1,091 research outputs found
Experimental Demonstration of Squeezed State Quantum Averaging
We propose and experimentally demonstrate a universal quantum averaging
process implementing the harmonic mean of quadrature variances. The harmonic
mean protocol can be used to efficiently stabilize a set of fragile squeezed
light sources with statistically fluctuating noise levels. The averaged
variances are prepared probabilistically by means of linear optical
interference and measurement induced conditioning. We verify that the
implemented harmonic mean outperforms the standard arithmetic mean strategy.
The effect of quantum averaging is experimentally tested both for uncorrelated
and partially correlated noise sources with sub-Poissonian shot noise or
super-Poissonian shot noise characteristics.Comment: 4 pages, 5 figure
Cytisine versus varenicline for smoking cessation for MÄori (the indigenous people of New Zealand) and their extended family:Protocol for a randomized nonâinferiority trial
Background and aims Cytisine, a nicotinic acetylcholine receptor partial agonist (like varenicline) found in some plants, is a low-cost, effective smoking cessation medication that may appeal to MÄori [the indigenous people of New Zealand (NZ)]. The RAUORA trial aims to determine the effectiveness, safety and cost-effectiveness of cytisine (TabexÂŽ) versus varenicline (ChampixÂŽ) for smoking cessation in MÄori and the whÄnau (extended family) of MÄori. Design Pragmatic, community-based, open-label randomized non-inferiority trial. Setting Lakes District Health Board region, NZ. Participants Daily smokers (n = 2140) who self-identify as MÄori or whÄnau of MÄori, and are: aged ⼠18 years, motivated to quit smoking in the next 2 weeks, eligible for subsidized varenicline, able to provide verbal consent and have daily access to a mobile phone/internet. Recruitment uses multi-media advertising. Intervention and comparator Participants are randomized (1 : 1 ratio) to receive a prescription for 12 weeks of cytisine tablets [following the manufacturerâs dosing regimen for 25 days, then one 1.5-mg tablet every 6 hours (two per day) until 12 weeks] or varenicline tablets (following the manufacturerâs dosing regimen). Both groups receive brief stop-smoking advice from the prescribing doctor and withdrawal-orientated behavioural support via community-based stop-smoking counselling services (frequency, duration and mode of delivery tailored for participants) or a research assistant (six weekly 10â15- minute calls). Participants are advised to reduce their smoking over the first 4 days of treatment, with day 5 as their designated quit-date. Measurements The primary outcome is carbon monoxide-verified continuous abstinence at 6 months post-quit date. Secondary outcomes at 1, 3, 6 and 12 months post-quit date include: self-reported continuous abstinence, 7-day point prevalence abstinence, cigarettes per day, time to (re)lapse, adverse events, treatment adherence/compliance, treatment acceptability, nicotine withdrawal/urge to smoke and health-care utilization/health- related quality of life. Comments This trial compares cytisine and varenicline when used by the indigenous people of NZ and their extended family for smoking cessation
Xanthogranuloma of the lacrimal sac as a manifestation of Wegener's granulomatosis
McGill Univ, Ctr Hlth, Dept Ophthalmol & Pathol, Montreal, PQ H3A 2B4, CanadaHenry C Witelson Ocular Pathol Lab, Montreal, PQ, CanadaUniversidade Federal de SĂŁo Paulo, Dept Ophthalmol, UNIFESP, EPM, SĂŁo Paulo, BrazilMcGill Univ, Ctr Hlth, Dept Ophthalmol, Montreal, PQ H3A 2B4, CanadaUniversidade Federal de SĂŁo Paulo, Dept Ophthalmol, UNIFESP, EPM, SĂŁo Paulo, BrazilWeb of Scienc
Inner ear tissue preservation by rapid freezing: improving fixation by high-pressure freezing and hybrid methods
In the preservation of tissues in as âclose to lifeâ state as possible, rapid freeze fixation has many benefits over conventional chemical fixation. One technique by which rapid freeze-fixation can be achieved, high pressure freezing (HPF), has been shown to enable ice crystal artefact-free freezing and tissue preservation to greater depths (more than 40Îźm) than other quick-freezing methods. Despite increasingly becoming routine in electron microscopy, the use of HPF for the fixation of inner ear tissue has been limited. Assessment of the quality of preservation showed routine HPF techniques were suitable for preparation of inner ear tissues in a variety of species. Good preservation throughout the depth of sensory epithelia was achievable. Comparison to chemically fixed tissue indicated that fresh frozen preparations exhibited overall superior structural preservation of cells. However, HPF fixation caused characteristic artefacts in stereocilia that suggested poor quality freezing of the actin bundles. The hybrid technique of pre-fixation and high pressure freezing was shown to produce cellular preservation throughout the tissue, similar to that seen in HPF alone. Pre-fixation HPF produced consistent high quality preservation of stereociliary actin bundles. Optimising the preparation of samples with minimal artefact formation allows analysis of the links between ultrastructure and function in inner ear tissues
On Kedlaya type inequalities for weighted means
In 2016 we proved that for every symmetric, repetition invariant and Jensen
concave mean the Kedlaya-type inequality holds for an
arbitrary ( stands for the arithmetic mean). We are going
to prove the weighted counterpart of this inequality. More precisely, if
is a vector with corresponding (non-normalized) weights
and denotes the weighted mean then, under
analogous conditions on , the inequality holds for every and such that the sequence
is decreasing.Comment: J. Inequal. Appl. (2018
Strontium as a tracer of weathering processes in a silicate catchment polluted by acid atmospheric inputs, Strengbach, France
This paper determines the weathering and atmospheric contributions of Ca in surface water from a small spruce forested silicate catchment (NâE France) receiving acid atmospheric inputs. The bedrock is a granite with K-feldspar and albite as dominant phases. The calcium content in plagioclase is low and the Ca/Na ratio in surface water is high, reflecting other sources of calcium from those expected from the weathering of major mineral phases. The biotite content is low. Only traces of apatite were detected while no calcite was found in spite of a major hydrothermal event having affected the granite. The strontium isotopic ratio 87Sr/86Sr and Sr content was used as a tracer of weathering and was determined in minerals and bulk bedrock, open field precipitation, throughfall, soil solution, spring and stream water. The Sr isotopic ratio of the reacting weathering end-member was predicted by simulating the alteration of the granite minerals by incorporating strontium into the waterârock interaction kinetic code KINDIS. In the early stages of waterârock interaction, K-feldspar and biotite strongly influence the isotopic composition of the weathering solution whereas, the Na-rich plagioclase appears to be the main long-term reactive weathering end-member. Approximately 50% of dissolved Sr in streamwater are atmospherically derived. The 87Sr/86Sr ratios of exchangeable Sr in the fine fraction at 1-m depth from a soil profile indicate that the amount of exchangeable Sr seems essentially controlled by atmospheric inputs. The exception is the deep saprolite where weathering processes could supply the Sr (and Ca). Na-Plagioclase weathering obviously control the chemistry and the isotopic composition of surface waters. The weathering of trace mineral plays a secondary role, the exception is for apatite when plagioclase is absent. Our hydrochemical, mineralogical and isotopic investigations show that a major part of the strong Ca losses detected in catchment hydrochemical budgets that result from the neutralization of acid precipitation has an atmospheric origin. Consequently, in the long term, in such areas, the availability of such an exchangeable base cation might be strongly limited and surface waters consequently acidified
Geophysical studies with laser-beam detectors of gravitational waves
The existing high technology laser-beam detectors of gravitational waves may
find very useful applications in an unexpected area - geophysics. To make
possible the detection of weak gravitational waves in the region of high
frequencies of astrophysical interest, ~ 30 - 10^3 Hz, control systems of laser
interferometers must permanently monitor, record and compensate much larger
external interventions that take place in the region of low frequencies of
geophysical interest, ~ 10^{-5} - 3 X 10^{-3} Hz. Such phenomena as tidal
perturbations of land and gravity, normal mode oscillations of Earth,
oscillations of the inner core of Earth, etc. will inevitably affect the
performance of the interferometers and, therefore, the information about them
will be stored in the data of control systems. We specifically identify the
low-frequency information contained in distances between the interferometer
mirrors (deformation of Earth) and angles between the mirrors' suspensions
(deviations of local gravity vectors and plumb lines). We show that the access
to the angular information may require some modest amendments to the optical
scheme of the interferometers, and we suggest the ways of doing that. The
detailed evaluation of environmental and instrumental noises indicates that
they will not prevent, even if only marginally, the detection of interesting
geophysical phenomena. Gravitational-wave instruments seem to be capable of
reaching, as a by-product of their continuous operation, very ambitious
geophysical goals, such as observation of the Earth's inner core oscillations.Comment: 29 pages including 8 figures, modifications and clarifications in
response to referees' comments, to be published in Class. Quant. Gra
UK Large-scale Wind Power Programme from 1970 to 1990: the Carmarthen Bay experiments and the Musgrove Vertical-Axis Turbines
This article describes the development of the Musgrove Vertical Axis Wind Turbine (VAWT)
concept, the UK âCarmarthen Bayâ wind turbine test programme, and UK governmentâs wind
power programme to 1990. One of the most significant developments in the story of British
wind power occurred during the 1970s, 1980s, and 1990s, with the development of the
Musgrove vertical axis wind turbine and its inclusion within the UK Governmentâs wind
turbine test programme. Evolving from a supervisorâs idea for an undergraduate project at
Reading University, the Musgrove VAWT was once seen as an able competitor to the
horizontal axis wind systems that were also being encouraged at the time by both the UK
government and the Central Electricity Generating Board, the then nationalised electricity
utility for England and Wales. During the 1980s and 1990s the most developed Musgrove
VAWT system, along with three other commercial turbine designs was tested at
Carmarthen Bay, South Wales as part of a national wind power test programme. From these
developmental tests, operational data was collected and lessons learnt, which were
incorporated into subsequent wind power operations.http://dx.doi.org/10.1260/03095240677860621
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