4,558 research outputs found
The feasibility of a programmed heat shield for solar cell performance control
Feasibility of programmed heat shield for temperature and power control for spacecraft on-board powe
A Project Based Approach to Statistics and Data Science
In an increasingly data-driven world, facility with statistics is more
important than ever for our students. At institutions without a statistician,
it often falls to the mathematics faculty to teach statistics courses. This
paper presents a model that a mathematician asked to teach statistics can
follow. This model entails connecting with faculty from numerous departments on
campus to develop a list of topics, building a repository of real-world
datasets from these faculty, and creating projects where students interface
with these datasets to write lab reports aimed at consumers of statistics in
other disciplines. The end result is students who are well prepared for
interdisciplinary research, who are accustomed to coping with the
idiosyncrasies of real data, and who have sharpened their technical writing and
speaking skills
Ab Initio Liquid Hydrogen Muon Cooling Simulations with ELMS in ICOOL
This paper presents new theoretical results on the passage of muons through
liquid hydrogen which have been confirmed in a recent experiment. These are
used to demonstrate that muon bunches may be compressed by ionisation cooling
more effectively than suggested by previous calculations.
Muon cooling depends on the differential cross section for energy loss and
scattering of muons. We have calculated this cross section for liquid H2 from
first principles and atomic data, avoiding traditional assumptions. Thence, 2-D
probability maps of energy loss and scattering in mm-scale thicknesses are
derived by folding, and stored in a database. Large first-order correlations
between energy loss and scattering are found for H2, which are absent in other
simulations. This code is named ELMS, Energy Loss & Multiple Scattering. Single
particle trajectories may then be tracked by Monte Carlo sampling from this
database on a scale of 1 mm or less. This processor has been inserted into the
cooling code ICOOL. Significant improvements in 6-D muon cooling are predicted
compared with previous predictions based on GEANT. This is examined in various
geometries. The large correlation effect is found to have only a small effect
on cooling. The experimental scattering observed for liquid H2 in the MUSCAT
experiment has recently been reported to be in good agreement with the ELMS
prediction, but in poor agreement with GEANT simulation.Comment: 6 pages, 3 figure
Self-conscious emotions in patients suffering from chronic musculoskeletal pain: a brief report.
OBJECTIVE: The role of self-conscious emotions (SCEs) including shame, guilt, humiliation and embarrassment are of increasing interest within health. Yet, little is known about SCEs in the experience of chronic pain. This study explored prevalence and experience of SCEs in chronic pain patients compared to controls and assessed the relationship between SCEs and disability in pain patients. DESIGN AND MEASURES: Questionnaire assessment comparing musculoskeletal pain patients (n=64) and pain-free control participants (n=63). Pain was assessed using the McGill Pain Questionnaire; disability, using the Roland-Morris Disability Questionnaire; and six SCEs derived from three measures (i) Test of Self-Conscious Affect-3 yielding subscales of shame, guilt, externalisation and detachment (ii) The Brief Fear of Negative Evaluation Scale and (iii) The Pain Self-Perception Scale assessing mental defeat. RESULTS: Significantly greater levels of shame, guilt, fear of negative evaluation and mental defeat were observed in chronic pain patients compared to controls. In the pain group, SCE variables significantly predicted affective pain intensity; only mental defeat was significantly related to disability. CONCLUSION: Findings highlight the prevalence of negative SCEs and their importance in assessment and management of chronic pain. The role of mood in this relationship is yet to be explored
Urban transportation: Perspectives on mobility and choice
A study of urban transportation systems are presented characterized by intensive scrutiny of many ideas, philosophies, and academic perspectives. This report is intended to communicate some dimensions of the urban transportation problem to the general public
Boolean delay equations on networks: An application to economic damage propagation
We introduce economic models based on Boolean Delay Equations: this formalism
makes easier to take into account the complexity of the interactions between
firms and is particularly appropriate for studying the propagation of an
initial damage due to a catastrophe. Here we concentrate on simple cases, which
allow to understand the effects of multiple concurrent production paths as well
as the presence of stochasticity in the path time lengths or in the network
structure.
In absence of flexibility, the shortening of production of a single firm in
an isolated network with multiple connections usually ends up by attaining a
finite fraction of the firms or the whole economy, whereas the interactions
with the outside allow a partial recovering of the activity, giving rise to
periodic solutions with waves of damage which propagate across the structure.
The damage propagation speed is strongly dependent upon the topology. The
existence of multiple concurrent production paths does not necessarily imply a
slowing down of the propagation, which can be as fast as the shortest path.Comment: Latex, 52 pages with 22 eps figure
GRB 050408: An Atypical Gamma-Ray Burst as a Probe of an Atypical Galactic Environment
The bright GRB 050408 was localized by HETE-II near local midnight, enabling
an impressive ground-based followup effort as well as space-based followup from
Swift. The Swift data from the X-Ray Telescope (XRT) and our own optical
photometry and spectrum of the afterglow provide the cornerstone for our
analysis. Under the traditional assumption that the visible waveband was above
the peak synchrotron frequency and below the cooling frequency, the optical
photometry from 0.03 to 5.03 days show an afterglow decay corresponding to an
electron energy index of p_lc = 2.05 +/- 0.04, without a jet break as suggested
by others. A break is seen in the X-ray data at early times (at ~12600 sec
after the GRB). The spectral slope of the optical spectrum is consistent with
p_lc assuming a host-galaxy extinction of A_V = 1.18 mag. The optical-NIR
broadband spectrum is also consistent with p = 2.05, but prefers A_V = 0.57
mag. The X-ray afterglow shows a break at 1.26 x 10^4 sec, which may be the
result of a refreshed shock. This burst stands out in that the optical and
X-ray data suggest a large H I column density of N_HI ~ 10^22 cm^-2; it is very
likely a damped Lyman alpha system and so the faintness of the host galaxy (M_V
> -18 mag) is noteworthy. Moreover, we detect extraordinarily strong Ti II
absorption lines with a column density through the GRB host that exceeds the
largest values observed for the Milky Way by an order of magnitude.
Furthermore, the Ti II equivalent width is in the top 1% of Mg II
absorption-selected QSOs. This suggests that the large-scale environment of GRB
050408 has significantly lower Ti depletion than the Milky Way and a large
velocity width (delta v > 200 km/s).Comment: ApJ submitte
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Synthesis and antiviral properties of spirocyclic [1,2,3]-triazolooxazine nucleosides
An efficient synthesis of spirocyclic triazolooxazine nucleosides is described. This was achieved by the conversion of β-D-psicofuranose to the corresponding azido-derivative, followed by alkylation of the primary alcohol with a range of propargyl bromides - obtained via Sonogashira chemistry. The products of these reactions underwent 1,3-dipolar addition smoothly to generate the protected spirocyclic adducts. These were easily deprotected to give the corresponding ribose nucleosides. The library of compounds obtained was investigated for its antiviral activity, using MHV (Mouse Hepatitis Virus) as a model wherein derivative 3f showed the most promising activity and tolerability
Extended Cave Drip Water Time Series Captures the 2015–2016 El Niño in Northern Borneo
Time series of cave drip water oxygen isotopes (δ18O) provide site‐specific assessments of the contributions of climate and karst processes to stalagmite δ18O records employed for hydroclimate reconstructions. We present ~12‐year‐long time series of biweekly cave drip water δ18O variations from three sites as well as a daily resolved local rainfall δ18O record from Gunung Mulu National Park in northern Borneo. Drip water δ18O variations closely match rainfall δ18O variations averaged over the preceding 3–18 months. We observe coherent interannual drip water δ18O variability of ~3‰ to 5‰ related to the El Niño–Southern Oscillation (ENSO), with sustained positive rainfall and drip water δ18O anomalies observed during the 2015/2016 El Niño. Evidence of nonlinear behavior at one of three drip water monitoring sites implies a time‐varying contribution from a longer‐term reservoir. Our results suggest that well‐replicated, high‐resolution stalagmite δ18O reconstructions from Mulu could characterize past ENSO‐related variability in regional hydroclimate.Plain Language SummaryCave stalagmites allow for the reconstruction of past regional rainfall variability over the last hundreds of thousands of years with robust age control. Such reconstructions rely on the fact that differences in the isotopic composition of rainwater set by regional rainfall patterns is preserved as the rainwater travels through cave bedrock to feed the cave drip waters forming stalagmites. Long‐term monitoring of rainwater and cave drip water isotopes ground truth the climate to stalagmite relationship across modern‐day changes in regional rainfall. Twelve years of monitoring data presented in this study identify individual El Niño–Southern Oscillation events in rainfall and cave drip water isotopic composition, providing a strong foundation for stalagmite‐based climate reconstructions from this site.Key PointsThree 12‐year‐long cave drip water δ18O time series capture El Niño and La Niña events in northern BorneoEstimates of karst residence times range from 3 to 18 months, with a secondary contribution from a longer‐term reservoir at one drip siteDrip water nonstationarity implies multiple stalagmites are required to reconstruct El Niño–Southern Oscillation variability over timePeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154266/1/grl60264-sup-0002-2019GL086363-SI.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154266/2/grl60264_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154266/3/grl60264.pd
Asthma management programs in managed care organizations
The aim of this work was to investigate how managed care organizations (MCOs) currently approach asthma treatment and management and to determine factors affecting asthma outcomes. A Web-based survey was administered to a national sample of 351 medical directors of MCOs to investigate the asthma management program components in their organizations as well as gaps and barriers in the management of patients with asthma. All 134 (38.2%) responding medical directors reported that their organizations monitor asthma patients. Plans use a variety of asthma management activities, including general member education (90%), member education by mail (87%), self-management education (85%), and provider education (82%). Educational resources (89%) and telephone advice nurse (77%) were the most common self-management strategies offered. Among factors impeding the provision of effective asthma care, noncompliance with asthma treatment, the inappropriate use of medications, and the need for multiple medications were cited by virtually all respondents. Health plans rely on an array of strategies to manage asthma patients. Education encouraging patient self-management is a key component of asthma management programs. However, a considerable number of treatment approach barriers are impeding the achievement of proper asthma care. Without innovative approaches to care, it appears that current MCOs’ asthma management efforts may not result in substantial improvements in asthma outcomes
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