543 research outputs found
Primena molekularnih markera u napretku stočarstva
With recent developments in DNA technologies, a large number of genetic polymorphisms at DNA sequence level has been introduced over the last decades as named DNA-based markers. The discovery of new class of DNA profiling markers has facilitated the development of marker-based gene tags, mapbased cloning of livestock important genes, variability studies, phylogenetic analysis, synteny mapping, marker-assisted selection of favourable genotypes, etc. The most commonly used DNA-based markers have advantages over the traditional phenotypic and biochemical markers since they provide data that can be analyzed objectively. In this article the main applications of molecular markers in present-day breeding strategies for livestock improvement - parentage determination, genetic distance estimation, genetic diversity, gene mapping and marker-assisted selection have been reviewed.Sa razvojem DNK tehnologija, veliki broj genetskih polimorfizama na nivou DNK sekvence su predstavljene poseldnjih godina pod nazivom DNK markeri. Otkriće novih klasa DNK markera je olakšalo razvoj marker gena, kloniranja gena od važnosti u stočarstvu i to na bazi mapa, ispitivanje varijabilnosti, filogenetske analize, mapiranja, selekcije poželjnih genotipova pomoću markera, itd. Markeri na bazi DNK koji se najčešće koriste imaju prednost u odnosu na tradicionalne fenotiske i biohemijske markere jer obezbeđuju podatke koji se mogu objektivno analizirati. U ovom radu su predstavljeni načini korišćenja i aplikacija molekularnih markera u postojećim odgajivačkim strategijama odn. napretku stočarstva - određivanje porekla, ocena genetske distance, genetskog diverziteta, mapiranje gena i selekcija pomoću markera
Models of spin-orbit coupled oligomers
We address the stability and dynamics of eigenmodes in linearly-shaped
strings (dimers, trimers, tetramers, and pentamers) built of droplets of a
binary Bose-Einstein condensate (BEC). The binary BEC is composed of atoms in
two pseudo-spin states with attractive interactions, dressed by properly
arranged laser fields, which induce the (pseudo-) spin-orbit (SO) coupling. We
demonstrate that the SO-coupling terms help to create eigenmodes of particular
types in the strings. Dimer, trimer, and pentamer eigenmodes of the linear
system, which correspond to the zero eigenvalue (EV, alias chemical potential)
extend into the nonlinear ones, keeping an exact analytical form, while
tetramers do not admit such a continuation, because the respective spectrum
does not contain a zero EV. Stability areas of these modes shrink with the
increasing nonlinearity. Besides these modes, other types of nonlinear states,
which are produced by the continuation of their linear counterparts
corresponding to some nonzero EVs, are found in a numerical form (including
ones for the tetramer system). They are stable in nearly entire existence
regions in trimer and pentamer systems, but only in a very small area for the
tetramers. Similar results are also obtained, but not displayed in detail, for
hexa- and septamers.Comment: Chaos, in pres
Interface solitons in locally linked two-dimensional lattices
Existence, stability and dynamics of soliton complexes, centered at the site
of a single transverse link connecting two parallel 2D (two-dimensional)
lattices, are investigated. The system with the on-site cubic self-focusing
nonlinearity is modeled by the pair of discrete nonlinear Schr\"{o}dinger
equations linearly coupled at the single site. Symmetric, antisymmetric and
asymmetric complexes are constructed by means of the variational approximation
(VA) and numerical methods. The VA demonstrates that the antisymmetric soliton
complexes exist in the entire parameter space, while the symmetric and
asymmetric modes can be found below a critical value of the coupling parameter.
Numerical results confirm these predictions. The symmetric complexes are
destabilized via a supercritical symmetry-breaking pitchfork bifurcation, which
gives rise to stable asymmetric modes. The antisymmetric complexes are subject
to oscillatory and exponentially instabilities in narrow parametric regions. In
bistability areas, stable antisymmetric solitons coexist with either symmetric
or asymmetric ones.Comment: 9 figure
Investigation of gene pool and genealogical links between sheep breeds of southern Russia by blood groups and DNA microsatellites
To study the gene pool and the establishment of genealogical relationships between breeds of sheep of different directions productivity bred in Russia, were used two classes of genetic markers - blood and DNA microsatellites. The included sample sheep are fine-wool Merino breeds: Grozny (GR), Caucasian (CA), Manychskij merino (MM), the Soviet Merino (SM), Stavropol (ST) and coarse wool breeds: Edilbaevskaya (ED), Karakul (CR) and Romanov (RO). For the study of erythrocyte, were selected antigens (blood group) in 1159 samples from 11 breeding farms. For microsatellite DNA study - 598 from 10 breeding farms. Microsatellite analysis revealed that the most polymorphic were Stavropol breed sheep that have identified an average of 18.27 alleles per locus were relatively conservative Romanov breed sheep - 9.7 alleles per locus. The minimum genetic distances established between Grozny and Soviet Merino - 0.0569 (for microsatellites) and 0.0741 (blood groups - later in the same sequence). The rocks of the Stavropol - Grozny were 0.0861 and 0, 0810. Whereas Stavropol and Soviet Merino 0.0861 and 0.1094. Also relatively close between Grozny - Edilbaevskoy, Grozny Karakul, Edilbaevskoy - Karakul: 0.1364 and 0.0851, respectively; 0.1620 and 0.1208; 0.1875 and 0.1192. The highest genetic distances were between Stavropol and Karakul 0.2664 and 0.1804, as well as between the Romanov and all studied species - 0.2491 ... 0.3211 and 0.1734 ... 0.2235
Study of the growth traits relationship of lambs in the postnatal development
Data from the Pirot improved sheep were use to estimate postnatal development and growth traits relationship of lambs from birth to weaning. The experiment included 360 lambs, divided into three groups (I, II, III). Lamb traits included BW at birth and approximately 30d, 60d and 90d (weaning). Lambs managed under conditions typical of the area. Male lambs in-group I had a total gain of 22.97 kg (0.255 kg/d), in group II 25.97 kg (0.286 kg/d) (P (lt) 0.01). Lambs in-group III the total gain was 24.64 kg (0.274 kg/d), which was lower than lambs of group II (P>0.05). On the other side, III group of lambs had a higher gain than the I group (P (lt) 0.01). Development of female lambs in the postnatal period was slightly weaker. Lambs of I group, from birth to weaning had a total gain of 21.27 kg, (0.236 kg/d), II group was 23.32 kg (0.259 kg/d). The difference was statistically very significant (P (lt) 0.01). Lambs of group III had a total gain of 23.54 kg (0.261kg/d) and higher growth rate then lambs of group II, but not significant (P>0.05). From the other side, the difference in comparison with the groups III and I was very significant (P (lt) 0.01). Correlations between BWB and BW30, 60, 90 are ranged from low to moderate among the respective traits and ranged between positive from 0.001 to 0.365 and negative from -0.005 to -0.279. Can conclude that the selection should direct towards producing lambs with intermediate birth weight
Uticaj genotipa i perioda laktacije na količinu, fizičke i hemijske osobine ovčijeg mleka
Two genotype of sheep have been utilized in the conduct of the experiment composed of 60 ewes from Pirot x Virtemberg as genotype 1 and 60 ewes of Improved Pirot as genotype 2. All the ewes were reared under identical conditions and without any differences in nutrition and management during the whole period under study. The collection of Milk sampling was done in morning and evening during periods (1, 2, 3) of lactation duration. The average lactation duration and average total milk of the two genotypes were very close and has a minimal difference of 0.467 day and 1.562 kg, in favor of genotype 2. The differences between genotypes were not significant (P>0,05). Regarding physical and chemical properties of milk for both genotypes, the difference were very minimal such as follows; viscosity Pa x s - 0.006, electrical conductivity Ω - 0.018, density kg/m3 -0,001, freezing, t 0C - 0.013, LD number - 0.028 total solids, % - 0.014, fat,% - 0,026, protein,% - 0.085, lactose,% - 0.038, ash,% - 0,021, acidity, 0SH - 0.209. The results indicated that the properties of milk for both genotypes were very near to each other. It can be interpreted that the breeds utilized in the experiment were comparable due to similar characteristics perhaps. The effect of genotype was very significant only for the % protein of the milk. The lactation periods were highly significant in all physical and chemical properties of milk.Istraživanja su obavljena kod dve rase ovaca i to 60 grla Pirotska x Virtemberg kao genotip 1 i 60 ovaca pirotske oplemenjene populacije, kao genotip 2. Sve životinje su držane u istim proizvodnim uslovima na farmi u Vrnjačkoj Banji. Prosečne vrednosti trajanja laktacije i mleka dobijenog u periodu laktacije su bile vrlo ujednačene, tako da nije utvrđen uticaj genotipa na ova svojstva. Takođe, razlike između fizičko hemijskih osobina mleka, u većini slučajeva su bile nesignifikantne. Uticaj genotipa kao fiksnog faktora je bio vrlo signifikantan samo kod sadržaja proteina u mleku ovaca (P (lt) 0.01). Međutim utvrđeno je da period laktacije ima vrlo signifikantan uticaj na sva posmatrana fizička i hemijska svojstva mleka
Magnetic field enhanced structural instability in EuTiO_{3}
EuTiO_{3} undergoes a structural phase transition from cubic to tetragonal at
T_S = 282 K which is not accompanied by any long range magnetic order. However,
it is related to the oxygen ocathedra rotation driven by a zone boundary
acoustic mode softening. Here we show that this displacive second order
structural phase transition can be shifted to higher temperatures by the
application of an external magnetic field (increased by 4 K for mu_{0}H = 9 T).
This observed field dependence is in agreement with theoretical predictions
based on a coupled spin-anharmonic-phonon interaction model.Comment: 4 pages, 4 figure
Molekularna genetika i SSR markeri kao nova praksa u genomskoj analizi farmskih životinja u reprodukciji i kontroli bolesti
Molecular genetics investigates the genetic makeup of individuals at the DNA level. That includes the identification and mapping of molecular genetic markers and genetic polymorphisms. Molecular genetic markers (DNA markers) are one of the most powerful means for the genomic analysis and allow the connection of hereditary traits with genomic variation. Molecular marker technology has developed rapidly over the last decade and two shapes of specific DNA based marker, Simple Sequence Repeats (SSRs), also known as microsatellites, and Single Nucleotide Polymorphisms (SNPs) prevail applications in modern genetic analysis. Genomic simple sequence repeats (SSRs, microsatellites) have been used for a variety of purposes, including gene tagging, physical mapping, genome mapping, estimation of genetic diversity, phylogenetic and conservation genetic purposes in farm animal breeding. SSR analyses are applied successfully in parentage verification and pedigree analysis, as disease markers and to locate the mutation in genetic disorders in livestock animals. The ultimate use of SSRs markers is for mapping quantitative trait loci (QTL), marker assisted selection (MAS) in order to practice genomic selection and improve the farm animal health. Developments in 'omics' technologies, such as genomic selection, may help overcome several of the limitations of traditional breeding programmes and will be especially beneficial in breeding for lowly heritable disease traits that only manifest themselves following exposure to pathogens or environmental stressors in adulthood. The current paper provides a brief overview of the present - day application of microsatellites markers in animal breeding and make significant contribution to the overall farm animal health and resistance to disease.Molekularna genetika istražuje genetski sastav pojedinaca na nivou DNK. To uključuje identifikaciju i mapiranje molekularnih genetskih markera i genetskih polimorfizama. Molekularni genetski markeri (DNK markeri) su jedan od najmoćnijih sredstava genomske analize i pružaju mogućnost povezivanja naslednih osobina sa genomskim varijacijama. Tehnologija molekularnih markera se brzo razvila u poslednjoj deceniji, a dva oblika markera na bazi DNK, Simple Sequence Repeats (SSR), takođe poznati kao mikrosateliti, i polimorfizam pojedinačnih nukleotida - Single Nucleotide Polymorphisms (SNP) preovlađuju u primeni u modernoj genetskoj analizi. Genomske sekvence - ponavljanja (Simple Sequence Repeats - SSR, mikrosateliti) se koriste za razne svrhe, uključujući označavanje gena, fizičko mapiranje, mapiranje genoma, procena genetičke raznovrsnosti, filogenetske i u svrhu genetičke konzervacije u uzgoju farmskih životinja. SSR analiza se uspešno primenjuju u verifikaciji roditeljstva, i analizi pedigrea, kao markeri bolesti i u pronalaženju mutacije i genetskih poremećaja kod farmskih životinja. Krajnja upotreba SSR markera je za mapiranje lokusa kvantitativnih osobina (QTL), selekciji pomoću markera (MAS), kako bi se u praksi primenjivala genomska selekciju i unapređenje zdravlja farmskih životinja. Razvoj u tehnologijama 'omics'', kao što je genomska selekcija, može pomoći u prevazilaženju nekoliko ograničenja tradicionalnih odgajivačkih programa a posebno će biti korisna za oplemenjivanje i odgoj na nižu naslednost naslednih osobina bolesti koje se ispoljavaju tek nakon izloženosti patogenima ili ekološkim stresorima u odraslom dobu. Ovaj rad daje kratak pregled današnje primene mikrosatelit markera u stočarstvu i daje značajan doprinos ukupnom zdravlju životinja uzgajanih na farmi i otpornosti na bolesti
An Ultra-High-Vacuum Rotating Sample Manipulator with Cryogenic Cooling
We report a homebuilt ultra-high-vacuum (UHV) rotating sample manipulator
with cryogenic cooling. The sample holder is thermally anchored to a built-in
cryogenic cold head through flexible copper beryllium strips, permitting
continuous sample rotation. A similar contact mechanism is implemented for the
electrical wiring to the sample holder for thermometry. The apparatus thus
enables continuous sample rotation at regulated cryogenic temperatures in a UHV
environment. We discuss the potential applications of this apparatus for
cryogenic sputtering.Comment: Cryogenics, ultra-high vacuum, sample manipulato
Multi-band Superconductivity in the Chevrel Phases SnMo6S8 and PbMo6S8
Sub-Kelvin scanning tunnelling spectroscopy in the Chevrel Phases SnMo6S8 and
PbMo6S8 reveals two distinct superconducting gaps with Delta_1 = 3 meV, Delta_2
~ 1.0 meV and Delta_1 = 3.1 meV, Delta_2 ~ 1.4 meV respectively. The gap
distribution is strongly anisotropic, with Delta_2 predominantly seen when
scanning across unit-cell steps on the (001) sample surface. The spectra are
well-fitted by an anisotropic two-band BCS s-wave gap function. Our
spectroscopic data are confirmed by electronic heat capacity measurements which
also provide evidence for a twin-gap scenario.Comment: 5 pages, 4 figure
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