A continuum from clear to cloudy hot-Jupiter exoplanets without primordial water depletion.

Thousands of transiting exoplanets have been discovered, but spectral analysis of their atmospheres has so far been dominated by a small number of exoplanets and data spanning relatively narrow wavelength ranges (such as 1.1-1.7 micrometres). Recent studies show that some hot-Jupiter exoplanets have much weaker water absorption features in their near-infrared spectra than predicted. The low amplitude of water signatures could be explained by very low water abundances, which may be a sign that water was depleted in the protoplanetary disk at the planet's formation location, but it is unclear whether this level of depletion can actually occur. Alternatively, these weak signals could be the result of obscuration by clouds or hazes, as found in some optical spectra. Here we report results from a comparative study of ten hot Jupiters covering the wavelength range 0.3-5 micrometres, which allows us to resolve both the optical scattering and infrared molecular absorption spectroscopically. Our results reveal a diverse group of hot Jupiters that exhibit a continuum from clear to cloudy atmospheres. We find that the difference between the planetary radius measured at optical and infrared wavelengths is an effective metric for distinguishing different atmosphere types. The difference correlates with the spectral strength of water, so that strong water absorption lines are seen in clear-atmosphere planets and the weakest features are associated with clouds and hazes. This result strongly suggests that primordial water depletion during formation is unlikely and that clouds and hazes are the cause of weaker spectral signatures.

Highlights in the study of exoplanet atmospheres.

Exoplanets are now being discovered in profusion. To understand their character, however, we require spectral models and data. These elements of remote sensing can yield temperatures, compositions and even weather patterns, but only if significant improvements in both the parameter retrieval process and measurements are made. Despite heroic efforts to garner constraining data on exoplanet atmospheres and dynamics, reliable interpretation has frequently lagged behind ambition. I summarize the most productive, and at times novel, methods used to probe exoplanet atmospheres; highlight some of the most interesting results obtained; and suggest various broad theoretical topics in which further work could pay significant dividends.

Kinetic and Electromyographic Responses to Traditional and Assisted Nordic Hamstring Exercise.

Burrows, AP, Cleather, D, Mahaffey, R, and Cimadoro, G. Kinetic and electromyographic responses to traditional and assisted Nordic hamstring exercise. J Strength Cond Res 34(10): 2715-2724, 2020-The Nordic hamstring exercise (NHE) is performed to increase hamstring strength, elicit morphological changes, and reduce injury risk. However, to date, the NHE assisted by the means of an external resistance has not been investigated. Thus, this study compared the eccentric knee flexor strength, rating of perceived exertion (RPE), and electromyographic responses of the biceps femoris (BF) and semitendinosus (ST) when performing the NHE under assisted or unassisted conditions. Sixteen professional soccer players (aged 19.4 ± 2.2 years) performed 5 sets of 3 NHE unassisted and with assisting loads (5-20% of the body mass) using the Keiser machine. Eccentric knee flexor strength was measured from the subjects' dominant limb. Peak surface electromyography (sEMG) of the BF and ST was recorded from the dominant limb; the ratio was also calculated. Subjects rated the intensity of each condition of the NHE on a ten-point RPE Borg scale. All assisted conditions displayed significantly lower (p < 0.05) absolute and relative eccentric knee flexor strength than unassisted conditions. Rating of perceived exertion for each loading condition was significantly lower (p < 0.05) as the assisting load increased except for the difference between the 10 and 15% assisted conditions. Surface electromyography of the BF and ST was not significantly lower (p < 0.05) during all assisted conditions compared with the unassisted NHE, neither there were significant between-muscle differences or sEMG ratios. Our findings suggest that the assisted NHE reduces the load and difficulty of the exercise. Practitioners can use the assisted NHE to manipulate intensity and difficulty if that is appropriate for their programming.

Spectra as windows into exoplanet atmospheres.

Understanding a planet's atmosphere is a necessary condition for understanding not only the planet itself, but also its formation, structure, evolution, and habitability. This requirement puts a premium on obtaining spectra and developing credible interpretative tools with which to retrieve vital planetary information. However, for exoplanets, these twin goals are far from being realized. In this paper, I provide a personal perspective on exoplanet theory and remote sensing via photometry and low-resolution spectroscopy. Although not a review in any sense, this paper highlights the limitations in our knowledge of compositions, thermal profiles, and the effects of stellar irradiation, focusing on, but not restricted to, transiting giant planets. I suggest that the true function of the recent past of exoplanet atmospheric research has been not to constrain planet properties for all time, but to train a new generation of scientists who, by rapid trial and error, are fast establishing a solid future foundation for a robust science of exoplanets.

Astronomical reach of fundamental physics.

Using basic physical arguments, we derive by dimensional and physical analysis the characteristic masses and sizes of important objects in the universe in terms of just a few fundamental constants. This exercise illustrates the unifying power of physics and the profound connections between the small and the large in the cosmos we inhabit. We focus on the minimum and maximum masses of normal stars, the corresponding quantities for neutron stars, the maximum mass of a rocky planet, the maximum mass of a white dwarf, and the mass of a typical galaxy. To zeroth order, we show that all these masses can be expressed in terms of either the Planck mass or the Chandrasekar mass, in combination with various dimensionless quantities. With these examples, we expose the deep interrelationships imposed by nature between disparate realms of the universe and the amazing consequences of the unifying character of physical law.

First light of the Gemini Planet imager.

The Gemini Planet Imager is a dedicated facility for directly imaging and spectroscopically characterizing extrasolar planets. It combines a very high-order adaptive optics system, a diffraction-suppressing coronagraph, and an integral field spectrograph with low spectral resolution but high spatial resolution. Every aspect of the Gemini Planet Imager has been tuned for maximum sensitivity to faint planets near bright stars. During first-light observations, we achieved an estimated H band Strehl ratio of 0.89 and a 5-σ contrast of 10(6) at 0.75 arcseconds and 10(5) at 0.35 arcseconds. Observations of Beta Pictoris clearly detect the planet, Beta Pictoris b, in a single 60-s exposure with minimal postprocessing. Beta Pictoris b is observed at a separation of 434 ± 6 milliarcseconds (mas) and position angle 211.8 ± 0.5°. Fitting the Keplerian orbit of Beta Pic b using the new position together with previous astrometry gives a factor of 3 improvement in most parameters over previous solutions. The planet orbits at a semimajor axis of [Formula: see text] near the 3:2 resonance with the previously known 6-AU asteroidal belt and is aligned with the inner warped disk. The observations give a 4% probability of a transit of the planet in late 2017.

Strong water absorption in the dayside emission spectrum of the planet HD 189733b.

Recent observations of the extrasolar planet HD 189733b did not reveal the presence of water in the emission spectrum of the planet. Yet models of such 'hot-Jupiter' planets predict an abundance of atmospheric water vapour. Validating and constraining these models is crucial to understanding the physics and chemistry of planetary atmospheres in extreme environments. Indications of the presence of water in the atmosphere of HD 189733b have recently been found in transmission spectra, where the planet's atmosphere selectively absorbs the light of the parent star, and in broadband photometry. Here we report the detection of strong water absorption in a high-signal-to-noise, mid-infrared emission spectrum of the planet itself. We find both a strong downturn in the flux ratio below 10 microm and discrete spectral features that are characteristic of strong absorption by water vapour. The differences between these and previous observations are significant and admit the possibility that predicted planetary-scale dynamical weather structures may alter the emission spectrum over time. Models that match the observed spectrum and the broadband photometry suggest that heat redistribution from the dayside to the nightside is weak. Reconciling this with the high nightside temperature will require a better understanding of atmospheric circulation or possible additional energy sources.

Direct imaging and astrometric detection of a gas giant planet orbiting an accelerating star.

Direct imaging of gas giant exoplanets provides information on their atmospheres and the architectures of planetary systems. However, few planets have been detected in blind surveys with direct imaging. Using astrometry from the Gaia and Hipparcos spacecraft, we identified dynamical evidence for a gas giant planet around the nearby star HIP 99770. We confirmed the detection of this planet with direct imaging using the Subaru Coronagraphic Extreme Adaptive Optics instrument. The planet, HIP 99770 b, orbits 17 astronomical units from its host star, receiving an amount of light similar to that reaching Jupiter. Its dynamical mass is 13.9 to 16.1 Jupiter masses. The planet-to-star mass ratio [(7 to 8) × 10-3] is similar to that of other directly imaged planets. The planet's atmospheric spectrum indicates an older, less cloudy analog of the previously imaged exoplanets around HR 8799.

A theoretical look at the direct detection of giant planets outside the Solar System.

Astronomy is at times a science of unexpected discovery. When it is, and if we are lucky, new intellectual territories emerge to challenge our views of the cosmos. The recent indirect detections using high-precision Doppler spectroscopy of more than 100 giant planets orbiting more than 100 nearby stars is an example of such rare serendipity. What has been learned has shaken out preconceptions, for none of the planetary systems discovered so far is like our own. The key to unlocking a planet's chemical, structural, and evolutionary secrets, however, is the direct detection of the planet's light. Because there have been as yet no confirmed detections, a theoretical analysis of such a planet's atmosphere is necessary for guiding our search.

Impact of a modified progressive Copenhagen adduction exercise programme on hip adduction strength and postexercise muscle soreness in professional footballers.

BACKGROUND: Reduced hip adduction strength has been identified as a key predisposing factor in developing hip and groin injuries. The Copenhagen adduction programme has been shown to increase hip adduction strength in semiprofessional footballers but can cause muscle soreness. Therefore, a modified progressive Copenhagen adduction (MPCA) programme has been designed to increase hip adduction strength while limiting muscle soreness. OBJECTIVE: To investigate the effect of an 8-week MPCA exercise on eccentric hip adduction and abduction strength in senior professional footballers. METHODS: 25 senior professional footballers completed an 8-week MPCA strengthening programme. Eccentric hip adduction (EHAD) and eccentric hip abduction (EHAB) strengths were measured. Changes in preintervention and postintervention strengths and EHAD:EHAB ratios were calculated. The statistical significance between strength changes was assessed with dependent t-tests and Wilcoxon signed-rank tests due to the distribution of the data (p<0.05). Delayed onset of muscle soreness (DOMS) and rate of perceived exertion were measured throughout the programme. RESULTS: There were statistically significant increases in EHAD strength (24% and 25%, left and right), EHAB strength (10% and 13%, left and right) and the EHAD:EHAB ratio (12% and 10%, left and right) (p<0.01).Professional footballers were able to complete the MPCA exercise with low levels of DOMS. CONCLUSION: An 8-week MPCA exercise elicited significant EHAD and EHAB strength increases with reduced levels of muscle soreness in senior professional footballers.

Exoplanet atmosphere. Thermal structure of an exoplanet atmosphere from phase-resolved emission spectroscopy.

Exoplanets that orbit close to their host stars are much more highly irradiated than their solar system counterparts. Understanding the thermal structures and appearances of these planets requires investigating how their atmospheres respond to such extreme stellar forcing. We present spectroscopic thermal emission measurements as a function of orbital phase ("phase-curve observations") for the highly irradiated exoplanet WASP-43b spanning three full planet rotations using the Hubble Space Telescope. With these data, we construct a map of the planet's atmospheric thermal structure, from which we find large day-night temperature variations at all measured altitudes and a monotonically decreasing temperature with pressure at all longitudes. We also derive a Bond albedo of 0.18(-0.12)(+0.07) and an altitude dependence in the hot-spot offset relative to the substellar point.

Chief resident immersion training in the care of older adults: an innovative interspecialty education and leadership intervention.

Chief residents (CRs) play a crucial role in training residents and students but may have limited geriatrics training or formal preparation for their CR role. A 2-day off-site chief resident immersion training (CRIT) addressed these challenges. Objectives were to foster collaboration between disciplines in the management of complex older patients, increase knowledge of geriatrics principles to incorporate into teaching, enhance leadership skills, and help CRs develop an achievable project for implementation in their CR year. Three cohorts totaling 47 trainees and 18 faculty mentors from 13 medical and surgical disciplines participated over 3 successive years. The curriculum, developed and taught by a multidisciplinary team, featured an interactive surgical case, mini-lectures on geriatrics topics, seminars to enhance teaching and leadership skills, and one-on-one mentoring to develop a project in geriatric care or education. Evaluation included pre- and postprogram tests and self-report surveys and two follow-up surveys or interviews. In 2006 and 2007, scores on a 12-item objective knowledge test increased significantly (P<.001) from before to immediately after CRIT. Self-report knowledge and confidence in teaching geriatrics also increased significantly (P<.05) in all formally covered topics. Mean enhancement of CR skills was 4.3 (1=not at all, 5=very much). Eleven months after CRIT, all but five CRs had implemented at least part of their action projects. CRs reported improved care of older patients, better leadership skills, more and better geriatrics teaching, and more collaboration between disciplines. A 2-day interactive program for CRs can increase institutional capacity regarding geriatrics teaching and care of elderly patients across medical specialties.

A new mechanism for gravitational-wave emission in core-collapse supernovae.

We present a new theory for the gravitational-wave signatures of core-collapse supernovae. Previous studies identified axisymmetric rotating core collapse, core bounce, postbounce convection, and anisotropic neutrino emission as the primary processes and phases for the radiation of gravitational waves. Our results, which are based on axisymmetric Newtonian supernova simulations, indicate that the dominant emission process of gravitational waves in core-collapse supernovae may be the oscillations of the protoneutron star core. The oscillations are predominantly of mode character, are excited hundreds of milliseconds after bounce, and typically last for several hundred milliseconds. Our results suggest that even nonrotating core-collapse supernovae should be visible to current LIGO-class detectors throughout the Galaxy, and depending on progenitor structure, possibly out to megaparsec distances.

A randomized, placebo-controlled trial of paroxetine in nursing home residents with non-major depression.

Depression is common across a broad spectrum of severity among nursing home residents. Previous research has demonstrated the effectiveness of antidepressants in nursing home residents with major depression, but it is not known whether antidepressants are helpful in residents with less severe forms of depression. We conducted a randomized double-blind placebo-controlled 8-week trial comparing paroxetine and placebo in very old nursing home residents with non-major depression. The main outcome measure was the primary nurse's Clinical Impression of Change (CGI-C). Additional outcome measures were improvement on the interview-derived Hamilton Depression Rating Scale (HDRS) and Cornell Scale for Depression (CS) scores. Twenty-four subjects with a mean age of 87.9 were enrolled and twenty subjects completed the trial. Placebo response was high, and when all subjects were considered, there were no differences in improvement between the paroxetine and placebo groups. Two subjects that received paroxetine developed delirium, and subjects that received paroxetine were more likely to experience a decrease in Mini Mental State Exam scores (P =.03). There were no differences in serum anticholinergic activity between groups. In a subgroup analysis of 15 subjects with higher baseline HDRS and CS scores, there was a trend toward greater improvement in the paroxetine group in an outcome measure that combined the CGI-C and interview-based measures (P =.06). Paroxetine is not clearly superior to placebo in this small study of very old nursing home residents with non-major depression, and there is a risk of adverse cognitive effects. Because of the high placebo response and the trend towards improvement in the more severely ill patients, it is possible that a larger study would have demonstrated a significant therapeutic effect for paroxetine as compared with placebo. The study also illustrates the discordance between patient and caregiver ratings, and the difficulties in studying very elderly patients with mood disorders.