A mathematical model for simulating the spread of a disease through a country divided into geographical regions with different population densities.

The SIR (susceptible-infectious-recovered) model is a well known method for predicting the number of people (or animals) in a population who become infected by and then recover from a disease. Modifications can include categories such people who have been exposed to the disease but are not yet infectious or those who die from the disease. However, the model has nearly always been applied to the entire population of a country or state but there is considerable observational evidence that diseases can spread at different rates in densely populated urban regions and sparsely populated rural areas.

Analysis of Thermal and Roughness Effects on the Turbulent Characteristics of Experimentally Simulated Boundary Layers in a Wind Tunnel.

The aim of this paper is to analyse the thermal effects in a wind tunnel experiment to simulate the planetary boundary layer (PBL). Experiments were performed in the wind tunnel of the Laboratory of Constructions Aerodynamics at the Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul State, Brazil. This wind tunnel is a closed return low-speed wind tunnel specifically designed for dynamic and static studies on civil construction models.

Comparison of Chicken Cecal Microbiota after Metaphylactic Treatment or Following Administration of Feed Additives in a Broiler Farm with Enterococcal Spondylitis History.

Minimizing the clinical signs of infections causing enterococcal spondylitis in broiler herds is successful when initiated as metaphylaxis in the first week of life. Mechanistically, either the species present at that time are reduced by antibiotic treatment or antibiotic treatment might induce changes in intestinal microbiota composition with an indirect and subsequent influence. The aim of the present study was to examine the cecal microbiota of chickens after administering lincospectin or different additives to evaluate whether these additives have lincospectin-like effects on microbiota.

β-Adrenergic modulation of spontaneous spatiotemporal activity patterns and synchrony in hyperexcitable hippocampal circuits.

A description of healthy and pathological brain dynamics requires an understanding of spatiotemporal patterns of neural activity and characteristics of its propagation between interconnected circuits. However, the structure and modulation of the neural activation maps underlying these patterns and their propagation remain elusive. We investigated effects of β-adrenergic receptor (β-AR) stimulation on the spatiotemporal characteristics of emergent activity in rat hippocampal circuits.

The Heisenberg-Weyl algebra on the circle and a related quantum mechanical model for hindered rotation.

We discuss a periodic variant of the Heisenberg-Weyl algebra, associated with the group of translations and modulations on the circle. Our study of uncertainty minimizers leads to a periodic version of canonical coherent states. Unlike the canonical, Cartesian case, there are states for which the uncertainty product associated with the generators of the algebra vanishes.

Three-dimensional isotropic wavelets for post-acquisitional extraction of latent images of atherosclerotic plaque components from micro-computed tomography of human coronary arteries.

Rationale And Objectives: The capability of wavelet transforms to separate signals into frequency bands is the basis for its use in image compression and storage, data management and transmission, and, recently, extraction of latent images of tissue components from noisy medical images. Analysis of temporal variations of radiofrequency backscatter of intravascular ultrasound with one-dimensional wavelets can detect lipid-laden plaque in coronary arteries with a sensitivity and specificity of >80%. In this study we evaluate the capability of a novel, 3-dimensional isotropic wavelet analysis to perform high resolution, non-directionally biased, statistically reliable, non-invasive discrimination between components of human coronary atherosclerotic plaques in micro-CT.

Quantification of roughness of calcific deposits in computed tomography scans of human coronary arteries.

Objectives: The incidence of coronary artery disease has been shown to be greater in patients with calcific deposits than in those without. It has been suggested that the pattern of distribution of coronary calcific deposits within coronary arteries is of greater predictive value for acute coronary events than the overall quantity. Whether roughness of calcific deposits is a predictor of acute coronary events is not known.

Usefulness of multidetector computed tomography for noninvasive evaluation of coronary arteries in asymptomatic patients.

This editorial addresses the capabilities, limitations, and potential of multidetector computed tomography (MDCT) for the noninvasive evaluation of coronary arteries in asymptomatic patients. The quantification of coronary calcium with MDCT correlates highly with that obtained by electron-beam computed tomography, but to date, neither has the capability of assessing the distribution of various morphologic patterns of calcium and their relation to other "soft" plaque components. Although MDCT can assess the thickness of the atherosclerotic wall and can readily identify calcific deposits, further plaque characterization (e.

General discrete modelling of lung sound production in normal subjects.

Lung sound analysis is of a major importance in diagnostic malfunctions of the respiratory system. In normal subjects, it is known that these sounds are caused by the interaction of the respiratory flows with the bronchial tree structure. However, the detailed knowledge of the reasons for the spectral characteristics of such sounds remains to be elucidated.

General fractal-discrete scheme for high-frequency lung sound production.

A general scheme is proposed to explain the observed spectral properties of high-frequency human respiratory sounds in terms of the interaction between the respiratory flux and a bronchial tree of fractal properties. The air flux is treated as composed of discrete decoupled elements while the tree is assumed to have a Cantor-based geometry. According to this model, the affine behavior often observed in the high-frequency (log-log) spectral range is a direct consequence of the fractal geometry of the bronchial tree in both qualitative and quantitative aspects.

Improved limits on nu(e) emission from mu+ decay.

We investigated mu(+) decays at rest produced at the ISIS beam stop target. Lepton flavor (LF) conservation has been tested by searching for nu(e) via the detection reaction p(nu(e),e(+))n. No nu(e) signal from LF violating mu(+) decays was identified.