41 research outputs found
Using blogs to make peer-reviewed research more accessible
Discipline-based education researchers produce knowledge that aims to help
instructors improve student learning and educational outcomes. Yet, the
information produced may not even reach the educators it is intended to
influence. Prior work has found that instructors often face barriers to
implementing practices in peer-reviewed literature. Some of these barriers are
related to accessing the knowledge in the first place such as difficulty
finding and understanding research and a lack of time to do so. To lower these
barriers, we created an online blog, PERbites, that summarizes recent
discipline-based education research in short posts that use plain language.
Having covered nearly 100 papers to date, we conducted a survey to see if we
were addressing the need we had originally set out to address. We posted a
23-item survey on our website and received 24 usable responses. The results
suggested that readers do generally agree that we are meeting our original
goals. Readers reported that our articles were easier to understand and used
more plain language than a typical discipline-based education research (DBER)
journal article. At the same time, readers thought that all the important
information was still included. Finally, readers said that this approach helped
them keep up with DBER studies and read about papers they otherwise would not
have. However, most readers did not indicate they changed their teaching and
research practice as a result of reading our blog. Our results suggest that
alternative methods of sharing research (e.g., non-peer reviewed publications
or conference talks) can be an effective method of connecting research with
practitioners, and future work should consider how we as a community might
build on these efforts to ensure education research can make meaningful changes
in the classroom.Comment: Published in the Proceedings of the 2022 Physics Education Research
Conference, Grand Rapids, MI, US July 13th - July 14t
Can Extreme Bacteria Teach Us About Extraterrestrial Life?
Have you ever wondered if there is life beyond Earth? Scientists have been studying this topic for a long time and believe the answer might lie in extremophilic microbes, small organisms that thrive in extreme environments. In a 2022 study, scientists took extremophilic microbes from an analogue environment, or place on Earth similar to Mars, and put them in simulated Martian conditions. After exposing them to higher ultraviolet radiation levels, low oxygen levels, a dry atmosphere, and moisture-free Mars-like soil, these microbes still were able to survive. This research is important in helping us understand if Mars can house life and give us clues into what that life might look like beyond Earth
Speckle Space-Time Covariance in High-Contrast Imaging
We introduce a new framework for point-spread function (PSF) subtraction
based on the spatio-temporal variation of speckle noise in high-contrast
imaging data where the sampling timescale is faster than the speckle evolution
timescale. One way that space-time covariance arises in the pupil is as
atmospheric layers translate across the telescope aperture and create small,
time-varying perturbations in the phase of the incoming wavefront. The
propagation of this field to the focal plane preserves some of that space-time
covariance. To utilize this covariance, our new approach uses a
Karhunen-Lo\'eve transform on an image sequence, as opposed to a set of single
reference images as in previous applications of Karhunen-Lo\'eve Image
Processing (KLIP) for high-contrast imaging. With the recent development of
photon-counting detectors, such as microwave kinetic inductance detectors
(MKIDs), this technique now has the potential to improve contrast when used as
a post-processing step. Preliminary testing on simulated data shows this
technique can improve contrast by at least 10-20% from the original image, with
significant potential for further improvement. For certain choices of
parameters, this algorithm may provide larger contrast gains than spatial-only
KLIP.Comment: Accepted to A
Astrobites as a Community-led Model for Education, Science Communication, and Accessibility in Astrophysics
Support for early career astronomers who are just beginning to explore
astronomy research is imperative to increase retention of diverse practitioners
in the field. Since 2010, Astrobites has played an instrumental role in
engaging members of the community -- particularly undergraduate and graduate
students -- in research. In this white paper, the Astrobites collaboration
outlines our multi-faceted online education platform that both eases the
transition into astronomy research and promotes inclusive professional
development opportunities. We additionally offer recommendations for how the
astronomy community can reduce barriers to entry to astronomy research in the
coming decade
Surveying Nearby Brown Dwarfs with HGCA: Direct Imaging Discovery of a Faint, High-Mass Brown Dwarf Orbiting HD 176535 A
Brown dwarfs with well-measured masses, ages and luminosities provide direct
benchmark tests of substellar formation and evolutionary models. We report the
first results from a direct imaging survey aiming to find and characterize
substellar companions to nearby accelerating stars with the assistance of the
Hipparcos-Gaia Catalog of Accelerations (HGCA). In this paper, we present a
joint high-contrast imaging and astrometric discovery of a substellar companion
to HD 176535 A, a K3.5V main-sequence star aged approximately
Gyrs at a distance of pc. In advance of
our high-contrast imaging observations, we combined precision HARPS RVs and
HGCA astrometry to predict the potential companion's location and mass. We
thereafter acquired two nights of KeckAO/NIRC2 direct imaging observations in
the band, which revealed a companion with a contrast of mag at a projected separation of 0.\!\!''35
(13 AU) from the host star. We revise our orbital fit by incorporating
our dual-epoch relative astrometry using the open-source MCMC orbit fitting
code . HD 176535 B is a new benchmark dwarf useful for constraining
the evolutionary and atmospheric models of high-mass brown dwarfs. We found a
luminosity of and a model-dependent
effective temperature of K for HD 176535 B. Our dynamical mass
suggests that some substellar evolutionary models may be underestimating
luminosity for high-mass T dwarfs. Given its angular separation and luminosity,
HD 176535 B would make a promising candidate for Aperture Masking
Interferometry with JWST and GRAVITY/KPIC, and further spectroscopic
characterization with instruments like the CHARIS/SCExAO/Subaru integral field
spectrograph
Second asymptomatic carotid surgery trial (ACST-2): a randomised comparison of carotid artery stenting versus carotid endarterectomy
Background: Among asymptomatic patients with severe carotid artery stenosis but no recent stroke or transient cerebral ischaemia, either carotid artery stenting (CAS) or carotid endarterectomy (CEA) can restore patency and reduce long-term stroke risks. However, from recent national registry data, each option causes about 1% procedural risk of disabling stroke or death. Comparison of their long-term protective effects requires large-scale randomised evidence. Methods: ACST-2 is an international multicentre randomised trial of CAS versus CEA among asymptomatic patients with severe stenosis thought to require intervention, interpreted with all other relevant trials. Patients were eligible if they had severe unilateral or bilateral carotid artery stenosis and both doctor and patient agreed that a carotid procedure should be undertaken, but they were substantially uncertain which one to choose. Patients were randomly allocated to CAS or CEA and followed up at 1 month and then annually, for a mean 5 years. Procedural events were those within 30 days of the intervention. Intention-to-treat analyses are provided. Analyses including procedural hazards use tabular methods. Analyses and meta-analyses of non-procedural strokes use Kaplan-Meier and log-rank methods. The trial is registered with the ISRCTN registry, ISRCTN21144362. Findings: Between Jan 15, 2008, and Dec 31, 2020, 3625 patients in 130 centres were randomly allocated, 1811 to CAS and 1814 to CEA, with good compliance, good medical therapy and a mean 5 years of follow-up. Overall, 1% had disabling stroke or death procedurally (15 allocated to CAS and 18 to CEA) and 2% had non-disabling procedural stroke (48 allocated to CAS and 29 to CEA). Kaplan-Meier estimates of 5-year non-procedural stroke were 2·5% in each group for fatal or disabling stroke, and 5·3% with CAS versus 4·5% with CEA for any stroke (rate ratio [RR] 1·16, 95% CI 0·86–1·57; p=0·33). Combining RRs for any non-procedural stroke in all CAS versus CEA trials, the RR was similar in symptomatic and asymptomatic patients (overall RR 1·11, 95% CI 0·91–1·32; p=0·21). Interpretation: Serious complications are similarly uncommon after competent CAS and CEA, and the long-term effects of these two carotid artery procedures on fatal or disabling stroke are comparable. Funding: UK Medical Research Council and Health Technology Assessment Programme