788 research outputs found
New constraints on the Pion EM form factor using Pi'(-Q^2)
We study the constraints arising on the expansion parameters c and d of the
Pion electromagnetic form factor from the inclusion of pure space-like data and
the phase of time-like data along with one space-like datum, using as input the
first derivative of the QCD polarization amplitude Pi'(-Q^2). These constraints
when combined with other analyses, provide a valuable check on a determination
of c due to Guo et al. and on our previous work where pionic contribution to
the (g-2) of the muon was used as the input. This work further illustrates the
power of analyticity techniques in form factor analysis.Comment: 8 pages latex, uses EPJA style files, contains 12 figures; replaced
with version accepted for publication in EPJA, minor typos corrected,
discussion improved, reference adde
India's Health Initiative: Financing Issues and Options
In response to the challenge of sustaining the health gains achieved in the better-performing states and ensuring that the lagging states catch up with the rest of the country, the Indian government has launched the National Rural Health Mission. A central goal of the effort is to increase public spending on health from the current 1.1 percent of GDP to roughly 2–3 percent of GDP within the next five years. In this paper, we examine the current status of health financing in India, as well as alternatives for realizing maximal health gains for the incremental expenditures.health financing, public spending, India, cost-effectiveness
Magnetic resonance imaging (MRI) of heavy-metal transport and fate in an artificial biofilm
Unlike planktonic systems, reaction rates in biofilms are often limited by mass transport, which controls the rate of supply of contaminants into the biofilm matrix. To help understand this phenomenon, we investigated the potential of magnetic resonance imaging (MRI) to spatially quantify copper transport and fate in biofilms. For this initial study we utilized an artificial biofilm composed of a 50:50 mix of bacteria and agar. MRI successfully mapped Cu2+ uptake into the artificial biofilm by mapping T2 relaxation rates. A calibration protocol was used to convert T2 values into actual copper concentrations. Immobilization rates in the artificial biofilm were slow compared to the rapid equilibration of planktonic systems. Even after 36 h, the copper front had migrated only 3 mm into the artificial biofilm and at this distance from the copper source, concentrations were very low. This slow equilibration is a result of (1) the time it takes copper to diffuse over such distances and (2) the adsorption of copper onto cell surfaces, which further impedes copper diffusion. The success of this trial run indicates MRI could be used to quantitatively map heavy metal transport and immobilization in natural biofilms
Studies in Ultrafine Particle Production
Ultra fine grinding has attracted many industries for the better product quality. It has been seen that new developments in electronic industries have demand for the desired size distribution (narrow distribution) offine sizes. Attrition mill has specific advantage over other conventional milling equipment such as Ball Mill and fluid
energy mill due to the energy saving in the combination process. An attempt has been made to study the performance of grinding in a laboratory Attrition millfor the control of the product size distribution.The experiments were carried in the laboratory Attrition mill and the effect of ball size distribution on product size distribution was studied. The study was concentrated in the estimation of the comm inution functions such as specific rate grinding by experimental techniques. The experimentally estimated breakage distribution functions were used to predict the rate of grinding, and the product size distribution
Supersolid and solitonic phases in one-dimensional Extended Bose-Hubbard model
We report our findings on quantum phase transitions in cold bosonic atoms in
a one dimensional optical lattice using the finite size density matrix
renormalization group method in the framework of the extended Bose-Hubbard
model. We consider wide ranges of values for the filling factors and the
nearest neighbor interactions. At commensurate fillings, we obtain two
different types of charge density wave phases and a Mott insulator phase.
However, departure from commensurate fillings yield the exotic supersolid phase
where both the crystalline and the superfluid orders coexist. In addition, we
obtain signatures for solitary waves and also superfluidity.Comment: 7 pages, 11 figure
Local Projections of Low-Momentum Potentials
Nuclear interactions evolved via renormalization group methods to lower
resolution become increasingly non-local (off-diagonal in coordinate space) as
they are softened. This inhibits both the development of intuition about the
interactions and their use with some methods for solving the quantum many-body
problem. By applying "local projections", a softened interaction can be reduced
to a local effective interaction plus a non-local residual interaction. At the
two-body level, a local projection after similarity renormalization group (SRG)
evolution manifests the elimination of short-range repulsive cores and the flow
toward universal low-momentum interactions. The SRG residual interaction is
found to be relatively weak at low energy, which motivates a perturbative
treatment
Can intracranial time-of-flight-MR angiography predict extracranial carotid artery stenosis?
Objectives: Extracranial stenosis of the internal carotid artery (ICA) is an important cause of ischemic stroke and transient ischemic attack (TIA). It can be diagnosed using contrast-enhanced CT or MR angiography (MRA) as well as Doppler ultrasound. In this study, we assessed the diagnostic value of intracranial time-of-flight (TOF) MRA to predict extracranial ICA stenosis (ICAS).
Methods: We retrospectively analyzed consecutive patients with acute ischemic stroke or TIA and middle- (50-69%) or high-grade (70-99%) unilateral extracranial ICAS according to NASCET criteria assessed by ultrasound between January 2016 and August 2018. The control group consisted of patients without extracranial ICAS. Intraluminal signal intensities (SI) of the intracranial ICA on the side of the extracranial stenosis were compared to the contralesional side on TOF-MRA source images. SI ratios (SIR) of contralesional:lesional side were compared between groups.
Results: In total, 151 patients were included in the main analysis. Contralesional:lesional SIR in the intracranial C4-segment was significantly higher in patients with ipsilateral extracranial ICA stenosis (n = 51, median 74 years, 57% male) compared to the control group (n = 100, median 68 years, 48% male). Mean SIR was 1.463 vs. 1.035 (p < 0.001) for right-sided stenosis and 1.362 vs. 1.000 (p < 0.001) for left-sided stenosis. Receiver-operating characteristic curve demonstrated a cut-off value of 1.086 for right-sided [sensitivity/specificity 75%/81%; area under the curve (AUC) 0.81] and 1.104 for left-sided stenosis (sensitivity/specificity 70%/84%; AUC 0.80) in C4 as a good predictor for high-grade extracranial ICAS.
Conclusions: SIR on TOF-MRA can be a marker of extracranial ICAS
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