3,985 research outputs found
Phase sensitive detection of dipole radiation in a fiber-based high numerical aperture optical system
We theoretically study the problem of detecting dipole radiation in an
optical system of high numerical aperture in which the detector is sensitive to
\textit{field amplitude}. In particular, we model the phase sensitive detector
as a single-mode cylindrical optical fiber. We find that the maximum in
collection efficiency of the dipole radiation does not coincide with the
optimum resolution for the light gathering instrument. The calculated results
are important for analyzing fiber-based confocal microscope performance in
fluorescence and spectroscopic studies of single molecules and/or quantum dots.Comment: 12 pages, 2 figure
Strong extinction of a far-field laser beam by a single quantum dot
Through the utilization of index-matched GaAs immersion lens techniques we
demonstrate a record extinction (12%) of a far-field focused laser by a single
InAs/GaAs quantum dot. This contrast level enables us to report for the first
time resonant laser transmission spectroscopy on a single InAs/GaAs quantum dot
without the need for phase-sensitive lock-in detection
On attributes of a Rotating Neutron star with a Hyperon core
We study the effect of rotation on global properties of neutron star with a
hyperon core in an effective chiral model with varying nucleon effective mass
within a mean field approach. The resulting gross properties of the rotating
compact star sequences are then compared and analyzed with other theoretical
predictions and observations from neutron stars. The maximum mass of the
compact star predicted by the model lies in the range at
Kepler frequency , which is consistant with recent observation of
high mass stars thereby reflecting the sensitivity of the underlying nucleon
effective mass in the dense matter EoS. We also discuss the implications of the
experimental constraints from the flow data from heavy-ion collisions on the
global properties of the rotating neutron stars.Comment: 11 Pages, 10 Figures and 2 Table
PV-0276: Adaptive radiotherapy: rate of "marginal" failure after "replanning" in combined treatment of NSCLC
Permeability of self-affine rough fractures
The permeability of two-dimensional fractures with self-affine fractal
roughness is studied via analytic arguments and numerical simulations. The
limit where the roughness amplitude is small compared with average fracture
aperture is analyzed by a perturbation method, while in the opposite case of
narrow aperture, we use heuristic arguments based on lubrication theory.
Numerical simulations, using the lattice Boltzmann method, are used to examine
the complete range of aperture sizes, and confirm the analytic arguments.Comment: 11 pages, 9 figure
Early improvement of glycaemic control after virus clearance in patients with chronic hepatitis C and severe liver fibrosis: a cohort study
HCV has been recognized as the cause of chronic hepatitis C (CHC) since 1990. CHC is associated with
progressive liver damage and extrahepatic conditions. Direct antiviral agents (DAAs), approved in 2014,
have shown effectiveness in eradicating HCV in most patients. However, little is known about the effect of
viral eradication on hepatic and extra-hepatic damage.
We performed a historical cohort study of patients with HCV-related liver diseases who achieved SVR
from March 2015 to October 2016 at INMI Lazzaro Spallanzani liver Unit in Rome (Italy). Repeated measures of glycaemia were analysed through a multilevel analysis framework to assess short time kinetics of
blood glucose level at different times after therapy and for different levels of HCV viremia.
The analysis included 205 patients. A model assessing temporal kinetics and variation of glycaemia according to HCV viremia provided evidence that blood glucose levels significantly dropped in patients with
diabetes achieving SVR. Most of the variations occurred at 3-5 weeks of therapy (-17.96 mg/dL; p<0.001)
and in coincidence with HCV clearance (-13.92 mg/dL; p<0.001). A weak, non-statistically significant reduction was observed in normoglycemic patients.
Our study provides evidence that DAAs therapy may significantly improve glycaemic control in patients
with CHC achieving SVR even when liver diseases are already established
Spatial modes for transmission of chikungunya virus during a large chikungunya outbreak in Italy: a modeling analysis
14openInternationalBothBackground
The spatial spread of many mosquito-borne diseases occurs by focal spread at the scale of a few hundred meters and over longer distances due to human mobility. The relative contributions of different spatial scales for transmission of chikungunya virus require definition to improve outbreak vector control recommendations.
Methods
We analyzed data from a large chikungunya outbreak mediated by the mosquito Aedes albopictus in the Lazio region, Italy, consisting of 414 reported human cases between June and November 2017. Using dates of symptom onset, geographic coordinates of residence, and information from epidemiological questionnaires, we reconstructed transmission chains related to that outbreak.
Results
Focal spread (within 1 km) accounted for 54.9% of all cases, 15.8% were transmitted at a local scale (1–15 km) and the remaining 29.3% were exported from the main areas of chikungunya circulation in Lazio to longer distances such as Rome and other geographical areas. Seventy percent of focal infections (corresponding to 38% of the total 414 cases) were transmitted within a distance of 200 m (the buffer distance adopted by the national guidelines for insecticide spraying). Two main epidemic clusters were identified, with a radius expanding at a rate of 300–600 m per month. The majority of exported cases resulted in either sporadic or no further transmission in the region.
Conclusions
Evidence suggest that human mobility contributes to seeding a relevant number of secondary cases and new foci of transmission over several kilometers. Reactive vector control based on current guidelines might allow a significant number of secondary clusters in untreated areas, especially if the outbreak is not detected early. Existing policies and guidelines for control during outbreaks should recommend the prioritization of preventive measures in neighboring territories with known mobility flows to the main areas of transmission.openGuzzetta, Giorgio; Vairo, Francesco; Mammone, Alessia; Lanini, Simone; Poletti, Piero; Manica, Mattia; Rosa, Roberto; Caputo, Beniamino; Solimini, Angelo; Torre, Alessandra Della; Scognamiglio, Paola; Zumla, Alimuddin; Ippolito, Giuseppe; Merler, StefanoGuzzetta, G.; Vairo, F.; Mammone, A.; Lanini, S.; Poletti, P.; Manica, M.; Rosa, R.; Caputo, B.; Solimini, A.; Torre, A.D.; Scognamiglio, P.; Zumla, A.; Ippolito, G.; Merler, S
Spatial modes for transmission of chikungunya virus during a large chikungunya outbreak in Italy. A modeling analysis
Background
The spatial spread of many mosquito-borne diseases occurs by focal spread at the scale of a few hundred meters and over longer distances due to human mobility. The relative contributions of different spatial scales for transmission of chikungunya virus require definition to improve outbreak vector control recommendations.
Methods
We analyzed data from a large chikungunya outbreak mediated by the mosquito Aedes albopictus in the Lazio region, Italy, consisting of 414 reported human cases between June and November 2017. Using dates of symptom onset, geographic coordinates of residence, and information from epidemiological questionnaires, we reconstructed transmission chains related to that outbreak.
Results
Focal spread (within 1 km) accounted for 54.9% of all cases, 15.8% were transmitted at a local scale (1–15 km) and the remaining 29.3% were exported from the main areas of chikungunya circulation in Lazio to longer distances such as Rome and other geographical areas. Seventy percent of focal infections (corresponding to 38% of the total 414 cases) were transmitted within a distance of 200 m (the buffer distance adopted by the national guidelines for insecticide spraying). Two main epidemic clusters were identified, with a radius expanding at a rate of 300–600 m per month. The majority of exported cases resulted in either sporadic or no further transmission in the region.
Conclusions
Evidence suggest that human mobility contributes to seeding a relevant number of secondary cases and new foci of transmission over several kilometers. Reactive vector control based on current guidelines might allow a significant number of secondary clusters in untreated areas, especially if the outbreak is not detected early. Existing policies and guidelines for control during outbreaks should recommend the prioritization of preventive measures in neighboring territories with known mobility flows to the main areas of transmission
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