Theoretical reactor kinetic models and experimental verification

Call number: LD2668 .T4 1960 D6

RESEARCH BRIEF: An Examination of the Social and Clinical Influences in Prostate Cancer Treatment in African American and White Men

BACKGROUND: The death rate for prostate cancer (PrCA), the most commonly diagnosed cancer in African-American (AA) men, is twice the rate of European-American (EA) men. AA men in South Carolina have the highest age-adjusted death rate in the nation. Studies have shown that treatment offered to AA men with PrCA is systematically different from that offered to EA men. METHODS: Surveys were mailed to 1,866 men in South Carolina with a diagnosis of PrCA. South Carolina men diagnosed with PrCA between 1996 and 2002 were eligible to participate. We performed a descriptive assessment of the factors that influenced PrCA treatment decisions. RESULTS: The treatment choices of AA men were significantly more likely to be influenced by pain and significantly less likely to be influenced by potential for cure compared to EA men. CONCLUSIONS: Providers must be cognizant of the factors that influence treatment, particularly in AA men. Despite the national undertaking to eliminate health disparities, the United States is far from implementing a comprehensive focus on the health of AA men, despite their elevated PrCA morbidity and mortality rates

Social and clinical predictors of prostate cancer treatment decisions among men in South Carolina

OBJECTIVE: To assess social and clinical influences of prostate cancer treatment decisions among white and black men in the Midlands of South Carolina. METHODS: We linked data collected on treatment decision making in men diagnosed with prostate cancer from 1996 through 2002 with clinical and sociodemographic factors collected routinely by the South Carolina Central Cancer Registry (SCCCR). Unconditional logistic regression was used to assess social and clinical influences on treatment decision. RESULTS: A total of 435 men were evaluated. Men of both races who chose surgery (versus radiation) were more likely to be influenced by their physician and by family/friends. Black men who chose surgery also were ~5 times more likely to make independent decisions (i.e., rather than be influenced by their doctor). White men who chose surgery were twice as likely to be influenced by the desire for cure and less likely to consider the side effects of impotence (odds ratio (OR) = 0.40; 95% confidence interval (CI): 0.18, 0.88) and incontinence (OR = 0.27; 95% CI: 0.12, 0.63); by contrast, there was a suggestion of an opposite effect in black men, whose decision regarding surgery tended to be more strongly influenced by these side effects. CONCLUSION: Results suggest that both clinical and social predictors play an important role for men in choosing a prostate cancer treatment, but these influences may differ by race

New Discoveries in Planetary Systems and Star Formation through Advances in Laboratory Astrophysics

As the panel on Planetary Systems and Star Formation (PSF) is fully aware, the next decade will see major advances in our understanding of these areas of research. To quote from their charge, these advances will occur in studies of solar system bodies (other than the Sun) and extrasolar planets, debris disks, exobiology, the formation of individual stars, protostellar and protoplanetary disks, molecular clouds and the cold ISM, dust, and astrochemistry. Central to the progress in these areas are the corresponding advances in laboratory astro- physics which are required for fully realizing the PSF scientific opportunities in the decade 2010-2020. Laboratory astrophysics comprises both theoretical and experimental studies of the underlying physics and chemistry which produce the observed spectra and describe the astrophysical processes. We discuss four areas of laboratory astrophysics relevant to the PSF panel: atomic, molecular, solid matter, and plasma physics. Section 2 describes some of the new opportunities and compelling themes which will be enabled by advances in laboratory astrophysics. Section 3 provides the scientific context for these opportunities. Section 4 discusses some experimental and theoretical advances in laboratory astrophysics required to realize the PSF scientific opportunities of the next decade. As requested in the Call for White Papers, we present in Section 5 four central questions and one area with unusual discovery potential. We give a short postlude in Section 6.Comment: White paper submitted by the AAS Working Group on Laboratory Astrophysics (WGLA) to the PSF SFP of the Astronomy and Astrophysics Decadal Survey (Astro2010

Laboratory Astrophysics and the State of Astronomy and Astrophysics

Laboratory astrophysics and complementary theoretical calculations are the foundations of astronomy and astrophysics and will remain so into the foreseeable future. The impact of laboratory astrophysics ranges from the scientific conception stage for ground-based, airborne, and space-based observatories, all the way through to the scientific return of these projects and missions. It is our understanding of the under-lying physical processes and the measurements of critical physical parameters that allows us to address fundamental questions in astronomy and astrophysics. In this regard, laboratory astrophysics is much like detector and instrument development at NASA, NSF, and DOE. These efforts are necessary for the success of astronomical research being funded by the agencies. Without concomitant efforts in all three directions (observational facilities, detector/instrument development, and laboratory astrophysics) the future progress of astronomy and astrophysics is imperiled. In addition, new developments in experimental technologies have allowed laboratory studies to take on a new role as some questions which previously could only be studied theoretically can now be addressed directly in the lab. With this in mind we, the members of the AAS Working Group on Laboratory Astrophysics, have prepared this State of the Profession Position Paper on the laboratory astrophysics infrastructure needed to ensure the advancement of astronomy and astrophysics in the next decade.Comment: Position paper submitted by the AAS Working Group on Laboratory Astrophysics (WGLA) to the State of the Profession (Facilities, Funding and Programs Study Group) of the Astronomy and Astrophysics Decadal Survey (Astro2010

Phase-locked modulation delay between the poles of pulsar B1055-52

We present a detailed single pulse study of PSR B1055-52 based on observations at the Parkes radio telescope. The radio emission is found to have a complex modulation dominated by a periodicity of ~20 times its rotational period P (0.197s), whose phase and strength depends on pulse longitude. This periodicity exhibits a phase-locked delay of about 2.5P between the main pulse (MP) and interpulse (IP), presumed to be the opposite poles of the pulsar. This delay corresponds to a light travel distance of many times the light cylinder radius. More complex modulations are found within the MP on timescales down to about 9P, and both these and the principal modulation vary strongly across the (at least) 7 components which the MP and IP exhibit. The nature of the single pulse emission, which ranges from smooth and longitudinally extended to `spiky', is also component-dependent. Despite these disparities, the total pulse intensity distributions at the MP and IP are virtually identical in shape, suggesting a common emission mechanism. In an attempt to account for the complex modulations we examine a number of physical models, both intrinsic (which presuppose the pulsar to be an isolated neutron star) and extrinsic (appealing to the presence of circumstellar material to modulate the emission). Significant objections can be made to each model, so this pulsar's behaviour patterns remain a crucial challenge to theorists.Comment: 13 pages, 8 figures, submitted to MNRA

Feminism, Abortion and Disability: irreconcilable differences?

There has been considerable discussion of the political allegiance between the feminist and disability movements, but the question of abortion remains a thorny one. Disability rights advocates have been keen to demonstrate that it is possible to believe in a woman's right to sovereignty over the body and, yet, be opposed to the selective abortion of an impaired foetus – describing the latter as a form of 'weak' eugenics. The aim of this paper is to show that whilst there may be some points of agreement between the feminist and disability movements on the question of abortion, there exist fundamental and irreconcilable differences

Gene expression signature of estrogen receptor α status in breast cancer

BACKGROUND: Estrogens are known to regulate the proliferation of breast cancer cells and to modify their phenotypic properties. Identification of estrogen-regulated genes in human breast tumors is an essential step toward understanding the molecular mechanisms of estrogen action in cancer. To this end we generated and compared the Serial Analysis of Gene Expression (SAGE) profiles of 26 human breast carcinomas based on their estrogen receptor α (ER) status. Thus, producing a breast cancer SAGE database of almost 2.5 million tags, representing over 50,000 transcripts. RESULTS: We identified 520 transcripts differentially expressed between ERα-positive (+) and ERα-negative (-) primary breast tumors (Fold change ≥ 2; p < 0.05). Furthermore, we identified 220 high-affinity Estrogen Responsive Elements (EREs) distributed on the promoter regions of 163 out of the 473 up-modulated genes in ERα (+) breast tumors. In brief, we observed predominantly up-regulation of cell growth related genes, DNA binding and transcription factor activity related genes based on Gene Ontology (GO) biological functional annotation. GO terms over-representation analysis showed a statistically significant enrichment of various transcript families including: metal ion binding related transcripts (p = 0.011), calcium ion binding related transcripts (p = 0.033) and steroid hormone receptor activity related transcripts (p = 0.031). SAGE data associated with ERα status was compared with reported information from breast cancer DNA microarrays studies. A significant proportion of ERα associated gene expression changes was validated by this cross-platform comparison. However, our SAGE study also identified novel sets of genes as highly expressed in ERα (+) invasive breast tumors not previously reported. These observations were further validated in an independent set of human breast tumors by means of real time RT-PCR. CONCLUSION: The integration of the breast cancer comparative transcriptome analysis based on ERα status coupled to the genome-wide identification of high-affinity EREs and GO over-representation analysis, provide useful information for validation and discovery of signaling networks related to estrogen response in this malignancy

Probable detection of starlight reflected from the giant exoplanet orbiting tau Bootis

Giant planets orbiting stars other than the Sun are clearly detectable through precise radial-velocity measurements of the orbital reflex motion of the parent star. In the four years since the discovery of the companion to the star 51 Peg, similar low-amplitude ``Doppler star wobbles'' have revealed the presence of some 20 planets orbiting nearby solar-type stars. Several of these newly-discovered planets are very close to their parent stars, in orbits with periods of only a few days. Being an indirect technique, however, the reflex-velocity method has little to say about the sizes or compositions of the planets, and can only place lower limits on their masses. Here we report the use of high-resolution optical spectroscopy to achieve a probable detection of the Doppler-shifted signature of starlight reflected from one of these objects, the giant exoplanet orbiting the star tau Bootis. Our data give the planet's orbital inclination i=29 degrees, indicating that its mass is some 8 times that of Jupiter, and suggest strongly that the planet has the size and reflectivity expected for a gas-giant planet.Comment: 15 pages, 4 figures. (Fig 1 and equation for epsilon on p1 para 2 revised; changed from double to single spacing