Photo- and Electroproduction of Eta Mesons

Eta photo- and electroproduction off the nucleon is investigated in an effective lagrangian approach that contains Born terms and both vector meson and nucleon resonance contributions. In particular, we review and develop the formalism for coincidence experiments with polarization degrees of freedom. The different response functions appearing in single and double polarization experiments have been studied. We will present calculations for structure functions and kinematical conditions that are most sensitive to details of the lagrangian, in particular with regard to contributions of nucleon resonances beyond the dominant $S_{11}$(1535) resonance.Comment: 24 pages RevTeX/LaTeX2.09, NFSS1, 13 figures (in separate file (tar,gzip and uue)), accepted for publication in Z. Phys.

The Concentration of Affluence in the United States, 1990

The author examines the concentration of affluent households in affluent neighborhoods in U.S. metropolitan areas in 1990. The rate of concentrated affluence, the percentage of affluent households living in affluent neighborhoods, is considered for the total population and separately for blacks and whites. Also, differences in the rate of concentrated affluence between blacks and whites are explored. Models of concentrated affluence that incorporate variables suggested by the literature on economic restructuring in the late twentieth century and by the literature on racial differences in the residential return to individual resources are developed and tested. In general, variables measuring industry/occupation employment mix influence the rate of concentrated affluence mainly through the levels of income they generate. Racial differences in the rate of concentrated affluence are influenced more by income differences between blacks and whites than by residential segregation.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Do leaders matter? : Chinese politics, leadership transition and the 17th Party Congress

The opaque nature of decision making in China has generated considerable interest in the internecine machinations of elite politics. Particularly, but not only, when it comes to issues of leadership transition, considerations of factional formation and conflict come to the fore. This is partly to explain the transition process itself, but also out of concern for how new leaders might change the direction of Chinese policy. This paper suggests that whilst leaders and leadership changes do matter, they matter less than they once did. This is partly a result of the de-ideologicization and increasing diverse nature of elite interests and group formation. But it is also partly a result of the changed nature of China’s political economy; in short, there is less desire and less ability for new leaders to impose a clear paradigm shift

ω(→π+π−π0) \omega (\to \pi^+\pi^-\pi^0) meson photoproduction on proton

The cross section is estimated for the $\pi^+\pi^-\pi^0$ invariant mass distribution in the $\gamma p$ reaction in the GeV region. This reaction is assumed to proceed through the formation of the $\omega$ meson in the intermediate state, since the production cross section for this meson in the $\gamma p$ reaction in GeV region is significant and it has large branching ratio (88.8%) in the $\pi^+\pi^-\pi^0$ channel. The cross sections for this reaction have been calculated using the energy dependent reaction amplitude, i.e., $f_{\gamma p \to \omega p}(0)$, extracted from the latest $\omega$ meson photoproduction data. We use established procedure to calculate other factors, like width and propagator of the $\omega$ meson, so that our calculation can provide reliable cross section. The calculated results reproduce the measured $\pi^+\pi^-\pi^0$ invariant mass distribution spectra in the $\gamma p$ reaction.Comment: 13 pages, 5 figure

Molecular marks for epigenetic identification of developmental and cancer stem cells

Epigenetic regulations of genes by reversible methylation of DNA (at the carbon-5 of cytosine) and numerous reversible modifications of histones play important roles in normal physiology and development, and epigenetic deregulations are associated with developmental disorders and various disease states, including cancer. Stem cells have the capacity to self-renew indefinitely. Similar to stem cells, some malignant cells have the capacity to divide indefinitely and are referred to as cancer stem cells. In recent times, direct correlation between epigenetic modifications and reprogramming of stem cell and cancer stem cell is emerging. Major discoveries were made with investigations on reprogramming gene products, also known as master regulators of totipotency and inducer of pluoripotency, namely, OCT4, NANOG, cMYC, SOX2, Klf4, and LIN28. The challenge to induce pluripotency is the insertion of four reprogramming genes (Oct4, Sox2, Klf4, and c-Myc) into the genome. There are always risks of silencing of these genes by epigenetic modifications in the host cells, particularly, when introduced through retroviral techniques. In this contribution, we will discuss some of the major discoveries on epigenetic modifications within the chromatin of various genes associated with cancer progression and cancer stem cells in comparison to normal development of stem cell. These modifications may be considered as molecular signatures for predicting disorders of development and for identifying disease states