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.

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

Relativistic calculations for photonuclear reactions; 2, nonrelativistic reductions and nuclear medium effects

The relativistic amplitude for the direct knock-out contribution to \left( \gamma, p \right) reactions on nuclei is reduced to a nonrelativistic form using an effective Pauli reduction scheme. The reduction is carried out to second order in the inverse nucleon mass. It is found that the interaction Hamiltonian appearing in the nonrelativistic amplitude has significant dependence, starting at second order, on the vector and scalar mean nuclear potentials. These strong medium modifications are absent in traditional nonrelativistic calculations. Detailed comparisons show that these modifications are crucial to understanding the differences between relativistic and nonrelativistic models. These differences are also examined through reduction of the relativistic amplitude via the Foldy-Wouthuysen transformation. Similar medium modifications are obtained in this case as well. We discuss the implications of these medium modifications for the consistency of existing nonrelativistic calculations

Plasma oxysterol level in patients with coronary artery stenosis and its changes in response to the treatment with atorvastatin

Background: Considering the increasing incidence of coronary artery stenosis and its related complications, the importance of its etiology and inconsistent reports we aimed to determine the relationship between oxysterol, serum levels and severity of coronary atherosclerosis and effect of statins on oxysterol. Methods: A total of 85 patients referred to Taleghani Hospital, Tehran, Iran during 2011-2012 with coronary artery stenosis more than 75, as determined by angiography, participated in the current study. Their demographic information and history of smoking and taking atorvastatin was carefully recorded. Two milliliters of venous blood was obtained from each patient. The serum oxysterol level of samples was measured using the enzyme-linked immunosorbent assay (ELISA) method. Statistical analysis was performed using SPSS v.19. Results: Eighty five patients completed the study. Mean age of patients was 64.4 years; 51 (60) were male; 55 (68) had acute coronary syndrome and 30 (32) had chronic stable angina. Mean±SD of plasma level of oxysterol was 24.8±0.2 pmol/ml. The normal range of oxysterol level was 13pmol/ml. Mean±SD of plasma oxysterol level in patients under statin therapy was 24.4±2.1 pmol/ml. In patients without receiving statins, plasma oxysterol level was 26.38±1.6pmol/ml. Conclusion: Findings of the present study indicated significant correlation between serum oxysterol and severity of coronary artery stenosis. It also demonstrated that receiving atorvastatin is associated with significant reduction of plasma oxysterol level

Nuclear Medium Effects in the Relativistic Treatment of Quasifree Electron Scattering

Non-relativistic reduction of the S-matrix for the quasifree electron scattering process $A\left(~e, e'p~\right)A-1$ is studied in order to understand the source of differences between non-relativistic and relativistic models. We perform an effective Pauli reduction on the relativistic expression for the S-matrix in the one-photon exchange approximation. The reduction is applied to the nucleon current only; the electrons are treated fully relativistically. An expansion of the amplitude results in a power series in the nuclear potentials. The series is found to converge rapidly only if the nuclear potentials are included in the nuclear current operator. The results can be cast in a form which reproduces the non-relativistic amplitudes in the limit that the potentials are removed from the nuclear current operator. Large differences can be found between calculations which do and do not include the nuclear potentials in the different orders of the nuclear current operator. In the high missing momentum region we find that the non-relativistic calculations with potentials included in the nuclear current up to second order give results which are close to those of the fully relativistic calculation. This behavior is an indication of the importance of the medium modifications of the nuclear currents in this model, which are naturally built into the relativistic treatment of the reaction.Comment: Latex, 26 pages including 5 uuencoded postscript figures. accepted for publication in Phys. Rev. C

Non-locality and Medium Effects in the Exclusive Photoproduction of Eta Mesons on Nuclei

A relativistic model for the quasifree exclusive photoproduction of $\eta$ mesons on nuclei is extended to include both non-local and medium effects. The reaction is assumed to proceed via the dominant contribution of the S$_{11}$(1535) resonance. The complicated integrals resulting from the non-locality are simplified using a modified version of a method given by Cooper and Maxwell. The non-locality effects are found to affect the magnitude of the cross section. Some possibilities reflecting the effects of the medium on the propagation and properties of the intermediate S$_{11}$ resonance are studied. The effects of allowing the S$_{11}$ to interact with the medium via mean field scalar and vector potentials are considered. Both broadening of width and reduction in mass of the resonance lead to a suppression of the calculated cross sections.Comment: 19 pages, 7 figure

The effect of Aerobic Training and Cinnamon Zeylanicum Intake on Total Antioxidant Capacity in Active Women

Aims: Imbalance between the production of free radicals and the antioxidant defense system leads to oxidative stress. In addition, plants can reduce stress-induced oxidative damage. In this study we evaluated the effects of aerobic exercise with cinnamon intake on serum oxidative capacity in active women. Materials & Methods: 28 female students of physical education with age range 30-20 years, and the average BMI 22/71 kg/m² were voluntarily selected and randomly divided to 5 groups: 1) aerobic exercise 2) aerobic exercise combined with cinnamon 3) aerobic exercise with placebo 4 ) cinnamon and 5) control group. Intensity aerobic exercise was performed for 6 weeks within 65-80% of maximum heart rate and formula was 220-age. Blood samples were collected at the beginning and end of the study and the significance level was set at (p<0.05). Findings: TAC ( Total Antioxidant Capacity), uric acid and bilirubin in the aerobic exercise group with cinnamon consumption showed no significant difference (p<0.05). Conclusion: Probably sports activities with 65-80% of maximal oxygen consumption intensity more than 6 weeks with the consumption of cinnamon can improve the TAC level in active women