142 research outputs found
Behaviorally informed policies for household financial decisionmaking
This is the final version of the article. Available from the publisher via the DOI in this record.Low incomes, limited financial literacy, fraud, and deception are just a few of the many intractable economic and social factors that contribute to the financial difficulties that households face today. Addressing these issues directly is difficult and costly. But poor financial outcomes also result from systematic psychological tendencies, including imperfect optimization, biased judgments and preferences, and susceptibility to inïŹuence by the actions and opinions of others. Some of these psychological tendencies and the problems they cause may be countered by policies and interventions that are both low cost and scalable. We detail the ways that these behavioral factors contribute to consumers' financial mistakes and suggest a set of interventions that the federal government, in its dual roles as regulator and employer, could feasibly test or implement to improve household financial outcomes in a variety of domains: retirement, short-term savings, debt management, the take-up of government benefits, and tax optimization
Probing the Sub-Parsec Dust of a Supermassive Black Hole with the Tidal Disruption Event AT 2020mot
AT 2020mot is a typical UV/optical tidal disruption event (TDE) with no radio
or X-ray signatures in a quiescent host. We find an i-band excess and
re-brightening along the decline of the light curve which could be due to two
consecutive dust echoes from a TDE. We model our observations following van
Velzen et al. (2016) and find that the near-infrared light curve can be
explained by concentric rings of thin dust within 0.1 parsecs of a 6e6
M supermassive black hole (SMBH), among the smallest scales at which
dust has been inferred near SMBHs. We find dust covering factors of order fc
2%, much lower than found for dusty tori of active galactic nuclei.
These results highlight the potential of TDEs for uncovering the environments
around black holes when including near-infrared observations in high-cadence
transient studies
Operational Research in Education
Operational Research (OR) techniques have been applied, from the early stages of the discipline, to a wide variety of issues in education. At the government level, these include questions of what resources should be allocated to education as a whole and how these should be divided amongst the individual sectors of education and the institutions within the sectors. Another pertinent issue concerns the efficient operation of institutions, how to measure it, and whether resource allocation can be used to incentivise efficiency savings. Local governments, as well as being concerned with issues of resource allocation, may also need to make decisions regarding, for example, the creation and location of new institutions or closure of existing ones, as well as the day-to-day logistics of getting pupils to schools. Issues of concern for managers within schools and colleges include allocating the budgets, scheduling lessons and the assignment of students to courses. This survey provides an overview of the diverse problems faced by government, managers and consumers of education, and the OR techniques which have typically been applied in an effort to improve operations and provide solutions
Condom Versus Indwelling Urinary Catheters: A Randomized Trial
To compare condom and indwelling urinary catheters in terms of infection risk and patient satisfaction. DESIGN : A prospective, randomized, unblinded, controlled trial. SETTING : An academically affiliated Veterans Affairs Medical Center. PARTICIPANTS : Hospitalized men aged 40 and older who required a urinary collection device. MEASUREMENTS : The incidence of adverse outcomes (bacteriuria, symptomatic urinary tract infection (UTI), or death) and patient device-related satisfaction as determined according to a questionnaire. Dementia status was recorded to assess effect modification by the presence of dementia. RESULTS : Seventy-five subjects were randomized: 41 receiving an indwelling catheter and 34 a condom catheter. The incidence of an adverse outcome was 131/1,000 patient-days with an indwelling catheter and 70/1,000 patient-days with a condom catheter ( P =.07). The median time to an adverse event was 7 days in the indwelling group and 11 days in the condom group. After adjusting for other risk factors, it was found that condom catheter use reduced adverse outcomes ( P =.04). Patients without dementia who had an indwelling catheter were approximately five times as likely to develop bacteriuria or symptomatic UTI or to die (hazard ratio=4.84, 95% confidence interval=1.46â16.02) as those with a condom catheter ( P =.01). Patients reported that condom catheters were more comfortable ( P =.02) and less painful ( P =.02) than indwelling catheters. CONCLUSION : The use of condom catheters is less likely to lead to bacteriuria, symptomatic UTI, or death than the use of indwelling catheters. This protection is especially apparent in men without dementia.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66301/1/j.1532-5415.2006.00785.x.pd
Evolution of A Peculiar Type Ibn Supernova SN 2019wep
We present a high-cadence short term photometric and spectroscopic monitoring
campaign of a type Ibn SN 2019wep, which is one of the rare SN Ibn after SNe
2010al and 2019uo to display signatures of flash ionization (\ion{He}{2},
\ion{C}{3}, \ion{N}{3}). We compare the decline rates and rise time of SN
2019wep with other SNe Ibn and fast transients. The post-peak decline in all
bands (0.1 mag d) are consistent with SNe Ibn but less than the fast
transients. On the other hand, the m values are slightly lower
than the average values for SNe Ibn but consistent with the fast transients.
The rise time is typically shorter than SNe Ibn but longer than fast
transients. SN 2019wep lies at the fainter end of SNe Ibn but possesses an
average luminosity amongst the fast transients sample. The peculiar color
evolution places it between SNe Ib and the most extreme SNe Ibn. The bolometric
light curve modelling shows resemblance with SN 2019uo with ejecta masses
consistent with SNe Ib. SN 2019wep belongs to the "P cygni" sub-class of SNe
Ibn and shows faster evolution in line velocities as compared to the "emission"
sub-class. The post-maximum spectra show close resemblance with ASASSN-15ed
hinting it to be of SN Ib nature. The low \ion{He}{1} CSM velocities and
residual H further justifies it and gives evidence of an intermittent
progenitor between WR and LBV star.Comment: 19 pages, 14 figures, 2 Tables, Accepted for publication in ApJ main
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JWST Imaging of the Cartwheel Galaxy Reveals Dust Associated with SN 2021afdx
We present near- and mid-infrared (0.9-18 m) photometry of supernova
(SN) 2021afdx, which was imaged serendipitously with the James Webb Space
Telescope (JWST) as part of its Early Release Observations of the Cartwheel
Galaxy. Our ground-based optical observations show it is likely to be a Type
IIb SN, the explosion of a yellow supergiant, and its infrared spectral energy
distribution (SED) 200 days after explosion shows two distinct
components, which we attribute to hot ejecta and warm dust. By fitting models
of dust emission to the SED, we derive a dust mass of , which is the highest yet observed in a Type IIb SN
but consistent with other Type II SNe observed by the Spitzer Space Telescope.
We also find that the radius of the dust is significantly larger than the
radius of the ejecta, as derived from spectroscopic velocities during the
photospheric phase, which implies that we are seeing an infrared echo off of
preexisting dust in the progenitor environment, rather than dust newly formed
by the SN. Our results show the power of JWST to address questions of dust
formation in SNe, and therefore the presence of dust in the early universe,
with much larger samples than have been previously possible.Comment: updated to match accepted versio
Assessing the risk of stress in organizations:Getting the measure of organizational-level stressors
Great Britainâs Health and Safety Executive (HSE) developed the Management Standards Indicator Tool to help organizations to assess and monitor organizational risks of work-related stress through surveying employees about the psychosocial risks for stress in their jobs. The use of employee-level data for deriving an organizational-level measure of psychosocial risks assumes that the constructs have equivalent meanings at different levels. However, this isomorphic condition has never been tested and this study fills this gap. Using data collected by the Italian Workersâ Compensation Authority (INAIL) from 66,188 employees nested in 775 organizations, we demonstrate that the organizational-level measure representing the seven dimensions of the Management Standards Indicator Tool is equivalent, though not identical, to the individual-level measure. This implies that the organizational level is not a mirror of the aggregation of the individual level, and that the risk of work-related stress in an organization may derive not simply from bottom-up processes, but may be generated by top-down influences (e.g., organizational policies). Interventions may then be meaningfully targeted at the organizational level in the expectation that they will reduce the risk of work-related stress among the entire workforce, the valid measurement of which can be performed through the HSEâs Management Standards Indicator Tool
SN 2019ewu: A Peculiar Supernova with Early Strong Carbon and Weak Oxygen Features from a New Sample of Young SN Ic Spectra
With the advent of high cadence, all-sky automated surveys, supernovae (SNe)
are now discovered closer than ever to their dates of explosion. However, young
pre-maximum light follow-up spectra of Type Ic supernovae (SNe Ic), probably
arising from the most stripped massive stars, remain rare despite their
importance. In this paper we present a set of 49 optical spectra observed with
the Las Cumbres Observatory through the Global Supernova Project for 6 SNe Ic,
including a total of 17 pre-maximum spectra, of which 8 are observed more than
a week before V-band maximum light. This dataset increases the total number of
publicly available pre-maximum light SN Ic spectra by 25% and we provide
publicly available SNID templates that will significantly aid in the fast
identification of young SNe Ic in the future. We present detailed analysis of
these spectra, including Fe II 5169 velocity measurements, O I 7774 line
strengths, and continuum shapes. We compare our results to published samples of
stripped supernovae in the literature and find one SN in our sample that stands
out. SN 2019ewu has a unique combination of features for a SN Ic: an extremely
blue continuum, high absorption velocities, a P-cygni shaped feature almost 2
weeks before maximum light that TARDIS radiative transfer modeling attributes
to C II rather than H, and weak or non-existent O I 7774 absorption
feature until maximum light.Comment: Submitted to the Astrophysical Journal. 15 pages, 6 figure
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