We report observations of a stellar occultation by Pluto on 2019 July 17. A single-chord high-speed (time resolution = 2 s) photometry dataset was obtained with a CMOS camera mounted on the Tohoku ...University 60 cm telescope (Haleakala, Hawaii). The occultation light curve is satisfactorily fitted to an existing atmospheric model of Pluto. We find the lowest pressure value at a reference radius of
r
= 1215 km among those reported after 2012. These reports indicate a possible rapid (approximately 21
−5
+4
% of the previous value) pressure drop between 2016, which is the latest reported estimate, and 2019. However, this drop is detected at a 2.4
σ
level only and still requires confirmation from future observations. If real, this trend is opposite from the monotonic increase of Pluto’s atmospheric pressure reported by previous studies. The observed decrease trend is possibly caused by ongoing N
2
condensation processes in the Sputnik Planitia glacier associated with an orbitally driven decline of solar insolation, as predicted by previous theoretical models. However, the observed amplitude of the pressure decrease is larger than the model predictions.
The impact of resolving western boundary currents and mesoscale eddies on a carbon circulation simulation for the North Pacific Ocean is investigated to evaluate the merits of using high‐resolution ...ocean biogeochemical models for climate projections. Simulations by a 100‐km resolution global ocean biogeochemical model with and without embedding a 10‐km resolution model in the North Pacific Ocean are compared. The major improvement in the high‐resolution simulation is the representation of the Kuroshio, its extension current, and the recirculation gyres formed to its south and north, resulting in a proper representation of the North Pacific subtropical mode water (STMW) and an increase in storage of the anthropogenic CO2 (Canth) in STMW by about two‐thirds. The larger storage rate in STMW is caused by supply of a larger amount of warm surface water containing rich Canth to the formation region by the intensified Kuroshio. A huge buoyancy loss from this warm water results in the increased formation of STMW that occupies a vast area in the western subtropical gyre. The surface uptake of Canth in the formation region of STMW is slightly increased but is largely comparable to that of the low‐resolution model. Moreover, there is no structural difference in Canth uptake in other parts of the subtropical region. Thus, the improvement of Canth distribution can be understood as a redistribution of water mass in the subtropical gyre by the improved circulation. The present assessment motivates the use of a high horizontal resolution ocean model in next‐generation projection experiments with carbon cycles.
Plain Language Summary
Accurately representing absorption and accumulation of anthropogenic CO2 (Canth) by the ocean in Earth system models is important to reliably project future climate change. This study investigates the impact of realistically expressing the Kuroshio, which is not expressed adequately in the majority of current Earth system models, on a carbon circulation simulation for the North Pacific Ocean. Two simulations differing in the horizontal grid spacing, about 100 and 10 km, are compared. The intensified Kuroshio in the fine resolution model results in an improved oceanic structure for the upper 500‐m depths in the western North Pacific Ocean, and more Canth is accumulated there, which is closer to observations. Budget analysis suggests that source for the increased Canth accumulation is not local surface flux but a supply of Canth‐rich surface water from low latitudes by the intensified Kuroshio. Such improvements would give more fidelity to projections of regional subsurface water acidification rate. Overall, the use of a fine horizontal resolution ocean model can be recommended in next‐generation projection experiments with carbon cycles for the North Pacific Ocean.
Key Points
Storage of anthropogenic carbon in the western North Pacific Ocean is improved by using a 10‐km horizontal resolution ocean model
Improvement in the formation and distribution of the North Pacific subtropical mode water is a key
Use of 10‐km class high horizontal resolution ocean models is recommended as part of Earth system models with carbon cycles
The JAXA Hayabusa-2 mission was approved in 2010 and launched on December 3, 2014. The spacecraft will arrive at the near-Earth asteroid 162173 Ryugu (1999 JU3) in 2018 where it will perform a ...survey, land and obtainsurface material, then depart in December 2019 and return to Earth in December 2020. We observed Ryugu with the Herschel Space Observatory in April 2012 at far-infrared thermal wavelengths, supported by several ground-based observations to obtain optical lightcurves. We reanalysed previously published Subaru-COMICS and AKARI-IRC observations and merged them with a Spitzer-IRS data set. In addition, we used a large set of Spitzer-IRAC observations obtained in the period January to May, 2013. The data set includes two complete rotational lightcurves and a series of ten “point-and-shoot” observations, all at 3.6 and 4.5 μm. The almost spherical shape of the target together with the insufficient lightcurve quality forced us to combine radiometric and lightcurve inversion techniques in different ways to find the object’s spin-axis orientation, its shape and to improve the quality of the key physical and thermal parameters. Handling thermal data in inversion techniques remains challenging: thermal inertia, roughness or local structures influence the temperature distribution on the surface. The constraints for size, spin or thermal properties therefore heavily depend on the wavelengths of the observations. We find that the solution which best matches our data sets leads to this C class asteroid having a retrograde rotation with a spin-axis orientation of (λ = 310°−340°; β = −40° ± ~ 15°) in ecliptic coordinates, an effective diameter (of an equal-volume sphere) of 850 to 880 m, a geometric albedo of 0.044 to 0.050 and a thermal inertia in the range 150 to 300 J m-2 s-0.5 K-1. Based on estimated thermal conductivities of the top-layer surface in the range 0.1 to 0.6 W K-1 m-1, we calculated that the grain sizes are approximately equal to between 1 and 10 mm. The finely constrained values for this asteroid serve as a “design reference model”, which is currently used for various planning, operational and modelling purposes by the Hayabusa-2 team.
Background
In recent years, the use of Indocyanine Green (ICG) fluorescence-guided surgery during open and laparoscopic procedures has exponentially expanded across various clinical settings. The ...European Association of Endoscopic Surgery (EAES) initiated a consensus development conference on this topic with the aim of creating evidence-based statements and recommendations for the surgical community.
Methods
An expert panel of surgeons has been selected and invited to participate to this project. Systematic reviews of the PubMed, Embase and Cochrane libraries were performed to identify evidence on potential benefits of ICG fluorescence-guided surgery on clinical practice and patient outcomes. Statements and recommendations were prepared and unanimously agreed by the panel; they were then submitted to all EAES members through a two-rounds online survey and results presented at the EAES annual congress, Barcelona, November 2021.
Results
A total of 18,273 abstracts were screened with 117 articles included. 22 statements and 16 recommendations were generated and approved. In some areas, such as the use of ICG fluorescence-guided surgery during laparoscopic cholecystectomy, the perfusion assessment in colorectal surgery and the search for the sentinel lymph nodes in gynaecological malignancies, the large number of evidences in literature has allowed us to strongly recommend the use of ICG for a better anatomical definition and a reduction in post-operative complications.
Conclusions
Overall, from the systematic literature review performed by the experts panel and the survey extended to all EAES members, ICG fluorescence-guided surgery could be considered a safe and effective technology. Future robust clinical research is required to specifically validate multiple organ-specific applications and the potential benefits of this technique on clinical outcomes.
Background
Although there is some evidence that massage therapy, especially compression at myofascial trigger points (MTrPs), is effective for sub‐acute and chronic low back pain, the effectiveness ...of massage therapy with compression at MTrPs for acute low back pain has not been studied.
Methods
To evaluate the effectiveness of compression at MTrPs for acute low back pain, 63 patients with acute low back pain were randomly assigned to one of three groups: the MTrP group who received compression at MTrPs (N = 23), the non‐MTrP group who received compression at non‐trigger points (N = 21), and the effleurage massage group who received superficial massage (N = 19). The patients received the assigned treatment 3 times/week for 2 weeks. The subjective pain intensity in static and dynamic conditions and disability caused by low back pain were measured by the visual analogue scale (VAS) and Roland–Morris questionnaire (RMQ), respectively; along with the range of motion (ROM) at the lumbar region and pressure pain threshold (PPT) at trigger points before treatment (baseline), 1 week after the start of treatment, and 1 month after the end of treatment (follow‐up).
Results
Static and dynamic VAS score, PPT and ROM were significantly improved in the MTrP group compared with those in the non‐MTrP and effleurage groups.
Conclusions
These results indicate that compression at MTrPs is effective to treat acute low back pain compared with compression at non‐MTrPs and superficial massage.
For this article, a commentary is available at the Wiley Online Library.
Author Affiliation: (1) Department of Surgery, Section of Colon & Rectal Surgery, Weill Cornell Medicine/New York Presbyterian Hospital, 525 East 68th Street, K-801, 10065, New York, NY, USA (f) ...mim2035@med.cornell.edu Article History: Registration Date: 12/27/2020 Received Date: 10/19/2020 Accepted Date: 12/27/2020 Online Date: 01/18/2021 Byline:
Context. The near-Earth asteroid 3200 Phaethon (1983 TB) is an attractive object not only from a scientific viewpoint but also because of JAXA’s DESTINY+ target. The rotational lightcurve and spin ...properties were investigated based on the data obtained in the ground-based observation campaign of Phaethon. Aims. We aim to refine the lightcurves and shape model of Phaethon using all available lightcurve datasets obtained via optical observation, as well as our time-series observation data from the 2017 apparition. Methods. Using eight 12-m telescopes and an optical imager, we acquired the optical lightcurves and derived the spin parameters of Phaethon. We applied the lightcurve inversion method and SAGE algorithm to deduce the convex and non-convex shape model and pole orientations. Results. We analysed the optical lightcurve of Phaethon and derived a synodic and a sidereal rotational periods of 3.6039 h, with an axis ratio of a∕b = 1.07. The ecliptic longitude (λp) and latitude (βp) of the pole orientation were determined as (308°, −52°) and (322°, −40°) via two independent methods. A non-convex model from the SAGE method, which exhibits a concavity feature, is also presented.
Context. Near-Earth asteroid 162173 (1999 JU3) is a potential flyby and rendezvous target for interplanetary missions because of its easy-to-reach orbit. The physical and thermal properties of the ...asteroid are relevant for establishing the scientific mission goals and also important in the context of near-Earth object studies in general. Aims. Our goal was to derive key physical parameters such as shape, spin-vector, size, geometric albedo, and surface properties of 162173 (1999 JU3). Methods. With three sets of published thermal observations (ground-based N-band, Akari IRC, Spitzer IRS), we applied a thermophysical model to derive the radiometric properties of the asteroid. The calculations were performed for the full range of possible shape and spin-vector solutions derived from the available sample of visual lightcurve observations. Results. The near-Earth asteroid 162173 (1999 JU3) has an effective diameter of 0.87 ± 0.03 km and a geometric albedo of 0.070 ± 0.006. The χ2-test reveals a strong preference for a retrograde sense of rotation with a spin-axis orientation of λecl = 73°, βecl = −62° and Psid = 7.63 ± 0.01 h. The most likely thermal inertia ranges between 200 and 600 J m-2 s-0.5 K-1, about a factor of 2 lower than the value for 25143 Itokawa. This indicates that the surface lies somewhere between a thick-dust regolith and a rock/boulder/cm-sized, gravel-dominated surface like that of 25143 Itokawa. Our analysis represents the first time that shape and spin-vector information has been derived from a combined data set of visual lightcurves (reflected light) and mid-infrared photometry and spectroscopy (thermal emission).
Physical studies of asteroids depend on an availability of lightcurve data. Targets that are easy to observe and analyse naturally have more data available, so their synodic periods are confirmed ...from multiple sources. Also, thanks to availability of data from a number of apparitions, their spin and shape models can often be obtained, with a precise value of sidereal period and spin axis coordinates.
Almost half of bright (H≤11mag) main-belt asteroid population with known lightcurve parameters have rotation periods considered long (P≥12h) and are rarely chosen for photometric observations. There is a similar selection effect against asteroids with low lightcurve amplitudes (amax≤0.25mag). As a result such targets, though numerous in this brightness range, are underrepresented in the sample of spin and shape modelled asteroids. In the range of fainter targets such effects are stronger. These selection effects can influence what is now known about asteroid spin vs. size distribution, on asteroid internal structure and densities and on spatial orientation of asteroid spin axes.
To reduce both biases at the same time, we started a photometric survey of a substantial sample of those bright main-belt asteroids that displayed both features: periods longer than 12h, and amplitudes that did not exceed 0.25magnitude. First we aim at finding synodic periods of rotation, and after a few observed apparitions, obtaining spin and shape models of the studied targets.
As an initial result of our survey we found that a quarter of the studied sample (8 out of 34 targets) have rotation periods different from those widely accepted. We publish here these newly found period values with the lightcurves.
The size/frequency plot might in reality look different in the long-period range. Further studies of asteroid spins, shapes, and structure should take into account serious biases that are present in the parameters available today. Photometric studies should concentrate on such difficult targets to remove the biases and to complete the sample.
•Observing selection effects in asteroid spins and shapes are studied.•Asteroids with long periods and low amplitudes lack multi-apparition data.•We conduct an observing campaign to counteract these effects.•1/4 of the sample occurred to have substantially different periods from LCDB values.•Refined periods are mostly longer, and must largely be primordial.
Densification in the ocean interior upon mixing at high latitudes, due to the nonlinear equation of state (EoS) of seawater, enhances the meridional overturning circulation (MOC). However, recent ...calculations using numerical simulations of global ocean circulation have shown that the nonlinearity of the EoS leads to a sink of gravitational potential energy (PE), from which one might infer that there is less energy available to be released to the MOC. Here the available PE (APE) budget of the global ocean is investigated using a numerical model with a nonlinear EoS under a realistic configuration. The results show that, while the nonlinearity of the EoS leads to a loss of gravitational PE, it is a source of APE. For the model used in this study, nonlinearity of the EoS is as significant as surface buoyancy forcing in generating APE.
Key Points
While the nonlinearity of the EoS leads to a loss of PE, it is a source of APEThe net nonlinear effects are a substantial fraction of total APE productionThe nonlinear effects of EoS on APE is consistent with its effect on the MOC
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