37 research outputs found

    EC 10246−2707: an eclipsing subdwarf B + M dwarf binary★

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    We announce the discovery of a new eclipsing hot subdwarf B + M dwarf binary, EC 10246-2707, and present multi-colour photometric and spectroscopic observations of this system. Similar to other HW Vir-type binaries, the light curve shows both primary and secondary eclipses, along with a strong reflection effect from the M dwarf; no intrinsic light contribution is detected from the cool companion. The orbital period is 0.118 507 993 6 ± 0.000 000 000 9 days, or about three hours. Analysis of our time- series spectroscopy reveals a velocity semi-amplitude of K1 = 71.6 ± 1.7 km s−1 for the sdB and best-fitting atmospheric parameters of Teff = 28900 ± 500 K, log g = 5.64 ± 0.06, and log N(He)/N(H) = -2.5 ± 0.2. Although we cannot claim a unique solution from modeling the light curve, the best–fitting model has an sdB mass of 0.45 M⊙ and a cool companion mass of 0.12 M⊙. These results are roughly consistent with a canonical–mass sdB and M dwarf separated by a ∼ 0.84 R⊙. We find no evidence of pulsations in the light curve and limit the amplitude of rapid photometric oscillations to 7.2×10−12. If EC 10246- 2707 evolves into a cataclysmic variable, its period should fall below the famous CV period gap

    Intraoperative radiation therapy for early-stage breast cancer: a single-institution experience

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    Background: To assess outcomes and toxicity after low-energy intraoperative radiotherapy (IORT) for early-stage breast cancer (ESBC).  Materials and methods: We reviewed patients with unilateral ESBC treated with breast-conserving surgery and 50-kV IORT at our institution. Patients were prescribed 20 Gy to the surface of the spherical applicator, fitted to the surgical cavity during surgery. Patients who did not meet institutional guidelines for IORT alone on final pathology were recommended adjuvant treatment, including additional surgery and/or external-beam radiation therapy (EBRT). We analyzed ipsilateral breast tumor recurrence, overall survival, recurrence-free survival and toxicity. Results: Among 201 patients (median follow-up, 5.1 years; median age, 67 years), 88% were Her2 negative and ER positive and/or PR positive, 98% had invasive ductal carcinoma, 87% had grade 1 or 2, and 95% had clinical T1 disease. Most had pathological stage T1 (93%) N0 (95%) disease. Mean IORT applicator dose at 1-cm depth was 6.3 Gy. Post-IORT treatment included additional surgery, 10%; EBRT, 11%; adjuvant chemotherapy, 9%; and adjuvant hormonal therapy, 74%. Median total EBRT dose was 42.4 (range, 40.05-63) Gy and median dose per fraction was 2.65 Gy. At 5 years, the cumulative incidence of ipsilateral breast tumor recurrence was 2.7%, the overall survival rate was 95% with no breast cancer-related deaths, and the recurrence-free survival rate was 96%. For patients who were deemed unsuitable for postoperative IORT alone and did not receive recommended risk-adapted EBRT, the IBTR rate was 4.7% versus 1.7% (p = 0.23) for patients who were either suitable for IORT alone or unsuitable and received adjuvant EBRT. Cosmetic toxicity data was available for 83%, with 7% experiencing grade 3 breast toxicity and no grade 4–5 toxicity. Conclusions: IORT for select patients with ESBC results in acceptable outcomes in regard to ipsilateral breast tumor recurrence and toxicity

    EC 10246-2707: a new eclipsing sdB + M dwarf binary⋆

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    We announce the discovery of a new eclipsing hot subdwarf B + M dwarf binary, EC 10246-2707, and present multi-colour photometric and spectroscopic observations of this system. Similar to other HW Vir-type binaries, the light curve shows both primary and secondary eclipses, along with a strong reflection effect from the M dwarf; no intrinsic light contribution is detected from the cool companion. The orbital period is 0.118 507 993 6 ± 0.000 000 000 9 days, or about three hours. Analysis of our time- series spectroscopy reveals a velocity semi-amplitude of K1 = 71.6 ± 1.7 km s−1 for the sdB and best-fitting atmospheric parameters of Teff = 28900 ± 500 K, log g = 5.64 ± 0.06, and log N(He)/N(H) = -2.5 ± 0.2. Although we cannot claim a unique solution from modeling the light curve, the best–fitting model has an sdB mass of 0.45 M⊙ and a cool companion mass of 0.12 M⊙. These results are roughly consistent with a canonical–mass sdB and M dwarf separated by a ∼ 0.84 R⊙. We find no evidence of pulsations in the light curve and limit the amplitude of rapid photometric oscillations to < 0.08%. Using 15 years of eclipse timings, we construct an O-C diagram but find no statistically significant period changes; we rule out | ˙P | > 7.2×10−12. If EC 10246- 2707 evolves into a cataclysmic variable, its period should fall below the famous CV period gap.Web of Scienc

    Evidence for Diffuse Central Retinal Edema In Vivo in Diabetic Male Sprague Dawley Rats

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    Background: Investigations into the mechanism of diffuse retinal edema in diabetic subjects have been limited by a lack of animal models and techniques that co-localized retinal thickness and hydration in vivo. In this study we test the hypothesis that a previously reported supernormal central retinal thickness on MRI measured in experimental diabetic retinopathy in vivo represents a persistent and diffuse edema. Methodology/Principal Findings: In diabetic and age-matched control rats, and in rats experiencing dilutional hyponatremia (as a positive edema control), whole central retinal thickness, intraretinal water content and apparent diffusion coefficients (ADC, ‘water mobility’) were measured in vivo using quantitative MRI methods. Glycated hemoglobin and retinal thickness ex vivo (histology) were also measured in control and diabetic groups. In the dilutional hyponatremia model, central retinal thickness and water content were supernormal by quantitative MRI, and intraretinal water mobility profiles changed in a manner consistent with intracellular edema. Groups of diabetic (2, 3, 4, 6, and 9 mo of diabetes), and age-matched controls were then investigated with MRI and all diabetic rats showed supernormal whole central retinal thickness. In a separate study in 4 mo diabetic rats (and controls), MRI retinal thickness and water content metrics were significantly greater than normal, and ADC was subnormal in the outer retina; the increase in retinal thickness was not detected histologically on sections of fixed and dehydrated retinas from these rats

    How to Use Design Thinking for Building Better Services for the Third Sector: A Workshop

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    The critical role played by the third sector organisations is becoming increasingly visible across the world, particularly in developing countries and in solving “wicked problems” — a phrase for intractable problems described by Hors Rittel and Melvin Webber (1973). Wicked problems in social sector are novel, unique, ill-understood problems with no real right or wrong answers and often not understood until after the formulation of a solution. These problems in the social sector therefore pose unique challenges but also call for solutions that should take into account peoples’ perspectives, diversity, needs, and innovation all rooted in iterative processes with rapidly building and testing models that may or may not work (an approach often defined as “fail fast early”). A popular approach to designing services and fostering innovation that has increasingly been applied to community services sector settings is Design Thinking
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