3,718 research outputs found
\u27Do It Yourself (DIY)\u27 E-Business Solutions for Small and Medium Enterprises
The potential benefits and cost of adopting and implementing e-business solutions are both high. They are major attraction and concern for Small and Medium sized Enterprises (SMEs) respectively. If a right tradeoff point is not balanced between the two, a breakthrough progress is unlikely to become true. This paper addresses this very issue by proposing and developing a new approach based on the concept of âportaletsâ that are used as building blocks to develop e-business solutions with no or varying degree of customization efforts. Portalets are designed following the platform for deriving the software product lines. This âDo It Yourself (DI)â approach significantly reduces the time and effort to an affordable level while capturing the unique business logics into the solutions. In this paper, the necessity, feasibility, and the challenging issues of the proposed DIY e-business approach will be discussed. Case studies will be presented to demonstrate the approach and directions for further work
Prognostic Value of Bone Scintigraphy in Cancer Patients With Osteonecrosis of the Jaw
identifying imaging predictors of healing of osteonecrosis of the jaw (ONJ) in cancer patients may assist in better stratification of treatment strategies.
MATERIALS AND METHODS:
patients with ONJ were followed prospectively and underwent bone scintigraphy, both planar and single-photon emission computed tomography (SPECT) imaging. End points were time to healing and the number of recurrences. Studied parameters included lesion visibility, pattern of uptake, and quantification of uptake relative to the unaffected side.
RESULTS:
a total of 22 patients were recruited (3 men; 19 women) with a stage 1 ONJ lesion in 8, stage 2 in 9, and stage 3 ONJ in 5 patients. Median duration of follow-up was 12 months (range, 6-37). SPECT acquisitions proved superior over planar images in detecting ONJ lesions (P = 0.03). Quantification of tracer uptake in the ONJ lesion relative to the unaffected side showed increasing uptake with higher stages of ONJ: mean, 1.67 (95% confidence interval [CI], 1.17-2.18) in stage 1, 2.72 (95% CI, 2.24-3.20) in stage 2, and 4.62 (95% CI, 3.98-5.26) in stage 3. In addition, this relative ratio of uptake was found to be an independent predictor of ONJ healing (hazard ratio, 0.24; 95% CI, 0.07-0.82; P = 0.02). Neither ONJ stage nor relative ratio of uptake were predictors of the occurrence of ONJ relapses.
CONCLUSIONS:
bone scintigraphy in patients with ONJ is feasible and SPECT acquisitions are preferred over planar images. Relative quantification of tracer uptake provides prognostic information independent of clinical stage that may assist in identifying patients with a poor prognosis
Optimizing fire station locations for the Istanbul metropolitan municipality
Copyright @ 2013 INFORMSThe Istanbul Metropolitan Municipality (IMM) seeks to determine locations for additional fire stations to build in Istanbul; its objective is to make residences and historic sites reachable by emergency vehicles within five minutes of a fire stationâs receipt of a service request. In this paper, we discuss our development of a mathematical model to aid IMM in determining these locations by using data retrieved from its fire incident records. We use a geographic information system to implement the model on Istanbulâs road network, and solve two location modelsâset-covering and maximal-coveringâas what-if scenarios. We discuss 10 scenarios, including the situation that existed when we initiated the project and the scenario that IMM implemented. The scenario implemented increases the cityâs fire station coverage from 58.6 percent to 85.9 percent, based on a five-minute response time, with an implementation plan that spans three years
The impact of current CH4 and N2O atmospheric loss process uncertainties on calculated ozone abundances and trends
The atmospheric loss processes of N2O and CH4, their estimated uncertainties, lifetimes, and impacts on ozone abundance and long-term trends are examined using atmospheric model calculations and updated kinetic and photochemical parameters and uncertainty factors from SPARC [2013]. The uncertainty ranges in calculated N2O and CH4 global lifetimes computed using the SPARC estimated uncertainties are reduced by nearly a factor of two compared with uncertainties from Sander et al. [2011]. Uncertainties in CH4 loss due to reaction with OH and O(1D) have relatively small impacts on present day global total ozone (±0.2-0.3%). Uncertainty in the Cl + CH4 reaction affects the amount of chlorine in radical vs. reservoir forms and has a modest impact on present day SH polar ozone (~±6%), and on the rate of past ozone decline and future recovery. Uncertainty in the total rate coefficient for the O(1D) + N2O reaction results in a substantial range in present day stratospheric odd nitrogen (±20-25%) and global total ozone (±1.5-2.5%). Uncertainty in the O(1D) + N2O reaction branching ratio for the O2 + N2 and 2*NO product channels results in moderate impacts on odd nitrogen (±10%) and global ozone (±1%),with uncertainty in N2O photolysis resulting in relatively small impacts (±5% in odd nitrogen, ±0.5% in global ozone). Uncertainties in the O(1D) + N2O reaction and its branching ratio also affect the rate of past global total ozone decline and future recovery, with a range in future ozone projections of ±1-1.5% by 2100, relative to present day
A Close Nuclear Black Hole Pair in the Spiral Galaxy NGC 3393
The current picture of galaxy evolution advocates co-evolution of galaxies
and their nuclear massive black holes (MBHs), through accretion and merging.
Quasar pairs (6,000-300,000 light-years separation) exemplify the first stages
of this gravitational interaction. The final stages, through binary MBHs and
final collapse with gravitational wave emission, are consistent with the
sub-light-year separation MBHs inferred from optical spectra and
light-variability of two quasars. The double active nuclei of few nearby
galaxies with disrupted morphology and intense star formation (e.g., NGC 6240
and Mkn 463; ~2,400 and ~12,000 light-years separation respectively)
demonstrate the importance of major mergers of equal mass spirals in this
evolution, leading to an elliptical galaxy, as in the case of the double radio
nucleus (~15 light-years separation) elliptical 0402+379. Minor mergers of
galaxies with a smaller companion should be a more common occurrence, evolving
into spiral galaxies with active MBH pairs, but have hitherto not been seen.
Here we report the presence of two active MBHs, separated by ~430 light-years,
in the Seyfert galaxy NGC 3393. The regular spiral morphology and predominantly
old circum-nuclear stellar population of this galaxy, and the closeness of the
MBHs embedded in the bulge, suggest the result of minor merger evolution.Comment: Preprint (not final) version of a paper to appear in Natur
Development of a Health-Protective Drinking Water Level for Perchlorate
We evaluated animal and human toxicity data for perchlorate and identified reduction of thyroidal iodide uptake as the critical end point in the development of a health-protective drinking water level [also known as the public health goal (PHG)] for the chemical. This work was performed under the drinking water program of the Office of Environmental Health Hazard Assessment of the California Environmental Protection Agency. For doseâresponse characterization, we applied benchmark-dose modeling to human data and determined a point of departure (the 95% lower confidence limit for 5% inhibition of iodide uptake) of 0.0037 mg/kg/day. A PHG of 6 ppb was calculated by using an uncertainty factor of 10, a relative source contribution of 60%, and exposure assumptions specific to pregnant women. The California Department of Health Services will use the PHG, together with other considerations such as economic impact and engineering feasibility, to develop a California maximum contaminant level for perchlorate. We consider the PHG to be adequately protective of sensitive subpopulations, including pregnant women, their fetuses, infants, and people with hypothyroidism
Manipulating infrared photons using plasmons in transparent graphene superlattices
Superlattices are artificial periodic nanostructures which can control the
flow of electrons. Their operation typically relies on the periodic modulation
of the electric potential in the direction of electron wave propagation. Here
we demonstrate transparent graphene superlattices which can manipulate infrared
photons utilizing the collective oscillations of carriers, i.e., plasmons of
the ensemble of multiple graphene layers. The superlattice is formed by
depositing alternating wafer-scale graphene sheets and thin insulating layers,
followed by patterning them all together into 3-dimensional
photonic-crystal-like structures. We demonstrate experimentally that the
collective oscillation of Dirac fermions in such graphene superlattices is
unambiguously nonclassical: compared to doping single layer graphene,
distributing carriers into multiple graphene layers strongly enhances the
plasmonic resonance frequency and magnitude, which is fundamentally different
from that in a conventional semiconductor superlattice. This property allows us
to construct widely tunable far-infrared notch filters with 8.2 dB rejection
ratio and terahertz linear polarizers with 9.5 dB extinction ratio, using a
superlattice with merely five graphene atomic layers. Moreover, an unpatterned
superlattice shields up to 97.5% of the electromagnetic radiations below 1.2
terahertz. This demonstration also opens an avenue for the realization of other
transparent mid- and far-infrared photonic devices such as detectors,
modulators, and 3-dimensional meta-material systems.Comment: under revie
Platypnea-orthodeoxia associated with a fenestrated atrial septal aneurysm: Case Report
BACKGROUND: Platypnea-orthodeoxia describes the condition of combined dyspnea and hypoxia respectively, whilst in the upright position, which improves in the recumbent position. CASE REPORT: We present a case of platypnea-orthodeoxia due to a fenestrated atrial septal defect associated with an atrial septal aneurysm. Due to the fenestrated nature of the atrial septal defect, surgical rather than percutaneous correction was performed. CONCLUSION: A high index of suspicion is required to diagnose the syndrome of platypnea-orthodeoxia. Careful echocardiographic evaluation is required to identify the syndrome, and to determine suitability for percutaneous repair
Radiographic Image Enhancement by Wiener Decorrelation
The primary focus of the application of image processing to radiography is the problem of segmentation. The general segmentation problem has been attacked on a broad front [1, 2], and thresholding, in particular, is a popular method [1, 3-6]. Unfortunately, geometric unsharpness destroys the crisp edges needed for unambiguous decisions, and this difficulty can be considered a problem in filtering in which the object is to devise a high-pass (sharpening) filter. This approach has been studied for more than 20 years [7-13]
DNA-based Self-Assembly of Chiral Plasmonic Nanostructures with Tailored Optical Response
Surface plasmon resonances generated in metallic nanostructures can be
utilized to tailor electromagnetic fields. The precise spatial arrangement of
such structures can result in surprising optical properties that are not found
in any naturally occurring material. Here, the designed activity emerges from
collective effects of singular components equipped with limited individual
functionality. Top-down fabrication of plasmonic materials with a predesigned
optical response in the visible range by conventional lithographic methods has
remained challenging due to their limited resolution, the complexity of
scaling, and the difficulty to extend these techniques to three-dimensional
architectures. Molecular self-assembly provides an alternative route to create
such materials which is not bound by the above limitations. We demonstrate how
the DNA origami method can be used to produce plasmonic materials with a
tailored optical response at visible wavelengths. Harnessing the assembly power
of 3D DNA origami, we arranged metal nanoparticles with a spatial accuracy of 2
nm into nanoscale helices. The helical structures assemble in solution in a
massively parallel fashion and with near quantitative yields. As a designed
optical response, we generated giant circular dichroism and optical rotary
dispersion in the visible range that originates from the collective
plasmon-plasmon interactions within the nanohelices. We also show that the
optical response can be tuned through the visible spectrum by changing the
composition of the metal nanoparticles. The observed effects are independent of
the direction of the incident light and can be switched by design between left-
and right-handed orientation. Our work demonstrates the production of complex
bulk materials from precisely designed nanoscopic assemblies and highlights the
potential of DNA self-assembly for the fabrication of plasmonic nanostructures.Comment: 5 pages, 4 figure
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