26,937 research outputs found
Experimental Observations of Group Synchrony in a System of Chaotic Optoelectronic Oscillators
We experimentally demonstrate group synchrony in a network of four nonlinear
optoelectronic oscillators with time-delayed coupling. We divide the nodes into
two groups of two each, by giving each group different parameters and by
enabling only inter-group coupling. When coupled in this fashion, the two
groups display different dynamics, with no isochronal synchrony between them,
but the nodes in a single group are isochronally synchronized, even though
there is no intra-group coupling. We compare experimental behavior with
theoretical and numerical results
Chemical mechanical polishing of thin film diamond
The demonstration that Nanocrystalline Diamond (NCD) can retain the superior
Young's modulus (1,100 GPa) of single crystal diamond twinned with its ability
to be grown at low temperatures (<450 {\deg}C) has driven a revival into the
growth and applications of NCD thin films. However, owing to the competitive
growth of crystals the resulting film has a roughness that evolves with film
thickness, preventing NCD films from reaching their full potential in devices
where a smooth film is required. To reduce this roughness, films have been
polished using Chemical Mechanical Polishing (CMP). A Logitech Tribo CMP tool
equipped with a polyurethane/polyester polishing cloth and an alkaline
colloidal silica polishing fluid has been used to polish NCD films. The
resulting films have been characterised with Atomic Force Microscopy, Scanning
Electron Microscopy and X-ray Photoelectron Spectroscopy. Root mean square
roughness values have been reduced from 18.3 nm to 1.7 nm over 25 {\mu}m,
with roughness values as low as 0.42 nm over ~ 0.25 {\mu}m. A polishing
mechanism of wet oxidation of the surface, attachment of silica particles and
subsequent shearing away of carbon has also been proposed.Comment: 6 pages, 6 figure
Observation of Multiple-Gap Structure in Hidden Order State of URu2Si2 from Optical Conductivity
We have measured the far infrared reflectance of the heavy fermion compound
URuSi through the phase transition at T=17.5 K dubbed 'hidden
order' with light polarized along both the a- and c-axes of the tetragonal
structure. The optical conductivity allows the formation of the hidden order
gap to be investigated in detail. We find that both the conductivity and the
gap structure are anisotropic, and that the c-axis conductivity shows evidence
for a double gap structure, with meV and
meV respectively at 4 K, while the gap seen in the a-axis conductivity has a
value of meV at 4 K. The opening of the gaps does not follow the
behaviour expected from mean field theory in the vicinity of the transition.Comment: 6 pages, 5 figure
Twenty-four hour behaviour patterns and budgets of free-ranging reindeer in winter
Activities of free-ranging reindeer (Rangifer tarandus) on the Seward Peninsula, Alaska were studied to determine 24-hour behaviour patterns and budgets in winter. Use of daytime active-rest data to predict nighttime behaviour resulted in as much as 37% underestimate of nighttime resting and 37% overestimate of nighttime activity. Three active-rest cycles occurred daily, synchronous with photoperiod.Tjuefiretimers adferdsmønster- og budsjett hos fritt beitende reinsdyr om vinteren.Abstract in Norwegian / Sammendrag: Aktiviteter hos fritt beitende reinsdyr {Rangifer tarandus) på Seward Peninsula, Alaska ble undersøkt for bestemmelse av 24 timers adferdsmønster og -budsjett om vinteren. Bruk av dagtids data for aktivitets-hvile til å forutsi nattlig adferd resulterte i 37% underestimering av natt-hvile og 37% overes-timering av natt-aktivitet. Tre aktivitet-hvile cykler inntraff daglig, synkront med fotoperiode.Vapaana laiduntavan poron vuorokautinen kayttaytyminen ja budjetti talvella.Abstract in Finnish / Yhteenveto: Vapaana laiduntavan poron (Rangifer tarandus) aktiivisuutta tutkittiin Sewardin niemimaalla Alaskassa mààrittàmàllà 24 tunnin kayttaytymismallit ja budjetit talvella. Kàyttàmàllâ pàivàajan aktiivisu-us - lepo -tietoja yôajan kåyttåytymisen ennustamiseen ne alittivat jopa 30%:lla yollisen lepoajan ja ylitti-våt 40%:lla yôajan aktiivisuuden. Påivittain esiintyi kolme aktiivisuus - lepo -sykliå samanaikaisesti valo-jaksojen kanssa
Adjunctive interferon-γ immunotherapy for the treatment of HIV-associated cryptococcal meningitis: a randomized controlled trial.
BACKGROUND: Interferon-gamma (IFNγ) is of key importance in the immune response to Cryptococcus neoformans. Mortality related to cryptococcal meningitis remains high, and novel treatment strategies are needed. We performed a randomized controlled trial to determine whether addition of IFNγ to standard therapy increased the rate of clearance of cryptococcal infection in HIV-associated cryptococcal meningitis. METHODS: Patients were randomized to amphotericin B 1 mg/kg per day and 5FC 100 mg/kg per day for 2 weeks (standard therapy), standard therapy and IFNγ1b 100 μg days 1 and 3 (IFNγ two doses), or standard therapy and IFNγ1b 100 μg days 1, 3, 5, 8, 10 and 12 (IFNγ six doses). Primary outcome was rate of clearance of cryptococcus from the cerebrospinal fluid (CSF) (early fungicidal activity, EFA) calculated from serial quantitative cultures, previously shown to be independently associated with survival. RESULTS: Rate of fungal clearance was significantly faster in IFNγ containing groups than with standard treatment. Mean EFA [log colony forming unit (CFU)/ml per day] was -0.49 with standard treatment, -0.64 with IFNγ two doses, and -0.64 with IFNγ six doses. Difference in EFA was -0.15 [confidence interval (95% CI) -0.02 to -0.27, P=0.02] between standard treatment and IFNγ two doses, and -0.15 (95% CI -0.05 to -0.26, P=0.006) between standard treatment and IFNγ six doses. Mortality was 16% (14/88) at 2 weeks and 31% (27/87) at 10 weeks, with no significant difference between groups. All treatments were well tolerated. CONCLUSION: Addition of short-course IFNγ to standard treatment significantly increased the rate of clearance of cryptococcal infection from the CSF, and was not associated with any increase in adverse events. Two doses of IFNγ are as effective as six doses
Questioning flecainide's mechanism of action in the treatment of catecholaminergic polymorphic ventricular tachycardia
The Score Reliability Of Draw-A-Person Intellectual Ability Test (DAP: IQ) For Rural Malawi Students
In this brief article, the reliability of scores for the Draw-A-Person Intellectual Ability Test for Children, Adolescents, and Adults (DAP: IQ; Reynolds & Hickman, 2004) was examined through several analyses with a sample of 147 children from rural Malawi, Africa using a Chichewa translation of instructions. Cronbach alpha coefficients for the 23 test items were calculated for the total sample, the six age groups represented in the sample, and gender. The interscorer reliability of test scores was also calculated. The obtained alpha coefficients for the 23 items for total sample (.81), the six age groups represented (.68 - .92), and gender (male .79, female .83) were comparable to those listed in the examiner’s manual. The coefficient for interscorer reliability was .85.
2006 Housing in the Nation's Capital
Explores the interdependent relationship between public school systems and housing markets, and examines the ability of coordinated investment in affordable housing and quality education to revitalize Washington, D.C., metropolitan area neighborhoods
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