2,232 research outputs found
Preparing for the quantum revolution -- what is the role of higher education?
Quantum sensing, quantum networking and communication, and quantum computing
have attracted significant attention recently, as these quantum technologies
offer significant advantages over existing technologies. In order to accelerate
the commercialization of these quantum technologies the workforce must be
equipped with the necessary skills. Through a qualitative study of the quantum
industry, in a series of interviews with 21 U.S. companies carried out in Fall
2019, we describe the types of activities being carried out in the quantum
industry, profile the types of jobs that exist, and describe the skills valued
across the quantum industry, as well as in each type of job. The current routes
into the quantum industry are detailed, providing a picture of the current role
of higher education in training the quantum workforce. Finally, we present the
training and hiring challenges the quantum industry is facing and how higher
education may optimize the important role it is currently playing
Microwave Temperature Profiler Mounted in a Standard Airborne Research Canister
Many atmospheric research aircraft use a standard canister design to mount instruments, as this significantly facilitates their electrical and mechanical integration and thereby reduces cost. Based on more than 30 years of airborne science experience with the Microwave Temperature Profiler (MTP), the MTP has been repackaged with state-of-the-art electronics and other design improvements to fly in one of these standard canisters. All of the controlling electronics are integrated on a single 4 ~5-in. (.10 ~13- cm) multi-layer PCB (printed circuit board) with surface-mount hardware. Improved circuit design, including a self-calibrating RTD (resistive temperature detector) multiplexer, was implemented in order to reduce the size and mass of the electronics while providing increased capability. A new microcontroller-based temperature controller board was designed, providing better control with fewer components. Five such boards are used to provide local control of the temperature in various areas of the instrument, improving radiometric performance. The new stepper motor has an embedded controller eliminating the need for a separate controller board. The reference target is heated to avoid possible emissivity (and hence calibration) changes due to moisture contamination in humid environments, as well as avoiding issues with ambient targets during ascent and descent. The radiometer is a double-sideband heterodyne receiver tuned sequentially to individual oxygen emission lines near 60 GHz, with the line selection and intermediate frequency bandwidths chosen to accommodate the altitude range of the aircraft and mission
Stock assessment of Australian east coast Spanish mackerel (Scomberomorus commerson)
Spanish mackerel, Scomberomorus commerson, are large offshore pelagic fish. On the east coast of Australia, Spanish mackerel form a single genetic stock between Cape York Peninsula in north Queensland and Newcastle on the New South Wales mid-coast.
This stock assessment used an annual time-step, two-sex, age-structured population model. The model incorporated data from 1911 to 2020, including estimated commercial, charter and recreational harvest for Queensland and New South Wales, Queensland commercial standardised catch rates, fish age-length frequencies, and key long-term fishery information on fishing power changes and catch rates. Eight model scenarios were run, covering a range of modelling assumptions and fixed parameters. The stock assessment estimates the spawning biomass of east coast Spanish mackerel in 2020 was between 14 and 27% of unfished levels in 1911. The base case model estimate was most likely at 17% of unfished biomass in 2019–2020. This report provides estimates of sustainable harvests for all sectors—commercial, charter and recreational across Queensland and New South Wales—and supports the harvest strategy defined in the Queensland’s Sustainable Fisheries Strategy 2017–2027 (Department of Agriculture and Fisheries 2017)
The relation of C - reactive protein to chronic kidney disease in African Americans: the Jackson Heart Study
<p>Abstract</p> <p>Background</p> <p>African Americans have an increased incidence and worse prognosis with chronic kidney disease (CKD - estimated glomerular filtration rate [eGFR] <60 ml/min/1.73 m<sup>2</sup>) than their counterparts of European-descent. Inflammation has been related to renal disease in non-Hispanic whites, but there are limited data on the role of inflammation in renal dysfunction in African Americans in the community.</p> <p>Methods</p> <p>We examined the cross-sectional relation of log transformed C-reactive protein (CRP) to renal function (eGFR by Modification of Diet and Renal Disease equation) in African American participants of the community-based Jackson Heart Study's first examination (2000 to 2004). We conducted multivariable linear regression relating CRP to eGFR adjusting for age, sex, body mass index, systolic and diastolic blood pressure, diabetes, total/HDL cholesterol, triglycerides, smoking, antihypertensive therapy, lipid lowering therapy, hormone replacement therapy, and prevalent cardiovascular disease events. In a secondary analysis we assessed the association of CRP with albuminuria (defined as albumin-to-creatinine ratio > 30 mg/g).</p> <p>Results</p> <p>Participants (n = 4320, 63.2% women) had a mean age ± SD of 54.0 ± 12.8 years. The prevalence of CKD was 5.2% (n = 228 cases). In multivariable regression, CRP concentrations were higher in those with CKD compared to those without CKD (mean CRP 3.2 ± 1.1 mg/L vs. 2.4 ± 1.0 mg/L, respectively p < 0.0001). CRP was significantly associated with albuminuria in sex and age adjusted model however not in the multivariable adjusted model (p > 0.05).</p> <p>Conclusion</p> <p>CRP was associated with CKD however not albuminuria in multivariable-adjusted analyses. The study of inflammation in the progression of renal disease in African Americans merits further investigation.</p
On the Possibility of Large Axion Decay Constants
The decay constant of the QCD axion is required by observation to be small
compared to the Planck scale. In theories of "natural inflation," and certain
proposed anthropic solutions of the cosmological constant problem, it would be
interesting to obtain a large decay constant for axion-like fields from
microscopic physics. String theory is the only context in which one can
sensibly address this question. Here we survey a number of periodic fields in
string theory in a variety of string vacua. In some examples, the decay
constant can be parameterically larger than the Planck scale but the effective
action then contains appreciable harmonics of order . As a result,
these fields are no better inflaton candidates than Planck scale axions.Comment: 17 pages, no figures, minor change mad
Rosetta-Alice Observations of Exospheric Hydrogen and Oxygen on Mars
The European Space Agency's Rosetta spacecraft, en route to a 2014 encounter
with comet 67P/Churyumov-Gerasimenko, made a gravity assist swing-by of Mars on
25 February 2007, closest approach being at 01:54UT. The Alice instrument on
board Rosetta, a lightweight far-ultraviolet imaging spectrograph optimized for
in situ cometary spectroscopy in the 750-2000 A spectral band, was used to
study the daytime Mars upper atmosphere including emissions from exospheric
hydrogen and oxygen. Offset pointing, obtained five hours before closest
approach, enabled us to detect and map the HI Lyman-alpha and Lyman-beta
emissions from exospheric hydrogen out beyond 30,000 km from the planet's
center. These data are fit with a Chamberlain exospheric model from which we
derive the hydrogen density at the 200 km exobase and the H escape flux. The
results are comparable to those found from the the Ultraviolet Spectrometer
experiment on the Mariner 6 and 7 fly-bys of Mars in 1969. Atomic oxygen
emission at 1304 A is detected at altitudes of 400 to 1000 km above the limb
during limb scans shortly after closest approach. However, the derived oxygen
scale height is not consistent with recent models of oxygen escape based on the
production of suprathermal oxygen atoms by the dissociative recombination of
O2+.Comment: 17 pages, 8 figures, accepted for publication in Icaru
Delayed presentation of acute ischemic strokes during the COVID-19 crisis
This article is made available for unrestricted research re-use and secondary analysis in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.Background: The COVID-19 pandemic has disrupted established care paths worldwide. Patient awareness of the pandemic and executive limitations imposed on public life have changed the perception of when to seek care for acute conditions in some cases. We sought to study whether there is a delay in presentation for acute ischemic stroke patients in the first month of the pandemic in the US.
Methods: The interval between last-known-well (LKW) time and presentation of 710 consecutive patients presenting with acute ischemic strokes to 12 stroke centers across the US were extracted from a prospectively maintained quality database. We analyzed the timing and severity of the presentation in the baseline period from February to March 2019 and compared results with the timeframe of February and March 2020.
Results: There were 320 patients in the 2-month baseline period in 2019, there was a marked decrease in patients from February to March of 2020 (227 patients in February, and 163 patients in March). There was no difference in the severity of the presentation between groups and no difference in age between the baseline and the COVID period. The mean interval from LKW to the presentation was significantly longer in the COVID period (603±1035 min) compared with the baseline period (442±435 min, P<0.02).
Conclusion: We present data supporting an association between public awareness and limitations imposed on public life during the COVID-19 pandemic in the US and a delay in presentation for acute ischemic stroke patients to a stroke center
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