516 research outputs found
Effects of ileo-rectal anastomosis on cholesterol metabolism in pigs fed either casein or extruded soya beans.
Towards non-parametric fiber-specific relaxometry in the human brain
Purpose: To estimate fiber-specific values, i.e. proxies for myelin
content, in heterogeneous brain tissue. Methods: A diffusion- correlation
experiment was carried out on an in vivo human brain using tensor-valued
diffusion encoding and multiple repetition times. The acquired data was
inverted using a Monte-Carlo inversion algorithm that retrieves non-parametric
distributions of diffusion tensors and
longitudinal relaxation rates . Orientation distribution functions
(ODFs) of the highly anisotropic components of
were defined to visualize orientation-specific diffusion-relaxation properties.
Finally, Monte-Carlo density-peak clustering (MC-DPC) was performed to quantify
fiber-specific features and investigate microstructural differences between
white-matter fiber bundles. Results: Parameter maps corresponding to
's statistical descriptors were obtained,
exhibiting the expected contrast between brain-tissue types. Our ODFs
recovered local orientations consistent with the known anatomy and indicated
possible differences in relaxation between major fiber bundles. These
differences, confirmed by MC-DPC, were in qualitative agreement with previous
model-based works but seem biased by the limitations of our current
experimental setup. Conclusions: Our Monte-Carlo framework enables the
non-parametric estimation of fiber-specific diffusion- features, thereby
showing potential for characterizing developmental or pathological changes in
within a given fiber bundle, and for investigating inter-bundle
differences.Comment: 11 pages, 6 figures, submitted to Magnetic Resonance in Medicine
(MRM) on the 14th of June 202
Addressing drinking water salinity due to sea water intrusion in Praia de Leste, Parana, by a brackish water desalination pilot plant
Seawater intrusion into the Pombas River, source of freshwater to Praia de Leste on the coast of
Parana in Brazil presents a problem to the water utility as most water treatment plants in Brazil
are conventional. To find a solution to this problem, a pilot plant (1 m3
/h) consisting of ultrafiltration (UF) followed by reverse osmosis (RO) was developed and evaluated. For testing, brackish
water was produced with a concentration of 1,500 Âą 100 mg/L of total dissolved solids (TDS), mixing
seawater and fresh water. To evaluate the water quality, TDS, electrical conductivity, pH, temperature,
apparent color, turbidity, alkalinity, total hardness, calcium, chloride and sulfate were monitored.
For operational performance, flowrates, osmotic pressure, filtration rate, recovery rate and mass balance were analyzed. On average, the UF system removed 96.4% of turbidity and 98.6% of apparent
color; whereas the RO system removed 99.4% of TDS. The overall average recovery (UF and RO)
was 45.81% with average osmotic pressure of 8.21 bar, filtration rate of 30.7 L/h/m2
in the UF system
and 21.7 L/h/m2
in the RO system. From a water quality point of view, the system was effective in
processing brackish into fresh water of high quality
Red (660 nm) and infrared (830 nm) low-level laser therapy in skeletal muscle fatigue in humans: what is better?
In animal and clinical trials low-level laser therapy (LLLT) using red, infrared and mixed wavelengths has been shown to delay the development of skeletal muscle fatigue. However, the parameters employed in these studies do not allow a conclusion as to which wavelength range is better in delaying the development of skeletal muscle fatigue. With this perspective in mind, we compared the effects of red and infrared LLLT on skeletal muscle fatigue. A randomized double-blind placebo-controlled crossover trial was performed in ten healthy male volunteers. They were treated with active red LLLT, active infrared LLLT (660 or 830Â nm, 50Â mW, 17.85Â W/cm2, 100Â s irradiation per point, 5Â J, 1,785Â J/cm2 at each point irradiated, total 20Â J irradiated per muscle) or an identical placebo LLLT at four points of the biceps brachii muscle for 3Â min before exercise (voluntary isometric elbow flexion for 60Â s). The mean peak force was significantly greater (pâ<â0.05) following red (12.14%) and infrared LLLT (14.49%) than following placebo LLLT, and the mean average force was also significantly greater (pâ<â0.05) following red (13.09%) and infrared LLLT (13.24%) than following placebo LLLT. There were no significant differences in mean average force or mean peak force between red and infrared LLLT. We conclude that both red than infrared LLLT are effective in delaying the development skeletal muscle fatigue and in enhancement of skeletal muscle performance. Further studies are needed to identify the specific mechanisms through which each wavelength acts
Mortalidade infantil em Cuiabå, Mato Grosso, Brasil, 2005: comparação entre o cålculo direto e após o linkage entre bancos de dados de nascidos vivos e óbitos infantis
Compressed representation of a partially defined integer function over multiple arguments
In OLAP (OnLine Analitical Processing) data are analysed in an n-dimensional cube. The cube may be represented as a partially defined function over n arguments. Considering that often the function is not defined everywhere, we ask: is there a known way of representing the function or the points in which it is defined, in a more compact manner than the trivial one
Search for new physics with same-sign isolated dilepton events with jets and missing transverse energy
A search for new physics is performed in events with two same-sign isolated
leptons, hadronic jets, and missing transverse energy in the final state. The
analysis is based on a data sample corresponding to an integrated luminosity of
4.98 inverse femtobarns produced in pp collisions at a center-of-mass energy of
7 TeV collected by the CMS experiment at the LHC. This constitutes a factor of
140 increase in integrated luminosity over previously published results. The
observed yields agree with the standard model predictions and thus no evidence
for new physics is found. The observations are used to set upper limits on
possible new physics contributions and to constrain supersymmetric models. To
facilitate the interpretation of the data in a broader range of new physics
scenarios, information on the event selection, detector response, and
efficiencies is provided.Comment: Published in Physical Review Letter
X-ray emission from the Sombrero galaxy: discrete sources
We present a study of discrete X-ray sources in and around the
bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival
Chandra observations with a total exposure of ~200 ks. With a detection limit
of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30
kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler
et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS
observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray
binaries (LMXBs). We quantify the differential luminosity functions (LFs) for
both the detected GC and field LMXBs, whose power-low indices (~1.1 for the
GC-LF and ~1.6 for field-LF) are consistent with previous studies for
elliptical galaxies. With precise sky positions of the GCs without a detected
X-ray source, we further quantify, through a fluctuation analysis, the GC LF at
fainter luminosities down to 1E35 erg/s. The derived index rules out a
faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent
findings in several elliptical galaxies and the bulge of M31. On the other
hand, the 2-6 keV unresolved emission places a tight constraint on the field
LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101
sources in the halo of Sombrero. The presence of these sources cannot be
interpreted as galactic LMXBs whose spatial distribution empirically follows
the starlight. Their number is also higher than the expected number of cosmic
AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray
surveys. We suggest that either the cosmic X-ray background is unusually high
in the direction of Sombrero, or a distinct population of X-ray sources is
present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
Azimuthal anisotropy of charged particles at high transverse momenta in PbPb collisions at sqrt(s[NN]) = 2.76 TeV
The azimuthal anisotropy of charged particles in PbPb collisions at
nucleon-nucleon center-of-mass energy of 2.76 TeV is measured with the CMS
detector at the LHC over an extended transverse momentum (pt) range up to
approximately 60 GeV. The data cover both the low-pt region associated with
hydrodynamic flow phenomena and the high-pt region where the anisotropies may
reflect the path-length dependence of parton energy loss in the created medium.
The anisotropy parameter (v2) of the particles is extracted by correlating
charged tracks with respect to the event-plane reconstructed by using the
energy deposited in forward-angle calorimeters. For the six bins of collision
centrality studied, spanning the range of 0-60% most-central events, the
observed v2 values are found to first increase with pt, reaching a maximum
around pt = 3 GeV, and then to gradually decrease to almost zero, with the
decline persisting up to at least pt = 40 GeV over the full centrality range
measured.Comment: Replaced with published version. Added journal reference and DO
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