3,639 research outputs found
Don't be so BOLD: Potential limitations in the use of BOLD MRI for studies of renal oxygenation
A millimeter-wave antireflection coating for cryogenic silicon lenses
We have developed and tested an antireflection (AR) coating method for
silicon lenses at cryogenic temperatures and millimeter wavelengths. Our
particular application is a measurement of the cosmic microwave background. The
coating consists of machined pieces of Cirlex glued to the silicon. The
measured reflection from an AR coated flat piece is less than 1.5% at the
design wavelength. The coating has been applied to flats and lenses and has
survived multiple thermal cycles from 300 to 4 K. We present the manufacturing
method, the material properties, the tests performed, and estimates of the loss
that can be achieved in practical lenses
A compact and reconfigurable silicon nitride time-bin entanglement circuit
Photonic chip based time-bin entanglement has attracted significant attention
because of its potential for quantum communication and computation. Useful
time-bin entanglement systems must be able to generate, manipulate and analyze
entangled photons on a photonic chip for stable, scalable and reconfigurable
operation. Here we report the first time-bin entanglement photonic chip that
integrates time-bin generation, wavelength demultiplexing and entanglement
analysis. A two-photon interference fringe with an 88.4% visibility is measured
(without subtracting any noise), indicating the high performance of the chip.
Our approach, based on a silicon nitride photonic circuit, which combines the
low-loss characteristic of silica and tight integration features of silicon,
paves the way for scalable real-world quantum information processors.Comment: 4 pages, 5 figure
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Repurposing Albendazole: new potential as a chemotherapeutic agent with preferential activity against HPV-negative head and neck squamous cell cancer.
Albendazole is an anti-helminthic drug that has been shown to exhibit anti-cancer properties, however its activity in head and neck squamous cell cancer (HNSCC) was unknown. Using a series of in vitro assays, we assessed the ability of albendazole to inhibit proliferation in 20 HNSCC cell lines across a range of albendazole doses (1 nM-10 ÎĽM). Cell lines that responded to treatment were further examined for cell death, inhibition of migration and cell cycle arrest. Thirteen of fourteen human papillomavirus-negative HNSCC cell lines responded to albendazole, with an average IC50 of 152 nM. In contrast, only 3 of 6 human papillomavirus-positive HNSCC cell lines responded. Albendazole treatment resulted in apoptosis, inhibition of cell migration, cell cycle arrest in the G2/M phase and altered tubulin distribution. Normal control cells were not measurably affected by any dose tested. This study indicates that albendazole acts to inhibit the proliferation of human papillomavirus-negative HNSCC cell lines and thus warrants further study as a potential chemotherapeutic agent for patients suffering from head and neck cancer
Experiential Persona: Towards Supporting Richer and Unfinalized Representations of People
The Persona, as a 2D poster, is a commonly created and used tool in user-centred design activities. Whilst popular, many in HCI have critiqued its depictions of g€the user' as reductive, shallow, and static. Yet, there are not many alternatives. In this late-breaking work, we present our efforts to imagine and create an alternative to this 2D persona - one that consists of a carefully curated, staged collection of artifacts. We call this an Experiential Persona because it allows designers to interact with and explore the artifacts, individually and as a collection, to imagine and experience the world of g€the user'. This more embodied, interactive and open-ended persona can potentially support richer sense making; encouraging a more open, emergent, and unfinalized view of people we design for. This study contributes to extending design tools, and exploring novel use of tangible artifacts to support design, as well as a way to represent design knowledge
ACBAR: The Arcminute Cosmology Bolometer Array Receiver
We describe the Arcminute Cosmology Bolometer Array Receiver (ACBAR); a
multifrequency millimeter-wave receiver designed for observations of the Cosmic
Microwave Background (CMB) and the Sunyaev-Zel'dovich effect in clusters of
galaxies. The ACBAR focal plane consists of a 16-pixel, background-limited, 240
mK bolometer array that can be configured to observe simultaneously at 150,
220, 280, and 350 GHz. With 4-5' FWHM Gaussian beam sizes and a 3 degree
azimuth chop, ACBAR is sensitive to a wide range of angular scales. ACBAR was
installed on the 2 m Viper telescope at the South Pole in January 2001. We
describe the design of the instrument and its performance during the 2001 and
2002 observing seasons.Comment: 59 pages, 16 figures -- updated to reflect version published in ApJ
Rainbow Smelt (Osmerus mordax) Genomic Library and EST Resources
Genomic resources in rainbow smelt (Osmerus mordax) enable us to examine the genome duplication process in salmonids and test hypotheses relating to the fate of duplicated genes. They further enable us to pursue physiological and ecological studies in smelt. A bacterial artificial chromosome library containing 52,410 clones with an average insert size of 146Â kb was constructed. This library represents an 11-fold average coverage of the rainbow smelt (O. mordax) genome. In addition, several complementary deoxyribonucleic acid libraries were constructed, and 36,758 sequences were obtained and combined into 12,159 transcripts. Over half of these transcripts have been identified, several of which have been associated with cold adaptation. These basic resources show high levels of similarity (86%) to salmonid genes and provide initial support for genome duplication in the salmonid ancestor. They also facilitate identification of genes important to fish and direct us toward new technologies for other studies in fish biology
Serous cystic neoplasm of the pancreas: A multinational study of 2622 patients under the auspices of the International Association of Pancreatology and European Pancreatic Club (European Study Group on Cystic Tumors of the Pancreas)
OBJECTIVES:
Serous cystic neoplasm (SCN) is a cystic neoplasm of the pancreas whose natural history is poorly known. The purpose of the study was to attempt to describe the natural history of SCN, including the specific mortality.
DESIGN:
Retrospective multinational study including SCN diagnosed between 1990 and 2014.
RESULTS:
2622 patients were included. Seventy-four per cent were women, and median age at diagnosis was 58\u2005years (16-99). Patients presented with non-specific abdominal pain (27%), pancreaticobiliary symptoms (9%), diabetes mellitus (5%), other symptoms (4%) and/or were asymptomatic (61%). Fifty-two per cent of patients were operated on during the first year after diagnosis (median size: 40\u2005mm (2-200)), 9% had resection beyond 1\u2005year of follow-up (3\u2005years (1-20), size at diagnosis: 25\u2005mm (4-140)) and 39% had no surgery (3.6\u2005years (1-23), 25.5\u2005mm (1-200)). Surgical indications were (not exclusive) uncertain diagnosis (60%), symptoms (23%), size increase (12%), large size (6%) and adjacent organ compression (5%). In patients followed beyond 1\u2005year (n=1271), size increased in 37% (growth rate: 4\u2005mm/year), was stable in 57% and decreased in 6%. Three serous cystadenocarcinomas were recorded. Postoperative mortality was 0.6% (n=10), and SCN's related mortality was 0.1% (n=1).
CONCLUSIONS:
After a 3-year follow-up, clinical relevant symptoms occurred in a very small proportion of patients and size slowly increased in less than half. Surgical treatment should be proposed only for diagnosis remaining uncertain after complete workup, significant and related symptoms or exceptionally when exists concern with malignancy. This study supports an initial conservative management in the majority of patients with SCN
The 10 Meter South Pole Telescope
The South Pole Telescope (SPT) is a 10 m diameter, wide-field, offset
Gregorian telescope with a 966-pixel, multi-color, millimeter-wave, bolometer
camera. It is located at the Amundsen-Scott South Pole station in Antarctica.
The design of the SPT emphasizes careful control of spillover and scattering,
to minimize noise and false signals due to ground pickup. The key initial
project is a large-area survey at wavelengths of 3, 2 and 1.3 mm, to detect
clusters of galaxies via the Sunyaev-Zeldovich effect and to measure the
small-scale angular power spectrum of the cosmic microwave background (CMB).
The data will be used to characterize the primordial matter power spectrum and
to place constraints on the equation of state of dark energy. A
second-generation camera will measure the polarization of the CMB, potentially
leading to constraints on the neutrino mass and the energy scale of inflation.Comment: 47 pages, 14 figures, updated to match version to be published in
PASP 123 903 (May, 2011
Radiological characterisation in view of nuclear reactor decommissioning: On-site benchmarking exercise of a biological shield
Nearly all decommissioning and dismantling (D&D) projects are steered by the characterisation of the plant being dismantled. This radiological characterisation is a complex process that is updated and modified during the course of the D&D. One of the tools for carrying out this characterisation is the performance of in-situ measurements.
There is a wide variety of equipment and methodologies used to carry out on-site measurements, depending on the environment in which they are to be carried out and also on the specific objectives of the measurements and the financial and personnel resources available. The extent to which measurements carried out with different types of equipment or methodologies providing comparable results can be crucial in view of the D&D strategy development and the decision-making process.
This paper concerns an on-site benchmarking exercise carried out at the activated biological shield of Belgian Reactor 3 (BR3). This activity allows comparison and validation of characterisation methodologies and different equipment used as well as future interpretation of final results in terms of uncertainties and sensitivities. This paper describes the measurements and results from the analysis of this exercise. Other aspects of this exercise will be reported in separate papers. This paper provides an overview of the on-site benchmarking exercise, outlines the participating organisations and the measurement equipment used for total gamma, dose rate and gamma spectrometry measurements and finally, results obtained and their interpretations are discussed for each type of measurement as a function of detector type.
Regarding the dose measurements, results obtained by using a large variety of equipment are very consistent. In view of mapping the inner surface of the biological shield the most appropriate equipment tested might be the organic scintillator, the BGO or even the ionisation chamber. In addition, for mapping this surface, the most appropriate total gamma equipment tested might be the LaBr(Ce), the thick organic scintillator or the BGO. These measurements can only be used as a secondary parameter in a relative way. Results for the gamma spectrometry are very consistent for all the equipment used and the main parameters to be determined
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