for women in academia (WIA). Some of the initiatives have been the societal support of the WIA committee, the addition of professional development opportunities targeting women in academic careers, providing recognition and awards, and aiding in networking opportunities. These all lead toward career advancement, making SWE more attractive to women engineers in the academe. To further our understanding of available opportunities and those opportunities that will make membership and active participation more attractive to members in academia, a survey was developed. Information gathered by the survey include demographics, perceived needs, and potential contributions the individual could make in furthering the creation of professional development opportunities for this population. This work is intended to share the results of this survey, using descriptive statistics, further developing our understanding of this underserved population within SWE

    Reproducibility of age determination by scale and vertebra in pontic shad (Alosa pontica Eichwald, 1838), from the Danube

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    Specimens of Pontic shad (Alosa pontica Eichwald, 1838) were collected during April and May of 2006 in the Danube River (rkm 863) just downstream of the Iron Gate (Djerdap) II dam. Twenty-eight scales and 30 vertebrae were prepared and given to five interpreters with fish aging experience of from 3 to 30 years and with shad aging experience of from 0 to 12 years. Interpreters with experience in shad age determination showed lower values for the index of average percent error (IAPE) and an index of coefficient of variation (ICV). In regard to within-interpreter reproducibility, no significant differences were found between scale and vertebrae as structure for age determination. The most experienced reader showed the lowest value for IAPE, while the least experienced reader showed the highest value for IAPE. The results of this work indicate that experience in age determination by particular structure had more impact on age determination precision than specificity of structure, scale or vertebra. More work is needed on adopting standard protocols that must include some sort of common interaction between responsible age readers.U ovoj studiji analizirana je primenljivost starosne determinacije pomoću krljušti i pršljenova kod Alosa pontica Eichwald, 1838 iz Dunava. Neophodno je više studija o sačinjavanju standardnih protokola koji bi bili evaluirani od strane kompetentnih stručnjaka.Projekat ministarstva br. 14304
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