A COMPARISON OF IN VIVO CELLULAR RESPONSES TO CS-137 GAMMA RAYS AND 320-KV X RAYS

Research reported here relates to comparing the relative effectiveness of 320-kV X rays compared to Cs-137 gamma rays for two in vivo endpoints in C.B-17 mice after whole-body exposure: (1) cytotoxicity to bone marrow cells and splenocytes evaluated at 24-hours post exposure and (2) bone marrow and spleen reconstitution deficits (repopulation short- falls) evaluated at 6 weeks post exposure. We show that cytotoxicity dose-response rela- tionships for bone marrow cells and splenocytes are complex, involving negative curvature (decreasing slope as dose increases), presumably implicating a mixed cell population com- prised of large numbers of hypersensitive, modestly radiosensitive, and resistant cells. The radiosensitive cells appear to respond with 50% being killed by a dose \u3c 0.5 Gy. The X-ray relative biological effectiveness (RBE), relative to gamma rays, for destroying bone mar- row cells in vivo is \u3e 1, while for destroying splenocytes it is \u3c 1. In contrast, dose-response relationships for reconstitution deficits in the bone marrow and spleen of C.B-17 mice at 6 weeks after radiation exposure were of the threshold type with gamma rays being more effective in causing reconstitution deficit

SMALL γ-RAY DOSES PREVENT RATHER THAN INCREASE LUNG TUMORS IN MICE

We show evidence for low doses of γ rays preventing spontaneous hyperplastic foci and adenomas in the lungs of mice, presumably via activating natural anticancer defenses. The evidence partly relates to a new study we conducted whereby a small number of female A/J mice received 6 biweekly dose fractions (100 mGy per fraction) of γ rays to the total body which prevented the occurrence of spontaneous hyperplastic foci in the lung. We also analyzed data from a much earlier Oak Ridge National Laboratory study involving more than 10,000 female RFMf/Un mice whereby single γ-ray doses from 100 to 1,000 mGy prevented spontaneous lung adenomas. We point out the possibility that the decrease in lung cancer mortality observed in The National Lung Screening Trial Research Team study involving lung tumor screening using low-dose computed tomography (CT) may relate at least in part to low-dose X-rays activating the body’s natural anticancer defenses (i.e., radiation hormesis). This possibility was apparently not recognized by the indicated research team

Statistical nature of non-Gaussianity from cubic order primordial perturbations: CMB map simulations and genus statistic

We simulate CMB maps including non-Gaussianity arising from cubic order perturbations of the primordial gravitational potential, characterized by the non-linearity parameter $g_{NL}$. The maps are used to study the characteristic nature of the resulting non-Gaussian temperature fluctuations. We measure the genus and investigate how it deviates from Gaussian shape as a function of $g_{NL}$ and smoothing scale. We find that the deviation of the non-Gaussian genus curve from the Gaussian one has an antisymmetric, sine function like shape, implying more hot and more cold spots for $g_{NL}>0$ and less of both for $g_{NL}<0$. The deviation increases linearly with $g_{NL}$ and also exhibits mild increase as the smoothing scale increases. We further study other statistics derived from the genus, namely, the number of hot spots, the number of cold spots, combined number of hot and cold spots and the slope of the genus curve at mean temperature fluctuation. We find that these observables carry signatures of $g_{NL}$ that are clearly distinct from the quadratic order perturbations, encoded in the parameter $f_{NL}$. Hence they can be very useful tools for distinguishing not only between non-Gaussian temperature fluctuations and Gaussian ones but also between $g_{NL}$ and $f_{NL}$ type non-Gaussianities.Comment: 18+1 page

Observers in an accelerated universe

If the current acceleration of our Universe is due to a cosmological constant, then a Coleman-De Luccia bubble will nucleate in our Universe. In this work, we consider that our observations could be likely in this framework, consisting in two infinite spaces, if a foliation by constant mean curvature hypersurfaces is taken to count the events in the spacetime. Thus, we obtain and study a particular foliation, which covers the existence of most observers in our part of spacetime.Comment: revised version, accepted in EPJ

Holding onto womanhood: a qualitative study of heterosexual women with sexual desire loss

This article explores heterosexual women’s accounts of sexual desire loss, particularly the ways in which it can affect their sense of themselves as women. In-depth interviews were conducted with 17 participants recruited through a psychosexual clinic in England, and the data analysed using a material-discursive approach. The findings showed that having sexual desire loss often challenged participants’ perceptions of themselves as women. Specific challenges related to dealing with isolation and ‘otherness’, addressing their own feelings of not being ‘proper wives’ because they did not sexually satisfy their partners and maintaining a sense of sexual attractiveness in the absence of sexual desire. Participants responded to these challenges in various ways, often renegotiating their identities as women. The findings are discussed in relation to theorizing women’s sexuality and their implications for health care