Particle production and classical condensates in de Sitter space

The cosmological particle production in a $k=0$ expanding de Sitter universe with a Hubble parameter $H_0$ is considered for various values of mass or conformal coupling of a free, scalar field. One finds that, for a minimally coupled field with mass $0 \leq m^2 < 9 H_0^2/4$ (except for $m^2= 2H_0^2$), the one-mode occupation number grows to unity soon after the physical wavelength of the mode becomes larger than the Hubble radius, and afterwards diverges as $n(t) \sim O(1)(\lambda_{phys}(t)/H_0^{-1})^{2\nu}$, where $\nu \equiv [9/4 - m^2/H_0^2]^{1/2}$. However, for a field with $m^2 > 9H_0^2/4$, the occupation number of a mode outside the Hubble radius is rapidly oscillating and bounded and does not exceed unity. These results, readily generalized for cases of a nonminimal coupling, provide a clear argument that the long-wavelength vacuum fluctuations of low-mass fields in an inflationary universe do show classical behavior, while those of heavy fields do not. The interaction or self-interaction does not appear necessary for the emergence of classical features, which are entirely due to the rapid expansion of the de Sitter background and the upside-down nature of quantum oscillators for modes outside the Hubble radius.Comment: Revtex + 5 postscript figures. Accepted for Phys Rev D15. Revision of Aug 1996 preprint limited to the inclusion and discussion of references suggested by the referee

INFLUENCE OF WEATHER CONDITIONS ON HONEY BEE VISITS (Apis mellifera carnica) DURING SUNFLOWER (Helianthus annuus L.) BLOOMING PERIOD

The objective of the investigation was to determine influence of weather conditions on activity of honey bees during blooming time of six sunflower hybrids. The investigation was carried out in 2002 growing season at Kneževi Vinogradi located in Baranja county, north-eastern edge of Croatia. Honey bees communities were moved to the field trial site inside Langstroth-Rooth\u27s bee-hives. Honey bees visiting sunflower head inflorescence was measured at 100, 200, and 300 meters by counting honey bees four times a day (9.00 am, 11.00 am, 1.00 pm, and 5.00 pm). The influence of weather conditions was analysed by Spearman correlation coefficient. Results of the investigation show significant differences regarding honey-bee visit to the head inflorescences in six hybrids, as well as significant influence of air temperature, humidity, precipitation, minimum and maximum air temperature, as well as wind strength

MAGE-A3/4 and NY-ESO-1 antigens expression in metastatic esophageal squamous cell carcinoma

In the present study we analyzed immunohistochemical expression of MAGE-A 3/4 and NY-ESO-1 in 55 samples of esophageal squamous cell carcinomas (ESCC) and their respective lymph node metastases. To our knowledge this is the first study to assess and compare the expression of these antigens in ESCC lymph node metastases

The No-Boundary Wave Function and the Duration of the Inflationary Period

For the simplest minisuperspace model based on a homogeneous, isotropic metric and a minimally coupled scalar field we derive analytic expressions for the caustic which separates Euklidean and Minkowskian region and its breakdown value \p_*. This value represents the prediction of the no-boundary wave function for the scalar field at the beginning of inflation. We use our results to search for inflationary models which can render the no-boundary wave function consistent with the requirement of a sufficiently long inflationary period.Comment: 11 pages, TUM-HEP-206/94, 2 figures (added as uu-encoded postscript file

Hamiltonian analysis of Poincar\'e gauge theory scalar modes

The Hamiltonian constraint formalism is used to obtain the first explicit complete analysis of non-trivial viable dynamic modes for the Poincar\'e gauge theory of gravity. Two modes with propagating spin-zero torsion are analyzed. The explicit form of the Hamiltonian is presented. All constraints are obtained and classified. The Lagrange multipliers are derived. It is shown that a massive spin-$0^-$ mode has normal dynamical propagation but the associated massless $0^-$ is pure gauge. The spin-$0^+$ mode investigated here is also viable in general. Both modes exhibit a simple type of ``constraint bifurcation'' for certain special field/parameter values.Comment: 28 pages, LaTex, submitted to International Journal of Modern Physics

PATH COEFFICIENT ANALYSIS OF SEVERAL COMPONENTS OIL YIELD IN SUNFLOWER (HELIANTHUS ANNUUS L.)

Cilj je istraživanja bio analizirati komponente prinosa ulja, njihove međusobne odnose putem jednostavnih koeficijenata korelacije te izravne i neizravne učinke na prinos ulja putem path analize. Istraživanje je obuhvatilo 24 hibrida suncokreta, a analizirani su: visina biljke, promjer glavice, masa 1000 zrna, hektolitarska masa, prinos zrna, sadržaj ulja i prinos ulja. Potpuna korelacija utvrđena je izmeđ u prinosa zrna i prinosa ulja, jaka između hektolitarske mase i prinosa ulja te srednja između prinosa ulja i svojstava: masa 1000 zrna, visina biljke te sadržaj ulja. Između prinosa zrna i sadržaja ulja nije utvrđena korelacija. Najveći izravan utjecaj na prinos ulja ostvario je prinos zrna, zatim slijedi sadržaj ulja, a preostala četiri svojstva su u neznatnoj mjeri utjecala na prinos ulja jer je njihovo djelovanje bilo prikriveno neizravnim utjecajem, u prvom redu prinosom zrna.The objective of investigation was to analyse oil yield components and their relations by simple coefficient correlations as well as direct and indirect effects to oil yield by path analysis. Twenty-four sunflower hybrids were included in the investigation and their seven traits (plant height, head diameter, 1000 seed weight, hec- tolitar mass, grain yield, oil content and oil yield). Very strong positive correlation was estimated between grain yield and oil yield, strong positive correlation between hectolitar mass and oil yield, and middle corre- lation among oil yield and: 1000 seed weight, plaint height and oil content. There was no correlation between grain yields and oil content. Grain yield showed the strongest effect to oil yield. Oil content had lower effect to oil yield. Other traits showed no significant effect to oil yield, and their effect to oil yield was covered by indirect effect of grain yield

OIL YIELD STABILITY OF SEVERAL SUNFLOWER OS HYBRIDS

Cilj je istraživanja bio procijeniti visinu, stabilnost i adaptabilnost prinosa ulja nekoliko domaćih hibrida suncokreta. Pokusi su provedeni na tri lokaliteta (Osijek, Karanac i Feričanci) tijekom 2002. i 2003. godine, a obuhvaćali su 9 eksperimentalnih i pet priznatih hibrida suncokreta Poljoprivrednog instituta Osijek. U analizi stabilnosti i adaptabilnosti korištena su četiri parametra: ekovalenca, koeficijent regresije, odstupanje od regresije te model prema Francisu i Kannenbergu. Dobiveni rezultati ukazali su da postoje razlike u visini prinosa ulja te stabilnosti i adaptabilnosti između pojedinih hibrida. Visokim prinosima, stabilnošću i širokom adaptabilnošću izdvojili su se hibridi: Apolon, Olio, (59A x 5B) x O3 i (253A x 5B) x O3. Nisu utvrđene značajne korelacije između prinosa zrna i ulja i parametara stabilnosti, što upućuje da je moguće stvoriti visokog i stabilnog prinosa, široke opće adaptabilnosti. Jaka visoko značajna korelacija između ekovalence i varijance odstupanja od regresije upućuje na to da se procjena stabilnosti može izvršiti samo s jednim parametrom.The aim of this research work was to assess height, stability and adaptability of oil yield in several Croatian sun- flower hybrids. Trials were conducted on three locations (Osijek, Karanac and Feri anci) during vegetation years 2002 and 2003. In the research work nine experimental and five recognized sunflower hybrids of Agricultural Institute Osijek were included. Four parameters were used for analysis of stability and adaptability: ecovalence, regression coefficient, deviation from regression, Francis and Kannenberg model. The results showed differences between hybrids in oil yield, stability and adaptability. High oil yield, stability and wide adaptability have hybrids: Apolon, Olio, (59A x 5B) x O3 and (253A x 5B) x O3. There were no significant correlations between kernel and oil yield and stability parameters. It indicates possibility for creation of hybrids with high and stabile yield and wide general adaptability. Highly significant correlation between ecovalence and deviation of regression showed that it is possible to assess stability with just one parameter

Phenolic Compounds and Peroxidases in Sunflower Near-Isogenic Lines After Downy Mildew Infection

Two near-isogenic lines of sunflower, resistant (+Pl6 gene) and susceptible (-P16 gene) to downy mildew were used in this paper. Secondary infection with a suspension of Plasmopara halstedii spores was done on the plants in the phase of first pair of leaves. In the samples taken 12 h after infection, content of phenolic compounds in methanolic extracts from frozen leaves was analysed by HPLC. POD activity was determined spectrophotmetrically and POD isoforms by isoelectrophoresis. Constitutive level of phenolic compounds and their accumulation after infection were higher in the susceptible than in the resistant line. Increased POD amount in leaf, constitutively present in NS-H-26R, was in correlation with increased guaiacol-dependent POD activity and low total phenolics contents. After infection, guaiacol- and chlorogenic acid-dependent POD activity significantly increased in both lines. Scopoletin-dependent POD activity was induced upon infection only in NS-H-26R. IEF electrophoresis revealed existance of four anionic isoforms of peroxidase in leaves of both lines. The main isoform with pI 5 was particularly intesified in the resistant line. In conclusion, scopoletin-dependent POD activity that was induced upon infection only in resistant NIL indicates a specific role of POD in coumarin metabolism that is possibly connected with the presence of Pl6 gene

Fresh inflation and decoherence of super Hubble fluctuations

I study a stochastic approach to the recently introduced fresh inflation model for super Hubble scales. I find that the state loses its coherence at the end of the fresh inflationary period as a consequence of the damping of the interference function in the reduced density matrix. This fact should be a consequence of a) the relative evolutions of both the scale factor and the horizon and b) the additional thermal and dissipative effects. This implies a relevant difference with respect to supercooled inflationary scenarios which require a very rapid expansion of the scale factor to give the decoherence of super Hubble fluctuations.Comment: version with minor changes. To appear in Phys. Rev.

Cascade Birth of Universes in Multidimensional Spaces

The formation mechanism of universes with distinctly different properties is considered within the framework of pure gravity in a space of D > 4 dimensions. The emergence of the Planck scale and its relationship to the inflaton mass are discussed.Comment: 10 p., minor correction