On Wheeler's delayed-choice Gedankenexperiment and its laboratory realization

Here, we present an analysis and interpretation of the experiment performed by Jacques et al. (2007 Science 315, 966), which represents a realization of Wheeler's delayed-choice Gedankenexperiment. Our analysis is based on the evolution of the photon state, since the photon enters into the Mach-Zehnder interferometer with a removable beam-splitter until it exits. Given the same incident photon state onto the output beam-splitter, BS_output, the photon's state at the exit will be very different depending on whether BS_output is on or off. Hence, the statistics of photon counts collected by the two detectors, positioned along orthogonal directions at the exit of the interferometer, is also going to be very different in either case. Therefore, it is not that the choice of inserting (on) or removing (off) a beam-splitter leads to a delayed influence on the photon behavior before arriving at the beam-splitter, but that such a choice influences the photon state at and after BS_output, i.e., after it has exited from the Mach-Zehnder interferometer. The random on/off choice at BS_output has no delayed effect on the photon to behave as a wave or a corpuscle at the entrance and inside the interferometer, but influences the subsequent evolution of the photon state incident onto BS_output.Comment: 7 pages, 4 figure

Coherence loss and revivals in atomic interferometry: A quantum-recoil analysis

The coherence effects induced by external photons coupled to matter waves inside a Mach-Zehnder three-grating interferometer are analyzed. Alternatively to atom-photon entanglement scenarios, the model considered here only relies on the atomic wave function and the momentum shift induced in it by the photon scattering events. A functional dependence is thus found between the observables, namely the fringe visibility and the phase shift, and the transversal momentum transfer distribution. A good quantitative agreement is found when comparing the results obtained from our model with the experimental data.Comment: 18 pages, 4 figure

Kovalentne modifikacije proteina biološki aktivnim hinonima

The avarone/avarol quinone/hydroquinone couple shows considerable antitumor activity. In this work, covalent modification of beta-lactoglobulin by avarone and its derivatives as well as by the synthetic steroidal quinone 2,5(10)-estradiene-1,4,17-trione and its derivatives were studied. The techniques for studying chemical modification of beta-lactoglobulin by quinones were: UV/Vis spectrophotometry, SDS PAGE and isoelectrofocusing. SDS PAGE results suggest that polymerization of the protein Occurs. It Could be seen that the protein of 18 kD gives the bands of 20 kD, 36 kD, 40 kD, 45 kD, 64 kD and 128 kD depending on modification agent. The shift of the pl of the protein (5.4) upon modification toward lower values (from pl 5.0 to 5.3) indicated that lysine amino groups are the principal site of the reaction of beta-lactoglobulin with the quinones.Hinonsko/hidrohinonski par avaron/avarol pokazuje značajnu antitumorsku aktivnost. U ovom radu proučavane su kovalentne modifikacije β-laktoglobulina avaronom, sintetičkim steroidnim hinonom 2,5(10)-estradien-1,4,17-trionom i njihovim derivatima. Tehnike za praćenje hemijske modifikacije bile su: UV/Vis spektrofotometrija, SDS PAGE i izoelektrofokusiranje. Rezultati SDS PAGE ukazuju da se dešava polimerizacija proteina.Može se videti da protein od 18 kD daje trake od 20 kD, 36 kD, 40 kD, 45 kD, 64 kD i 128 kD u zavisnosti od agensa za modifikaciju. Pomeranje pI vrednosti proteina (5,4) nakon modifikacije ka nižim vrednostima (od pI 5,0 do 5,3) pokazuje da su amino-grupe lizina glavna mesta reakcije β-laktoglobulina sa hinonima

Uticaj transgenaze na kvalitet i prinos mesa kunića

In this paper results of the effect of transgenesis on quality and yield of rabbit meat are presented. During the trial body mass of transgenic progeny of F1 generation was monitored and compared to control group (nontransgenic animals of same age). Subsequent to slaughtering, meat yield, ratio between certain musculature parts and meat quality (proteins, lipids, water) were analyzed. Obtained data was compared to control group of animals of same age but standard genotype. Meat colour was evaluated on apparatus Specol 11 and expressed as percentage of remission on wave length of 540 μm. Content of elements in thigh muscle was established subsequent to dry mineralization in spectro-photometer UNICAM 939 Cambridge UK. Phosphorus content was measured spectro-photometrically on apparatus SPECOL 11. Subsequent to measuring and systematization, data was statistically analyzed and processed. Arithmetic mean values for certain groups of data were calculated, and their values compared using t-test (Hadživuković, 1991). Changes established in regard to content of water, lipids, energy and water binding capacity, were relative to changes in histological structure and level of metabolic processes. It is possible that these changes are result of pleiotropic effect of integrated gene. However, in order to confirm and interpret these changes, it is necessary to carry out further researches of the microscopic structure and metabolic processes of muscle tissues in transgenic rabbits.U radu su prikazani rezultati uticaja transgeneze na kvalitet i prinos mesa kunića. Ogled je vršen na komercijalnim tovnim hibridima nastalim ukrštanjem Novozelandskih belih i Kalifornijskih kunića. Dobijeni podaci upoređeni su sa kontrolnom grupom vršnjaka standardnog genotipa. Posmatrani su sledeći parametri kod obe grupe životinja: telesna masa (1, 2, 5, 10, 20 i 30- tog dana starosti), klanični podaci (w-težina pre žrtvovanja, dw- težina nakon iskrvarenja, s-težina kože, sp-težina distalnih delova zadnjih nogu, b- težina polutke sa kožom, hd-težina glave bez kože, fl- težina prednjih nogu, t- težina butova, r-težina rebara (grudi), bk - težina leđa, ht- težina srca, ky-težina bubrega, l- težina pluća, lvtežina jetre, git- težina stomaka i creva sa sadržajem, gite-težina praznog stomaka i creva, f- težina masnoće, bt- težina kostiju nogu, mt-težina mišića nogu, bf- težina kostiju prednjih nogu, c- prinos mesa (obraslost muskulaturom %); kvalitet mesa butova (cw- sadržaj vode, cp - sadržaj proteina, cf- sadržaj masti, ce- energija, pH, cc- boja, bw- kapacitet zadržavanja vode) i sadržaj mikroelemenata u mesu buta (Cu, Zn, Fe, K, Na, Mg, P, Ca). Posle merenja i sistematizacije podaci su statistički obrađeni. Izvršena su izračunavanja aritmetičkih sredina pojedinih grupa podataka, a zatim poređenje njihovih vrednosti t-testom (Hadživuković, 1991). Nizak nivo varijabiliteta u svim starosnim kategorijama u obe posmatrane grupe je jasno vidljiv iz vrednosti standardne greške aritmetičke sredine. To je manifestovano statistički značajnim uticajem procesa transgeneze na živu masu pri rođenju uprkos činjenici da je apsolutna razlika aritmetičkih sredina transgene i kontrolne grupe samo 0,005 kg (0,063±0,001 nasuprot 0,058±0,002) (tabela 1). Ovaj uticaj je na granici P=0,05 u tabeli analize varijanse (tabela 2). Razlika aritmetičkih sredina nije statistički značajna kod ostalih starosnih kategorija i ona se gubi već nakon 48 časova. Može se konstatovati da integrisani gen nema uticaja na porast transgenih kunića. Statistički značaj uticaja integrisanog gena je utvrđen kod parametara koji se odnose na masu distalnih delova transgenih i netransgenih kunića (0,062±0,001 nasuprot 0,069±0,001 kg), težine glave (0,119±0,003 nasuprot 0,128±0,003 kg) i težine butova (0,405±0,010 nasuprot 0,433±0,009 kg). Kod ostalih klaničnih karakteristika koje su testirane nisu utvrđene statistički značajne razlike koje bi bile uslovljene integracijom gena (tabele 3 i 4). Na uzorcima mesa nogu (butovi) praćene su vrednosti koje se odnose na kvalitet mesa (tabele 5 i 6). Dobijeni podaci koji se odnose na sastav mesa (tabela 5) ukazuju da je uticaj integracije gena bio statistički značajan (p (lt) 0,05) u grupi transgenih kunića u poređenju sa netransgenim u pogledu sledećih karakteristika: sadržaj proteina (74,03±0,26 nasuprot 74,84±0,28%), sadržaj masnoće (3,66±0,40 nasuprot 2,32±0,44%), sadržaja energije (495,43±11,81 nasuprot 458,07±12,94%), kapacitet zadržavanja vode (31,66±0,84 nasuprot 35,63±0,92%). Statistički značajne razlike kao posledica uticaja integrisanog gena nisu utvrđene kod ostalih posmatranih parametara (tabela 6). Srednje vrednosti sadržaja elemenata u tkivu mišića pokazale su najveće varijacije od svih posmatranih parametara. Najizraženije varijacije bile su u grupi netransgenih kunića (tabela 7). Broj životinja ili ponavljanja je igrao veliku ulogu. Za većinu posmatranih karakteristika može se reći da nisu pokazale uticaj integrisanog WAP- hFVIII gena u genotipu kunića. Značajnije razlike pojavile su se samo u okviru nekih parametara kvaliteta mesa (tabela 8). Rezultati ukazuju da nije utvrđeno ni prisustvo rhFVIII u skeletnim mišićima transgenih kunića

On the influence of resonance photon scattering on atom interference

Here, the influence of resonance photon-atom scattering on the atom interference pattern at the exit of a three-grating Mach-Zehnder interferometer is studied. It is assumed that the scattering process does not destroy the atomic wave function describing the state of the atom before the scattering process takes place, but only induces a certain shift and change of its phase. We find that the visibility of the interference strongly depends on the statistical distribution of transferred momenta to the atom during the photon-atom scattering event. This also explains the experimentally observed (Chapman et al 1995 Phys. Rev. Lett. 75 2783) dependence of the visibility on the ratio d_p/\lambda_i = y'_{12} (2\pi/kd\lambda_i), where y'_{12} is distance between the place where the scattering event occurs and the first grating, k is the wave number of the atomic center-of-mass motion, $d$ is the grating constant and \lambda_i is the photon wavelength. Furthermore, it is remarkable that photon-atom scattering events happen experimentally within the Fresnel region, i.e. the near field region, associated with the first grating, which should be taken into account when drawing conclusions about the relevance of "which-way" information for the interference visibility.Comment: 9 pages, 1 figur

Mucositis Grades and Yeast Species

Surgically treated patients with oral, head and neck cancer commonly develop mucositis during additional irradiation therapy. Oral mucosa inflammation other than irradiation is mostly caused by Candida albicans, yeast of Candida genus. This study evaluated possible connection between grades of oral mucositis and oral yeast profile in irradiated patients before, during and after irradiation. In 25 examined patients mucosits grades »0« to »2« before irradiation with 20% positive smears and only two different species of yeasts (C. krusei 4%, C. albicans 16%) during the irradiation changed into »0« to »4« and 36% positive smears with five different species of oral yeasts (C. albicans 12%, C. glabrata 12%, C. parapsilosis 4%, C. guilliermondii 4% and Saccharomyces cerevisiae 4%). Three weeks after irradiation was finished mucositis decreased into »1« to »3« with 20% positive smears and again only two species of yeasts (C. albicans 16%, C. guilliermondii 4%). Mucositis grades was increased significantly (p=0.0037) with changes in fungi profile

Properties and nature of Be stars 30. Reliable physical properties of a semi-detached B9.5e+G8III binary BR CMi = HD 61273 compared to those of other well studied semi-detached emission-line binaries

Reliable determination of the basic physical properties of hot emission-line binaries with Roche-lobe filling secondaries is important for developing the theory of mass exchange in binaries. It is a very hard task, however, which is complicated by the presence of circumstellar matter in these systems. So far, only a small number of systems with accurate values of component masses, radii, and other properties are known. Here, we report the first detailed study of a new representative of this class of binaries, BR CMi, based on the analysis of radial velocities and multichannel photometry from several observatories, and compare its physical properties with those for other well-studied systems. BR CMi is an ellipsoidal variable seen under an intermediate orbital inclination of ~51 degrees, and it has an orbital period of 12.919059(15) d and a circular orbit. We used the disentangled component spectra to estimate the effective temperatures 9500(200) K and 4655(50) K by comparing them with model spectra. They correspond to spectral types B9.5e and G8III. We also used the disentangled spectra of both binary components as templates for the 2-D cross-correlation to obtain accurate RVs and a reliable orbital solution. Some evidence of a secular period increase at a rate of 1.1+/-0.5 s per year was found. This, together with a very low mass ratio of 0.06 and a normal mass and radius of the mass gaining component, indicates that BR CMi is in a slow phase of the mass exchange after the mass-ratio reversal. It thus belongs to a still poorly populated subgroup of Be stars for which the origin of Balmer emission lines is safely explained as a consequence of mass transfer between the binary components.Comment: 17 pages, 5 figures, accepted for publication in Astronomy and Astrophysics. appears in Astronomy and Astrophysics 201

MOST FREQUENT CARP (Cyprinus carpio L.) DISEASES IN PONDS FROM 1994. TO 1998

Zdravstveno stanje šarana praćeno je na 252 ribnjaka od godine 1994. do 1998. Rezultati zdravstvenoga stanja varirali su ovisno o primjeni ihtiotehnoloških, ihtiosanitarnih i ihtiohigijenskih profilaktičnih mjera. Najčešće utvr|ene bolesti bile su eritrodermatitis šarana u 5,82 %, ihtioftirijaza u 13,51 %, trihodinijaza u 33,568 %, daktilogiroza i girodaktiloza u 35,75 %, botriocefaloza u 14,99 % te upala ribljega mjehura uzrokovana mikroorganizmom Sphaerospora angulata u 17,77 % pregledanih ribnjaka.Fish health monitoring was carried out in the period from 1994. to 1998. for 252 fresh water ponds. Findings about health status depended upon the quality of health control measures such as ichthyotechnic, ichthyosanitary and ichthyohygieni methods. Most frequently diagnosed diseases and their percentages of incidence were: carp erythrodermatytis in 5,82 %, ichthyophtiriasis in 13,51 %, trihodiniasis in 33,568 %, dactylogirosis and gyrodactilosis in 35,75 %, botriocephalosis in 14,99 % and swimbladder inflammation caused by Sphaerospora angulata in 17,77 % examined ponds