7,398 research outputs found

    Witten's Invariants of Rational Homology Spheres at Prime Values of KK and Trivial Connection Contribution

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    We establish a relation between the coefficients of asymptotic expansion of trivial connection contribution to Witten's invariant of rational homology spheres and the invariants that T.~Ohtsuki extracted from Witten's invariant at prime values of KK. We also rederive the properties of prime KK invariants discovered by H.~Murakami and T.~Ohtsuki. We do this by using the bounds on Taylor series expansion of the Jones polynomial of algebraically split links, studied in our previous paper. These bounds are enough to prove that Ohtsuki's invariants are of finite type. The relation between Ohtsuki's invariants and trivial connection contribution is verified explicitly for lens spaces and Seifert manifolds.Comment: 32 pages, no figures, LaTe

    Dispersion of Magnetic Fields in Molecular Clouds. II.

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    We expand our study on the dispersion of polarization angles in molecular clouds. We show how the effect of signal integration through the thickness of the cloud as well as across the area subtended by the telescope beam inherent to dust continuum measurements can be incorporated in our analysis to correctly account for its effect on the measured angular dispersion and inferred turbulent to large-scale magnetic field strength ratio. We further show how to evaluate the turbulent magnetic field correlation scale from polarization data of sufficient spatial resolution and high enough spatial sampling rate. We apply our results to the molecular cloud OMC-1, where we find a turbulent correlation length of δ ≈ 16 mpc, a turbulent to large-scale magnetic field strength ratio of approximately 0.5, and a plane-of-the-sky large-scale magnetic field strength of approximately 760 μG

    "It doesn't exist…": negotiating palliative care from a culturally and linguistically diverse patient and caregiver perspective.

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    BACKGROUND: The end of life represents a therapeutic context that acutely raises cultural and linguistic specificities, yet there is very little evidence illustrating the importance of such dynamics in shaping choices, trajectories and care practices. Culture and language interplay to offer considerable potential challenges to both patient and provider, with further work needed to explore patient and caregiver perspectives across cultures and linguistic groups, and provider perspectives. The objective of this study was to develop a critical, evidence-based understanding of the experiences of people from Culturally and Linguistically Diverse (CALD) backgrounds, and their caregivers, in a palliative care setting. METHODS: A qualitative study, using semi-structured interviews to explore key experiences and perspectives of CALD patients and caregivers currently undergoing treatment under oncology or palliative care specialists in two Australian hospitals. Interviews were digitally audio recorded and transcribed in full. A thematic analysis was conducted utilising the framework approach. RESULTS: Sixteen patients and fourteen caregivers from a range of CALD backgrounds participated in semi-structured interviews. The research identified four prevalent themes among participants: (1) Terminology in the transition to palliative care; (2) Communication, culture and pain management; (3) (Not) Talking about death and dying; and, (4) Religious faith as a coping strategy: challenging the terminal diagnosis. CONCLUSIONS: CALD patients and caregivers' experiences are multifaceted, particularly in negotiating linguistic difficulties, beliefs about treatment, and issues related to death and dying. Greater attention is needed to develop effective communication skills, recognise CALD patients' particular cultural, linguistic and spiritual values and needs, and acknowledge the unique nature of each doctor-patient interaction

    Design and Initial Performance of SHARP, a Polarimeter for the SHARC-II Camera at the Caltech Submillimeter Observatory

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    We have developed a fore-optics module that converts the SHARC-II camera at the Caltech Submillimeter Observatory into a sensitive imaging polarimeter at wavelengths of 350 and 450 microns. We refer to this module as "SHARP". SHARP splits the incident radiation into two orthogonally polarized beams that are then re-imaged onto opposite ends of the 32 x 12 pixel detector array in SHARC-II. A rotating half-wave plate is used just upstream from the polarization-splitting optics. The effect of SHARP is to convert SHARC-II into a dual-beam 12 x 12 pixel polarimeter. A novel feature of SHARP's design is the use of a crossed grid in a submillimeter polarimeter. Here we describe the detailed optical design of SHARP and present results of tests carried out during our first few observing runs. At 350 microns, the beam size (9 arcseconds), throughput (75%), and instrumental polarization (< 1%) are all very close to our design goals.Comment: submitted to Applied Optic

    Absorption spectrum in the wings of the potassium second resonance doublet broadened by helium

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    We have measured the reduced absorption coefficients occurring in the wings of the potassium 4S-5P doublet lines at 404.414 nm and at 404.720 nm broadened by helium gas at pressures of several hundred Torr. At the experimental temperature of 900 K, we have detected a shoulder-like broadening feature on the blue wing of the doublet which is relatively flat between 401.8 nm and 402.8 nm and which drops off rapidly for shorter wavelengths, corresponding to absorption from the X doublet Sigma+ state to the C doublet Sigma+ state of the K-He quasimolecule. The accurate measurements of the line profiles in the present work will sharply constrain future calculations of potential energy surfaces and transition dipole moments correlating to the asymptotes He-K(5p), He-K(5s), and He-K(3d).Comment: 2 figure

    Prevalence of sexual harassment among Norwegian female elite athletes in relation to sport type

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    Although it is often assumed that the prevalence of sexual harassment is different in different sports, this assumption has not been empirically tested. This study considers whether the experience of sexual harassment varies by sport. The female elite athletes (N = 553) in the study participated in 56 different sport disciplines. These were grouped as follows :1) team or individual sports; 2) extent to which clothing required for competition is revealing ; 3) gender structure (male-or female dominated membership statistics); and 4) gender culture (masculine, gender-neutral, or feminine). The data show that sexual harassment occurs in every sport group. Female elite athletes who participated in ‘masculine’ sports appear to experience more harassment than women in the other groups. We conclude that, when it comes to female athletes’ experiences of sexual harassment, sport type matters far less than sport participation per se

    Criteria for flatness and injectivity

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    Let RR be a commutative Noetherian ring. We give criteria for flatness of RR-modules in terms of associated primes and torsion-freeness of certain tensor products. This allows us to develop a criterion for regularity if RR has characteristic pp, or more generally if it has a locally contracting endomorphism. Dualizing, we give criteria for injectivity of RR-modules in terms of coassociated primes and (h-)divisibility of certain \Hom-modules. Along the way, we develop tools to achieve such a dual result. These include a careful analysis of the notions of divisibility and h-divisibility (including a localization result), a theorem on coassociated primes across a \Hom-module base change, and a local criterion for injectivity.Comment: 19 page

    Voluntary versus ABC breath-hold in the context of VMAT for breast and locoregional lymph node radiotherapy including the internal mammary chain

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    Background: Deep-inspiration breath-hold (DIBH) reduces radiation dose to the heart in patients undergoing locoregional breast radiotherapy. In the context of tangential irradiation of the breast/ chest wall, a voluntary breath hold (vDIBH) technique has been shown to be as reproducible as a machine-assisted breath hold technique using the active breathing co-ordinator (ABCTM, Elekta, Crawley, UK, ABC_DIBH). This study compares set-up reproducibility for vDIBH versus ABC_DIBH in patients undergoing volumetric-modulated arc radiotherapy (VMAT) for breast cancer, both with and without wax bolus. Method: Patients with breast cancer requiring pan regional lymph node VMAT +/� wax bolus in breathhold were CT scanned in vDIBH and ABC_DIBH. Patients were randomised to receive one technique for fractions 1–7 and the other for fractions 8–15. Daily cone beam computed tomography (CBCT) was performed and registered to planning-CT using bony anatomy. Within-patient comparisons of mean daily chest wall position were made using a paired t-test. Population, systematic (P) and random errors (a) were estimated. Intrafraction reproducibility was assessed by comparing chest wall position and diaphragm movement between consecutive breath holds on CBCT. Results: 16 patients were recruited. All completed treatment with both techniques (9 patients with wax bolus, 7 patients without). CBCT derived P were 2.1–6.4 mm (ABC_DIBH) and 2.1–4.9 mm (vDIBH), a were 1.7–2.6 mm (ABC_DIBH) and 2.2–2.7 mm (vDIBH) and mean daily chest wall displacements (MD) were 0.0–1.5 mm (ABC_DIBH) and - 0.1–1.6 vDIBH (all p non-significant). Chest wall and diaphragm position was equivalent between consecutive breath holds in ABC and vDIBH (median difference 1.0 mm and 0.8 mm respectively, non p significant) demonstrating equivalent intrafraction reproducibility. Conclusion: This study demonstrates that a simple voluntary breath hold technique is feasible in combination with VMAT (+/� bolus) and is as reproducible as ABC_DIBH with VMAT for the irradiation of the breast and axillary and IMC lymph nodes in breast cancer patients
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