The CHARA Array is a six 1 m telescope optical/IR interferometric array located on Mount Wilson, California, designed and built by the Center for High Angular Resolution Astronomy of Georgia State ...University. In this paper we describe the main elements of the Array hardware and software control systems, as well as the data reduction methods currently being used. Our plans for upgrades in the near future are also described.
A classical nova occurs when material accreting onto the surface of a white dwarf in a close binary system ignites in a thermonuclear runaway. Complex structures observed in the ejecta at late stages ...could result from interactions with the companion during the common-envelope phase. Alternatively, the explosion could be intrinsically bipolar, resulting from a localized ignition on the surface of the white dwarf or as a consequence of rotational distortion. Studying the structure of novae during the earliest phases is challenging because of the high spatial resolution needed to measure their small sizes. Here we report near-infrared interferometric measurements of the angular size of Nova Delphini 2013, starting one day after the explosion and continuing with extensive time coverage during the first 43 days. Changes in the apparent expansion rate can be explained by an explosion model consisting of an optically thick core surrounded by a diffuse envelope. The optical depth of the ejected material changes as it expands. We detect an ellipticity in the light distribution, suggesting a prolate or bipolar structure that develops as early as the second day. Combining the angular expansion rate with radial velocity measurements, we derive a geometric distance to the nova of 4.54 ± 0.59 kiloparsecs from the Sun.
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DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Chronic wasting disease (CWD) is a highly contagious, fatal neurodegenerative disease caused by infectious prions (PrP
) affecting wild and captive cervids. Although experimental feeding studies have ...demonstrated prions in feces of crows (Corvus brachyrhynchos), coyotes (Canis latrans), and cougars (Puma concolor), the role of scavengers and predators in CWD epidemiology remains poorly understood. Here we applied the real-time quaking-induced conversion (RT-QuIC) assay to detect PrP
in feces from cervid consumers, to advance surveillance approaches, which could be used to improve disease research and adaptive management of CWD. We assessed recovery and detection of PrP
by experimental spiking of PrP
into carnivore feces from 9 species sourced from CWD-free populations or captive facilities. We then applied this technique to detect PrP
from feces of predators and scavengers in free-ranging populations. Our results demonstrate that spiked PrP
is detectable from feces of free-ranging mammalian and avian carnivores using RT-QuIC. Results show that PrP
acquired in natural settings is detectable in feces from free-ranging carnivores, and that PrP
rates of detection in carnivore feces reflect relative prevalence estimates observed in the corresponding cervid populations. This study adapts an important diagnostic tool for CWD, allowing investigation of the epidemiology of CWD at the community-level.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Chronic wasting disease (CWD) is a fatal neurodegenerative disease caused by infectious prions (PrP
) affecting cervids. Circulating PrP
in blood may pose a risk for indirect transmission by way of ...hematophagous ectoparasites acting as mechanical vectors. Cervids can carry high tick infestations and exhibit allogrooming, a common tick defense strategy between conspecifics. Ingestion of ticks during allogrooming may expose naïve animals to CWD, if ticks harbor PrP
. This study investigates whether ticks can harbor transmission-relevant quantities of PrP
by combining experimental tick feeding trials and evaluation of ticks from free-ranging white-tailed deer (Odocoileus virginianus). Using the real-time quaking-induced conversion (RT-QuIC) assay, we show that black-legged ticks (Ixodes scapularis) fed PrP
-spiked blood using artificial membranes ingest and excrete PrP
. Combining results of RT-QuIC and protein misfolding cyclic amplification, we detected seeding activity from 6 of 15 (40%) pooled tick samples collected from wild CWD-infected white-tailed deer. Seeding activities in ticks were analogous to 10-1000 ng of CWD-positive retropharyngeal lymph node collected from deer upon which they were feeding. Estimates revealed a median infectious dose range of 0.3-42.4 per tick, suggesting that ticks can take up transmission-relevant amounts of PrP
and may pose a CWD risk to cervids.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Breast cancer in young women is typically characterised by aggressive disease, and treatment with adjuvant chemotherapy is generally recommended. Chemotherapy has conferred significant improvements ...in disease-free and overall survival for young women with breast cancer; however, with improved cure rates, long-term adverse effects of cytotoxic treatment, such as premature ovarian failure (POF) and infertility, have become increasingly important. A potential fertility preservation strategy is administration of gonadotropin-releasing hormone agonists (GnRHas) during adjuvant chemotherapy.
This review analyses and summarises the current evidence for use of GnRHa in preserving ovarian function in young breast cancer patients.
Twelve trials, both non-randomised and randomised, have now been conducted assessing GnRHas in fertility preservation in young breast cancer patients, with conflicting results. Limitations of the current data include the use of poorly sensitive end points for fertility preservation, variable age of enrolled patients and limited pregnancy data.
The utility of GnRHa as a fertility preservation strategy remains uncertain, and use outside of a clinical trial generally not recommended. Further research into this under-recognised issue is vital.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Context.Only a handful of debris disks have been imaged up to now. Due to the need for high dynamic range and high angular resolution, very little is known about the inner planetary region, where ...small amounts of warm dust are expected to be found. Aims.We investigate the close neighbourhood of Vega with the help of infrared stellar interferometry and estimate the integrated K-band flux originating from the central 8 AU of the debris disk. Methods.We performed precise visibility measurements at both short (~30 m) and long (~150 m) baselines with the FLUOR beam-combiner installed at the CHARA Array (Mt Wilson, California) in order to separately resolve the emissions from the extended debris disk (short baselines) and from the stellar photosphere (long baselines). Results.After revising Vega's K-band angular diameter ($\theta_{\rm UD} = 3.202$ ± 0.005 mas), we show that a significant deficit in squared visibility ($\Delta V^2 = 1.88$ ± 0.34%) is detected at short baselines with respect to the best-fit uniform disk stellar model. This deficit can be either attributed to the presence of a low-mass stellar companion around Vega, or as the signature of the thermal and scattered emissions from the debris disk. We show that the presence of a close companion is highly unlikely, as well as other possible perturbations (stellar morphology, calibration), and deduce that we have most probably detected the presence of dust in the close neighbourhood of Vega. The resulting flux ratio between the stellar photosphere and the debris disk amounts to 1.29 ± 0.19% within the FLUOR field-of-view (~7.8 AU). Finally, we complement our K-band study with archival photometric and interferometric data in order to evaluate the main physical properties of the inner dust disk. The inferred properties suggest that the Vega system could be currently undergoing major dynamical perturbations.
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FMFMET, NUK, UL, UM, UPUK
Objective We used validated sensitive and specific questions associated with clinically confirmed diagnoses of unexplained vulvar pain (vulvodynia) to compare the cumulative incidence of vulvar pain ...and prevalence of care-seeking behavior in Boston metropolitan area (BMA) and in Minneapolis/Saint Paul metropolitan area (MSP) from 2001 through 2005 using census-based data, and 2010 through 2012, using outpatient community-clinic data, respectively. Study Design We received self-administered questionnaires from 5440 women in BMA and 13,681 in MSP, 18-40 years of age, describing their history of vulvar burning or pain on contact that persisted >3 months that limited/prevented intercourse. Results By age 40 years, 7-8% in BMA and MSP reported vulvar pain consistent with vulvodynia. Women of Hispanic origin compared to whites were 1.4 times more likely to develop vulvar pain symptoms (95% confidence interval, 1.1–1.8). Many women in MSP (48%) and BMA (30%) never sought treatment, and >50% who sought care with known health care access received no diagnosis. Conclusion Using identical screening methods, we report high prevalence of vulvar pain in 2 geographic regions, and that access to health care does not increase the likelihood of seeking care for chronic vulvar pain.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Planted forests are increasingly recognised for the provision of habitats for species threatened with extinction. Despite this development, a limited number of empirical studies have been undertaken ...to estimate the economic value of this ecosystem service. New Zealand's planted forests provide habitat to at least 118 threatened species. These forests can be managed to increase the abundance of many of these species. We present findings from survey data obtained in a discrete choice experiment designed to estimate the non-market values for a proposed biodiversity enhancement programme in New Zealand's planted forests. We used a two-stage modelling process. First we estimated the individual specific willingness to pay values and then we explored their socio-economic and spatial determinants. The first stage modelling process, which used a random parameters logit model with error components, suggested that willingness to pay was higher for increasing the abundance of native bird than for non-bird species. The second stage model used a least squares panel random-effects regression. Results from this method suggested that socioeconomic characteristics, such as attitudes toward the programme and distance from large planted forests, influenced willingness to pay for biodiversity enhancement.
•Biodiversity enhancement is valued in New Zealand's exotic planted forests•Results suggest higher WTP values for conservation of birds than for other species•Participation in conservation groups has the greatest positive influence on WTP•WTP values are influenced by the level of understanding of choice questions•Close proximity to large planted forests affects WTP positively and significantly
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
We have measured the angular diameters of six M dwarfs with the CHARA Array, a long-baseline optical interferometer located at Mount Wilson Observatory. Spectral types range from M1.0 V to M3.0 V and ...linear radii from 0.38 to 0.69 R sub( ). These results are consistent with the seven other M dwarf radii measurements from optical interferometry and with those for 14 stars in eclipsing binary systems. We compare all directly measured M dwarf radii to model predictions and find that current models underestimate the true stellar radii by up to 15%-20%. The differences are small among the metal-poor stars but become significantly larger with increasing metallicity. This suggests that theoretical models for low-mass stars may be missing some opacity source that alters the computed stellar radii.
We present the results of long-baseline optical interferometry observations using the Precision Astronomical Visual Observations (PAVO) beam combiner at the Center for High Angular Resolution ...Astronomy (CHARA) Array to measure the angular sizes of three bright Kepler stars: θ Cygni, and both components of the binary system 16 Cygni. Supporting infrared observations were made with the Michigan Infrared Combiner (MIRC) and Classic beam combiner, also at the CHARA Array. We find limb-darkened angular diameters of 0.753 ± 0.009 mas for θ Cyg, 0.539 ± 0.007 mas for 16 Cyg A and 0.490 ± 0.006 mas for 16 Cyg B. The Kepler Mission has observed these stars with outstanding photometric precision, revealing the presence of solar-like oscillations. Due to the brightness of these stars the oscillations have exceptional signal-to-noise, allowing for detailed study through asteroseismology, and are well constrained by other observations. We have combined our interferometric diameters with Hipparcos parallaxes, spectrophotometric bolometric fluxes and the asteroseismic large frequency separation to measure linear radii (θ Cyg: 1.48 ± 0.02 R, 16 Cyg A: 1.22 ± 0.02 R, 16 Cyg B: 1.12 ± 0.02 R), effective temperatures (θ Cyg: 6749 ± 44 K, 16 Cyg A: 5839 ± 42 K, 16 Cyg B: 5809 ± 39 K) and masses (θ Cyg: 1.37 ± 0.04 M, 16 Cyg A: 1.07 ± 0.05 M, 16 Cyg B: 1.05 ± 0.04 M) for each star with very little model dependence. The measurements presented here will provide strong constraints for future stellar modelling efforts.
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