We operate a fiberbased cavity with an inserted diamond membrane containing ensembles of silicon vacancy centers (SiV\(^-\)) at cryogenic temperatures \( \geq4~\)K. The setup, sample fabrication and ...spectroscopic characterization is described, together with a demonstration of the cavity influence by the Purcell effect. This paves the way towards solid state qubits coupled to optical interfaces as long-lived quantum memories.
Hydrodynamic escape is the most efficient atmospheric mechanism of planetary mass loss and has a large impact on planetary evolution. Three hydrodynamic escape regimes have been identified ...theoretically: energy-limited, recombination-limited, and photon-limited. However, no evidence of these regimes had been reported until now. Here, we report evidence of these three regimes via an analysis of helium I triplet at 10830 angstroms and Ly-\(\alpha\) absorption involving a 1D hydrodynamic model that allows us to estimate hydrogen recombination and advection rates. In particular, we show that HD 209458 b is in the energy-limited regime, HD 189733 b is in the recombination-limited regime, and GJ 3470 b is in the photon-limited regime. These exoplanets can be considered as benchmark cases for their respective regimes.
Close-in gas planets are subject to continuous photoevaporation that can erode their volatile envelopes. Today, ongoing mass loss has been confirmed in a few individual systems via transit ...observations in the ultraviolet spectral range. We demonstrate that the Ultraviolet/Optical Telescope (UVOT) onboard the Neil Gehrels Swift Observatory enables photometry to a relative accuracy of about 0.5% and present the first near-UV (200-270 nm, NUV) transit observations of WASP-121 b, a hot Jupiter with one of the highest predicted mass-loss rates. The data cover the orbital phases 0.85 to 1.15 with three visits. We measure a broad-band NUV transit depth of \(2.10\pm0.29\)%. While still consistent with the optical value of 1.55%, the NUV data indicate excess absorption of 0.55% at a 1.9\(\sigma\) level. Such excess absorption is known from the WASP-12 system, and both of these hot Jupiters are expected to undergo mass loss at extremely high rates. With a CLOUDY simulation, we show that absorption lines of Fe II in a dense extended atmosphere can cause broad-band NUV absorption at the 0.5% level. Given the numerous lines of low-ionization metals, the NUV range is a promising tracer of photoevaporation in the hottest gas planets.
Low socioeconomic status, inner city Black adults, aged 20 to 49 yr (24 males and 45 females), were randomly selected from East Baltimore, MD to study plasma lipid and lipoprotein levels. Several ...factors known to affect these levels also were examined: dietary intake, alcohol intake, degree of obesity (measured by body mass index), physical activity level, smoking, and hormone use. Compared to women, the men consumed 9.3 more calories/kg body weight (p less than 0.005), 273 mg more cholesterol/day (p less than 0.005), and 7% fewer calories as sucrose (p less than 0.01). The P/S ratio of both their diets was 0.5. The men also had a lower body mass index than the women (23.9 kg/m2 versus 29.0; p less than 0.001). Mean lipid and lipoprotein levels were similar in the men and women. However, the men's total cholesterol (167 mg/dl) and low density lipoprotein cholesterol (94 mg/dl) levels were lower than those of adult Blacks in other studies, while the levels of the East Baltimore women were similar to those in other studies. For women, body mass index and high density lipoprotein cholesterol were negatively correlated (p less than 0.01); triglycerides and oral contraceptive use were positively correlated (p less than 0.01). None of the factors studied explained the relatively low total cholesterol and low density lipoprotein cholesterol levels in these inner city Black adult men.
Characterising the atmospheres of exoplanets is key to understanding their nature and provides hints about their formation and evolution. High-resolution measurements of the helium triplet, ...He(2\(^{3}\)S), absorption of highly irradiated planets have been recently reported, which provide a new mean to study their atmospheric escape. In this work, we study the escape of the upper atmospheres of HD 189733 b and GJ 3470 b by analysing high-resolution He(2\(^{3}\)S) absorption measurements and using a 1D hydrodynamic model coupled with a non-LTE model for the He(2\(^{3}\)S) state. We also use the H density derived from Ly\(\alpha\) observations to further constrain their temperatures, T, mass-loss rates,\(\dot M\), and H/He ratios. We have significantly improved our knowledge of the upper atmospheres of these planets. While HD 189733 b has a rather compressed atmosphere and small gas radial velocities, GJ 3470 b, with a gravitational potential ten times smaller, exhibits a very extended atmosphere and large radial outflow velocities. Hence, although GJ 3470 b is much less irradiated in the XUV, and its upper atmosphere is much cooler, it evaporates at a comparable rate. In particular, we find that the upper atmosphere of HD 189733 b is compact and hot, with a maximum T of 12400\(^{+400}_{-300}\) K, with very low mean molecular mass (H/He=(99.2/0.8)\(\pm0.1\)), almost fully ionised above 1.1 R\(_p\), and with \(\dot M\)=(1.1\(\pm0.1\))\(\times\)10\(^{11}\) g/s. In contrast, the upper atmosphere of GJ 3470 b is highly extended and relatively cold, with a maximum T of 5100\(\pm900\) K, also with very low mean molecular mass (H/He=(98.5/1.5)\(^{+1.0}_{-1.5}\)), not strongly ionised and with \(\dot M\)=(1.9\(\pm1.1\))\(\times\)10\(^{11}\) g/s. Furthermore, our results suggest that the upper atmospheres of giant planets undergoing hydrodynamic escape tend to have very low mean molecular mass (H/He\(\gtrsim\)97/3).
CVSO 30 is a young, active, weak-line T Tauri star; it possibly hosts the only known planetary system with both a transiting hot-Jupiter and a cold-Jupiter candidate (CVSO 30 b and c). We analyzed ...archival ROSAT, Chandra, and XMM-Newton data to study the coronal emission in the system. According to our modeling, CVSO 30 shows a quiescent X-ray luminosity of about 8e29 erg/s. The X-ray absorbing column is consistent with interstellar absorption. XMM-Newton observed a flare, during which a transit of the candidate CVSO 30 b was expected, but no significant transit-induced variation in the X-ray flux is detectable. While the hot-Jupiter candidate CVSO 30 b has continuously been undergoing mass loss powered by the high-energy irradiation, we conclude that its evaporation lifetime is considerably longer than the estimated stellar age of 2.6 Myr.
HD 209458b is an exoplanet with an upper atmosphere undergoing blow-off escape that has mainly been studied using measurements of the Ly-alpha absorption. Recently, high-resolution measurements of ...absorption in the He I triplet line at 10830 angstroms of several exoplanets (including HD 209458b) have been reported, creating a new opportunity to probe escaping atmospheres. We aim to better understand the atmospheric regions of HD 209458b from where the escape originates. We developed a 1D hydrodynamic model with spherical symmetry for the HD 209458 b thermosphere coupled with a non-local thermodynamic model for the population of the He triplet state. In addition, we performed high-resolution radiative transfer calculations of synthetic spectra for the He triplet lines and compared them with the measured absorption spectrum in order to retrieve information about the atmospheric parameters. We find that the measured spectrum constrains the H/H\(^{+}\) transition altitude occurring in the range of 1.2 to 1.9Rp. H is almost fully ionised at altitudes above 2.9Rp. We also find that the X-ray and EUV absorption takes place at effective radii from 1.16 to 1.30Rp, and that the He triplet peak density occurs at altitudes from 1.04 to 1.60Rp. Additionally, the averaged mmw is confined to the 0.61-0.73 g/mole interval, and the thermospheric H/He ratio should be larger than 90/10, and most likely approximately 98/2. We also provide a one-to-one relationship between mass-loss rate and temperature. Based on the energy-limited escape approach and assuming heating efficiencies of 0.1-0.2, we find a mass-loss rate in the range of (0.42-1.00)\(\times 10^{11}\) g/s and a corresponding temperature range of 7125 to 8125K. The analysis of the measured He triplet absorption spectrum significantly constrains the thermospheric structure of HD 209458b and advances our knowledge of its escaping atmosphere.
We report energy intake and selected nutrient intakes-protein, fat (total, saturated, and polyunsaturated), carbohydrate (total, starch, and sucrose), and cholesterol-for 1251 white children ages ...6-19 years. The data were obtained, by means of a 24-h dietary recall, from children who were randomly selected from the North American populations studied by the Lipid Research Clinics Program. Females (N = 584) consumed about 2000 kcal daily, an intake that remained relatively constant throughout the age groups studied. Males (N = 667) had an energy intake of 2000 kcal/day during childhood that increased to over 3000 kcal/day in adolescence. Energy sources for both sexes were approximately 15% protein, 38% total fat, 15% saturated fat, 6% polyunsaturated fat, 48% total carbohydrate, 19% starch, and 11% sucrose; cholesterol intake averaged about 145 mg/1000 kcal. For both sexes, fat intake increased with age. Compared to females, males ingested greater amounts of cholesterol and total and saturated fat.
Abstract Purpose An initial description of a sonographic finding predictive of intrathoracic chest tube placement. Methods This was a prospective observational study using unembalmed cadaveric ...models. Chest tubes were randomly placed intra- and extrathoracically and evaluated using ultrasound. Chest tube location was confirmed using blunt dissection followed by tactile and visual confirmation. Sonographers were blinded to chest tube position. Sonographic images obtained in a transverse orientation revealed a subcutaneous hyperechoic arc, created by the chest tube, at the insertion site. The path of the hyperechoic arc was followed cephalad. Disappearance of the hyperechoic arc signified intrathoracic chest tube placement. In contrast, continuation of a subcutaneous hyperechoic arc for the full length of the chest tube signified extrathoracic chest tube placement (the Disappearance/Intrathoracic, Continuation/Extrathoracic sign). Results Ultrasound was used to evaluate 48 chest tube placements. All chest tube locations were identified correctly. In differentiating intra- vs extrathoracic chest tube placement, the Disappearance/Intrathoracic, Continuation/Extrathoracic sign revealed a sensitivity of 100% (95% confidence interval, 83%-100%) and a specificity of 100% (95% confidence interval, 83%-100%). Conclusions In this small study, bedside ultrasound appears to be highly sensitive and specific in differentiating intra- versus extrathoracic chest tube placement.
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