Purification and Properties of Diaminopimelate Decarboxylase from Micrococcus Glutamicus

Diaminopimelate decarboxylase (E. C. 4.1.1.20) from Micrococcus glutamicus horn-, lysine excreting strain, is purified 350- fold by ammonium sulphate precipitation, gel filtration on Sephadex G-150, and chromatography on hydroxylapatite and DEAE-Seph adex. The enzyme has a molecular weight of 53000, isoelectric point of 4.3, optimal pH for activity 7.7, energy of activation 11.1 kcal/mol, and Km for substrate 1.26 mM. For its stability, the presence of pyridoxal phosphate and sulphydril reagent is necessary, and most catalytic activity is retained within a pH range of 5.5 to 8.5. Aminoacids, L-lysine, L-norleucine, L- u- aminoadipic, L-glutamic and L-aspartic acid, are inhibitors of diaminopimelate decarboxylase from M. glutamicus horn-

Purification and Properties of Diaminopimelate Decarboxylase from Micrococcus Glutamicus

Diaminopimelate decarboxylase (E. C. 4.1.1.20) from Micrococcus glutamicus horn-, lysine excreting strain, is purified 350- fold by ammonium sulphate precipitation, gel filtration on Sephadex G-150, and chromatography on hydroxylapatite and DEAE-Seph adex. The enzyme has a molecular weight of 53000, isoelectric point of 4.3, optimal pH for activity 7.7, energy of activation 11.1 kcal/mol, and Km for substrate 1.26 mM. For its stability, the presence of pyridoxal phosphate and sulphydril reagent is necessary, and most catalytic activity is retained within a pH range of 5.5 to 8.5. Aminoacids, L-lysine, L-norleucine, L- u- aminoadipic, L-glutamic and L-aspartic acid, are inhibitors of diaminopimelate decarboxylase from M. glutamicus horn-

The Electrocrystallization of Metals. Investigation of Zinc

In electrodeposition of zinc depending on the condition of deposition, various effects of electrocrystallization can be observed. In acid solution of zinc sulfate the considerable surface diffusion overpotential appears at lower values of the total overpotential, indicating the surface diffusion of actions as the rate determining step. An interesting dependence of exchange current density on pH with a minimum at pH - 2 indicate the probable change in structure of the reacting particle. The mechanism of the reaction is evaluated. In alkaline zincate solutions no surface diffusion limitations can be detected. However, due to the rather low zincate ion concentration and high exchange current density zinc deposition proceeds practically always under the diffusion control. Morphology of zinc deposited depends considerably on the value of the electrode potential. This can be seen from the experiments in which the deposition morphology was observed with a scanning electron microscope. It was found possible to disrupt the deposition repeatedly for microscopic observation and than continue deposition. At low overpotentials (up to 50 mV) epitaxial layer type growth was observed with the linear increase of the microstep width with time. For this effect a theory is proposed which accounts also for the observed effects of substrate orientation. At larger overpotentials (50-100 mV) boulder type deposit was observed, most of which were not epitaxial with the substrate. They are suggested to be originated by nucleation. The boulder density per cm2 is first sharply increasing, and then slowly decreasing with time. A statistical calculation for this is given based on the model that large boulders consume the smaller ones. With further deposition a small fraction of the boulders develop into dendrites, their number being limited by the available total current

Modifications of the variable neighborhood search method and their applications to solving the file transfer scheduling problem

Metoda promenljivih okolina se u praksi pokazala vrlo uspesnom za resavanje pro- blema diskretne i kontinualne optimizacije. Glavna ideja ove metode je sistematska promena okolina unutar prostora resenja u potrazi za boljim resenjem. Za opti- mizaciju funkcija vise promenljivih koriste se metode koje nalaze lokalni minimum polazeci od zadate pocetne tacke. U slucaju kada kontinualna funkcija ima mnostvo lokalnih minimuma, nalazenje globalnog minimuma obicno nije lak zadatak jer najcesce dostignuti lokalni minimumi nisu optimalni. Kod uobicajenih implementa- cija sa ogranicenim okolinama razlicitih dijametara iz proizvoljne tacke nije moguce dostici sve tacke prostora resenja. Zbog toga je strategija koriscenja konacnog broja ogranicenih okolina primenjiva na probleme kod kojih optimalno resenje pripada nekom unapred poznatom ogranicenom podskupu skupa IRn. U cilju prevazilazenja pomenutog ogranicenja predlozena je nova varijanta meto- de, Gausovska metoda promenljivih okolina. Umesto denisanja niza razlicitih okolina iz kojih ce se birati slucajna tacka, u ovoj metodi se sve okoline pokla- paju sa celim prostorom resenja, a slucajne tacke se generisu koriscenjem razlicitih slucajnih raspodela Gausovog tipa. Na ovaj nacin se i tacke na vecem rastojanju od tekuce tacke mogu teorijski dostici mada sa manjom verovatnocom. U osnovnoj verziji metode promenljivih okolina neophodno je unapred denisati sistem okolina, njihov ukupan broj i velicinu, kao i tip raspodele koja ce se koristiti za odabir slucajne tacke unutar tih okolina. Gausovska metoda promenljivih okolina za razliku od osnovne verzije ima manje parametara jer su sve okoline teorijski iste velicine (jednake celom prostoru pretrage) i imaju jedinstvenu jednoparametarsku familiju raspodela Gausovu raspodelu slucajnih brojeva sa promenljivom dispe- rzijom. Problem raspored-ivanja prenosa datoteka (File transfer scheduling problem - FTSP) je optimizacioni problem koji svoju primenu pronalazi u mnogim oblastima poput telekomunikacijama, LAN i WAN mrezama, raspored-ivanju u okviru MIMD (multiple instruction multiple data) racunarskih sistema i dr. Spada u klasu NP teskih problema za cije resavanje se uobicajeno koriste heuristicke metode. Za- datak optimizacije FTSP sastoji se u trazenju odgovarajuceg rasporeda pojedinacnih prenosa datoteka, tj. vremenskih trenutaka kada ce svaka datoteka zapoceti svoj prenos tako da duzina vremenskog intervala od trenutka kada prva datoteka zapocne prenos do trenutka u kom poslednja zavrsi bude sto manja...The Variable neighborhood search method proved to be very successful for solving discrete and continuous optimization problems. The basic idea is a systematic change of neighborhood structures in search for the better solution. For optimiza- tion of multiple variable functions, methods for obtaining the local minimum starting from certain initial point are used. In case when the continuous function has many local minima, nding the global minimum is usually not an easy task since the obta- ined local minima in most cases are not optimal. In typical implementations with bounded neighborhoods of various diameters it is not possible, from arbitrary point, to reach all points in solution space. Consequently, the strategy of using the nite number of neighborhoods is suitable for problems with solutions belonging to some known bounded subset of IRn. In order to overcome the previously mentioned limitation the new variant of the method is proposed, Gaussian Variable neighborhood search method. Instead of dening the sequence of dierent neighborhoods from which the random point will be chosen, all neighborhoods coincide with the whole solution space, but with die- rent probability distributions of Gaussian type. With this approach, from arbitrary point another more distant point is theoretically reachable, although with smaller probability. In basic version of Variable neighborhood search method one must dene in advance the neighborhood structure system, their number and size, as well as the type of random distribution to be used for obtaining the random point from it. Gaussian Variable neighborhood search method has less parameters since all the neighborhoods are theoretically the same (equal to the solution space), and uses only one distribution family - Gaussian multivariate distribution with variable dispersion. File transfer scheduling problem (FTSP) is an optimization problem widely appli- cable to many areas such as Wide Area computer Networks (WAN), Local Area Ne- tworks (LAN), telecommunications, multiprocessor scheduling in a MIMD machines, task assignments in companies, etc. As it belongs to the NP-hard class of problems, heuristic methods are usually used for solving this kind of problems. The problem is to minimize the overall time needed to transfer all les to their destinations for a given collection of various sized les in a computer network, i.e. to nd the le transfer schedule with minimal length..

Propylene glycol energy supplementation during peripartal period in dairy cows and reproduction efficiency parameters

The aim of this work was to investigate the impact of two energy supplements based on propylene glycol in dairy cows diet on ovarian and follicular morphology, conception, insemination index and length of service period. A total number of 60 Holstein Friesian dairy cows, parity between 2-8, with an average milk production of 7000 kg/305 days of lactation were divided into three experimental groups (20 dairy cows per group). The first group of dairy cows was supplemented daily with "Energy-plus" (O1 group; 200 mL propylene-glycol supplement) and the second group was supplemented with "Ketal" (O2 group; 160 mL propylene-glycol supplement), two weeks before partus until 30 days post partum. The third experimental group were non supplemented dairy cows (O3, control group). Ultrasound examination of the reproductive system using real time echo camera Falco VET 100 (ESAOTE PieMedical, Holland, B-shaped scan with linear-array endorectal 5-8 MHz probe) was conducted on every animal starting from day 40 postpartum. The diameters of the ovaries (left and right) and of the dominant follicle(s) were recorded. Ultrasound testing was repeated on day 50 and 60 postpartum only in cows which in the meantime were not inseminated. Reproduction efficiency parameters (conception rate, number of inseminations and length of service period) were recorded individually. The statistical significance of the differences between groups was tested using ANOVA with LSD test at the level of significance p<0.05, chi-square test and Kaplan-Meier survival analysis (the length of service period). There was no significant impact of the propylene glycol supplementation on the ovarian and follicular morphology at the first ultrasound examination. At the second ultrasound examination there was a significant difference between left ovarian dominant follicle diameter in the control and supplemented dairy cows (1.67±0.53 vs 1.12±0.29 and 1.11±0.35 cm, p<0.05, O3 vs O1 and O2, respectively). The cumulative percentage of conception after the first and second insemination was 60%, 81% and 25% in groups O1, O2 and O3, respectively (p<0.05, chi-square test). The insemination index was lowest in group O2 and statistically significant differences were found between groups O2 and O3 (1.69±0.79 : 3.38±1.36, respectively, p<0,05). The length of the service period was significantly (p<0.05, LSD test) shorter in the O2 group (100±35 days) compared to groups O1 and O3 (168±59 and 157±52 days, respectively), that was confirmed by the Kaplan-Meier survival analysis of days open periods. The use of propylene glycol supplement in dairy cows diet during peripartal period induced higher percentage of pregnancy rates after the first and second insemination, significantly shortened the length of the service period and reduced the insemination index

Effects of recombinations on variability and heritability of traits in maize populations with exotic germplasm

The following maize populations were encompassed by the study: a population with 25% of exotic germplasm (1601/5xZPL913)F2R0 and populations developed after three (1601/5xZPL913)F2R3, that is, five (1601/5xZPL913)F2R5, gene recombination cycles. The S, progeny trial was set lip according to the nested design in two replications and two locations during two years (2001 and 2002). The average values for all traits except moisture at harvest increased. The changes of mean values of yields and other traits can be very important from the aspect of long-term breeding programmes. Different agroecological conditions, genotype, family x location interaction and family x location interaction within the set signficantly affected all observed traits of populations. Genetic and phenotypic variances for all traits except the 1000-kernel weight decreased under the effects of the number of recombination cycles, which was confirmed by the coefficients of heritability. A significant decrease was not detected in yields and ear lengths, which is particularly important for practical breeding. Three cycles of gene recombination are sufficient for this population prior to the application by various breeding methods

HONEY BEE COLONY PHEROMONES

U suprotnosti s hormonima, koji se izlučuju unutar organizma i djeluju isključivo na organizam koj ih je proizveo, feromoni se izlučuju van organizma i djeluju na različite jedinke iste vrste. Da bi bio efikasan, feromon mora biti usko specifičan tako da samo jedna životinjska vrsta reagira i vrlo djelotvoran tako da je potrebna vrlo mala količina da ne iscrpljuje organizam koji ga proizvodi. Komunikacija feromonima je najvažnija za životinje koje žive u složenim društvima, kao što su npr. mravi, pčele ili kunići. Ova socijalna bića moraju komunicirati u sakupljanju hrane, održavanju zajednice i u obrani. Kroz odašiljanje kemijskih poruka, ove se životinje mogu nadopunjavati i organizirati prema statusu i ulozi svake jedinke. Feromoni su jednako značajni za životinje koje žive pojedinačno, samo tada se kemijska komunikacija koristi rjeđe u specifičnim trenucima tijekom njihova života, npr. u vrijeme parenja. Zbog ekonomske važnosti, a jednako i zbog zanimanja za organizaciju socijalnog života, feromoni pčela su među najčešće istraživanima. Proizvodnja feromona u različitih jedinki u pčelinjoj zajednici ovisi o spolu i ulozi jedinke u zajednici, odnosno, o žlijezdama koje posjeduje jedinka. Trutovi neke žlijezde uopće nemaju, a neke su slabije razvijene nego u radilica ili u matice. Jednako tako, neke žljezde su u matice jako razvijene, a u radilica zakržljale i suprotno. Aktivnost pojedinih žlijezda vezana je za životnu dob, odnosno za poslove koje jedinka obavlja. Utvrđeno je da feromone proizvode mandibularna (prednjočeljusna), Nasanovljeva, Koschewnikowa, tergitne, tarzalne (stopalne) i voštane žlijezde, jednako kao i rektum matice i membrana na bazi žalca radilica. Isto tako, značajan izvor feromona je i pčelinje leglo. Istraživanja feromona imaju ekonomsko opravdanje jer se njihovom primjenom može manipulirati štetnim insektima na poljoprivrednim površinama, odnosno upravljati pčelama u vrijeme oprašivanja.ABSTRACT Pheromones are chemicals produced as liquids by specialised cells or glands and transmitted into the environment as liquids or gases. In contrary to hormones, which are excreted in organism and have effect exclusively on organism that produced them, pheromones are excreted outside organism and effect on different individuals of the same species. Pheromones mediate nearly all aspects of honeybee colony life including social defence, brood care, mating, orientation, foraging and reproduction. Pheromone investigation has high economic importance. With use of pheromones it is possible to manipulate with pest insects on crops or to direct honeybees during pollination on target plants

Energetska suplementacija propilen glikolom tokom peripartalnog perioda i parametri efikasnosti reprodukcije kod mlečnih krava

The aim of this work was to investigate the impact of two energy supplements based on propylene glycol in dairy cows diet on ovarian and follicular morphology, conception, insemination index and length of service period. A total number of 60 Holstein Friesian dairy cows, parity between 2-8, with an average milk production of 7000 kg/305 days of lactation were divided into three experimental groups (20 dairy cows per group). The first group of dairy cows was supplemented daily with 'Energy-plus' (O1 group; 200 mL propylene-glycol supplement) and the second group was supplemented with 'Ketal' (O2 group; 160 mL propylene-glycol supplement), two weeks before partus until 30 days post partum. The third experimental group were non supplemented dairy cows (O3, control group). Ultrasound examination of the reproductive system using real time echo camera Falco VET 100 (ESAOTE PieMedical, Holland, B-shaped scan with linear-array endorectal 5-8 MHz probe) was conducted on every animal starting from day 40 postpartum. The diameters of the ovaries (left and right) and of the dominant follicle(s) were recorded. Ultrasound testing was repeated on day 50 and 60 postpartum only in cows which in the meantime were not inseminated. Reproduction efficiency parameters (conception rate, number of inseminations and length of service period) were recorded individually. The statistical significance of the differences between groups was tested using ANOVA with LSD test at the level of significance p lt 0.05, chi-square test and Kaplan-Meier survival analysis (the length of service period). There was no significant impact of the propylene glycol supplementation on the ovarian and follicular morphology at the first ultrasound examination. At the second ultrasound examination there was a significant difference between left ovarian dominant follicle diameter in the control and supplemented dairy cows (1.67±0.53 vs 1.12±0.29 and 1.11±0.35 cm, p lt 0.05, O3 vs O1 and O2, respectively). The cumulative percentage of conception after the first and second insemination was 60%, 81% and 25% in groups O1, O2 and O3, respectively (p lt 0.05, chi-square test). The insemination index was lowest in group O2 and statistically significant differences were found between groups O2 and O3 (1.69±0.79 : 3.38±1.36, respectively, p lt 0,05). The length of the service period was significantly (p lt 0.05, LSD test) shorter in the O2 group (100±35 days) compared to groups O1 and O3 (168±59 and 157±52 days, respectively), that was confirmed by the Kaplan-Meier survival analysis of days open periods. The use of propylene glycol supplement in dairy cows diet during peripartal period induced higher percentage of pregnancy rates after the first and second insemination, significantly shortened the length of the service period and reduced the insemination index.Cilj ovog rada je bio da se ispita uticaj primene dva tipa energetskih dodataka u ishrani mlečnih krava na bazi propilen glikola na morfologiju jajnika i folikula, koncepciju, indeks osemenjavanja i dužinu servis perioda. U ogled je bilo uključeno ukupno 60 krava Holštajn Frizijske rase, u toku 2-8 laktacije, sa prosečnom proizvodnjom mleka od 7000 kg/305 dana laktacije, koje su bile podeljene u tri ogledne grupe (20 krava po grupi). Prva grupa mlečnih krava (O1) je svakodnevno suplementirana peroralnom aplikacijom 200 mL 'Energy-plus', druga grupa krava (O2) suplementirana je sa 160 mL 'Ketal-a', počevši od dve nedelje pre partusa do 30 dana nakon partusa. Treću grupu mlečnih krava (O3, kontrola) su predstavljale netretirane životinje. Ultrazvučni pregled reproduktivnog sistema vršen je sa uređajem Falco VET 100 (ESAOTE PieMedical, Holland), linearnom endorektalnom sondom od 5-8 MHz kod svake životinje najmanje dva puta počevši od 40 dana posle partusa. Ultrazvučni pregled je ponovljen sa 50 i/ili 60 dana posle partusa kod krava koje nisu u međuvremenu osemenjene. U toku svakog pregleda su registrovani prečnik oba jajnika i dominantnog folikula. Kod svake ogledne životinje su određeni parametri efikasnosti reprodukcije: stepen koncepcije, indeks osemenjavanja i servis period. Statistička značajnost razlika srednjih vrednosti dobijenih parametara određivana je ANOVA metodom i LSD testom na nivou značajnosti od p lt 0.05, hi-kvadrat testom i Kaplan-Majerovom analizom (dužina servis perioda). Rezultati prvog ultrazvučnog pregleda su ukazali da nema statistički značajnih razlika u morfologiji jajnika i dominantnog folikula između suplementiranih grupa u odnosu na kontrolnu grupu krava. Rezultati drugog ultrazvučnog pregleda su ukazali da postoji statistički značajna razlika između srednjih vrednosti prečnika dominantnog folikula na levom jajniku kod kontrolne grupe krava u odnosu na suplementirane životinje (1,67±0,53:1,12±0,29 i 1,11±0,35 cm, p lt 0.05, O3:O1 i O2). Zbirne vrednosti procenta koncepcije nakon prvog i drugog osemenjavanja bile su statistički značajno više kod suplementiranih krava u odnosu na kontrolnu grupu životinja (60% : 81% : 25%; O1:O2:O3, p lt 0,05, hi-kvadrat test). Najniža vrednost indeksa osemenjavanja je utvrđena kod ogledne grupe krava suplentirane Ketal-om (1.69±0.79), koja je bila značajno viša u odnosu na kontrolnu grupu krava (3.38±1.36, p lt 0,05). Dužina servis perioda je bila najmanja kod grupe krava suplementiranih Ketal-om (100±35 days) i značajno se razlikovala u odnosu na ostale ogledne grupe (168±59 i 157±52 dana, O1 i O2), što je potvrđeno Kaplan Majerovom analizom. Energetska suplementacija mlečnih krava propilen glikolom tokom peripartalnog perioda može dovesti do povećanja procenta gravidnih krava nakon prvog i drugog osemenjavanja, smanjenja vrednosti indeksa osemenjavanja i skraćenja dužine servis perioda

Effect of environment of the rutin content in leaves of Fagopyrum esculentum Moench.

The experiments were conducted in four locations in Serbia: Valjevo, Kucevo, Nova Pazova and Surduk in 2012 and 2013. A working hypothesis that growing conditions would not affect the rutin content in buckwheat leaves was set up. The content of rutin in leaves of buckwheat was determined by the HPLC/DAD technique, using the external standard calibration method. Out of the basic biometric parameters, average value, variance, and the variation coefficient were estimated. Results were processed by the analysis of variance for the factorial experiment. The analysis of variance showed existence of significant differences in the rutin content, over locations, but only in the first year of testing. The average content of rutin in the first and the second year was 3.30% and 2.61%, respectively, and in both years of testing it amounted on average to 2.82%. The variation in the rutin content was larger in the second year of testing. On the other hand, this variation was lower in the first year (5.3-29.0%) in comparison to the second year (16.2-28.6%). Relatively lower rutin contents were recorded in samples collected at lower-altitude locations