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Search Results: 1 - 10 of 173866 matches for " Carol E. Jones "
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On the Intrinsic Continuum Linear Polarization of Classical Be Stars: The Effects of Metallicity and One-Armed Density Perturbations
Robbie J. Halonen,Carol E. Jones
Physics , 2013, DOI: 10.1088/0067-0049/208/1/3
Abstract: We report on the effects of two disk properties on the continuum linear polarization signature of classical Be stars. First, we investigate the effect of including metallicity in computing the thermal structure of the circumstellar gas on the resulting polarimetric Balmer jump. The Balmer jump is a distinguishing feature of the polarization signature in these objects and, as such, can be used as a tool for differentiating classical Be stars from similar H alpha-emitters identified through conventional photometric techniques. We find that although low-metallicity environments will have hotter disk temperatures on average, the temperature change alone cannot account for the discrepancy in the frequency of Balmer jumps between low-metallicity and solar-metallicity stellar populations. Second, we investigate the effect of including a global one-armed oscillation in the gas density distribution of the modeled disk. We find that a non-axisymmetric perturbation pattern yields discernible variations in the predicted polarization level. If these density oscillations are present in the inner region of classical Be star disks, the polarimetric variations should produce a periodic signature which can help characterize the dynamical nature of the gas near the star.
On the Intrinsic Continuum Linear Polarization of Classical Be Stars during Disk Growth and Dissipation
Robbie J. Halonen,Carol E. Jones
Physics , 2013, DOI: 10.1088/0004-637X/765/1/17
Abstract: We investigate the intrinsic continuum linear polarization from axisymmetric density distributions of gas surrounding classical Be stars during the formation and dissipation of their circumstellar disks. We implement a Monte Carlo calculation of the Stokes parameters with the use of the non-LTE radiative transfer code of Sigut & Jones (2007) to reproduce the continuous polarimetric spectra of classical Be stars. The scattering of light in the nonspherical circumstellar envelopes of classical Be stars produces a distinct polarization signature that can be used to study the physical nature of the scattering environment. In this paper, we highlight the utility of polarimetric measurements as important diagnostics in the modeling of these systems. We illustrate the effects of using self-consistent calculation of the thermal structure of the circumstellar gas on the characteristic wavelength-dependence of the polarization spectrum. In showing that the principal features of the polarization spectrum originate from different parts of the disk, we emphasize the capability of polarimetric observations to trace the evolution of the disk on critical scales. We produce models that approximate the disk formation and dissipation periods and illustrate how the polarimetric properties of these systems can have a pivotal role in determining the mechanism for mass decretion from the central star.
Statistical Analysis of Interferometric Measurements of Axis Ratios for Classical Be Stars
Richard P. Cyr,Carol E. Jones,Christopher Tycner
Physics , 2014, DOI: 10.1088/0004-637X/799/1/33
Abstract: This work presents a novel method to estimate the effective opening angle of CBe star disks from projected axis ratio measurements, obtained by interferometry using Bayesian statistics. A Monte Carlo scheme was used to generate a large set of theoretical axis ratios from disk models using different distributions of disk densities and opening angles. These theoretical samples were then compared to observational samples, using a two-sample Kolmogorov-Smirnov test, to determine which theoretical distribution best reproduces the observations. The results suggest that the observed ratio distributions in the K-, H-, and N-band can best be explained by the presence of thin disks, with opening half-angles of the order of 0.15$^{\circ}$ to 4.0$^{\circ}$. Results for measurements over the H$\alpha$ line point toward slightly thicker disks, 3.7$^{\circ}$ to 14$^{\circ}$, which is consistent with a flaring disk predicted by the viscous disk model.
READING ENGAGEMENT: A COMPARISON BETWEEN E-BOOKS AND TRADITIONAL PRINT BOOKS IN AN ELEMENTARY CLASSROOM
Troy Jones,Carol Brown
International Journal of Instruction , 2011,
Abstract: Electronic books (e-books) are gaining popularity for personal reading. Options for access to a large selection of book titles and “anytime/anywhere” reading choices have added to the increased use of e-books. For this study, 22 third-grade students completed satisfaction surveys and reading comprehension tests on three separate reading sessions: one traditional print-based and two e-book titles. Indicators of reading engagement included motivation for independent reading and comprehension as measured by standardized tests on the print book and both e-books. Results showed that format was not as important as students’ identification with setting, characters, and theme of the book. Students did, however, indicate a preference for e-books when given the option of a wide selection of titles and the freedom to choose their own e-book. Students further indicated a preference for the amenities associated with e-book reading such as pop-up definitions and pronunciations of words, automatic page turning, and the option of read-aloud narration. The authors concluded that children quickly become comfortable with e-books and welcomed the technology. However, they are not completely ready to disregard print books.
The case for optical interferometric polarimetry
Nicholas M. Elias II,Carol E. Jones,Henrique R. Schmitt,Anders M. Jorgensen,Michael J. Ireland,Karine Perraut
Physics , 2008,
Abstract: Within the last 10 years, long-baseline optical interferometry (LBOI) has benefited significantly from increased sensitivity, spatial resolution, and spectral resolution, e.g., measuring the diameters and asymmetries of single stars, imaging/fitting the orbits of multiple stars, modeling Be star disks, and modeling AGN nuclei. Similarly, polarimetry has also yielded excellent astrophysical results, e.g., characterizing the atmospheres and shells of red giants/supergiants, modeling the envelopes of AGB stars, studying the morphology of Be stars, and monitoring the short- and long- term behavior of AGNs. The next logical evolutionary step in instrumentation is to combine LBOI with polarimetry, which is called optical interferometric polarimetry (OIP). In other words, measurements of spatial coherence are performed simultaneously with measurements of coherence between orthogonal polarization states.
Effects of chronic widespread pain on the health status and quality of life of women after breast cancer surgery
Carol S Burckhardt, Kim D Jones
Health and Quality of Life Outcomes , 2005, DOI: 10.1186/1477-7525-3-30
Abstract: A cross-sectional, descriptive design compared two groups of women with chronic pain that began after surgery: regional pain (n = 11) and widespread pain (n = 12). Demographics, characteristics of the surgery, as well as standardized questionnaires that measured pain (Brief Pain Inventory (BPI), Short Form McGill Pain Questionnaire (MPQ-SF)), disease impact (Fibromyalgia Impact Questionnaire (FIQ), Functional Assessment of Cancer Therapy-Breast (FACT-B)), health status (Medical Outcomes Short Form (SF-36)) and quality of life (Quality of Life Scale (QOLS)) were gathered.There were no significant differences between the groups on any demographic or type of surgery variable. A majority of both groups described their pain as aching, tender, and sharp on the MPQ-SF. On the BPI, intensity of pain and pain interference were significantly higher in the widespread pain group. Differences between the two groups reached statistical significance on the FIQ total score as well as the FACT-B physical well-being, emotional well-being and breast concerns subscales. The SF-36 physical function, physical role, and body pain subscales were significantly lower in the widespread pain group. QOLS scores were lower in the widespread pain group, but did not reach statistical significance.This preliminary work suggests that the women in this study who experienced widespread pain after breast cancer surgery had significantly more severity of pain, pain impact and lower physical health status than those with regional pain.Breast cancer is the most common form of cancer among women in the United States, Canada and Europe [1,2]. A sharp increase in incidence has been seen over the past two decades due in large part to use of mammography and subsequent earlier detection of disease. Earlier detection and treatment has led to increased survival rates approaching 90% for noninvasive cancers [3,4] Thus, a large majority of women with breast cancer will survive for many years after the initial diagn
Safety and anti-HIV assessments of natural vaginal cleansing products in an established topical microbicides in vitro testing algorithm
Carol S Lackman-Smith, Beth A Snyder, Katherine M Marotte, Mark C Osterling, Marie K Mankowski, Maureen Jones, Lourdes Nieves-Duran, Nicola Richardson-Harman, James E Cummins, Brigitte E Sanders-Beer
AIDS Research and Therapy , 2010, DOI: 10.1186/1742-6405-7-22
Abstract: Natural lime and lemon juice and household vinegar demonstrated anti-HIV-1 activity and cytotoxicity in transformed cell lines. Neutralization of the products reduced both anti-HIV-1 activity and cytotoxicity, resulting in a low therapeutic window for both acidic and neutralized formulations. For the natural juices and vinegar, the IC50 was ≤ 3.5 (0.8-3.5)% and the TC50 ≤ 6.3 (1.0-6.3)%. All three liquid products inhibited viability of beneficial Lactobacillus species associated with vaginal health. Comparison of three different toxicity endpoints in the cervical HeLa cell line revealed that all three products affected membrane integrity, cytosolic enzyme release, and dehydrogenase enzyme activity in living cells. The juices and vinegar also exerted strong cytotoxicity in cervico-vaginal cell lines, mainly due to their acidic pH. In human cervical explant tissues, treatment with 5% lemon or lime juice or 6% vinegar induced toxicity similar to application of 100 μg/ml nonoxynol-9, and exposure to 10% lime juice caused tissue damage comparable to treatment with 5% Triton-X-100.Lemon and lime juice and household vinegar do not fulfill the safety criteria mandated for a topical microbicide. As a result of their unphysiological formulation for the vaginal tract, they exhibit cytotoxicity to human cell lines, human vaginal tissues, and beneficial vaginal Lactobacillus species.Human immunodeficiency virus (HIV) infection and the resulting clinical disease, AIDS, has continued to be a world-wide epidemic since its discovery in 1982 [1,2]. Despite extensive international research efforts and funding support, no effective preventive measures for HIV apart from behavioral modifications and condom use have been shown fully effective to date [3]. Some of the research community has shifted its attention to the development of topical microbicides, defined as substances that prevent the sexual transmission of infectious agents [4]. Five chemical products were advanced to Phase III
Injectivity Radius Bounds in Hyperbolic I-Bundle Convex Cores
Carol E. Fan
Mathematics , 1999,
Abstract: A version of a conjecture of McMullen is as follows: Given a hyperbolizable 3-manifold M with incompressible boundary, there exists a uniform constant K such that if N is a hyperbolic 3-manifold homeomorphic to the interior of M, then the injectivity radius based at points in the convex core of N is bounded above by K. This conjecture suggests that convex cores are uniformly congested. We will give a proof in the case when M is an I-bundle over a closed surface, taking into account the possibility of cusps.
Injectivity Radius Bounds in Hyperbolic Convex Cores I
Carol E. Fan
Mathematics , 1999,
Abstract: A version of a conjecture of McMullen is as follows: Given a hyperbolizable 3-manifold M with incompressible boundary, there exists a uniform constant K such that if N is a hyperbolic 3-manifold homeomorphic to the interior of M, then the injectivity radius based at points in the convex core of N is bounded above by K. This conjecture suggests that convex cores are uniformly congested. In previous work, the author has proven the conjecture for $I$-bundles over a closed surface, taking into account the possibility of cusps. In this paper, we establish the conjecture in the case that M is a book of I-bundles or an acylindrical, hyperbolizable 3-manifold. In particular, we show that if M is a book of I-bundles, then the bound on injectivity radius depends on the number of generators in the fundamental group of M.
A conifer genomics resource of 200,000 spruce (Picea spp.) ESTs and 6,464 high-quality, sequence-finished full-length cDNAs for Sitka spruce (Picea sitchensis)
Steven G Ralph, Hye Chun, Natalia Kolosova, Dawn Cooper, Claire Oddy, Carol E Ritland, Robert Kirkpatrick, Richard Moore, Sarah Barber, Robert A Holt, Steven JM Jones, Marco A Marra, Carl J Douglas, Kermit Ritland, J?rg Bohlmann
BMC Genomics , 2008, DOI: 10.1186/1471-2164-9-484
Abstract: As part of a conifer genomics program to characterize defense against insects and adaptation to local environments, and to discover genes for the production of biomaterials, we developed 20 standard, normalized or full-length enriched cDNA libraries from Sitka spruce (P. sitchensis), white spruce (P. glauca), and interior spruce (P. glauca-engelmannii complex). We sequenced and analyzed 206,875 3'- or 5'-end ESTs from these libraries, and developed a resource of 6,464 high-quality sequence-finished FLcDNAs from Sitka spruce. Clustering and assembly of 147,146 3'-end ESTs resulted in 19,941 contigs and 26,804 singletons, representing 46,745 putative unique transcripts (PUTs). The 6,464 FLcDNAs were all obtained from a single Sitka spruce genotype and represent 5,718 PUTs.This paper provides detailed annotation and quality assessment of a large EST and FLcDNA resource for spruce. The 6,464 Sitka spruce FLcDNAs represent the third largest sequence-verified FLcDNA resource for any plant species, behind only rice (Oryza sativa) and Arabidopsis (Arabidopsis thaliana), and the only substantial FLcDNA resource for a gymnosperm. Our emphasis on capturing FLcDNAs and ESTs from cDNA libraries representing herbivore-, wound- or elicitor-treated induced spruce tissues, along with incorporating normalization to capture rare transcripts, resulted in a rich resource for functional genomics and proteomics studies. Sequence comparisons against five plant genomes and the non-redundant GenBank protein database revealed that a substantial number of spruce transcripts have no obvious similarity to known angiosperm gene sequences. Opportunities for future applications of the sequence and clone resources for comparative and functional genomics are discussed.Conifers (members of the pine family) have very large genomes (10 to 40 Gb, [1]), and this poses difficulties for both structural and functional genomic studies. In addition, their generation times are long and their habitual out-breedi
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