Inclusive Photoproduction of η\eta Mesons on Nuclei and the in-medium properties of the S11_{11} Resonance

A relativistic non-local model for the inclusive photoproduction of $\eta$ mesons from complex nuclei is introduced. The model is based on the dominance of the S$_{11}$(1535) resonance. We compare the results of our calculations with the available data on inclusive cross sections for the nuclei C, Al and Cu. Assuming the resonance propagates freely in the nuclear medium, we find that the calculated angular distribution and energy dependence of the cross sections reproduce the data in a reasonable fashion. The present non-local model allows the inclusion of density dependent mass and width in the calculations. Including these in the calculations reveals that the presently available data do not show clear preference for the inclusion of such modifications of the properties of the S$_{11}$(1535) in the nuclear medium.Comment: 15 pages, 8 figure

Relativistic Calculations for the Exclusive Photoproduction of Eta Mesons from Complex Nuclei

A relativistic model for the quasifree photoproduction of eta meson from complex nuclei is developed. The interactions between fields are introduced through effective Lagrangians. Contributions from several nucleon resonances as well as nucleon Born terms and vector meson exchange diagrams are included. Nucleon and eta wavefunctions are solutions of Dirac and Klein-Gordon equations, respectively. Final state interactions of the outgoing particles are included via optical potentials. The effects of these interactions on the cross sections and photon asymmetries are studied and are found to be large. Calculations indicate that at energies near threshold the exclusive reaction takes place mainly through formation of the S_{11}(1535) resonance. Comparisons with the non-relativistic calculations show differences between the two approaches both for the cross sections and photon asymmetries. We give some detailed predictions for the reaction observables for exclusive photoproduction on ^{12}C, ^{16}O and ^{40}Ca.Comment: Latex, 27 pages, 13 uuencoded postscript figures. Accepted for publication in Phys. Rev.

"Der Fremde Blick" – "ein fremdes Auge":Transmediale Inszenierung von Schrift und Bild in Herta Müllers Colagen

Der Artikel beschäftigt sich mit den in der Forschungsliteratur und der breiten Öffentlichkeit bisher kaum beachteten Bild-Text-Collagen Herta Müllers. Konkret erfolgt nach einer kurzen Einführung in Herta Müllers Werkcharakter und einer medialen und strukturellen Verortung der Bild-Text-Collagen eine Analyse der lyrischen und formalen Gestaltung des Textes, der medialen Inszenierung der Schriftelemente und der Bild-Text-Korrelationen am Beispiel der Bild-Text-Collagen des aktuellsten Collage-Bandes »Die blassen Herren mit den Mokkatassen« (2005). Die Strategie der Fremdheit, die Herta Müllers prosaische Werke durchziehen, erfährt in den Bild-Text-Collagen eine Zuspitzung und mediale Komponente

Short communication: Seasonal changes of blood serum ions in Beluga (Huso huso) cultured in brackish water

Living sturgeons (Acipenseridae) are representatives of the ancient group Chondrostei, which had a common origin with Palaeonisci, known from the Devonian period. In spite of their freshwater origin, in their history, they occupied different salinities and at present, they can live in both fresh and seawater mediums. Study of osmotic and ionic regulation in acipenserids, that connect to marine conditions in different extents (freshwater, diadromous brackish water, diadromous seawater), make it possible to establish the dependence of functional level of osmotic and ionic homeostatic mechanisms from medium salinity in some acipenserids. It was ascertained that in higher salinities, the functional level of these mechanisms increases. So investigation of osmo-ion regulation is one of the most important problems in the culture of sturgeon in new mediums

Probiotic Bacillus species and Saccharomyces boulardii improve performance, gut histology and immunity in broiler chickens

The aim of this study was to compare the effects of a new multispecies probiotic containing four Bacillus species and Saccharomyces boulardii (Microguard®) with a commercial probiotic (Protexin®) and a commonly used antibiotic in broilers. Six hundred one-day-old male Ross 308 broilers were randomized to six experimental treatments, with five replicates of 20 chicks each, for 42 days, receiving an ad libitum corn-soybean basal diet. Treatments were added to the basal diet and consisted of tetracycline as an antibiotic growth promoter (500 g/ton), three dosages of Microguard (50, 100 and150 g/ton) or Protexin (100 g/ton). The control group received the basal diet with no additive. The group fed with Microguard at 150 g/ton showed increased final bodyweight, weight gain, high density lipoprotein, triglyceride, and antibody titres against Newcastle disease (ND) and avian influenza (AI) levels. Improved feed conversion ratio, increased villus height, and villus highest crypt depth ratio, along with lower plasma gamma-glutamyl transpeptidase, alkaline phosphatase, alanine aminotransferase, were found in probiotic-supplemented broilers. Carcass yield, liver weights, breast muscle values, and abdominal fat weights were reduced in groups fed with 100 or 150 g/ton of Microguard. Caecal coliforms, Salmonella and Escherichia coli numbers decreased in groups fed with 100 or 150 g/ton of Microguard. These results show that Microguard at 150 g/ton is a promising probiotic to replace antibiotics in broiler feed as a growth-promoter while enhancing immune system responses and inducing beneficial modulations in the caecal microflora.Keywords: blood biochemistry, broiler chicks, carcass traits, performance, probioti

Nonlinear stability analysis of piecewise actuated piezoelectric microstructures

The main objective of this research is to provide a general nonlinear model of adjustable piezoelectric microwires with the ability to tune the stability conditions. In order to increase the controllability and improve system characteristics, only a part of the substrate is electrostatically actuated and the piezoelectric voltage is also applied. The governing equation of equilibrium (EOE) is derived from the principle of minimum total potential energy. The influences of the surface layer, size dependency, piezoelectricity, and dispersion forces are also included simultaneously. To solve the nonlinear differential equation, a numerical method is implemented and the obtained results are validated with available experimental and numerical results. Afterward, a set of parametric studies is carried out to examine the coupled effects of piezo-voltage, length/position of non-actuated pieces, nonlinear curvature, and molecular forces on the microresonators. It is found that the beam deflection and the pull-in voltage have sensitive-dependence on the system behavior. Furthermore, the beam deflection can increase or decrease with consideration of different positions of non-actuated pieces. This research is expected to fill a gap in the state of the art of the piezoelectric microstructures and present relevant results that are instrumental in the investigation of advanced actuated microdevices

The effects of mate switching tacticon reproductive performance of the severum cichlid, Heros severus

This study investigated the effects of mate switching on the reproductive performance of the severum cichlid, Heros severus, by advancing the egg and larval production in hatcheries. Two reproductive tactic treatments of “monogamous pair” and “mate switching” were used for evaluating 4 reproductive traits of egg production, hatching rate, spawning intervals, and starvation tolerance of the larvae in 6 spawning activities. The number of eggs was not significantly different between the two reproductive tactic treatments in the 6 spawning activities, but the spawning intervals, hatching rate, and survival activity index were all significantly different. Daily average egg and larval production in the mate switching treatment were estimated to be 87.3 eggs and 43.1 larvae per pair of fish, respectively, which was 2.89 times and 1.99 times of those in the monogamous pair treatment, who produced about 30.2 eggs and 21.6 larvae per pair. Our results clearly showed that the reproductive tactic of mate switching is a suitable method for increasing the egg and larval production rate of the severum cichlid

A greenhouse gas assessment of a stadium in Australia

A greenhouse gas (GHG) life cycle assessment (LCA) was performed on a stadium used for sporting events in a subtropical region in Australia. Inventories for the construction and operation of a stadium are presented and the GHG emissions from construction, operations and end-of-life waste management are assessed against the attendance of one person at one event. The inclusion of additional economic activities, patron travel, LCA methodology, attendance and stadium life-time assumptions are likely to affect the overall magnitude of the GHG emissions of one person's attendance. The assessment shows that the stadium operation accounted for 72.5% of GHG emissions, with the operation of baseload heating, ventilation and cooling, lighting and refrigeration systems dominating. The best opportunity to reduce GHG emissions is to reduce the need for the continual operation of these systems. Construction impacts account for 24.7% of impacts, while replacement materials, end-of-life management of materials are relatively insignificant, contributing to less than 3% of life cycle GHG emissions

Effects of different dietary energy levels on growth performance and sexual gonads development of Beluga (Huso huso) reared in brackish water

Culture of beluga (Huso huso) in new conditions such as inland brackish water necessitates studying nutritional requirements and effects of different diets on gonadic and somatic growth as well as physiological condition. In this research 74 beluga each 4 years old cultured in brackish water of earthen ponds in Bafgh Fisheries Research Station, were selected and distributed in 8 circular cement ponds. Feeding was done in 4 formulated diets with fixed protein level and 4 energy levels (400, 425, 450, 475kcal/l00g). Samples were biopsied at the start and the end of the experiment to determine sexuality and stage of maturation. To study gonad tissues, the hematoxylin-eosin method was used. Results indicated that somatic and gonadic growth indices were affected by diets. Somatic growth overlapped in both sexes. Sexual maturation stages were not the same in males and females and transition from stage II in males was more rapid than females. Considering the results in this study, diet treatments influenced on somatic growth in both sexes and gonadic growth in females. We conclude that somatic and especially gonadic growth in brackish water is suitable. Therefore, inland brackish water environment can be regarded suitable for beluga cultivation