Impacts due to near-Earth objects (NEOs) are responsible for causing some of the great mass extinctions on Earth. While nearly all NEOs of diameter > 1 km, capable of causing a global climatic ...disaster, have been discovered and have negligible chance of impacting in the near future, we are far from completion in our effort to detect and characterize smaller objects. In an effort to test our preparedness to respond to a potential NEO impact threat, we conducted a community-led global planetary defense exercise with support from the NASA Planetary Defense Coordination Office. The target of our exercise was 2012 TC4, the ~10 m diameter asteroid that made a close pass by the Earth on 2017 October 12 at a distance of about 50,000 km. The goal of the TC4 observing campaign was to recover, track, and characterize 2012 TC4 as a hypothetical impactor in order to exercise the global planetary defense system involving observations, modeling, prediction, and communication. We made three attempts with the Very Large Telescope (VLT) on 2017 July 27, 31 and on 2017 August 5 and recovered 2012 TC4 within its ephemeris uncertainty at 2.2 arcmin from the nominal prediction. At visual magnitude V = 27, the recovery of 2012 TC4 is the faintest NEA detection thus far. If an impact during the 2017 close approach had been possible based on the 2012 astrometric data, these recovery observations would have been sufficient to confirm or rule out the impact. The first automatic detection by a survey (Pan-STARRS1) was on September 25, which is the earliest that 2012 TC4 would have been discovered in survey mode, if it had not been discovered in 2012. We characterized 2012 TC4 using photometry, spectroscopy and radar techniques. Based on photometric observations, we determined a rotation period of 12.2 min with an amplitude of 0.9 magnitudes. An additional lower amplitude period was detected, indicating that 2012 TC4 was in a state of non-principal axis rotation. The combined visible and near-infrared spectrum puts it in the taxonomic X-class. Radar images at 1.875 m resolution placed only a few range pixels on the asteroid, reveal an angular, asymmetric, and elongated shape, and establish that 2012 TC4 is less than 20 m on its long axis. We estimate a circular polarization ratio of 0.57 + -0.08 that is relatively high among NEAs observed to date by radar. We also performed a probabilistic impact risk assessment exercise for hypothetical impactors based on the 2012 TC4 observing campaign. This exercise was performed as part of ongoing efforts to advance effective impact risk models and assessment processes for planetary defense. The 2012 TC4 close approach provided a valuable opportunity to test the application of these methods using realistically evolving observational data to define the modeling inputs. To this end, risk assessments were calculated at several epochs before and during the close approach, incorporating new information about 2012 TC4 as it became available. Two size ranges were assessed—one smaller size range (H = 26.7) similar to the actual 2012 TC4, and one larger size range (H = 21.9) to produce a greater-damage scenario for risk assessment. Across the epochs, we found that only irons caused significant damage for smaller size. For the larger size case, however, hydrous stones caused the greatest damage, anhydrous stones caused the least damage, and irons caused moderate damage. We note that the extent of damage depends on composition in different size regimes and, after astrometry, size is the most important physical property to determine for an incoming object.
•We conducted a community-led global planetary defense exercise•The goal was to recover, track, and characterize 2012 TC4 as a hypothetical impactor•We found that after astrometric observations, size of the asteroid is the most important property for an impactor
HD 163296 is a Herbig Ae star that underwent a dramatic∼0.8 magnitude drop in brightness in the V photometric band in 2001 and a brightening in the near-IR in 2002. Because the star possesses ...Herbig–Haro objects traveling in out flowing bipolar jets, it was suggested that the drop in brightness was due to a clump of dust entrained in a disk wind, blocking the line of sight toward the star. In order to quantify this hypothesis, we investigated the brightness drop at visible wavelengths and the brightening at near-IR wavelengths of HD 163296 using the Monte Carlo Radiative Transfer Code,HOCHUNK3D. We created three models to understand the events. Model 1 describes the quiescent state of the system. Model 2 describes the change in structure that led to the drop in brightness in 2001.Model 3 describes the structure needed to produce the observed 2002 brightening of the near-IR wavelengths. Models 2 and 3 utilize a combination of a disk wind and central bipolar flow. By introducing a filled bipolar cavity in Models 2 and 3, we were able to successfully simulate a jet-like structure for the star with a disk wind and created the drop and subsequent increase in brightness of the system. On the other hand, when the bipolar cavity is not filled, Model 1 replicates the quiescent state of the system
In an online study of purchase intent based on Chinese menu inspection, explicitly noticing grammatical errors by hotspot click was more detrimental to judgments of quality than implicit detection by ...error estimation. When they estimated errors in a survey question (ordinal measure), participants who reported many (more than nine) errors had lower purchase intent and ratings of quality compared to those with few (about six) or no errors. However, with the more novel, continuous measure based on hotspot detection, participant purchase intent did not decrease as the number of errors noticed increased. Importantly, there were no differences between the hotspot and no hot spot conditions on any of the variables of interest. Surprisingly throughout, detection of more errors was associated with lower self-ratings of xenophobia. Despite having similar levels of hotspot accuracy and efficiency, people with high xenophobia were more biased against reporting errors (i.e., they responded conservatively) than people with low xenophobia. High xenophobia was unrelated to quality and yet those with high xenophobia had significantly lower purchase intent. In summary, method of error detection did not alter results and many errors impacted measures of quality. People with high xenophobia tend not to notice errors but choose not to support a Chinese restaurant, irrespective of perceptions of quality.
Attentional biases to emotional words have frequently been investigated using an emotional Stroop task. Researchers are interested in examining when the affective dimension of the word, although ...irrelevant to the task, interferes with the color-naming task (e.g., longer reaction times to emotional words relative to neutral words). This interference is referred to as an emotional Stroop effect. Previous research has primarily focused on negative and/ or taboo words, not positive words or arousal. Furthermore, previous investigations have resulted in mixed findings due to presentation (e.g., blocked vs. mixed), or a lack of sensitivity in traditional measures (e.g., reaction time & accuracy). In the present study, we used computer mouse tracking to investigate whether taboo Stroop effects (Experiment 1) were similar to emotional Stroop effects (Experiment 2). In Experiments 1 and 2, we used a mixed presentation and participants were instructed to respond to the font color of each word by clicking on response options on the screen. In Experiment 2, we examined the effects across all levels of valence (negative, neutral, positive) and arousal (low, medium, high). In Experiment 1, we found that taboo words were responded to less efficiently than neutral words. In Experiment 2, we found that negative words were responded to less efficiently than neutral words, but only for low arousal words. Interestingly, for high arousing words, there was a trend that positive words were responded to less efficiently than neutral words. The results of the current study have important theoretical implications for theories of emotional language processing.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
We present Gemini Planet Imager polarized intensity imagery of HD 100453 in Y, J, and K1 bands that reveals an inner gap (9-18 au), an outer disk (18-39 au) with two prominent spiral arms, and two ...azimuthally localized dark features that are also present in Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) total intensity images. Spectral energy distribution fitting further suggests that the radial gap extends to 1 au. The narrow, wedge-like shape of the dark features appears similar to predictions of shadows cast by an inner disk that is misaligned with respect to the outer disk. Using the Monte Carlo radiative transfer code HOCHUNCK3D, we construct a model of the disk that allows us to determine its physical properties in more detail. From the angular separation of the features, we measure the difference in inclination between the disks (45deg) and their major axes, PA = 140deg east of north for the outer disk, and 100deg for the inner disk. We find an outer-disk inclination of 25deg +/- 10deg from face-on, in broad agreement with the Wagner et al. measurement of 34deg. SPHERE data in J and H bands indicate a reddish disk, which indicates that HD 100453 is evolving into a young debris disk.
OBJECTIVETo compare the analgesic effects of stimulation of the anterior cingulate cortex (ACC) or the posterior superior insula (PSI) against sham deep (d) repetitive (r) transcranial magnetic ...stimulation (TMS) in patients with central neuropathic pain (CNP) after stroke or spinal cord injury in a randomized, double-blinded, sham-controlled, 3-arm parallel study.
METHODSParticipants were randomly allocated into the active PSI-rTMS, ACC-rTMS, sham-PSI-rTMS, or sham-ACC-rTMS arms. Stimulations were performed for 12 weeks, and a comprehensive clinical and pain assessment, psychophysics, and cortical excitability measurements were performed at baseline and during treatment. The main outcome of the study was pain intensity (numeric rating scale NRS) after the last stimulation session.
RESULTSNinety-eight patients (age 55.02 ± 12.13 years) completed the study. NRS score was not significantly different between groups at the end of the study. Active rTMS treatments had no significant effects on pain interference with daily activities, pain dimensions, neuropathic pain symptoms, mood, medication use, cortical excitability measurements, or quality of life. Heat pain threshold was significantly increased after treatment in the PSI-dTMS group from baseline (1.58, 95% confidence interval CI 0.09–3.06) compared to sham-dTMS (−1.02, 95% CI −2.10 to 0.04, p = 0.014), and ACC-dTMS caused a significant decrease in anxiety scores (−2.96, 95% CI −4.1 to −1.7) compared to sham-dTMS (−0.78, 95% CI −1.9 to 0.3; p = 0.018).
CONCLUSIONSACC- and PSI-dTMS were not different from sham-dTMS for pain relief in CNP despite a significant antinociceptive effect after insular stimulation and anxiolytic effects of ACC-dTMS. These results showed that the different dimensions of pain can be modulated in humans noninvasively by directly stimulating deeper SNC cortical structures without necessarily affecting clinical pain per se.
CLINICALTRIALS.GOV IDENTIFIER:NCT01932905.
We analyze the CORALIE/HARPS sample of exoplanets (Mayor et al. 2011) found by the Doppler radial velocity method for signs of the predicted "desert" at 10-\(100 M_\odot\) caused by runaway gas ...accretion at semimajor axes of \(< 3\,\)AU. We find that these data are not consistent with this prediction. This result is similar to the finding by the MOA gravitational microlensing survey that found no desert in the exoplanet distribution for exoplanets in slightly longer period orbits and somewhat lower host masses (Suzuki et al. 2018). Together, these results imply that the runaway accretion scenario of the core accretion theory does not have a large influence on the final mass and semimajor axis distribution of exoplanets.
The efficacy of tocilizumab was tested in a randomized, controlled trial involving patients with Covid-19 who had fever, pulmonary infiltrates, or a need for supplemental oxygen. The treatment had no ...significant effect on disease progression, independence from supplemental oxygen, or death.
Reliable detections of Earth-sized planets in the habitable zone remain elusive in the Kepler sample, even for M dwarfs. The Kepler sample was once thought to contain a considerable number of M dwarf ...stars (\(T_\mathrm{eff} < 4000\) K), which hosted enough Earth-sized (\(0.5,1.5\) R\(_\oplus\)) planets to estimate their occurrence rate (\(\eta_\oplus\)) in the habitable zone. However, updated stellar properties from Gaia have shifted many Kepler stars to earlier spectral type classifications, with most stars (and their planets) now measured to be larger and hotter than previously believed. Today, only one partially-reliable Earth-sized candidate remains in the optimistic habitable zone, and zero in the conservative zone. Here we performed a new investigation of Kepler's Earth-sized planets orbiting M dwarf stars, using occurrence rate models with considerations of updated parameters and candidate reliability. Extrapolating our models to low instellations, we found an occurrence rate of \(\eta_\oplus={8.58}_{-8.22}^{+17.94}\%\) for the conservative habitable zone (and \({14.22}_{-12.71}^{+24.96}\%\) for the optimistic), consistent with previous works when considering the large uncertainties. Comparing these estimates to those from similarly comprehensive studies of Sun-like stars, we found that the current Kepler sample does not offer evidence to support an increase in \(\eta_\oplus\) from FGK to M stars. While the Kepler sample is too sparse to resolve an occurrence trend between early and mid-to-late M dwarfs for Earth-sized planets, studies including larger planets and/or data from the K2 and TESS missions are well-suited to this task.
Planet formation is expected to be severely limited in disks of low metallicity, owing to both the small solid mass reservoir and the low opacity accelerating the disk gas dissipation. While previous ...studies have found a weak correlation between the occurrence rates of small planets (\(\leq\)4R\(_\oplus\)) and stellar metallicity, so far no studies have probed below the metallicity limit beyond which planet formation is predicted to be suppressed. Here, we constructed a large catalog of ~110,000 metal-poor stars observed by the TESS mission with spectroscopically-derived metallicities, and systematically probed planet formation within the metal-poor regime (Fe/H \(\leq\) -0.5) for the first time. Extrapolating known higher-metallicity trends for small, short-period planets predicts the discovery of ~68 superEarths around these stars (~85,000 stars) after accounting for survey completeness; however, we detect none. As a result, we have placed the most stringent upper limit on super-Earth occurrence rates around metal-poor stars (-0.75 < Fe/H \(\leq\) -0.5) to date, \(\leq\) 1.67%, a statistically significant (p-value=0.000685) deviation from the prediction of metallicity trends derived with Kepler and K2. We find a clear host star metallicity cliff for super-Earths that could indicate the threshold below which planets are unable to grow beyond an Earth-mass at short orbital periods. This finding provides a crucial input to planet formation theories, and has implications for the small planet inventory of the Galaxy and the galactic epoch at which the formation of small planets started.
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