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Business Ecosystems: Towards a Classification Model
This paper contributes to the business ecosystem literature by offering a classification model, allowing the differentiation of intercompany connections. The problem arose for the researchers that the definition of a business ecosystem lacks separation in the types of connection between companies. Business ecosystems are found to differentiate significantly, starting from loosely coupled to highly regulated and organised company relationships. Some may even result in newly founded business ventures. The authors are proposing a classification model for business ecosystems to allow further classifications in studies
An observational prospective study of topical acidified nitrite for killing methicillin-resistant Staphylococcus aureus (MRSA) in contaminated wounds
Background Endogenous nitric oxide (NO) kills bacteria and other organisms as part of the innate immune response. When nitrite is exposed to low pH, NO is generated and has been used as an NO delivery system to treat skin infections. We demonstrated eradication of MRSA carriage from wounds using a topical formulation of citric acid (4.5%) and sodium nitrite (3%) creams co-applied for 5 days to 15 wounds in an observational prospective pilot study of 8 patients. Findings Following treatment with topical citric acid and sodium nitrite, 9 of 15 wounds (60%) and 3 of 8 patients (37%) were cleared of infection. MRSA isolates from these patients were all sensitive to acidified nitrite in vitro compared to methicillin-sensitive S. aureus and a reference strain of MRSA. Conclusions Nitric oxide and acidified nitrite offer a novel therapy for control of MRSA in wounds. Wounds that were not cleared of infection may have been re-contaminated or the bioavailability of acidified nitrite impaired by local factors in the tissue
Effect of Void Network on CMB Anisotropy
We study the effect of a void network on the CMB anisotropy in the
Einstein-de Sitter background using Thompson &Vishniac's model. We consider
comprehensively the Sacks-Wolfe effect, the Rees-Sciama effect and the
gravitational lensing effect. Our analysis includes the model of primordial
voids existing at recombination, which is realized in some inflationary models
associated with a first-order phase transition. If there exist primordial voids
whose comoving radius is larger than Mpc at recombination, not
only the Sachs-Wolfe effect but also the Rees-Sciama effect is appreciable even
for multipoles l\lsim1000 of the anisotropy spectrum. The gravitational
lensing effect, on the other hand, slightly smoothes the primary anisotropy;
quantitatively, our results for the void model are similar to the previous
results for a CDM model. All the effects, together, would give some constraints
on the configuration or origin of voids with high-resolution data of the CMB
anisotropy.Comment: 23 pages, latex, 12 eps figures, some calculations and discussions
are added, to appear in ApJ 510 (1999
Methodology for evaluating thermal track buckling in dual gauge tracks with continuous welded rail
In the National Spanish railway network, two types of track gauge with continuous welded rails are currently in use: the Iberian wide gauge (1668 mm) and the standard gauge (1435 mm). In order to improve links and freight traffic between different lines and with the rest of Europe, a dual gauge track with three rails was developed. This solution modifies the classical track configuration, so it is necessary to develop new methodologies and studies to understand its behavior. Among other loads applied on a continuous welded rail track, a considerable rise in temperature induces compressive stresses in the three rails that can lead to lateral track buckling. Moreover, on dual gauge tracks, the addition of the third rail increases the axial compression, which may lead to track instability. For this reason, a three-dimensional continuous welded rail model is developed in this study to be used for dual gauge track buckling analysis on straight tracks subjected to temperature load. The continuous welded rail dual gauge track model consists of beam, solid and spring elements, in which a non-linear behaviour of the ballast is considered. The results obtained may be used to predict the buckling capacity of the continuous welded rail on dual gauge tracks with respect to different parameters such as lateral resist-ance, lateral imperfections, sleeper spacing or torsional stiffness.Villalba Sanchis, I.; Insa Franco, R.; Salvador Zuriaga, P.; Martínez Fernández, P. (2017). Methodology for evaluating thermal track buckling in dual gauge tracks with continuous welded rail. Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit. 231(3):269-279. doi:10.1177/0954409715626957S269279231
The sizes of mini-voids in the local universe: an argument in favor of a warm dark matter model?
Using high-resolution simulations within the Cold and Warm Dark Matter models
we study the evolution of small scale structure in the Local Volume, a sphere
of 8 Mpc radius around the Local Group. We compare the observed spectrum of
mini-voids in the Local Volume with the spectrum of mini-voids determined from
the simulations. We show that the \LWDM model can easily explain both the
observed spectrum of mini-voids and the presence of low-mass galaxies observed
in the Local Volume, provided that all haloes with circular velocities greater
than 20 km/s host galaxies. On the contrary within the LCDM model the
distribution of the simulated mini-voids reflects the observed one if haloes
with maximal circular velocities larger than 35 km/s host galaxies. This
assumption is in contradiction with observations of galaxies with circular
velocities as low as 20 km/s in our Local Universe. A potential problem of the
LWDM model could be the late formation of the haloes in which the gas can be
efficiently photo-evaporated. Thus star formation is suppressed and low-mass
haloes might not host any galaxy at all.Comment: 13 pages, 10 figures, version 2, subsection 3.1 added, accepted to
MNRA
Automatic optic disc detection in colour fundus images by means of multispectral analysis and information content
The optic disc (OD) in retinal fundus images is widely used as a reference in computer-based systems for the measurement of the severity of retinal disease. A number of algorithms have been published in the past 5 years to locate and measure the OD in digital fundus images. Our proposed algorithm, automatically: (i) uses the three channels (RGB) of the digital colour image to locate the region of interest (ROI) where the OD lies, (ii) measures the Shannon information content per channel in the ROI, to decide which channel is most appropriate for searching for the OD centre using the circular Hough transform. A series of evaluations were undertaken to test our hypothesis that using the three channels gives a better performance than a single channel. Three different databases were used for evaluation purposes with a total of 2,371 colour images giving a misdetection error of 3% in the localisation of the centre of the OD. We find that the area determined by our algorithm which assumes that the OD is circular, is similar to that found by other algorithms that detected the shape of the OD. Five metrics were measured for comparison with other recent studies. Combining the two databases where expert delineation of the OD is available (1,240 images), the average results for our multispectral algorithm are: TPR = 0.879, FPR = 0.003, Accuracy = 0.994, Overlap = 80.6% and Dice index = 0.878
A 24-year experience of autologous stem cell transplantation for light chain amyloidosis patients in the United Kingdom
Autologous stem cell transplantation (ASCT) is considered to be the best method to achieve deep haematological/organ responses and improve survival in selected patients with AL amyloidosis. This field has been led by US centres and is less utilised in Europe. The introduction of effective chemotherapy agents for AL prompted us to re‐evaluate UK outcomes of ASCT in affected patients. A total of 264 AL amyloidosis patients treated with an ASCT between 1994 and 2018 were identified. Patient baseline characteristics, transplant‐related mortality (TRM) and overall survival (OS) were analysed. The median OS post‐ASCT was 87 months [95% confidence interval (CI): 77–106 months]. The median time from ASCT to next treatment was 48 months (95% CI: 29–55 months). A haematological response was achieved in 94·8% of patients and was a strong predictor of time to next treatment [P < 0·0001, hazard ratio (HR) = 1·75, 95% CI = 1·35–2·28] and OS (P = 0·007, HR = 1·91, 95% CI = 1·19–3·07). Organ response was: cardiac (n = 28, 60·9%), renal (n = 101, 76%) and liver (n = 7, 13·5%). Overall TRM was 8·7%, with a significant reduction over time (1994–2000: 18·8%; 2001–2006: 13·6%; 2007–2012: 6·2%; 2013–2018: 1·1%). In conclusion, ASCT is significantly safer and remains a highly effective treatment with excellent long‐term survival; it should be more widely considered as a treatment option for systemic AL amyloidosis
The fully connected N-dimensional skeleton: probing the evolution of the cosmic web
A method to compute the full hierarchy of the critical subsets of a density
field is presented. It is based on a watershed technique and uses a probability
propagation scheme to improve the quality of the segmentation by circumventing
the discreteness of the sampling. It can be applied within spaces of arbitrary
dimensions and geometry. This recursive segmentation of space yields, for a
-dimensional space, a succession of -dimensional subspaces that
fully characterize the topology of the density field. The final 1D manifold of
the hierarchy is the fully connected network of the primary critical lines of
the field : the skeleton. It corresponds to the subset of lines linking maxima
to saddle points, and provides a definition of the filaments that compose the
cosmic web as a precise physical object, which makes it possible to compute any
of its properties such as its length, curvature, connectivity etc... When the
skeleton extraction is applied to initial conditions of cosmological N-body
simulations and their present day non linear counterparts, it is shown that the
time evolution of the cosmic web, as traced by the skeleton, is well accounted
for by the Zel'dovich approximation. Comparing this skeleton to the initial
skeleton undergoing the Zel'dovich mapping shows that two effects are competing
during the formation of the cosmic web: a general dilation of the larger
filaments that is captured by a simple deformation of the skeleton of the
initial conditions on the one hand, and the shrinking, fusion and disappearance
of the more numerous smaller filaments on the other hand. Other applications of
the N dimensional skeleton and its peak patch hierarchy are discussed.Comment: Accepted for publication in MNRA
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