132 research outputs found
NGTS-4b: A sub-Neptune transiting in the desert
We report the discovery of NGTS-4b, a sub-Neptune-sized planet transiting a 13th magnitude K-dwarf in a 1.34âd orbit. NGTS-4b has a mass M = 20.6 ± 3.0âMâ and radius R = 3.18 ± 0.26âRâ, which places it well within the so-called âNeptunian Desertâ. The mean density of the planet (3.45 ± 0.95âgâcmâ3) is consistent with a composition of 100â perâcent H2O or a rocky core with a volatile envelope. NGTS-4b is likely to suffer significant mass loss due to relatively strong EUV/X-ray irradiation. Its survival in the Neptunian desert may be due to an unusually high-core mass, or it may have avoided the most intense X-ray irradiation by migrating after the initial activity of its host star had subsided. With a transit depth of 0.13 ± 0.02 perâcent, NGTS-4b represents the shallowest transiting system ever discovered from the ground, and is the smallest planet discovered in a wide-field ground-based photometric survey
Resistant starch and exercise independently attenuate weight regain on a high fat diet in a rat model of obesity
<p>Abstract</p> <p>Background</p> <p>Long-term weight reduction remains elusive for many obese individuals. Resistant starch (RS) and exercise may be useful for weight maintenance. The effects of RS, with or without exercise, on weight regain was examined during relapse to obesity on a high carbohydrate, high fat (HC/HF) diet.</p> <p>Methods</p> <p>Obesity-prone rats were fed <it>ad libitum </it>for 16 weeks then weight reduced on a low fat diet to induce a 17% body weight loss (weight reduced rats). Weight reduced rats were maintained on an energy-restricted low fat diet for 18 weeks, with or without a daily bout of treadmill exercise. Rats were then allowed free access to HC/HF diet containing low (0.3%) or high (5.9%) levels of RS. Weight regain, energy balance, body composition, adipocyte cellularity, and fuel utilization were monitored as rats relapsed to obesity and surpassed their original, obese weight.</p> <p>Results</p> <p>Both RS and exercise independently attenuated weight regain by reducing the energy gap between the drive to eat and suppressed energy requirements. Exercise attenuated the deposition of lean mass during relapse, whereas its combination with RS sustained lean mass accrual as body weight returned. Early in relapse, RS lowered insulin levels and reduced the deposition of fat in subcutaneous adipose tissue. Exercise cessation at five weeks of relapse led to increased weight gain, body fat, subcutaneous adipocytes, and decreased lean mass; all detrimental consequences to overall metabolic health.</p> <p>Conclusions</p> <p>These data are the first to show the complimentary effects of dietary RS and regular exercise in countering the metabolic drive to regain weight following weight loss and suggest that exercise cessation, in the context of relapse on a HC/HF diet, may have dire metabolic consequences.</p
Another chance? Concerns about inequality, support for the European Union and further European integration
Following the 2007â2008 financial crisis, it was expected that the economic downturn and the widening of economic disparities would produce lower support for the European Union (EU) and its continued integration. Using the 2009 European Election Study (EES) data in 27 EU member states, we find that citizens who see greater economic instability and insecurity, regardless of their current economic status, lower their support for the EU as it is but increase their support for continuing integration. Substantively, this suggests that EU citizens may offer the EU another chance to tackle this timely issue and counterbalance market-generated inequality
Shatavari supplementation in postmenopausal women improves handgrip strength and increases vastus lateralis myosin regulatory light chain phosphorylation but does not alter markers of bone turnover
Abstract: Shatavari has long been used as an Ayurvedic herb for womenâs health, but empirical evidence for its effectiveness has been lacking. Shatavari contains phytoestrogenic compounds that bind to the estradiol receptor. Postmenopausal estradiol deficiency contributes to sarcopenia and osteoporosis. In a randomised double-blind trial, 20 postmenopausal women (68.5 ± 6 years) in-gested either placebo (N = 10) or shatavari (N = 10; 1000 mg/d, equivalent to 26,500 mg/d fresh weight shatavari) for 6 weeks. Handgrip and knee extensor strength were measured at baseline and at 6 weeks. Vastus lateralis (VL) biopsy samples were obtained. Data are presented as difference scores (Week 6 â baseline, median ± interquartile range). Handgrip, (but not knee extensor) strength was improved by shatavari supplementation (shatavari +0.7 ± 1.1 kg, placebo -0.4 ± 1.3 kg; p=0.04). Myosin regulatory light chain phosphorylation, a known marker of improved myosin contractile function, was increased in VL following shatavari supplementation (immunoblotting; placebo -0.08 ± 0.5 a.u. shatavari +0.3 ± 1 arbitrary units (a.u.); p = 0.03). Shatavari increased phosphorylation of Aktser473 (Aktser473 (placebo -0.6 ± 0.6 a.u. shatavari +0.2 ± 1.3 a.u; p = 0.03) in VL. Shatavari supplementation did not alter plasma markers of bone turnover (P1NP, ÎČ-CTX) and stimulation of human osteoblasts with pooled sera (N = 8 per condition) from placebo and shatavari supplementation conditions did not alter cytokine or metabolic markers of osteoblast activity. Shatavari may improve muscle function and contractility via myosin conformational change and warrants further investigation in larger and more diverse cohorts of its utility in conserving and enhancing musculoskeletal functio
Scintillation-limited photometry with the 20-cm NGTS telescopes at Paranal Observatory
Ground-based photometry of bright stars is expected to be limited by atmospheric scintillation, although in practice observations are often limited by other sources of systematic noise. We analyse 122 nights of bright star (Gmag âČ 11.5) photometry using the 20-cm telescopes of the Next-Generation Transit Survey (NGTS) at the Paranal Observatory in Chile. We compare the noise properties to theoretical noise models and we demonstrate that NGTS photometry of bright stars is indeed limited by atmospheric scintillation. We determine a median scintillation coefficient at the Paranal Observatory of CY=1.54â , which is in good agreement with previous results derived from turbulence profiling measurements at the observatory. We find that separate NGTS telescopes make consistent measurements of scintillation when simultaneously monitoring the same field. Using contemporaneous meteorological data, we find that higher wind speeds at the tropopause correlate with a decrease in long-exposure (t = 10âs) scintillation. Hence, the winter months between June and August provide the best conditions for high-precision photometry of bright stars at the Paranal Observatory. This work demonstrates that NGTS photometric data, collected for searching for exoplanets, contains within it a record of the scintillation conditions at Paranal
NGTS clusters survey -- II. White-light flares from the youngest stars in Orion
We present the detection of high energy white-light flares from pre-main
sequence stars associated with the Orion complex, observed as part of the Next
Generation Transit Survey (NGTS). With energies up to erg
these flares are some of the most energetic white-light flare events seen to
date. We have used the NGTS observations of flaring and non-flaring stars to
measure the average flare occurrence rate for 4 Myr M0-M3 stars. We have also
combined our results with those from previous studies to predict average rates
for flares above ergs for early M stars in nearby young
associations.STFC ST/M001962/1; ST/P000495/
NGTS-28Ab:a short period transiting brown dwarf
We report the discovery of a brown dwarf orbiting a M1 host star. We first identified the brown dwarf within the Next Generation Transit Survey data, with supporting observations found in TESS sectors 11 and 38. We confirmed the discovery with follow-up photometry from the South African Astronomical Observatory, SPECULOOS-S, and TRAPPIST-S, and radial velocity measurements from HARPS, which allowed us to characterize the system. We find an orbital period of âŒ1.25 d, a mass of 69.0+5.3-4.8 MJ, close to the hydrogen burning limit, and a radius of 0.95 ± 0.05âRJ. We determine the age to be >0.5 Gyr, using model isochrones, which is found to be in agreement with spectral energy distribution fitting within errors. NGTS-28Ab is one of the shortest period systems found within the brown dwarf desert, as well as one of the highest mass brown dwarfs that transits an M dwarf. This makes NGTS-28Ab another important discovery within this scarcely populated region.</div
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Time-Efficient Inspiratory Muscle Strength Training Lowers Blood Pressure and Improves Endothelial Function, NO Bioavailability, and Oxidative Stress in Midlife/Older Adults With Above-Normal Blood Pressure
Background
Highâresistance inspiratory muscle strength training (IMST) is a novel, timeâefficient physical training modality.
Methods and Results
We performed a doubleâblind, randomized, shamâcontrolled trial to investigate whether 6 weeks of IMST (30 breaths/day, 6 days/week) improves blood pressure, endothelial function, and arterial stiffness in midlife/older adults (aged 50–79 years) with systolic blood pressure ≥120 mm Hg, while also investigating potential mechanisms and longâlasting effects. Thirtyâsix participants completed highâresistance IMST (75% maximal inspiratory pressure, n=18) or lowâresistance sham training (15% maximal inspiratory pressure, n=18). IMST was safe, well tolerated, and had excellent adherence (≈95% of training sessions completed). Casual systolic blood pressure decreased from 135±2 mm Hg to 126±3 mm Hg (P<0.01) with IMST, which was ≈75% sustained 6 weeks after IMST (P<0.01), whereas IMST modestly decreased casual diastolic blood pressure (79±2 mm Hg to 77±2 mm Hg, P=0.03); blood pressure was unaffected by sham training (all P>0.05). Twentyâfour hour systolic blood pressure was lower after IMST versus sham training (P=0.01). Brachial artery flowâmediated dilation improved ≈45% with IMST (P<0.01) but was unchanged with sham training (P=0.73). Human umbilical vein endothelial cells cultured with subject serum sampled after versus before IMST exhibited increased NO bioavailability, greater endothelial NO synthase activation, and lower reactive oxygen species bioactivity (P<0.05). IMST decreased Câreactive protein (P=0.05) and altered select circulating metabolites (targeted plasma metabolomics) associated with cardiovascular function. Neither IMST nor sham training influenced arterial stiffness (P>0.05).
Conclusions
Highâresistance IMST is a safe, highly adherable lifestyle intervention for improving blood pressure and endothelial function in midlife/older adults with aboveânormal initial systolic blood pressure.
Registration
URL: https://www.clinicaltrials.gov; Unique identifier: NCT03266510.
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Modulation of Glucose Transporter 1 (GLUT1) Expression Levels Alters Mouse Mammary Tumor Cell Growth In Vitro and In Vivo
Tumor cells exhibit an altered metabolism characterized by elevated aerobic glycolysis and lactate secretion which is supported by an increase in glucose transport and consumption. We hypothesized that reducing or eliminating the expression of the most prominently expressed glucose transporter(s) would decrease the amount of glucose available to breast cancer cells thereby decreasing their metabolic capacity and proliferative potential
2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation
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