Reducing overweight and obesity has been a longstanding focus of public health messaging and physician-patient interactions. Clinical guidelines by major public health organizations describe both ...overweight and obesity as risk factors for mortality and other health conditions. Accordingly, a majority of primary care physicians believe that overweight BMI (even without obesity) strongly increases mortality risk.
The current evidence base suggests that although both obese BMI and underweight BMI are consistently associated with increased all-cause mortality, overweight BMI (without obesity) is not meaningfully associated with increased mortality. In fact, a number of studies suggest modest protective, rather than detrimental, associations of overweight BMI with all-cause mortality. Given this current evidence base, clinical guidelines and physician perceptions substantially overstate all-cause mortality risks associated with the range of BMIs classified as "overweight" but not "obese." Discrepancies between evidence and communication regarding mortality raise the question of whether similar discrepancies exist for other health outcomes.
Health communication that inaccurately conveys current evidence may do more harm than good; this applies to communication from health authorities to health practitioners as well as to communication from health practitioners to individual patients. We give three recommendations to better align health communication with the current evidence. First, recommendations to the public and health practitioners should distinguish overweight from obese BMI and at this time should not describe overweight BMI as a risk factor for all-cause mortality. Second, primary care physicians' widespread misconceptions about overweight BMI should be rectified. Third, the evidence basis for other potential risks or benefits of overweight BMI should be rigorously examined and incorporated appropriately into health communication.
Most of the baryons from galaxies have been "missing" and several studies have attempted to map the circumgalactic medium (CGM) of galaxies in their quest. We report on X-ray observations made with ...the Chandra X-Ray Observatory probing the warm-hot phase of the CGM of our Milky Way at about 10 super(6) K. We detect O VII and O VIII absorption lines at z = 0 in extragalactic sight lines and measure accurate column densities using both K alpha and K beta lines of O VII. We then combine these measurements with the emission measure of the Galactic halo from literature to derive the density and the path length of the CGM. We show that the warm-hot phase of the CGM is massive, extending over a large region around the Milky Way, with a radius of over 100 kpc. The mass content of this phase is over 10 billion solar masses, many times more than that in cooler gas phases and comparable to the total baryonic mass in the disk of the Galaxy. The missing mass of the Galaxy appears to be in this warm-hot gas phase.
Abstract
Dark magnetic spots crossing the stellar disk lead to quasiperiodic brightness variations, which allow us to constrain stellar surface rotation and photometric activity. The current work is ...the second of this series, where we analyze the Kepler long-cadence data of 132,921 main-sequence F and G stars and late subgiant stars. Rotation-period candidates are obtained by combining wavelet analysis with autocorrelation function. Reliable rotation periods are then selected via a machine-learning (ML) algorithm, automatic selection, and complementary visual inspection. The ML training data set comprises 26,521 main-sequence K and M stars from Paper I. To supplement the training, we analyze in the same way as Paper I, i.e., automatic selection and visual inspection, 34,100 additional stars. We finally provide rotation periods
P
rot
and associated photometric activity proxy
S
ph
for 39,592 targets. Hotter stars are generally faster rotators than cooler stars. For main-sequence G stars,
S
ph
spans a wider range of values with increasing effective temperature, while F stars tend to have smaller
S
ph
values in comparison with cooler stars. Overall for G stars, fast rotators are photometrically more active than slow rotators, with
S
ph
saturating at short periods. The combined outcome of the two papers accounts for average
P
rot
and
S
ph
values for 55,232 main-sequence and subgiant FGKM stars (out of 159,442 targets), with 24,182 new
P
rot
detections in comparison with McQuillan et al. The upper edge of the
P
rot
distribution is located at longer
P
rot
than found previously.
Photosynthesis is amongst the plant cell functions that are highly sensitive to any type of changes. Sun and shade conditions are prevalent in fields as well as dense forests. Dense forests face ...extreme sun and shade conditions, and plants adapt themselves accordingly. Sun flecks cause changes in plant metabolic processes. In the field, plants have to face high light intensity and survive under such conditions. Sun and shade type of plants develops a respective type of chloroplasts which help plants to survive and perform photosynthesis under adverse conditions. PSII and Rubisco behave differently under different sun and shade conditions. In this review, morphological, physiological, and biochemical changes under conditions of sun (high light) and shade (low light) on the process of photosynthesis, as well as the tolerance and adaptive mechanisms involved for the same, were summarized.
Kepler allows the measurement of starspot variability in a large sample of field red giants for the first time. With a new method that combines autocorrelation and wavelet decomposition, we measure ...361 rotation periods from the full set of 17 377 oscillating red giants in our sample. This represents 2.08% of the stars, consistent with the fraction of spectroscopically detected rapidly rotating giants in the field. The remaining stars do not show enough variability to allow us to measure a reliable surface rotation period. Because the stars with detected rotation periods have measured oscillations, we can infer their global properties, e.g. mass and radius, and quantitatively evaluate the predictions of standard stellar evolution models as a function of mass. Consistent with results for cluster giants when we consider only the 4881 intermediate-mass stars, M > 2.0 M⊙ from our full red giant sample, we do not find the enhanced rates of rapid rotation expected from angular momentum conservation. We therefore suggest that either enhanced angular momentum loss or radial differential rotation must be occurring in these stars. Finally, when we examine the 575 low-mass (M< 1.1 M⊙) red clump stars in our sample, which were expected to exhibit slow (non-detectable) rotation, 15% of them actually have detectable rotation. This suggests a high rate of interactions and stellar mergers on the red giant branch.
Swift intensive accretion disk reverberation mapping of four AGN yielded light curves sampled ∼200-350 times in 0.3-10 keV X-ray and six UV/optical bands. Uniform reduction and cross-correlation ...analysis of these data sets yields three main results: (1) The X-ray/UV correlations are much weaker than those within the UV/optical, posing severe problems for the lamp-post reprocessing model in which variations in a central X-ray corona drive and power those in the surrounding accretion disk. (2) The UV/optical interband lags are generally consistent with as predicted by the centrally illuminated thin accretion disk model. While the average interband lags are somewhat larger than predicted, these results alone are not inconsistent with the thin disk model given the large systematic uncertainties involved. (3) The one exception is the U band lags, which are on average a factor of ∼2.2 larger than predicted from the surrounding band data and fits. This excess appears to be due to diffuse continuum emission from the broad-line region (BLR). The precise mixing of disk and BLR components cannot be determined from these data alone. The lags in different AGN appear to scale with mass or luminosity. We also find that there are systematic differences between the uncertainties derived by JAVELIN versus more standard lag measurement techniques, with JAVELIN reporting smaller uncertainties by a factor of 2.5 on average. In order to be conservative only standard techniques were used in the analyses reported herein.
Brightness variations due to dark spots on the stellar surface encode information about stellar surface rotation and magnetic activity. In this work, we analyze the Kepler long-cadence data of 26,521 ...main-sequence stars of spectral types M and K in order to measure their surface rotation and photometric activity level. Rotation-period estimates are obtained by the combination of a wavelet analysis and autocorrelation function of the light curves. Reliable rotation estimates are determined by comparing the results from the different rotation diagnostics and four data sets. We also measure the photometric activity proxy using the amplitude of the flux variations on an appropriate timescale. We report rotation periods and photometric activity proxies for about 60% of the sample, including 4431 targets for which McQuillan et al. did not report a rotation period. For the common targets with rotation estimates in this study and in McQuillan et al., our rotation periods agree within 99%. In this work, we also identify potential polluters, such as misclassified red giants and classical pulsator candidates. Within the parameter range we study, there is a mild tendency for hotter stars to have shorter rotation periods. The photometric activity proxy spans a wider range of values with increasing effective temperature. The rotation period and photometric activity proxy are also related, with being larger for fast rotators. Similar to McQuillan et al., we find a bimodal distribution of rotation periods.
Recent evidence that programmed intermittent epidural bolus (PIEB) improves maternal outcomes encouraged us to change our labour epidural analgesia protocols and investigate if we could achieve ...similar results in a clinical setting.
We conducted a prospective, controlled, before-and-after cohort study. Outcomes after labour analgesia delivered by continuous epidural infusion (CEI) with ropivacaine 0.2% and fentanyl 2μg ml−1 were compared with PIEB with patient controlled epidural analgesia (PIEB+PCEA) with ropivacaine 0.1% and fentanyl 2 μg ml−1. The primary outcome was lower limb motor block. Secondary outcomes were local anaesthetic and fentanyl dose, duration of the second stage of labour, mode of delivery, and maternal satisfaction. Outcomes were compared using univariate t-test, χ2 test or Fisher's exact test. Significant differences in outcomes were further evaluated by multiple regression analysis.
A total of 397 women completed the study (CEI 188; PIEB+PCEA 209). The PIEB+PCEA group had significantly fewer patients with motor block CEI 41/188 (21.8%) vs PCEA+PIEB 2/209 (1.0%), P<0.001, shorter second stage of labour for primiparous women CEI 108.2 (61.2), mean (standard deviation), min vs PIEB+PCA 79.4 (55.1) min, P<0.001, and received less ropivacaine CEI 72.5 (43.0) mg vs PIEB+PCEA 40.4 (23.8) mg, P<0.001. There was no significant difference in mode of delivery, fentanyl dose, or maternal satisfaction.
Benefits of PIEB+PCEA over CEI previously demonstrated in small randomised controlled trials were reproducible on a larger scale in a clinical setting.
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