In this letter, we address the problem of transceiver design in a non-regenerative MIMO relay system, where linear processing is applied at both the relay and destination to jointly minimize the ...mean-squared error (MSE) of symbol estimations. Under average power constraint at the relay station, we show that the optimal relay-precoder always loads power across channel eigenvectors and then decomposes the equivalent MIMO channel into a set of parallel SISO channels. Simulation results demonstrate that our method outperforms other relaying schemes in terms of both BER and MSE.
Summary In China, where air pollution has become a major threat to public health, public awareness of the detrimental effects of air pollution on respiratory health is increasing—particularly in ...relation to haze days. Air pollutant emission levels in China remain substantially higher than are those in developed countries. Moreover, industry, traffic, and household biomass combustion have become major sources of air pollutant emissions, with substantial spatial and temporal variations. In this Review, we focus on the major constituents of air pollutants and their impacts on chronic respiratory diseases. We highlight targets for interventions and recommendations for pollution reduction through industrial upgrading, vehicle and fuel renovation, improvements in public transportation, lowering of personal exposure, mitigation of the direct effects of air pollution through healthy city development, intervention at population-based level (systematic health education, intensive and individualised intervention, pre-emptive measures, and rehabilitation), and improvement in air quality. The implementation of a national environmental protection policy has become urgent.
Air pollution constitutes a significant stimulus of asthma exacerbations; however, the impacts of exposure to major air pollutants on asthma-related hospital admissions and emergency room visits ...(ERVs) have not been fully determined.
We sought to quantify the associations between short-term exposure to air pollutants ozone (O3), carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), and particulate matter ≤10 μm (PM10) and PM2.5 and the asthma-related emergency room visits (ERV) and hospitalizations.
Systematic computerized searches without language limitation were performed. Pooled relative risks (RRs) and 95% confidence intervals (95%CIs) were estimated using the random-effect models. Sensitivity analyses and subgroup analyses were also performed.
After screening of 246 studies, 87 were included in our analyses. Air pollutants were associated with significantly increased risks of asthma ERVs and hospitalizations O3: RR(95%CI), 1.009 (1.006, 1.011); I2 = 87.8%, population-attributable fraction (PAF) (95%CI): 0.8 (0.6, 1.1); CO: RR(95%CI), 1.045 (1.029, 1.061); I2 = 85.7%, PAF (95%CI): 4.3 (2.8, 5.7); NO2: RR(95%CI), 1.018 (1.014, 1.022); I2 = 87.6%, PAF (95%CI): 1.8 (1.4, 2.2); SO2: RR(95%CI), 1.011 (1.007, 1.015); I2 = 77.1%, PAF (95%CI): 1.1 (0.7, 1.5); PM10: RR(95%CI), 1.010 (1.008, 1.013); I2 = 69.1%, PAF (95%CI): 1.1 (0.8, 1.3); PM2.5: RR(95%CI), 1.023 (1.015, 1.031); I2 = 82.8%, PAF (95%CI): 2.3 (1.5, 3.1). Sensitivity analyses yielded compatible findings as compared with the overall analyses without publication bias. Stronger associations were found in hospitalized males, children and elderly patients in warm seasons with lag of 2 days or greater.
Short-term exposures to air pollutants account for increased risks of asthma-related ERVs and hospitalizations that constitute a considerable healthcare utilization and socioeconomic burden.
Macrophage polarization plays essential and diverse roles in most diseases, such as atherosclerosis, adipose tissue inflammation, and insulin resistance. Homeostasis dysfunction in M1/M2 macrophage ...polarization causes pathological conditions and inflammation. Neuroinflammation is characterized by microglial activation and the concomitant production of pro-inflammatory cytokines, leading to numerous neurodegenerative diseases and psychiatric disorders. Decreased neuroinflammation can be obtained by using natural compounds, including flavonoids, which are known to ameliorate inflammatory responses. Among flavonoids, quercetin possesses multiple pharmacological applications and regulates several biological activities. In the present study, we found that quercetin effectively inhibited the expression of lipocalin-2 in both macrophages and microglial cells stimulated by lipopolysaccharides (LPS). The production of nitric oxide (NO) and expression levels of the pro-inflammatory cytokines, inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2, were also attenuated by quercetin treatment. Our results also showed that quercetin significantly reduced the expression levels of the M1 markers, such as interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-1β, in the macrophages and microglia. The M1 polarization-associated chemokines, C-C motif chemokine ligand (CCL)-2 and C-X-C motif chemokine ligand (CXCL)-10, were also effectively reduced by the quercetin treatment. In addition, quercetin markedly reduced the production of various reactive oxygen species (ROS) in the microglia. The microglial phagocytic ability induced by the LPS was also effectively reduced by the quercetin treatment. Importantly, the quercetin increased the expression levels of the M2 marker, IL-10, and the endogenous antioxidants, heme oxygenase (HO)-1, glutamate-cysteine ligase catalytic subunit (GCLC), glutamate-cysteine ligase modifier subunit (GCLM), and NAD(P)H quinone oxidoreductase-1 (NQO1). The enhancement of the M2 markers and endogenous antioxidants by quercetin was activated by the AMP-activated protein kinase (AMPK) and Akt signaling pathways. Together, our study reported that the quercetin inhibited the effects of M1 polarization, including neuroinflammatory responses, ROS production, and phagocytosis. Moreover, the quercetin enhanced the M2 macrophage polarization and endogenous antioxidant expression in both macrophages and microglia. Our findings provide valuable information that quercetin may act as a potential drug for the treatment of diseases related to inflammatory disorders in the central nervous system.
Owing to the rising awareness of environmental protection and health, people put a high premium on air pollution in their living environment. It thus draws considerable attention to air quality ...monitoring in cities. The paper suggests using a vehicular sensor network (VSN) to tactically monitor metropolitan air quality and develops an efficient data gathering and estimation (EDGE) mechanism on VSN. EDGE has an objective to adaptively change data sampling rates of cars, such that the tradeoff between monitoring accuracy and communication cost is balanced. The monitoring accuracy is measured by the formal air quality index (AQI), whereas the communication cost considers the amount of sampling data and the monetary reward given to drivers. To do so, EDGE proposes dynamic grid partition based on the variation of pollutant concentration and computes the sampling rate by consulting car traffic in each grid. With the help of probabilistic reporting, it allows cars to collect air quality on more different positions and alleviate potential network congestion. Furthermore, EDGE applies the Delaunay triangulation to infer AQIs of the positions without any sensing data. Through simulation of urban mobility and industrial source complex, simulations are conducted based on practical metropolitan traffic and pollutant dispersion models. Experimental results demonstrate the significant effectiveness of the EDGE mechanism, under various scenarios.
Elton's diversity‐invasibility hypothesis predicts that diverse communities are more resistant against alien invaders. However, observational studies frequently find positive relationships between ...the numbers of alien and native species. It has been suggested, but rarely tested, that environmental heterogeneity may cause such positive relationships.
Here, we experimentally tested the effects of soil heterogeneity and diversity (species richness) on the invasibility of native communities. We first filled mesocosm pots with either a heterogeneous soil, consisting of one patch of sand, one patch of peat and one patch of an equal mixture of both substrates, or a homogeneous soil, consisting of the mixture only. Then, we planted those pots with 29 native communities consisting of one, four or eight species, and invaded them with populations of four individuals of one of five alien species.
In the heterogeneous soils, individual alien plants benefited more strongly from the resource‐rich peat soil than the native communities did. Moreover, in the mixture soil of the heterogeneous treatment, individual alien plant over‐proportionally produced more biomass than in the mixture soil of the homogeneous treatment. Consequently, the populations of naturalized alien plants in each pot benefited from heterogeneous soil conditions, and this tended to be particularly the case when a native community was present. The native communities did not respond to soil heterogeneity, but they had a negative effect on the naturalized plants, irrespective of their diversity.
Synthesis. Our results indicate that soil heterogeneity might alleviate the competitive effects of native communities on the alien invaders, as the latter took more advantage of the high resource patches than the natives did. The beneficial effect of heterogeneity on invasion success could thus explain why observational studies usually find positive relationships between the numbers of alien and native species.
We experimentally tested the effects of soil heterogeneity and diversity (species richness) on the invasibility of native communities. Our results indicate that soil heterogeneity might alleviate the competitive effects of native communities on the alien invaders, as the latter took more advantage of the high resource patches than the natives did. The beneficial effect of heterogeneity on invasion success could thus explain why observational studies usually find positive relationships between the numbers of alien and native species.
Dietary fiber is a widely recognized nutrient for human health. Previous studies proved that dietary fiber has significant implications for gastrointestinal health by regulating the gut microbiota. ...Moreover, mechanistic research showed that the physiological functions of different dietary fibers depend to a great extent on their physicochemical characteristics, one of which is solubility. Compared with insoluble dietary fiber, soluble dietary fiber can be easily accessed and metabolized by fiber-degrading microorganisms in the intestine and produce a series of beneficial and functional metabolites. In this review, we outlined the structures, characteristics, and physiological functions of soluble dietary fibers as important nutrients. We particularly focused on the effects of soluble dietary fiber on human health via regulating the gut microbiota and reviewed their effects on dietary and clinical interventions.
There are many cases in daily life and in the workplace which pose a decision problem. Some of them involve picking the best from among multiple available alternatives. However, no single alternative ...works best for all performance attributes. This research proposes a multiple attribute decision making (MADM) method, grey relational analysis (GRA), for solving this kind of problem. Two cases, facility layout and dispatching rules selection problem, which have been analyzed by data envelopment analysis (DEA), were also analyzed using the GRA procedure, in order to illustrate the use of GRA. In the case of the facility layout problem, 18 alternative layouts and 6 performance attributes were considered. In the case of the problem of selecting dispatching rules, 9 alternatives dispatching rules and 7 performance attributes were considered. For the two cases examined, the results of comparisons show that GRA is efficient for solving MADM problem.
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