260 research outputs found
Nova Sagittarii 1943 (V1148 Sgr): A Luminous Red Nova?
Nova Sagittarii 1943 (V1148 Sgr) was an 8th-mag optical transient that was
unusual in having a late-type spectrum during its outburst, in striking
contrast to the normal high-excitation spectra seen in classical novae.
Unfortunately, only an approximate position was given in the discovery
announcement, hampering follow-up attempts to observe its remnant. We have
identified the nova on two photographic plates in the Harvard archive, allowing
us to determine a precise astrometric position. Apart from these two plates,
obtained in 1943 and 1944, none of the photographs in the Harvard collection,
from 1897 to 1950, show V1148 Sgr to limits as faint as g ~ 18.3. Modern deep
images show a candidate remnant at i ~ 19.2, lying only 0".26 from the site of
the nova. V1148 Sgr may have been a luminous red nova (LRN), only the sixth one
known in the Milky Way. However, it lacks the near- and mid-infrared excesses,
and millimeter-wave emission, seen in other LRNe, leaving its nature uncertain.
We urge spectroscopy of the candidate remnant.Comment: Accepted by Astronomical Journa
Catalytic treatment of pharmaceutical contaminants for wastewater reclamation and reuse
Water quality is one of the most pressing issues for Oklahomans. Hence, wastewater is being reused to increase water availability. However, wastewater treatment plants do not remove all contaminants in wastewater which makes it unsuitable to reuse without further treatment. For example, antibiotics can go up to 85% undigested through the human body and persist in wastewater effluent. Ethylene cross bridged tetraazomamacrocycle catalysts are a potential treatment option to eliminate these contaminants to enable safe and efficient water reuse. The overall goal of this project was to analyze the extent that antibiotics can degrade with the help of catalysts.Findings from this work allow for safe reuse of wastewater that can provide Oklahomans with water for drinking as well as irrigation. In addition, these findings also address growing concerns of antibiotic resistance, a major public health threat.Biosystems and Agricultural Engineerin
Virus-mediated EpoR76E gene therapy preserves vision in a glaucoma model by modulating neuroinflammation and decreasing oxidative stress
Learning outcomes, learning support, and cohort cohesion on a virtual field trip: an analysis of student and staff perceptions
The rise seen in the use of the virtual field trip in 2020 and 2021 due to the global COVID-19 pandemic was unprecedented. Virtual field trips aim to replicate the learning outcomes and experiences of actual field trips by providing a digital alternative to in-field courses. They provide valuable opportunities for those unable to visit the field and alternative learning experiences for those that can. However, understanding their efficacy in terms of learning outcomes, the effectiveness of the learning support offered, and cohort cohesion generally remains untested. Here, we show how negative aspects of a virtual field trip both pre- and post-course are countered by positive outcomes in terms of the breadth of learning outcomes and experience. As part of our analysis, we tested methods to mitigate barriers to inclusion and learning on a virtual field trip, including internet connectivity and hardware access; the use of printed workbooks; and limitations to interaction, support, and cohort cohesion. Our results show that, although negative perceptions (as evidenced by questionnaire responses) are dominant, with 71 % of the 27 pre-course respondents and 88 % of the 21 post-course respondents commenting on these aspects across both student and staff cohorts, positive aspects of virtual field trips (43 %–57 %) also feature highly. Students show a positive shift in their perception of online teaching and learning over the course, with positive comments moving from 19 % pre-course to 71 % post-course, whereas positive comments by staff are low both pre- and post-course (at 14 %). Printed workbooks, staff-to-student ratios, and interaction are received positively. Overall, we find that negative perceptions of virtual field trips pre- and post-course exist but that both students and staff also identify positive elements, including the breadth of learning outcomes, particularly regarding data synthesis and analysis. We suggest ways to learn from these findings in order to design virtual field trips that deliver effectively in blended learning environments for the benefit of all.</p
Radio observations of the planetary nebula around the OH/IR Star OH354.88-0.54 (V1018 Sco)
We present radio observations of the unique, recently formed, planetary
nebula (PN) associated with a very long-period OH/IR variable star V1018 Sco
that is unequivocally still in its asymptoticgiant branch phase. Two regions
within the optical nebula are clearly detected in nonthermal radio continuum
emission, with radio spectral indices comparable to those seen in
colliding-wind Wolf-Rayet binaries. We suggest that these represent shocked
interactions between the hot, fast stellar wind and the cold nebular shell that
represents the PN's slow wind moving away from the central star. This same
interface produces both synchrotron radio continuum and the optical PN
emission. The fast wind is neither spherical in geometry nor aligned withany
obvious optical or radio axis. We also report the detection of transient H2O
maser emission in this nebula.Comment: 11 pages, LaTeX (mn2e.cls), incl. 9 PostScript (ps or eps) figures
and 2 tables. Accepted by MNRA
Confirmation of Color Dependent Centroid Shift Measured After 1.8 years with HST
We measured precise masses of the host and planet in OGLE-2003-BLG-235
system, when the lens and source were resolving, with 2018 Keck high resolution
images. This measurement is in agreement with the observation taken in 2005
with the Hubble Space Telescope (HST). In 2005 data, the lens and sources were
not resolved and the measurement was made using color-dependent centroid shift
only. Nancy Grace Roman Space Telescope will measure masses using data
typically taken within 3-4 years of the peak of the event which is much shorter
baseline compared to most of the mass measurements to date. Hence, color
dependent centroid shift will be one of the primary method of mass measurements
for Roman. Yet, mass measurements of only two events (OGLE-2003-BLG-235 and
OGLE-2005-BLG-071) are done using the color dependent centroid shift method so
far. The accuracy of the measurements using this method are neither completely
known nor well studied. The agreement of Keck and HST results, shown in this
paper, is very important since this agreement confirms the accuracy of the mass
measurements determined at a small lens-source separation using the color
dependent centroid shift method. This also shows that with >100 high resolution
images, Roman telescope will be able to use color dependent centroid shift at
3-4 years time baseline and produce mass measurements. We find that
OGLE-2003-BLG-235 is a planetary system consists of a 2.34 +- 0.43M_Jup planet
orbiting a 0.56 +- 0.06M_Sun K-dwarf host star at a distance of 5.26 +- 0.71
kpc from the Sun.Comment: Submitted to AJ, under review. arXiv admin note: substantial text
overlap with arXiv:2009.0232
Equatorial Pacific coral geochemical records show recent weakening of the Walker Circulation
Equatorial Pacific ocean-atmosphere interactions affect climate globally, and a key component of the coupled system is the Walker Circulation, which is driven by sea surface temperature (SST) gradients across the equatorial Pacific. There is conflicting evidence as to whether the SST gradient and Walker Circulation have strengthened or weakened over the late twentieth century. We present new records of SST and sea surface salinity (SSS) spanning 1959-2010 based on paired measurements of Sr/Ca and δ18O in a massive Porites coral from Butaritari atoll in the Gilbert Islands, Republic of Kiribati, in the central western equatorial Pacific. The records show 2-7 year variability correlated with the El Niño-Southern Oscillation (ENSO) and corresponding shifts in the extent of the Indo-Pacific Warm Pool, and decadal-scale signals related to the Pacific Decadal Oscillation and the Pacific Warm Pool Index. In addition, the Butaritari coral records reveal a small but significant increase in SST (0.39°C) from 1959 to 2010 with no accompanying change in SSS, a trend that persists even when ENSO variability is removed. In contrast, larger increases in SST and SSS are evident in coral records from the equatorial Pacific Line Islands, located east of Butaritari. Taken together, the equatorial Pacific coral records suggest an overall reduction in the east-west SST and SSS gradient over the last several decades, and a recent weakening of the Walker Circulation
Automated virtual reality cognitive therapy for people with psychosis: Protocol for a qualitative investigation using peer research methods
BACKGROUND:
Many people with psychosis experience difficulties in everyday social situations. Anxiety can make life challenging, leading to withdrawal. Cognitive therapy, using active in vivo learning, enables people to overcome fears. These treatments are not readily available to people with psychosis. Automated virtual reality (VR) therapy is a potential route to increase accessibility. The gameChange automated VR cognitive therapy is designed to help people overcome anxious avoidance and build confidence in everyday social situations. A virtual coach guides the person through the treatment. Understanding user experience is key to facilitating future implementation. Peer research methods, in which people with lived experience of the issues being studied are involved in collecting and analyzing data, may be useful in developing this understanding. This encourages researchers to draw on their lived experience to explore participant perspectives and co-create knowledge.
OBJECTIVE:
The primary objective is to use a peer research approach to explore the participant experience of a novel automated VR therapy for anxious social avoidance. This includes understanding (1) the experience of anxious social avoidance in people with psychosis, (2) the experience of the gameChange automated VR cognitive therapy, and (3) any potential impact of the therapy in people’s lives. This will inform future implementation strategies. The secondary objective is to explore how peer research can be used to co-create knowledge.
METHODS:
Semistructured interviews will be conducted with approximately 25 people with psychosis participating in the gameChange trial (ISRCTN17308399). Participants will be recruited from the five trial centers based in National Health Service mental health trusts across England. Interviews will be conducted by two researchers. One is a peer researcher with similar lived experience to the trial participants. The other has lived experiences of mental health issues that do not directly overlap with those of the trial participants. Interview questions will focus on an individual’s experience of anxious social avoidance, experiences of participating in the gameChange VR therapy, and any changes or impact following therapy. The interview schedule was developed in collaboration with the gameChange Lived Experience Advisory Panel (LEAP), comprising 10 project advisors with lived experience of psychosis. Interpretative phenomenological analysis and template analysis will be used to explore individual accounts. The LEAP will contribute to the analysis.
RESULTS:
Data collection will be conducted from April to September 2021, and analysis will be conducted from June to October 2021. As of September 28, 2021, 20 participants had been interviewed, and coding is underway.
CONCLUSIONS:
The study, employing a peer research approach, may provide a unique insight into the experiences of anxious social avoidance in people with psychosis and its treatment using automated VR therapy. This will inform potential future implementation of VR automated therapies in mental health services
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