2,912 research outputs found
High reflectivity grating waveguide coatings for 1064nm
We propose thin single-layer grating waveguide structures to be used as
high-reflectivity, but low thermal noise, alternative to conventional coatings
for gravitational wave detector test mass mirrors. Grating waveguide (GWG)
coatings can show a reflectivity of up to 100% with an overall thickness of
less than a wavelength. We theoretically investigate GWG coatings for 1064nm
based on tantala (Ta2O5) on a Silica substrate focussing on broad spectral
response and low thickness
Chromosome mapping: radiation hybrid data and stochastic spin models
This work approaches human chromosome mapping by developing algorithms for
ordering markers associated with radiation hybrid data. Motivated by recent
work of Boehnke et al. [1], we formulate the ordering problem by developing
stochastic spin models to search for minimum-break marker configurations. As a
particular application, the methods developed are applied to 14 human
chromosome-21 markers tested by Cox et al. [2]. The methods generate
configurations consistent with the best found by others. Additionally, we find
that the set of low-lying configurations is described by a Markov-like ordering
probability distribution. The distribution displays cluster correlations
reflecting closely linked loci.Comment: 26 Pages, uuencoded LaTex, Submitted to Phys. Rev. E,
[email protected], [email protected]
Sulfur- and boron-containing porous donor-acceptor polymers for photocatalytic hydrogen evolution
Current State of Ixodidae Research in Mongolia
Our research presents the Ixodidae-fauna in Mongolia. The current taxonomic state in Mongolia shows 19 Ixodidae taxa extracted in 308 locations from 115 bird and mammal species. In 1980, the species Ixodes persulcatus SCHULZE, 1930 and Ixodes berlesei Birula, 1895 were detected in Inget Tolgoi and Ixodes laguri OLENEV, 1929 on Meriones unguiculatus 10 km southeast of Ulaanbaatar for the first time. In 2000 the species Haemaphysalis concinna Koch, 1844 was detected in the Selenge-river area and Argas (Argas) vulgaris FILIPPOVA, 1961 was detected in the Gobi area. From the collection of M. and A. STUBBE 1 N (Nymphae) Ixodes persulcatus was detected on Microtus sp. at the Minž-gol (river in Khentey) on July 25, 2002
Biliary stenting in patients with pancreatic cancer: results from a population-based cohort study
We aimed to describe management of biliary obstruction (BO) in the context of pancreatic cancer within a population-based cohort.We examined management of BO in 1863 patients diagnosed as having pancreatic cancer in 2010/2011. We used descriptive statistics and logistic regression to describe patterns of biliary stent usage, complications and duration of patency, associations between preoperative stenting and surgical outcomes, and between patient factors and management of jaundice.Almost half of the people in the cohort (n = 909) were jaundiced within 12 months of diagnosis. Two-thirds of these had at least 1 stent inserted. Preoperative stenting, mostly with plastic stents, occurred for 72% of patients who experienced jaundice prior to an attempted resection but was not associated with surgical outcomes. Seventy percent of the jaundiced patients who did not have an attempted resection were stented. Metal stents were less frequently replaced within 30 days than plastic (9% vs 42%). Living in a rural area was associated with reduced likelihood of having jaundice managed.Plastic stents were still used frequently, despite guidelines recommending metal in most contexts. Patients living in rural areas were less likely to have BO managed. This work highlights the need to monitor current practice
Charge pumping in a quantum wire driven by a series of local time-periodic potentials
We develop a method to calculate electronic transport properties through a
mesoscopic scattering region in the presence of a series of time-periodic
potentials. Using the method, the quantum charge pumping driven by
time-periodic potentials is studied. Jumps in the pumped current are observed
at the peak positions of the Wigner delay time. Our main results in both the
weak pumping and strong pumping regimes are consistent with experimental
results. More interestingly, we also observed the nonzero pumping at the phase
difference phi=0 and addressed its relevance to the experimental result.Comment: 5 page
Absence of spin dependence in the final state interaction of the d(pol) p --> 3He eta reaction
The deuteron tensor analysing power t_{20} of the d(pol) p --> 3He eta
reaction has been measured at the COSY-ANKE facility in small steps in excess
energy Q up to Q = 11 MeV. Despite the square of the production amplitude
varying by over a factor of five through this range, t_{20} shows little or no
energy dependence. This is evidence that the final state interaction causing
the energy variation is not influenced by the spin configuration in the
entrance channel. The weak angular dependence observed for t_{20} provides
useful insight into the amplitude structure near threshold.Comment: 5 pages, 4 figure
Molar substitution and C2/C6 ratio of hydroxyethyl starch: influence on blood coagulation
Background. Development of hydroxyethyl starches (HES) with a low impact on blood coagulation but a long intravascular persistence is of clinical interest. A previous in vitro study showed that low substituted high molecular weight HES does not compromise blood coagulation more than medium molecular weight HES. In the present study we assessed the individual effects on blood coagulation of molar substitution and C2/C6 ratio of a high molecular weight HES. Methods. Blood was obtained from 30 healthy patients undergoing elective surgery and mixed with six high molecular weight (700 kDa) HES solutions differing in their molar substitution (0.42 and 0.51) and C2/C6 ratio (2.7, 7 and 14) to achieve 20, 40 and 60% dilution. Blood coagulation was assessed by Thrombelastograph® analysis (TEG) and plasma coagulation tests.Data were compared using a three-way analysis of variance model with repeated measures on the three factors. Results. Higher molar substitution compromised blood coagulation most (for all TEG parameters, P0.50). The higher molar substitution was associated with a lesser increase in PT (P=0.007) and a greater decrease in factor VIII (P=0.010). PTT, functional and antigenic von Willebrand factors were not significantly influenced by molar substitution (P for all >0.20). No significant differences between solutions with the same molar substitution but different C2/C6 ratios were found in plasma coagulation parameters (P for all >0.05). Conclusions. TEG analysis indicates that high molecular HES with a molar substitution of 0.42 and a C2/C6 ratio of 2.7 has the lowest effect on in vitro human blood coagulatio
New determination of the mass of the eta meson at COSY-ANKE
A value for the mass of the eta meson has been determined at the COSY-ANKE
facility through the measurement of a set of deuteron laboratory beam momenta
and associated 3He center-of-mass momenta in the d+p -> 3He+X reaction. The eta
was then identified by the missing-mass peak and the production threshold
determined. The individual beam momenta were fixed with a relative precision of
3 x 10^-5 for values around 3 GeV/c by using a polarized deuteron beam and
inducing an artificial depolarizing spin resonance, which occurs at a
well-defined frequency. The final-state momenta in the two-body d+p -> 3He+eta
reaction were investigated in detail by studying the size of the 3He momentum
ellipse with the forward detection system of the ANKE spectrometer. Final
alignment of the spectrometer for this high precision experiment was achieved
through a comprehensive study of the 3He final-state momenta as a function of
the center-of-mass angles, taking advantage of the full geometrical acceptance.
The value obtained for the mass, m(eta)=(547.873 +- 0.005(stat) +- 0.027(syst))
MeV/c^2, is consistent and competitive with other recent measurements, in which
the meson was detected through its decay products.Comment: 11 pages, 11 figures, 3 tables, published versio
Formation of a disk-structure and jets in the symbiotic prototype Z And during its 2006-2010 active phase
We present an analysis of spectrophotometric observations of the latest cycle
of activity of the symbiotic binary Z And from 2006 to 2010. We estimate the
temperature of the hot component of Z And to be \approx 150000 - 170000 K at
minimum brightness, decreasing to \approx 90000 K at the brightness maximum.
Our estimate of the electron density in the gaseous nebula is
N_{e}=10^{10}-10^{12} cm^{-3} in the region of formation of lines of neutral
helium and 10^6-10^7 cm^{-3} in the region of formation of the [OIII] and
[NeIII] nebular lines. A trend for the gas density derived from helium lines to
increase and the gas density derived from [OIII] and [NeIII] lines to
simultaneously decrease with increasing brightness of the system was observed.
Our estimates show that the ratios of the theoretical and observed fluxes in
the [OIII] and [NeIII] lines agree best when the O/Ne ratio is similar to its
value for planetary nebulae. The model spectral energy distribution showed
that, in addition to a cool component and gaseous nebula, a relatively cool
pseudophotosphere (5250-11 500 K) is present in the system. The simultaneous
presence of a relatively cool pseudophotosphere and high-ionization spectral
lines is probably related to a disk-like structure of the pseudophotosphere.
The pseudophotosphere formed very rapidly, over several weeks, during a period
of increasing brightness of Z And. We infer that in 2009, as in 2006, the
activity of the system was accompanied by a collimated bipolar ejection of
matter. In contrast to the situation in 2006, the jets were detected even
before the system reached its maximum brightness. Moreover, components with
velocities close to 1200 km/s disappeared at the maximum, while those with
velocities close to 1800 km/s appeared.Comment: 18 pages, 19 figures, Accepted for publication in Astronomy Report
- …