Is Asthma Related to Choroidal Neovascularization?

BACKGROUND: Age-related degeneration (AMD) and asthma are both diseases that are related to the activation of the complement system. The association between AMD and asthma has been debated in previous studies. The authors investigated the relationship between AMD and asthma systemically. PRINCIPAL FINDINGS: The epidemiological study showed that asthma was related to choroidal neovascularization (CNV) subtype (OR = 1.721, P = 0.023). However, the meta-analysis showed there was no association between AMD and asthma. In an animal model, we found more fluoresce in leakage of CNV lesions by FA analysis and more angiogenesis by histological analysis in rats with asthma. Western blot demonstrated an elevated level of C3α-chain, C3α'-chain and VEGF. After compstatin was intravitreally injected, CNV leakage decreased according to FA analysis, with the level of C3 and VEGF protein decreasing at the same time. SIGNIFICANCE: This study first investigated the relationship between AMD and asthma systematically, and it was found that asthma could be a risk factor for the development of AMD. The study may provide a better understanding of the disease, which may advance the potential for screening asthma patients in clinical practice

Statistical Coding and Decoding of Heartbeat Intervals

The heart integrates neuroregulatory messages into specific bands of frequency, such that the overall amplitude spectrum of the cardiac output reflects the variations of the autonomic nervous system. This modulatory mechanism seems to be well adjusted to the unpredictability of the cardiac demand, maintaining a proper cardiac regulation. A longstanding theory holds that biological organisms facing an ever-changing environment are likely to evolve adaptive mechanisms to extract essential features in order to adjust their behavior. The key question, however, has been to understand how the neural circuitry self-organizes these feature detectors to select behaviorally relevant information. Previous studies in computational perception suggest that a neural population enhances information that is important for survival by minimizing the statistical redundancy of the stimuli. Herein we investigate whether the cardiac system makes use of a redundancy reduction strategy to regulate the cardiac rhythm. Based on a network of neural filters optimized to code heartbeat intervals, we learn a population code that maximizes the information across the neural ensemble. The emerging population code displays filter tuning proprieties whose characteristics explain diverse aspects of the autonomic cardiac regulation, such as the compromise between fast and slow cardiac responses. We show that the filters yield responses that are quantitatively similar to observed heart rate responses during direct sympathetic or parasympathetic nerve stimulation. Our findings suggest that the heart decodes autonomic stimuli according to information theory principles analogous to how perceptual cues are encoded by sensory systems

The Plant Pathogen Pseudomonas syringae pv. tomato Is Genetically Monomorphic and under Strong Selection to Evade Tomato Immunity

Recently, genome sequencing of many isolates of genetically monomorphic bacterial human pathogens has given new insights into pathogen microevolution and phylogeography. Here, we report a genome-based micro-evolutionary study of a bacterial plant pathogen, Pseudomonas syringae pv. tomato. Only 267 mutations were identified between five sequenced isolates in 3,543,009 nt of analyzed genome sequence, which suggests a recent evolutionary origin of this pathogen. Further analysis with genome-derived markers of 89 world-wide isolates showed that several genotypes exist in North America and in Europe indicating frequent pathogen movement between these world regions. Genome-derived markers and molecular analyses of key pathogen loci important for virulence and motility both suggest ongoing adaptation to the tomato host. A mutational hotspot was found in the type III-secreted effector gene hopM1. These mutations abolish the cell death triggering activity of the full-length protein indicating strong selection for loss of function of this effector, which was previously considered a virulence factor. Two non-synonymous mutations in the flagellin-encoding gene fliC allowed identifying a new microbe associated molecular pattern (MAMP) in a region distinct from the known MAMP flg22. Interestingly, the ancestral allele of this MAMP induces a stronger tomato immune response than the derived alleles. The ancestral allele has largely disappeared from today's Pto populations suggesting that flagellin-triggered immunity limits pathogen fitness even in highly virulent pathogens. An additional non-synonymous mutation was identified in flg22 in South American isolates. Therefore, MAMPs are more variable than expected differing even between otherwise almost identical isolates of the same pathogen strain

Prevalence and causes of vision loss in Latin America and the Caribbean in 2015: magnitude, temporal trends and projections

Objective To estimate the prevalence and causes of blindness and vision impairment for distance and near in Latin America and the Caribbean (LAC) in 2015 and to forecast trends to 2020. Methods A meta-analysis from a global systematic review of 283 cross-sectional, population-representative studies from published and unpublished sources from 1980 to 2014 in the Global Vision Database included 17 published and 6 unpublished studies from LAC. Results In 2015, across LAC, age-standardised prevalence was 0.38% in all ages and 1.56% in those over age 50 for blindness; 2.06% in all ages and 7.86% in those over age 50 for moderate and severe vision impairment (MSVI); 1.89% in all ages and 6.93% in those over age 50 for mild vision impairment and 39.59% in all ages and 45.27% in those over 50 for near vision impairment (NVI). In 2015, 117.86 million persons were vision impaired; of those 2.34 million blind, 12.46 million with MSVI, 11.34 million mildly impaired and 91.72 million had NVI. Cataract is the most common cause of blindness. Undercorrected refractive-error is the most common cause of vision impairment. Conclusions These prevalence estimates indicate that one in five persons across LAC had some degree of vision loss in 2015. We predict that from 2015 to 2020, the absolute numbers of persons with vision loss will increase by 12% to 132.33 million, while the all-age age-standardised prevalence will decrease for blindness by 15% and for other distance vision impairment by 8%. All countries need epidemiologic research to establish accurate national estimates and trends. Universal eye health services must be included in universal health coverage reforms to address disparities, fragmentation and segmentation of healthcar

Busy Period Analysis of Multi-Server Retrial Queueing Systems

The literature on the busy period analysis in queueing theory is very limited due to the inherent complexity in its study. Recently, using the simulation approach the busy period for the classical multi-server queueing systems was studied by this author and some interesting observations were reported. In this paper we carry out a similar analysis but on a smaller scale in the case of multi-server retrial queueing systems. It should be pointed out that while the literature on retrial queueing system is vast, the same cannot be said about the busy period analysis in retrial queueing systems. Only a few papers with restricted assumptions are available in the literature. This paper is an attempt to fill the void

Diagnostics of incylinder flow during compression using PIV and analysis using proper orthogonal decomposition

Non-intrusive flow measurements are useful for the understanding of physical processes central to engine combustion and emission performance, such as fuel-air mixing. In the present work, a test rig with maximum optical access is designed and fabricated to study the incylinder flow due to reciprocating piston during compression using particle image velocimetry (PIV) and proper orthogonal decomposition (POD), a technique for investigating turbulent flows. Very few investigations of the incylinder flow using the PIV-POD combination are reported in literature. The effects of the piston configuration and the piston position on the incylinder flow are investigated, for two piston configurations, viz., flat piston, and spherical bowl, six piston positions, from the bottom dead centre (BDC) to 150° after BDC, in steps of 30°. PIV measurements are carried out in the vertical plane passing through ports at 600 rpm crank speed. The ensemble-averaged velocity fields obtained from PIV reveal a large scale rotation particularly in the early part of the compression stroke, i.e., from BDC to 90° after BDC (aBDC). In the later part of compression, the flow is observed to be directed towards the cylinder head. POD is applied to the measured instantaneous velocity to study the incylinder turbulent flow. The POD modes show the flow fluctuations due to the effect of turbulence and cycle-to-cycle variations. For the spherical bowl case at 150° aBDC, the share of the fluctuation kinetic energy in the second and higher POD modes is higher than that (a) at any other piston position (b) in the case of flat piston. Thus, the POD analysis of instantaneous velocity measured using PIV, indicates that a spherical bowl is a better choice in terms of turbulence production compared to a flat piston, for use in engines. Copyright © 2012 by the Japan Society of Mechanical Engineers

Evolution of flame-kernel in laser-induced spark ignited mixtures: A parametric study

The present work focuses on the early stages of flame-kernel development in laser-induced spark ignited mixtures issuing out of a Bunsen burner. The time-scale of 3 μs to 1 ms associated with the flame-kernel evolution stage of an ignition event is targeted in this work. A CH4/air mixture (equivalence ratio φ = 0.6) is studied as a base case, and compared with CH4/CO2/air (mole fractions = 0.059/0.029/0.912, respectively) and CH4/H2/air (mole fractions = 0.053/0.016/0.931, respectively) mixtures for nearly the same adiabatic flame temperature of 1649 K. The spatio-temporal flame-kernel evolution is imaged using planar laser induced fluorescence of the OH radical (OH-PLIF), simultaneously with H-alpha emission from the plasma. The H-alpha emission suggests that the plasma time-scale is well below 1 μs. The PLIF images indicate all the stages of kernel development from the elongated kernel to the toroidal formations and the subsequent appearance of a front-lobe. The different time-scales associated with these stages are identified from the rate of change of the kernel perimeter. The plasma is followed by a supersonic kernel-perimeter growth. Larger flame-kernel spread is found in the case of CH4/H2 mixtures. A distinct shift in the trends of evolution of LIF intensity and kernel perimeter is observed as the fuel concentration is varied near the lean flammability limit in CH4/air (φ = 0.35-0.65) and H2/air (φ = 0.05-0.31) mixtures. The flow velocity (Reynolds number, Re) effect in both laminar and turbulent flow regimes (Re = ~600-6000) indicates that the shape of the flame-kernel changes at higher velocities, but the size of the kernel does not change significantly for a given time from the moment of ignition. This could be due to a balance between two competing effects, namely, increase in the strain rate that causes local extinction and thus decreases the flame-kernel growth, and increase in the turbulence levels that facilitates increased flame-kernel surface area through wrinkling, which in turn increases the flame-kernel growth