2,436 research outputs found
A New Method to Determine Tooth Positions and Dental Arch Dimensions
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66726/2/10.1177_00220345720510042301.pd
Frequency division multiplexing readout of 60 low-noise transition-edge sensor bolometers
We demonstrate multiplexing readout of 60 transition edge sensor (TES) bolometers operating at 90 mK using a frequency division multiplexing readout chain with bias frequencies ranging from 1 to 3.5 MHz and with a typical frequency spacing of 32 kHz. The readout chain starts with a two-stage SQUID amplifier and has a noise level of 9.5 pA/ √{ Hz } . We compare current-voltage curves and noise spectra of TESs measured in a single-pixel mode and in a multiplexing mode. We also map the noise equivalent power (NEP) and the saturation power of the bolometers in both modes, where there are 43 pixels that do not show more than 10% difference in NEP and 5% in saturation power when measured in single pixel and multiplex modes. We have read out a TES with an NEP of 0.45 aW/ √{ Hz } in the multiplexing-mode, which demonstrates the capability of reading out ultra-low noise TES bolometer arrays for space applications
Electrical cross talk of a frequency division multiplexing readout for a transition edge sensor bolometer array
We have characterized and mapped the electrical cross talk (ECT) of a frequency division multiplexing (FDM) system with a transition edge sensor (TES) bolometer array, which is intended for space applications. By adding a small modulation at 120 Hz to the AC bias voltage of one bolometer and measuring the cross talk response in the current noise spectra of the others simultaneously, we have for the first time mapped the ECT level of 61 pixels with a nominal frequency spacing of 32 kHz in a 61 × 61 matrix and a carrier frequency ranging from 1 MHz to 4 MHz. We find that about 94% of the pixels show an ECT level of less than 0.4%. Only the adjacent pixels reach this level, and the ECT for the rest of the pixels is less than 0.1%. We also observe higher ECT levels, up to 10%, between some of the pixels, which have bundled long, parallel coplanar wires connecting TES bolometers to inductor-capacitor filters. In this case, the high mutual inductances dominate. To mitigate this source of ECT, the coplanar wires should be replaced by microstrip wires in the array. Our study suggests that an FDM system can have a relatively low ECT level, e.g., around 0.4% if the frequency spacing is 30 kHz. Our results successfully demonstrate a low electrical cross talk for a space FDM technology
Current discharge management of acute coronary syndromes: data from the Rijnmond Collective Cardiology Research (CCR) study
BACKGROUND: Medical discharge management of acute coronary syndromes (ACS) remains suboptimal outside randomised trials and constitutes an essential quality benchmark for ACS. We sought to evaluate the rates of key guideline-recommended pharmacological agents after ACS and characteristics associated with optimal treatment at discharge. METHODS: The Rijnmond Collective Cardiology Research (CCR) registry is an ongoing prospective, observational study in the Netherlands that aims to enrol 4000 patients with ACS. We examined discharge and 1-month follow-up medication use among the first 1000 patients enrolled in the CCR registry. Logistic regression was performed to identify patient and hospital characteristics associated with collective guideline-recommended pharmacotherapy at hospital discharge. RESULTS: At discharge, 94 % of patients received aspirin, 100 % thienopyridines, 80 % angiotensin-converting enzyme inhibitors/angiotensin-II receptor blockers, 87 % β-blockers, 96 % statins, and 65 % the combination of all 5 agents. ST-segment elevation myocardial infarction, hypertension, hypercholesterolaemia, and enrolment in an interventional centre were positive independent predictors of 5-drug combination therapy at discharge. Negative independent predictors were unstable angina and advanced age. CONCLUSION: Current data from the CCR registry reflect a high quality of care for ACS discharge management in the Rotterdam-Rijnmond region. However, potential still remains for further optimisation
The effect of RaceRunning on cardiometabolic disease risk factors and functional mobility in young people with moderate-to-severe cerebral palsy: protocol for a feasibility study
Copyright © Author(s) (or their employer(s)) 2020. Introduction: There is consistent evidence that people with cerebral (CP) do not engage in the recommended physical activity guidelines for the general population from a young age. Participation in moderate-to-vigorous physical activity is particularly reduced in people with CP who have moderate-to-severe disability. RaceRunning is a growing disability sport that provides an opportunity for people with moderate-to-severe disability to participate in physical activity in the community. It allows those who are unable to walk independently, to propel themselves using a RaceRunning bike, which has a breastplate for support but no pedals. The aim of this study is to examine the feasibility and acceptability of RaceRunning for young people with moderate-to-severe CP and the feasibility of conducting a definitive study of the effect of RaceRunning on cardiometabolic disease risk factors and functional mobility. Methods and analysis: Twenty-five young people (age 5-21 yr) with CP or acquired brain injury affecting co-ordination will be included in this single arm intervention study. Participants will take part in one RaceRunning session each week for 24 weeks. Outcomes assessed at baseline, 12 and 24 weeks include body mass index, waist circumference, blood pressure, muscle strength, cardiorespiratory fitness, physical activity and sedentary behaviour, functional mobility, activity competence and psychosocial impact. Adverse events will be systematically recorded throughout the 24 weeks. Focus groups will be conducted with participants and/or parents to explore their views and experiences of taking part in RaceRunning. Ethics and dissemination: Approval has been granted by Queen Margaret University Research Ethics Committee (REC) and the South East of Scotland REC. Results will be disseminated through peer-reviewed journals and distributed to people with CP and their families through RaceRunning and Athletic Clubs, NHS trusts, and organisations for people with disabilities. Trial registration number: ClinicalTrials.gov Identifier: NCT04034342. Protocol version 1.0; pre-results.Action Medical Research and Chartered Society of Physiotherapy Charitable Trust.Joint award from Action Medical Research and Chartered Society of Physiotherapy Charitable Trust
A Herschel/PACS Far Infrared Line Emission Survey of Local Luminous Infrared Galaxies
We present an analysis of [OI]63, [OIII]88, [NII]122 and [CII]158
far-infrared (FIR) fine-structure line observations obtained with
Herschel/PACS, for ~240 local luminous infrared galaxies (LIRGs) in the Great
Observatories All-sky LIRG Survey (GOALS). We find pronounced declines
-deficits- of line-to-FIR-continuum emission for [NII]122, [OI]63 and [CII]158
as a function of FIR color and infrared luminosity surface density,
. The median electron density of the ionized gas in LIRGs,
based on the [NII]122/[NII]205 ratio, is = 41 cm. We find
that the dispersion in the [CII]158 deficit of LIRGs is attributed to a varying
fractional contribution of photo-dissociation-regions (PDRs) to the observed
[CII]158 emission, f([CII]PDR) = [CII]PDR/[CII], which increases from ~60% to
~95% in the warmest LIRGs. The [OI]63/[CII]158PDR ratio is tightly correlated
with the PDR gas kinetic temperature in sources where [OI]63 is not
optically-thick or self-absorbed. For each galaxy, we derive the average PDR
hydrogen density, , and intensity of the interstellar radiation
field, in units of G, and find G/ ratios ~0.1-50 cm,
with ULIRGs populating the upper end of the distribution. There is a relation
between G/ and , showing a critical break at
~ 5 x 10 Lsun/kpc. Below , G/ remains constant, ~0.32 cm, and variations
in are driven by the number density of star-forming regions
within a galaxy, with no change in their PDR properties. Above , G/ increases rapidly with ,
signaling a departure from the typical PDR conditions found in normal
star-forming galaxies towards more intense/harder radiation fields and compact
geometries typical of starbursting sources.Comment: 23 pages, 12 figures. Submitted to ApJ, including 2nd round of
referee comments. Data tables can be found at: http://goals.ipac.caltech.edu/
and will also appear on the electronic version of the journa
Reflections and projections on a decade of climate science
To mark the tenth anniversary of Nature Climate Change, we asked a selection of researchers across the broad range of climate change disciplines to share their thoughts on notable developments of the past decade, as well as their hopes and expectations for the coming years of discovery. Much has changed in the last 10 years since the Nature Climate Change inaugural issue in April 2011. The effects of climate change are now more apparent, global leaders have reached a climate agreement, and public awareness and engagement, particularly in the younger generation, continues to grow. Here, ten researchers discuss advances in their field, highlighting the progress and drawing attention to what still needs to be done
Charge and Spin Structures of a Superconductor in the Proximity of an Antiferromagnetic Mott Insulator
To the Hubbard model on a square lattice we add an interaction, , which
depends upon the square of a near-neighbor hopping. We use zero temperature
quantum Monte Carlo simulations on lattice sizes up to , to show
that at half-filling and constant value of the Hubbard repulsion, the
interaction triggers a quantum transition between an antiferromagnetic Mott
insulator and a superconductor. With a combination of finite
temperature quantum Monte Carlo simulations and the Maximum Entropy method, we
study spin and charge degrees of freedom in the superconducting state. We give
numerical evidence for the occurrence of a finite temperature
Kosterlitz-Thouless transition to the superconducting state.
Above and below the Kosterlitz-Thouless transition temperature, , we
compute the one-electron density of states, , the spin relaxation
rate , as well as the imaginary and real part of the spin susceptibility
. The spin dynamics are characterized by the vanishing of
and divergence of in the low
temperature limit. As is approached develops a pseudo-gap
feature and below shows a peak
at finite frequency.Comment: 46 pages (latex) including 14 figures in encapsulated postscript
format. Submitted for publication in Phys. Rev.
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