273 research outputs found
Message and time efficient multi-broadcast schemes
We consider message and time efficient broadcasting and multi-broadcasting in
wireless ad-hoc networks, where a subset of nodes, each with a unique rumor,
wish to broadcast their rumors to all destinations while minimizing the total
number of transmissions and total time until all rumors arrive to their
destination. Under centralized settings, we introduce a novel approximation
algorithm that provides almost optimal results with respect to the number of
transmissions and total time, separately. Later on, we show how to efficiently
implement this algorithm under distributed settings, where the nodes have only
local information about their surroundings. In addition, we show multiple
approximation techniques based on the network collision detection capabilities
and explain how to calibrate the algorithms' parameters to produce optimal
results for time and messages.Comment: In Proceedings FOMC 2013, arXiv:1310.459
A Review of Carcinomas Arising in the Head and Neck Region in HIV-Positive Patients
The majority of malignancies arising in the head and neck among patients with AIDS are Kaposi sarcoma and non-Hodgkin lymphoma. Patients with HIV/AIDS are also at increased risk of developing several carcinomas of the head and neck. This paper focuses on these less common, albeit important, carcinomas. An English language literature search identified numerous population-based studies evaluating carcinomas in the head and neck of HIV-positive patients. Published results indicate that patients with HIV/AIDS are at an increased risk of developing mucosal squamous cell carcinoma, nasopharyngeal carcinoma, lymphoepithelial carcinoma of the salivary gland, and Merkel cell carcinoma in this anatomic region. Data also suggest that HIV-positive patients with these cancers present at a younger age, with more aggressive disease and worse prognosis compared to HIV-negative patients. Treatment involves surgical resection with or without radiation therapy and chemotherapy for locally advanced and metastatic disease. AIDS patients, however, are more likely to suffer radiation treatment complications. Highly active antiretroviral therapy (HAART) has not altered the incidence of these malignancies
Aging display's effect on interpretation of digital pathology slides
It is our conjecture that the variability of colors in a pathology image
effects the interpretation of pathology cases, whether it is diagnostic
accuracy, diagnostic confidence, or workflow efficiency. In this paper, digital
pathology images are analyzed to quantify the perceived difference in color
that occurs due to display aging, in particular a change in the maximum
luminance, white point, and color gamut. The digital pathology images studied
include diagnostically important features, such as the conspicuity of nuclei.
Three different display aging models are applied to images: aging of luminance
& chrominance, aging of chrominance only, and a stabilized luminance &
chrominance (i.e., no aging). These display models and images are then used to
compare conspicuity of nuclei using CIE deltaE2000, a perceptual color
difference metric. The effect of display aging using these display models and
images is further analyzed through a human reader study designed to quantify
the effects from a clinical perspective. Results from our reader study indicate
significant impact of aged displays on workflow as well as diagnosis as follow.
As compared to the originals (no-aging), slides with the effect of aging
simulated were significantly more difficult to read (p-value of 0.0005) and
took longer to score (p-value of 0.02). Moreover, luminance+chrominance aging
significantly reduced inter-session percent agreement of diagnostic scores
(p-value of 0.0418)
Oral diabetes medication monotherapy and short-term mortality in individuals with type 2 diabetes and coronary artery disease
Objective To determine whether sulfonylurea use, compared with non-sulfonylurea oral diabetes medication use, was associated with 2-year mortality in individuals with well-controlled diabetes and coronary artery disease (CAD). Research design and methods We studied 5352 US veterans with type 2 diabetes, obstructive CAD on coronary angiography, hemoglobin A1c ≤7.5% at the time of catheterization, and taking zero or one oral diabetes medication (categorized as no medications, non-sulfonylurea medication, or sulfonylurea). We estimated the association between medication category and 2-year mortality using inverse probability of treatment-weighted (IPW) standardized mortality differences and IPW multivariable Cox proportional hazards regression. Results 49%, 35%, and 16% of the participants were on no diabetes medications, non-sulfonylurea medications, and sulfonylureas, respectively. In individuals on no medications, non-sulfonylurea medications, and sulfonylureas, the unadjusted mortality rates were 6.6%, 5.2%, and 11.9%, respectively, and the IPW-standardized mortality rates were 5.9%, 6.5%, and 9.7%, respectively. The standardized absolute 2-year mortality difference between non-sulfonylurea and sulfonylurea groups was 3.2% (95% CI 0.7 to 5.7) (p=0.01). In Cox proportional hazards models, the point estimate suggested that sulfonylurea use might be associated with greater hazard of mortality than non-sulfonylurea medication use, but this finding was not statistically significant (HR 1.38 (95% CI 1.00 to 1.93), p=0.05). We did not observe significant mortality differences between individuals on no diabetes medications and non-sulfonylurea users. Conclusions Sulfonylurea use was common (nearly one-third of those taking medications) and was associated with increased 2-year mortality in individuals with obstructive CAD. The significance of the association between sulfonylurea use and mortality was attenuated in fully adjusted survival models. Caution with sulfonylurea use may be warranted for patients with well-controlled diabetes and CAD, and metformin or newer diabetes medications with cardiovascular safety data could be considered as alternatives when individualizing therapy
Editorial : Predictive mechanisms in action, perception, cognition, and clinical disorders
Acknowledgments The authors would like to acknowledge their funding sources (NIH F32 MH117933 to AD, Alon Fellowship to LR).Peer reviewedPublisher PD
Fracaso electromecánico inducido por el ejercicio dinámico
Se investiga el fracaso muscular tras la realización de un ejercicio
dinámico de alto esfuerzo, mediante la determinación de índices
cuantitativos de función contráctil. Cincuenta adultos practican
un test triangular en cicloergómetro bajo control ergoespirométrico,
midiendo en el cuádriceps femoral la variación de la
fuerza generada en la estimulación eléctrica (curva fuerzaflrecuencia),
de lafierza máxima voluntaria y del umbral de intensidad
y la cronaxia. Se observan distintos tipos de fatiga de origen
periférico, cuya magnitud no depende de la intensidad del esfuerzo.
La coincidencia del cambio de la fuerza tetánica, de la fuerza
voluntaria y de la cronaxia apoya la responsabilidad del defecto
excitatorio en la fatiga de alta frecuencia, la cual puede causar la
detención del ejercicio. El límite de la aptitud debe referirse a
una capacidad individual según la modificación de diversos parámetros,
entre los cuales debe incluirse una exploración funcional
muscularPeer Reviewe
Generating single photons at gigahertz modulation-speed using electrically controlled quantum dot microlenses
This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 108, 021104 (2016) and may be found at https://doi.org/10.1063/1.4939658.We report on the generation of single-photon pulse trains at a repetition rate of up to 1 GHz. We achieve this speed by modulating the external voltage applied on an electrically contacted quantum dot microlens, which is optically excited by a continuous-wave laser. By modulating the photoluminescence of the quantum dot microlens using a square-wave voltage, single-photon emission is triggered with a response time as short as (281 ± 19) ps, being 6 times faster than the radiative lifetime of (1.75 ± 0.02) ns. This large reduction in the characteristic emission time is enabled by a rapid capacitive gating of emission from the quantum dot, which is placed in the intrinsic region of a p-i-n-junction biased below the onset of electroluminescence. Here, since our circuit acts as a rectifying differentiator, the rising edge of the applied voltage pulses triggers the emission of single photons from the optically excited quantum dot. The non-classical nature of the photon pulse train generated at GHz-speed is proven by intensity autocorrelation measurements with g(2)(0) = 0.3 ± 0.1. Our results combine optical excitation with fast electrical gating and thus show promise for the generation of indistinguishable single photons at rates exceeding the limitations set by the intrinsic radiative lifetime.BMBF, 03V0630, Entwicklung einer Halbleiterbasierten Einzelphotonenquelle für die Quanteninformationstechnologie (QSOURCE)DFG, 43659573, SFB 787: Halbleiter - Nanophotonik: Materialien, Modelle, Bauelement
An Investigation into Glomeruli Detection in Kidney H&E and PAS Images using YOLO
Context: Analyzing digital pathology images is necessary to draw diagnostic
conclusions by investigating tissue patterns and cellular morphology. However,
manual evaluation can be time-consuming, expensive, and prone to inter- and
intra-observer variability. Objective: To assist pathologists using
computerized solutions, automated tissue structure detection and segmentation
must be proposed. Furthermore, generating pixel-level object annotations for
histopathology images is expensive and time-consuming. As a result, detection
models with bounding box labels may be a feasible solution. Design: This paper
studies. YOLO-v4 (You-Only-Look-Once), a real-time object detector for
microscopic images. YOLO uses a single neural network to predict several
bounding boxes and class probabilities for objects of interest. YOLO can
enhance detection performance by training on whole slide images. YOLO-v4 has
been used in this paper. for glomeruli detection in human kidney images.
Multiple experiments have been designed and conducted based on different
training data of two public datasets and a private dataset from the University
of Michigan for fine-tuning the model. The model was tested on the private
dataset from the University of Michigan, serving as an external validation of
two different stains, namely hematoxylin and eosin (H&E) and periodic
acid-Schiff (PAS). Results: Average specificity and sensitivity for all
experiments, and comparison of existing segmentation methods on the same
datasets are discussed. Conclusions: Automated glomeruli detection in human
kidney images is possible using modern AI models. The design and validation for
different stains still depends on variability of public multi-stain datasets
Discrete cilia modelling with singularity distributions
We discuss in detail techniques for modelling flows due to finite and infinite arrays of beating cilia. An efficient technique, based on concepts from previous ‘singularity models’ is described, that is accurate in both near and far-fields. Cilia are modelled as curved slender ellipsoidal bodies by distributing Stokeslet and potential source dipole singularities along their centrelines, leading to an integral equation that can be solved using a simple and efficient discretisation. The computed velocity on the cilium surface is found to compare favourably with the boundary condition. We then present results for two topics of current interest in biology. 1) We present the first theoretical results showing the mechanism by which rotating embryonic nodal cilia produce a leftward flow by a ‘posterior tilt,’ and track particle motion in an array of three simulated nodal cilia. We find that, contrary to recent suggestions, there is no continuous layer of negative fluid transport close to the ciliated boundary. The mean leftward particle transport is found to be just over 1 μm/s, within experimentally measured ranges. We also discuss the accuracy of models that represent the action of cilia by steady rotlet arrays, in particular, confirming the importance of image systems in the boundary in establishing the far-field fluid transport. Future modelling may lead to understanding of the mechanisms by which morphogen gradients or mechanosensing cilia convert a directional flow to asymmetric gene expression. 2) We develop a more complex and detailed model of flow patterns in the periciliary layer of the airway surface liquid. Our results confirm that shear flow of the mucous layer drives a significant volume of periciliary liquid in the direction of mucus transport even during the recovery stroke of the cilia. Finally, we discuss the advantages and disadvantages of the singularity technique and outline future theoretical and experimental developments required to apply this technique to various other biological problems, particularly in the reproductive system
- …