Differences in engineers' brain activity when CAD modelling from isometric and orthographic projections

A way of presenting information in visual representations of technical systems influences the progress and the outcome of the engineering design process. Consequently, improving the means by and through which information is utilised during the process is one suggested approach to advancing engineering design. Engineers' interaction with visual representations of technical systems is mainly visual and virtual. Although such interactions are cognitively complex, little is known about cognition (mental information processing) underlying the utilisation of design information during engineering design. To narrow the research gap, this study explores how visual representations of technical systems affect engineers' brain activity while generating computer-aided design (CAD) models based on them. More precisely, the brain activity of 20 engineers is captured and analysed using electroencephalography (EEG) during the visuospatially-intensive design tasks of CAD modelling in two conditions; when technical systems are presented with orthographic and isometric projections in technical drawings. The results imply the sensitivity of engineers' brain activity in CAD modelling to the visual representation from which a technical system is interpreted. In particular, significant differences are found in theta, alpha, and beta task-related power (TRP) over the cortex when interpreting the technical drawings and CAD modelling from them. Furthermore, the results reveal significant differences in theta and alpha TRP when considering the individual electrodes, the cortical hemispheres, and the cortical areas. In particular, theta TRP over the right hemisphere and the frontal area seems essential in distinguishing neurocognitive responses to the orthographic and isometric projections. As such, the conducted exploratory study sets the foundations for exploring engineers' brain activity while performing visuospatially-intensive design tasks, whose segments are relatable to the aspects of visuospatial thinking. Future work will explore brain activity in other design activities that are highly visuospatial, with a larger sample size and an EEG device of a higher spatial resolution

Occupational radiodermatitis in workers handling radium

Iznose se pojave profesionalnog radiodermita kod 3 osobe, koje su bile zaposlene na Radiološkom institutu kao manipulanti radiumom. Kod dva slučaja postojala je klinička slika ulceroznog radiodermita, dok je kod trećeg postojala maligna alteracija tog oblika radium oštećenja u smislu Epithelioma spinocellulare udružena s radionekrozom krajnje falange palca desne ruke.The occurrence of occupational radiodermatitis in 3 persons handling radium at the Radiological Institute is described. Clinical picture of two cases showed ulcerous radiodermatitis, while in one case there was a malign alteration similar to Epithelioma spinocellulare and combined with the radionecrosis of the distal thumb phalanx of the right hand

Proizvodni potencijal prvotelki simentalske rase u Srbiji

Cattle production in Serbia, and especially milk production, contributes significantly to the value of total agricultural production (20%) and livestock production (45%). Achieved annual rate of milk yield increase of approx.100 kg per cow cannot adequately compensate for drastic decrease of number of dairy cattle which dropped by fifth over last decade. This is especially important from the aspect of assessment of future production quotas for milk as part of Serbia's preparation for EU accession. From the aspect of the genetic potential of dairy cattle, the most significant measure aimed at increase of milk performance in future will be execution of systematic selection-breeding work in the main population. Special attention should be directed in future to selection of parents of dairy herd, criteria for selection of heifers and their adequate rearing in sense of nutrition and housing. For the purpose of establishing of production potential of first calving Simmental cows in Serbia, data was analyzed for 37.171 Simmental cows with completed lactations in the period 2007 to 2010. Research results showed moderate trend of increase in milk performance in first calving cows - average milk production of 4.348 kg, milk fat content of 3.93% and milk fat yield of 171.1 kg. Milk performance of first calving cows in average was lower by 147 kg compared to cows in other lactations and by 1.169 kg compared to bull dams in the observed period. In analysis of bulls - most common sires of studied first-calvers, it was established that eight of ten bull sires had negative values for milk yield, which indicated the need for better cooperation and organization in work of all services which are included in selection-breeding activities in dairy cattle breeding.Govedarstvo Srbije a posebno proizvodnja mleka značajno učestvuju u vrednosti ukupne poljoprivredne (20%) i stočarske proizvodnje (45%). Postignutim tempom rasta prinosa mleka od oko 100 kg po kravi godišnje ne može se adekvatno kompenzovati drastičan pad broja mlečnih grla koji je u protekloj deceniji opao za petinu. Ovo je posebno značajno sa aspekta procena budućih proizvodnih kvota za mleko u priprema Srbije za ulazak u EU. Sa aspekta genetskog potencijala mlečnih krava, najznačajnija mera za povećanja prinosa mleka u narednom periodu je sprovođenje sistematskog odgajivačko-selekcijskog rada u matičnoj populaciji. Izboru roditeljskih parova budućih generacija mlečnog stada, kriterijumima odabira junica i njihovom pravilnom odgoju u smislu ishrane i uslova držanja treba posvetiti primaran značaj. U cilju utvrđivanja proizvodnog potencijala prvotelki simentalske rase u Republici Srbiji analizirani su podaci 37.171 simentalskih krava koje su svoje prve laktacije zaključile u periodu od 2007-2010 godine. Rezultati istraživanja pokazali su umereni trend porasta mlečnosti prvotelki sa ostvarenom prosečnom proizvodnjom od 4.348 kg mleka, sadržajem od 3,93% i prinosom od 171,1 kg mlečne masti. Mlečnost prvotelki u proseku je bila niža za 147 kg od mlečnosti krava u ostalim laktacijama i za 1.169 kg od mlečnosti bikovskih majki u posmatranom periodu. Analizom bikova - najčešćih očeva ispitivanih prvotelki, utvrđeno je da je osam od deset bikova-očeva imalo negativne vrednosti za prinos mleka što upućuje na neophodnost bolje saradnje i organizacije u radu svih službi koje obavljaju odgajivačko-selekcijski rad u mlečnom govedarstvu

CHROMATOGRAPHIC BEHAVIOR AND LIPOPHILICITY OF N-(4-PHENYLSUBSTITUTED)-2,3-DIPHENYLPROPANAMIDES

Retention behavior of some N-(4-phenylsubstituted)-2,3-diphenylpropanamides was investigated on reversed phase thin layer chromatography (RP-C18). Retention constants of investigated compounds were determined in the following solvent systems: water-ethanol, watern-propanol and water-i-propanol. Linear relationships were obtained between retention, RM and volume fraction of organic solvent, ϕ. As a measure of lipophilicity of tested propanamides, Hansch`s lipophilicity parameter, π, were calculated. Chromatography retention constants RM0 were correlated with Hansch`s lipophilicity parameter, and good linear relationships were obtained. These results confirm, that retention constants, (RM0 ), determined in reversed phase thin-layer chromatography (RP-TCL) can be used, as criteria of lipophilicity

Ispitivanje naslednosti fenotipova plodnosti i mlečnosti simentalske rase goveda u Srbiji

Results of the effect of direct and indirect selection of quantitative traits of fertility and milk performance of first calving cows of Simmental breed in Serbia are presented. Investigation of genetic parameters of heritability (additive genetic variance in total phenotypic variability of quantitative traits) and analysis of milk traits was done in four breeding regions and several tenths of farms where 3980 daughters of 32 sires were housed and reared. Results of analysis were obtained by application of mathematical-statistical data analysis, using mixed models (Harvey, 1990). Mathematical-statistical analysis of data was done using linear methods, i.e. method of least squares (LS method). Based on obtained results it was established that bulls-sires and several paragenetic factors caused no significant variation of fertility traits in relation to general average (P (lt) 0.01). Quantitative milk traits of first calving cows, under the influence of breeding region, had significantly higher deviation from the general average (**P (lt) 0.01). Significant deviations (*P (lt) 0.05) were caused by year of calving on milk yield and yield of milk fat (4765.0 kg and milk fat 3.86%). Established heritability coefficients for reproductive traits were following: .102, .051 and .088, and milk traits .297, .207 and .197).Najbrojnija populacija goveda u Republici Srbiji pripada Simentalskoj rasi (oko 500.000 plotkinja ili više od 80%). Ako se imaju u vidu tekuće promene u genetskom poboljšanju goveda i veoma velikom napretku u tehnologijama reprodukcije, očigledno da će se sadašnji programi morati menjati i poboljšavati. S obzirom na to, da je ekonomski značaj reproduktivnih i osobina mlečnosti visok neophodno je poznavanje pojedinih faktora koji utiču na plodnost i mlečnost krava, a oni se dele na genetske i paragenetske. Uspeh u poboljšanju plodnosti genetskim putem je dosta ograničen niskim vrednostima heritabiliteta, što ne znači da geni ne deluju na ovu osobinu, već da je vrednost aditivne genetske varijacije mala. Naslednost, odnosno proučavanje aditivne genetske varijanse u ukupnoj fenotipskoj varijabilnosti kvantitativnih osobina, predstavlja deo najvažjnijih istraživanja sa gledišta stvaranja populacije goveda visokih genetskih potencijala i odabiranja roditeljskih parova budućih generacija. Vrednosti koeficijenata naslednosti za osobine plodnosti su pod uticajem različitih faktora, kao što su: genotip životinje, uzrast, intenzitet selekcije, metod odgajivanja, ambijentalni uslovi i dr. Cilj ovih istraživanja je bio da se ispitaju važniji genetski parametri plodnosti i mlečnosti, odnosno naslednosti ovih kvantitativnih osobina radi izbora pravca i daljeg oplemenjivanja ove populacije. Prikupljeni podaci za analizu potiču iz četiri regiona - odgajivačka područja u Srbiji. Istraživanja su uključila 3980 krava - prvotelki simentalske rase, kćeri 32 bika - oca, koje su oteljene u periodu od šest godina (2002-2007). Sva ispitivana grla (krave - prvotelke) su držana vezano i slobodno u posedu privatnih farmera (od 8 do 65 grla po farmi) i bila su standardno hranjena, a razlike su bile u količini, odnosu i kvalitetu kabaste i koncentrovane hrane (područje gajenja). Matematičko-statistička analiza podataka obavljena je primenom mešovitog modela najmanjih kvadrata (LS-Least Squares) primenom programa najmanjih kvadrata (LSMLMW), Harvey, (1990). Različiti broj individua u pojedinim klasama kao i postojanje više uticaja (područje, godina telenja, sezona telenja, bikovi očevi) koji su delovali na ispoljavanje ispitivanih osobina, uslovio je analizu u kojoj je korišćen metod najmanjih kvadrata. Bikovi-očevi i niz paragenetskih uticaja nisu prouzrokovali značajno variranje osobina plodnosti u odnosu na opšti prosek (P (lt) 0.01). Kvantitativne osobine mlečnosti krava prvotelki su pod uticajem odgajivačkog područja imale visoko značajno odstupanje od opšteg proseka (**P (lt) 0.01). Značajna odstupanja (P (lt) 0.05) je izazvala godina telenja na prinos mleka i mlečne masti. Godišnje doba početka laktacije krava obuhvaćenih našim istraživanjem pokazuje značajna odstupanja prinosa mleka i mlečne masti u odnosu na opšti prosek (P (lt) 0.01). Tako su junice oteljene u februaru , martu i aprilu imale značajno i visoko značajno više mleka i mlečne masti u odnosu na one koje su se otelile u drugim mesecima u godini. Ustanovljeni koeficijenti heritabiliteta reproduktivnih svojstava koji su dobijeni našim istraživanjem su imali niske vrednosti i bili su nižeg nivoa u odnosu na one koje su dobili Petrović et al. (1998, 2001, 2006). Rezultati naslednosti osobina mlečnosti dobijeni našim istraživanjima su bili viši u odnosu na koeficijente za iste osobine koje su objavili Panić and Vidović (2006), niži u odnosu na rezultate istraživanja Petrović et al. (1999) and Kapš and Špehar (2004) a u saglasnosti sa koeficijentima heritabiliteta koje su u turskoj populaciji simentalskih goveda ustanovili Ulek and Tekun (2006)

Kvantitativna analiza genetskog unapređenja fenotipova mlečnosti krava Simentalske rase

Results of the effect of direct and indirect selection on quantitative properties of milk production of first calving Simmental cows in Serbia, are presented in the paper. Analysis of quantitative phenotypic parameters was carried out in four breeding regions and certain number of smaller farms where 1319 daughters of 13 bull sires were reared. Results of the analysis were obtained by application of mathematical-statistical data analysis, using mixed models (Harvey, 1990). Mathematical-statistical analysis of data was carried out using linear methods with fixed effect, through method of least squares (LS method), and for evaluation of bull breeding value mixed model of random bull sire effect was used (BLUP method). Based on obtained results it was established that analyzed breeding region has statistically highly significantly (**P (lt) 0.01.) caused deviations of production phenotypes from general average. Season and year of calving (*P (lt) 0.05.) have caused significant variations of production properties. .U radu su prikazani rezultati efekata direktne i indirektne selekcije kvantitativnih svojstava mlečnosti krava-prvotelki simentalske rase goveda u Srbiji. Analiza kvanitativnih fenotipskih parametara je obavljena u četiri odgajivačka područja i na više desetina manjih farmi na kojima je držano i gajeno 1319 kćeri, 13 bikova-očeva. Rezultati analize su dobijeni primenom matematičko-statističke analize podataka, korišćenjem mešovitih modela (Harvey, 1990). Matematičko-statistička analiza podataka je obavljena korišćenjem linearnih metoda sa fiksnim uticajem, preko metoda najmanjih kvadrata (LS metod) a za ocenu priplodne vrednosti bikova korišćen je mešoviti model slučajnog uticaja oca (BLUP metod).Na osnovu dobijenih rezultata ustanovljeno je da je odgajivačko područje statistički analizirano visoko značajno (**P (lt) 0.01.) prouzrokovalo odstupanja proizvodnih fenotipova od opšteg proseka. Sezona telenja i godina (*P (lt) 0.05.) su prouzrokovali značajna variranja proizvodnih osobina. Rezultati odstupanja osobina proizvodnosti pod uticajem godine telenja ukazuju na pozitivne tendencije u povećanju prinosa mleka . Značajna odstupanja (P (lt) 0.05) je izazvala godina telenja i na prinos mleka i mlečne masti. Godišnje doba početka laktacije krava obuhvaćenih našim istraživanjem pokazuje visokoznačajna odstupanja prinosa mleka i mlečne masti u odnosu na opšti prosek (P (lt) 0.01). Tako su junice oteljene u februaru , martu i aprilu imale značajno i visoko značajno više mleka i mlečne masti u odnosu na one koje su se otelile u drugim mesecima u godini. Interakcija odgajivačkog područja i sezone telenja je prouzrokovala visoko značajna odstupanja prinosa mleka (**P (lt) 0.01), međutim nije bilo statističkih značajnih variranja sadržaja mlečne masti. Prema analizi negativnih i pozitivnih BLUP rešenja (priplodne vrednosti) za prinos 4%MKM formirana je ocena ranga prema kojoj je bik broj 13. najbolje ocenjen, a bik-otac br.9 bio je rangiran na poslednje mesto. Krave - prvotelke obuhvaćene našim istraživanjem proizvele su 4868 kg mleka sa 183.03 kg mlečne masti , odnosno 3.76% mle. mast i 4693kg 4%MKM. Rezultati dobijeni nasim istraživanjima su značajno viši u odnosu na rezultate o mlečnosti iste rase (Lazarevic R. i sar., 1986). viši od onih koje je ustanovio Petrovic M.M. i sar. (1997 i 2006). Dobijeni rezultati su u saglasnosti sa onima koje su dobili Petrović M.D. i sar. (2005) i Pantelić i sar.(2008). Naši rezultati su pokazali da postoji pozitivan genetski trend u smislu kvantitaivnih osobina mlečnosti domaćih somentalskih krava. Poredeći naše rezultate i rezultate napred navedenih autora može se zaključiti da se prinos mleka simentalskih krava (matični zapat) u Srbiji godišnje uvećava za najmanje 100 kg mleka po kravi (zavisno od genetike, područja, odnosno tehnologija ishrane i držanja)

Fuzzy Controller Optimized by the African Vultures Algorithm for Trajectory Tracking of a Two–Link Gripping Mechanism

This paper presents the proportional–derivative fuzzy controller for trajectory tracking of the gripping mechanism with two degrees of freedom. Aiming to achieve movement of the gripping mechanism without sudden starting and stopping, a polynomial velocity profile is utilized. The African vultures optimization, as one of the latest metaheuristic algorithms, is used to obtain the optimal input/output scaling gains of the proposed fuzzy controller according to the selected fitness function. The results obtained by this algorithm are compared with the other three new and popular metaheuristic algorithms: the whale optimization, the ant lion optimization and the sine cosine algorithm. Moreover, a simulation study was done for the defined initial position and for the scenario where there is a certain deviation because the gripping mechanism is not at its original initial position. Finally, the robustness of the controller is tested for the case when the masses of the segments increase three times. The results revealed that the suggested controller was capable of dealing with nonlinearities of the gripping mechanism, initial position and parameter changes. The movement of the gripping mechanism is smooth and follows the defined trajectory

Distribution of high-risk types of human papillomavirus compared to histopathological findings in cervical biopsies in women

Introduction: In over of 99% cases of cervical cancer its appearing is preceded by persistent cervical epithelium infection caused by high-risk oncogenic types of human papillomavirus (HPV). The aim of the study was to examine the distribution of high-risk oncogenic HPV types compared to patohistological diagnoses of cervical diseases in women. Materials and methods: The study included 56 women with suspected premalignant and malignant cervical lesions, due to suspected colposcopic and cytological findings (Papanicolaou test). The HPV typing by 'in situ' hybridization method on high-risk HPV types 16, 18, 31 and 33 was performed in all patients from cervical smear as well as cervical biopsy. Histological findings of cervical biopsy was a 'gold standard' in the analysis of materials. Results: Histologically detected premalignant or malignant changes of the cervix were found at 34 (60.7%) of all 56 examined women: 17 of them had LSIL, 13 of them had HSIL, while 4 had squamous cell carcinoma. A positive HPV test had a 47 (84%) of them with a prove of the presence of one or more types of HPV. The most common type of virus was HPV 16 and it was detected in 27 (48.2%) women, followed by HPV 31 that was detected in 26 (46.4%) women, HPV 18 in 18 (32.1%) of women and HPV 33 in 4 (7.1%) women. The infection caused by oncogenic type HPV16 was significantly more frequent in patients with HSIL and cervical cancer (p<0,001), while the infection caused by oncogenic type HPV 31 was significantly more frequent in patients with LSIL and cervicitis (p=0,003). The distribution of HPV 18 and HPV 33 types was not statistically significantly different in patients with different histological findings (HPV 18, p = 0.41; HPV 33, p = 1.0). Conclusion: Based on our results we can conclude that there is a good correlation of HPV infection with pre-malignant cervical lesions and cervical cancer. The incidence of HPV type 16 infection increased with severity of cervical lesions and it is usually detected high-risk oncogenic type virus in women with severe cervical lesions type like HSIL and cancer are. HPV 31 is the most common high-risk type of HPV of mild type lesions, like LSIL and cervicitis are. We believe that women infected by high-risk oncogenic HPV types, although without histologically diagnose of cervical lesion, should be more frequent control by colposcopy and cytology (Papanicolaou) test, because of possible disease progression to a more advanced level

The importance of buffalo in milk production and buffalo population in Serbia

This research paper gives an analysis on the size of world's domestic buffalo populations, their milk production and the size of buffalo population in Serbia. Population of domestic buffalo in the world is constantly increasing so that in 2013 there were 199 783 549 individuals, out of which in India in the same year they raised 57.77% of buffalo world population, in Pakistan 18.87%, and in China 11.64%. The share of total world production of buffalo milk in total world milk production in 2012 was 12.92 % or 97 417 135 t out of which 67.76% was produced in India. In Serbia buffalo is raised in the regions of Raška (about 1000 individuals) and Kosovo. Populations of buffalo in central Serbia show a tendency of decreasing in size what was the reason to start a programme of in situ conservation 10 years ago. On the sample of buffalo population encompassed by the programme of conservation the body measures were analysed indicating that the population of buffalo is quite unequalised and that average values obtained for exterior measures are similar to the results obtained by the authors of earlier period for the population of buffalo in the area of former Yugoslavia

Exploring the design space of metadata-focused file management systems

Operating systems both old and new are reliant on the venerable hierarchical file system. For some time now, however, attempts have been made to either define new file systems or to bolt on applications that offer much improved functionality to attach and use metadata. This is because researchers have shown that traditional file systems are not able to meet users' needs in terms of organising large numbers of files effectively, and to support expeditious retrieval of those files when they are needed at a later time. Numerous proposals for post-hierarchical file management systems have been described in the literature; researchers focus on different dimensions of such systems in order to solve or reduce identified limitations. In some cases this leads to significantly different file system architectures, while in other cases new functionality is added on top of a traditional system through special purpose user-space applications. Orthogonally, some proposals focus on tags while others favour named attribute-value pairs. Still other choices are, seemingly, made in an ad hoc and often implicit manner. This paper investigates the different dimensions and associated choices that participate in the proposal of new approaches and that affect their ability to improve on current systems. The Cartesian product of those dimensions and options forms a large design space; we map some of the existing literature onto that design space and discuss approaches to evaluate new proposals