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1.
Sci Total Environ ; 713: 136443, 2020 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-31954251

RESUMEN

The aerosol extinction coefficient was an important factor for air quality. To estimate the aerosol extinction levels, widely used pure statistical models are generally not based on aerosol vertical structures. In this study, we estimated large-scale aerosol extinction coefficients by developing a new layer-resolved model with explicit inference for aerosol vertical distribution. The CALIOP aerosol profile, MODIS AOD and reanalysis boundary layer height data are used. The layer-resolved model was formulated by developing an explicit, steady and straightforward relationship between aerosol within boundary layer and corresponding AOD values. The estimated surface extinction coefficient from this model was compared against the values derived from station visibility observations in China in 2016. The results revealed that our model had outperformed the traditional one-layer model and the simplified two-layer model. Specifically, the numbers of ground stations with an NME value < 0.4 are enhanced by a percentage > 100%, with the NME values significantly decreased from 46%, 48% to 36% and RMSE values from 0.27, 0.25 to 0.21 km-1. Our model is easy for operational implementation thanks to its clear structure and input, and also informative to understand aerosol vertical distributions. Furthermore, this work will also be beneficial to air quality modeling studies to improve accuracy estimating ground-level PM2.5 concentrations.

2.
Fish Shellfish Immunol ; 87: 193-201, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30639866

RESUMEN

The serum complement component C1q mediates a variety of immune regulatory functions. Herein, we identified a globular head C1q (ghC1q) gene in razor clam Sinonovacula constricta. The complete Sc-ghC1q gene was 872 bp long included an 81 bp 5'-untranslated region (UTR), a 95 bp 3'-UTR with a poly(A) tail, and an open reading frame (ORF) of 696 bp. The mRNA expression of Sc-ghC1q was upregulated in hepatopancreas and hemocytes. After Staphylococcus aureus or Vibrio anguillarum challenge, Sc-ghC1q mRNA transcript abundance was significantly upregulated in hemolymph. Recombinant Sc-ghC1q protein could bind lipopolysaccharide (LPS) and lipoteichoic acid (LTA), and it could agglutinate both Gram-positive and Gram-negative bacteria. Additionally, flow cytometry revealed that Sc-ghC1q strongly promoted phagocytosis in hemocytes. Together, these results demonstrated that Sc-ghC1q played an important role in innate immunity in S. constricta.


Asunto(s)
Complemento C1q/genética , Complemento C1q/inmunología , Regulación de la Expresión Génica/inmunología , Inmunidad Innata/genética , Penaeidae/genética , Penaeidae/inmunología , Pruebas de Aglutinación , Secuencia de Aminoácidos , Animales , Proteínas de Artrópodos/química , Proteínas de Artrópodos/genética , Proteínas de Artrópodos/inmunología , Complemento C1q/química , Perfilación de la Expresión Génica , Bacterias Gramnegativas/fisiología , Bacterias Grampositivas/fisiología , Lipopolisacáridos/farmacología , Filogenia , Alineación de Secuencia , Ácidos Teicoicos/farmacología
3.
Dev Comp Immunol ; 94: 16-21, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30641118

RESUMEN

C1q is an important immune gene that can mediate a variety of immune regulatory functions, and is involved in complement pathway activation. In the present study, a ghC1q gene from the razor clam Sinonovacula constricta was identified and named ScghC1q-1. The complete ScghC1q-1 gene is 692 bp in length, with an open reading frame (ORF) of 489 bp encoding a protein of 162 amino acids. ScghC1q-1 mRNA was widely expressed in various tissues, and transcript levels in the hemolymph were significantly up-regulated following Staphylococcus aureus or Vibrio anguillarum challenge. Recombinant ScghC1q-1 protein was found to agglutinate both Gram-positive and Gram-negative bacteria. These results indicate that ScghC1q-1 plays an essential role in the immune defense of S. constricta.


Asunto(s)
Proteínas de Artrópodos/genética , Bivalvos/inmunología , Complemento C1q/genética , Hemolinfa/fisiología , Infecciones Estafilocócicas/inmunología , Staphylococcus aureus/fisiología , Vibriosis/inmunología , Vibrio/fisiología , Animales , Proteínas de Artrópodos/metabolismo , Clonación Molecular , Complemento C1q/metabolismo , Perfilación de la Expresión Génica , Inmunidad Innata , Filogenia , Alineación de Secuencia , Regulación hacia Arriba
4.
Dev Comp Immunol ; 93: 11-17, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30389517

RESUMEN

Galectins are lectins possessing an evolutionarily conserved carbohydrate recognition domain (CRD) with affinity for ß-galactoside. The key role played by innate immunity in invertebrates has recently become apparent. Herein, a full-length galectin (ScGal) was identified in razor clam (Sinonovacula constricta). The 528 bp open reading frame encodes a polypeptide of 176 amino acids with a single CRD and no signal peptide. ScGal mRNA transcripts were mainly expressed in hemolymph and gill, and were significantly up-regulated following bacterial challenge. Recombinant rScGal protein binds to and aggregates various bacteria, and has affinity for peptidoglycan, lipoteichoic acid and d-galactose. The protein also stimulates hemocytes to phagocytose invading bacterial pathogens. ScGal is an important immune factor in innate immunity, and a small protein with multiple important functions.


Asunto(s)
Bacterias/inmunología , Bivalvos/genética , Bivalvos/inmunología , Galectinas/genética , Hemocitos/inmunología , Fagocitosis/inmunología , Aglutinación/inmunología , Animales , Galactosa/metabolismo , Branquias/metabolismo , Hemolinfa/metabolismo , Inmunidad Innata/genética , Lipopolisacáridos/metabolismo , Peptidoglicano/metabolismo , Fagocitosis/genética , Ácidos Teicoicos/metabolismo
5.
Sci Total Environ ; 655: 423-433, 2019 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-30472644

RESUMEN

Outdoor air pollution is a major killer worldwide and the fourth largest contributor to the burden of disease in China. China is the most populous country in the world and also has the largest number of air pollution deaths per year, yet the spatial resolution of existing national air pollution estimates for China is generally relatively low. We address this knowledge gap by developing and evaluating national empirical models for China incorporating land-use regression (LUR), satellite measurements, and universal kriging (UK). Land use, traffic and meteorological variables were included for model building. We tested the resulting models in several ways, including (1) comparing models developed using forward variable selection vs. partial least squares (PLS) variable reduction, (2) comparing models developed with and without satellite measurements, and with and without UK, and (3) 10-fold cross-validation (CV), Leave-One-Province-Out CV (LOPO-CV), and Leave-One-City-Out CV (LOCO-CV). Satellite data and kriging are complementary in making predictions more accurate: kriging improved the models in well-sampled areas; satellite data substantially improved performance at locations far away from monitors. Variable-selection models performed similarly to PLS models in 10-fold CV, but better in LOPO-CV. Our best models employed forward variable selection and UK, with 10-fold CV R2 of 0.89 (for both 2014 and 2015) for PM2.5 and of 0.73 (year-2014) and 0.78 (year-2015) for NO2. Population-weighted concentrations during 2014-2015 decreased for PM2.5 (58.7 µg/m3 to 52.3 µg/m3) and NO2 (29.6 µg/m3 to 26.8 µg/m3). We produced the first high resolution national LUR models for annual-average concentrations in China. Models were applied on 1 km grid to support future research. In 2015, >80% of the Chinese population lived in areas that exceeded the Chinese national PM2.5 standard, 35 µg/m3. Results here will be publicly available and may be useful for epidemiology, risk assessment, and environmental justice research.

6.
Front Public Health ; 6: 210, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30140667

RESUMEN

The on-going reassortment, human-adapted mutations, and spillover events of novel A(H7N9) avian influenza viruses pose a significant challenge to public health in China and globally. However, our understanding of the factors that disseminate the viruses and drive their geographic distributions is limited. We applied phylogenic analysis to examine the inter-subtype interactions between H7N9 viruses and the closest H9N2 lineages in China during 2010-2014. We reconstructed and compared the inter-provincial live poultry trading and viral propagation network via phylogeographic approach and network similarity technique. The substitution rates of the isolated viruses in live poultry markets and the characteristics of localized viral evolution were also evaluated. We discovered that viral propagation was geographically-structured and followed the live poultry trading network in China, with distinct north-to-east paths of spread and circular transmission between eastern and southern regions. The epicenter of H7N9 has moved from the Shanghai-Zhejiang region to Guangdong Province was also identified. Besides, higher substitution rate was observed among isolates sampled from live poultry markets, especially for those H7N9 viruses. Live poultry trading in China may have driven the network-structured expansion of the novel H7N9 viruses. From this perspective, long-distance geographic expansion of H7N9 were dominated by live poultry movements, while at local scales, diffusion was facilitated by live poultry markets with highly-evolved viruses.

7.
Dev Comp Immunol ; 87: 176-181, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29932964

RESUMEN

Growth arrest and DNA damage inducible 45-beta (Gadd45B) is essential for mitogen-activated protein kinases (MAPK) activities, and involved in regulating growth, apoptosis, and DNA demethylation. In the present study, the cDNA of gcGadd45Ba and gcGadd45Bb in grass carp was identified. And the expression levels show that they were widely distributed in the tested tissues and showed significant immune responses both in vitro and in vivo after challenge with bacteria and pathogen-associated molecular patterns (PAMPs). Overexpression of Gadd45B significantly induced the expression of pro-inflammatory cytokines (IL-1ß, IL-8, and TNF-α) and enhanced the phagocytosis activation of grass carp blood cells. These results indicate that Gadd45B plays an important role in innate immune responses.


Asunto(s)
Aeromonas hydrophila/inmunología , Carpas/inmunología , Citocinas/inmunología , Enfermedades de los Peces/inmunología , Proteínas de Peces/inmunología , Fagocitosis/inmunología , Aeromonas hydrophila/fisiología , Animales , Carpas/genética , Carpas/microbiología , Citocinas/genética , Enfermedades de los Peces/genética , Enfermedades de los Peces/microbiología , Proteínas de Peces/genética , Perfilación de la Expresión Génica , Regulación de la Expresión Génica/inmunología , Interacciones Huésped-Patógeno , Inmunidad Innata/genética , Inmunidad Innata/inmunología , Mediadores de Inflamación/inmunología , Mediadores de Inflamación/metabolismo , Fagocitosis/genética
8.
Fish Shellfish Immunol ; 80: 1-9, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-29807120

RESUMEN

Galectins are soluble lectins that perform a pattern recognition function in invertebrate immunity and specifically recognise ß-galactoside residues via conserved carbohydrate recognition domains. However, their function in bivalve molluscs has received little attention. Herein, a galectin (ScGal2) in razor clam (Sinonovacula constricta) consisting of a 507 bp open reading frame encoding a protein of 168 amino acids was identified and characterised. The protein includes a carbohydrate recognition domain (CRD), and several residues involved in dimerisation were found. ScGal2 mRNAs were mainly detected in hemolymph and liver, and expression was upregulated significantly following challenge with Vibrio anguillarum. Recombinant rScGal2 protein displayed strong agglutination activity toward Gram-negative bacteria, and flow cytometry revealed that ScGal2 strongly promoted phagocytosis in hemocytes. These results suggest that ScGal2 plays an indispensable role in innate immunity in razor clam, and likely participates in immune recognition and clearance processes.


Asunto(s)
Bivalvos/inmunología , Galectinas/inmunología , Aglutinación , Animales , Bacterias/inmunología , Bivalvos/genética , Bivalvos/metabolismo , Clonación Molecular , ADN Complementario/genética , Galectinas/genética , Galectinas/metabolismo , Branquias/metabolismo , Gónadas/metabolismo , Hemocitos/inmunología , Hemolinfa/metabolismo , Inmunidad Innata , Hígado/metabolismo , Fagocitosis , Filogenia , ARN Mensajero/metabolismo , Bazo/metabolismo
10.
Sci Rep ; 7: 46456, 2017 04 25.
Artículo en Inglés | MEDLINE | ID: mdl-28440282

RESUMEN

Long-term air quality observations are seldom analyzed from a dynamic view. This study analyzed fine particulate matter (PM2.5) pollution processes using long-term PM2.5 observations in three Chinese cities. Pollution processes were defined as linearly growing PM2.5 concentrations following the criteria of coefficient of determination R2 > 0.8 and duration time T ≥ 18 hrs. The linear slopes quantitatively measured pollution levels by PM2.5 concentrations rising rates (PMRR, µg/(m3·hr)). The 741, 210 and 193 pollution processes were filtered out, respectively, in Beijing (BJ), Shanghai (SH), and Guangzhou (GZ). Then the relationships between PMRR and wind speed, wind direction, 24-hr backward points, gaseous pollutants (CO, NO2 and SO2) concentrations, and regional PM2.5 levels were studied. Inverse relationships existed between PMRR and wind speed. The wind directions and 24-hr backward points converged in specific directions indicating long-range transport. Gaseous pollutants concentrations increased at variable rates in the three cities with growing PMRR values. PM2.5 levels at the upwind regions of BJ and SH increased at high PMRRs. Regional transport dominated the PM2.5 pollution processes of SH. In BJ, both local contributions and regional transport increased during high-PMRR pollution processes. In GZ, PM2.5 pollution processes were mainly caused by local emissions.


Asunto(s)
Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Material Particulado/análisis , China , Ciudades , Monitoreo del Ambiente , Contaminación Ambiental
11.
Euro Surveill ; 22(7)2017 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-28230525

RESUMEN

The recent emergence of A(H7N9) avian influenza poses a significant challenge to public health in China and around the world; however, understanding of the transmission dynamics and progression of influenza A(H7N9) infection in domestic poultry, as well as spillover transmission to humans, remains limited. Here, we develop a mathematical model-Bayesian inference system which combines a simple epidemic model and data assimilation method, and use it in conjunction with data on observed human influenza A(H7N9) cases from 19 February 2013 to 19 September 2015 to estimate key epidemiological parameters and to forecast infection in both poultry and humans. Our findings indicate a high outbreak attack rate of 33% among poultry but a low rate of chicken-to-human spillover transmission. In addition, we generated accurate forecasts of the peak timing and magnitude of human influenza A(H7N9) cases. This work demonstrates that transmission dynamics within an avian reservoir can be estimated and that real-time forecast of spillover avian influenza in humans is possible.


Asunto(s)
Teorema de Bayes , Brotes de Enfermedades , Predicción , Subtipo H7N9 del Virus de la Influenza A , Gripe Aviar/epidemiología , Modelos Teóricos , Animales , Aves , China/epidemiología , Humanos , Gripe Aviar/virología , Gripe Humana/epidemiología , Gripe Humana/virología , Aves de Corral/virología
12.
Lancet ; 389(10074): 1151-1164, 2017 03 18.
Artículo en Inglés | MEDLINE | ID: mdl-27856085

RESUMEN

The Lancet Countdown: tracking progress on health and climate change is an international, multidisciplinary research collaboration between academic institutions and practitioners across the world. It follows on from the work of the 2015 Lancet Commission, which concluded that the response to climate change could be "the greatest global health opportunity of the 21st century". The Lancet Countdown aims to track the health impacts of climate hazards; health resilience and adaptation; health co-benefits of climate change mitigation; economics and finance; and political and broader engagement. These focus areas form the five thematic working groups of the Lancet Countdown and represent different aspects of the complex association between health and climate change. These thematic groups will provide indicators for a global overview of health and climate change; national case studies highlighting countries leading the way or going against the trend; and engagement with a range of stakeholders. The Lancet Countdown ultimately aims to report annually on a series of indicators across these five working groups. This paper outlines the potential indicators and indicator domains to be tracked by the collaboration, with suggestions on the methodologies and datasets available to achieve this end. The proposed indicator domains require further refinement, and mark the beginning of an ongoing consultation process-from November, 2016 to early 2017-to develop these domains, identify key areas not currently covered, and change indicators where necessary. This collaboration will actively seek to engage with existing monitoring processes, such as the UN Sustainable Development Goals and WHO's climate and health country profiles. The indicators will also evolve over time through ongoing collaboration with experts and a range of stakeholders, and be dependent on the emergence of new evidence and knowledge. During the course of its work, the Lancet Countdown will adopt a collaborative and iterative process, which aims to complement existing initiatives, welcome engagement with new partners, and be open to developing new research projects on health and climate change.


Asunto(s)
Cambio Climático , Salud Global , Política de Salud , Conservación de los Recursos Naturales , Biomarcadores Ambientales , Humanos
13.
Sci Total Environ ; 580: 235-244, 2017 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-27986320

RESUMEN

The satellite-borne Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth (AOD) is widely used to estimate ground-level fine ambient particulate matter (PM2.5) concentrations to evaluate their health effects. The associated estimation accuracy is often reduced by AOD missing values and by insufficiently accounting for the spatio-temporal PM2.5 variations. In this study, we aim to estimate ground-level PM2.5 concentrations at a fine resolution with improved accuracy by fusing fine-scale satellite and ground observations in the populated and polluted Beijing-Tianjin-Hebei (BTH) area of China in 2014. We employed a Bayesian-based statistical downscaler to model the spatio-temporal linear AOD-PM2.5 relationships. We used a 3km MODIS AOD product, which was resampled to a 4km resolution in a Lambert conic conformal projection, to assist comparison and fusion with predictions by atmospheric chemistry models. A two-step method was used to fill the missing AOD values to obtain a full AOD dataset with complete spatial coverage. The downscaler has a good performance in the fitting procedure (R2=0.75) and in the cross validation procedure (R2=0.58 by random method and R2=0.47 by city-specific method). The number of missing AOD values was serious and related to elevated PM2.5 concentrations. The gap-filled AOD values corresponded well with our understanding of PM2.5 pollution conditions in BTH. The prediction accuracy of PM2.5 concentrations were improved in terms of their annual and seasonal mean. As a result of its fine spatio-temporal resolution and complete spatial coverage, the daily PM2.5 estimation dataset could provide extensive and insightful benefits to related studies in the BTH area. This may include understanding the formation processes of regional PM2.5 pollution episodes, evaluating daily human exposure, and establishing pollution controlling measures.

14.
Environ Sci Technol ; 50(9): 4752-9, 2016 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-27043852

RESUMEN

The accuracy in estimated fine particulate matter concentrations (PM2.5), obtained by fusing of station-based measurements and satellite-based aerosol optical depth (AOD), is often reduced without accounting for the spatial and temporal variations in PM2.5 and missing AOD observations. In this study, a city-specific linear regression model was first developed to fill in missing AOD data. A novel interpolation-based variable, PM2.5 spatial interpolator (PMSI2.5), was also introduced to account for the spatial dependence in PM2.5 across grid cells. A Bayesian hierarchical model was then developed to estimate spatiotemporal relationships between AOD and PM2.5. These methods were evaluated through a city-specific 10-fold cross-validation procedure in a case study in North China in 2014. The cross validation R(2) was 0.61 when PMSI2.5 was included and 0.48 when PMSI2.5 was excluded. The gap-filled AOD values also effectively improved predicted PM2.5 concentrations with an R(2) = 0.78. Daily ground-level PM2.5 concentration fields at a 12 km resolution were predicted with complete spatial and temporal coverage. This study also indicates that model prediction performance should be assessed by accounting for monitor clustering due to the potential misinterpretation of model accuracy in spatial prediction when validation monitors are randomly selected.


Asunto(s)
Teorema de Bayes , Monitoreo del Ambiente , Aerosoles , China , Material Particulado
15.
Environ Sci Technol ; 49(20): 12280-8, 2015 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-26310776

RESUMEN

Estimating exposures to PM2.5 within urban areas requires surface PM2.5 concentrations at high temporal and spatial resolutions. We developed a mixed effects model to derive daily estimations of surface PM2.5 levels in Beijing, using the 3 km resolution satellite aerosol optical depth (AOD) calibrated daily by the newly available high-density surface measurements. The mixed effects model accounts for daily variations of AOD-PM2.5 relationships and shows good performance in model predictions (R(2) of 0.81-0.83) and cross-validations (R(2) of 0.75-0.79). Satellite derived population-weighted mean PM2.5 for Beijing was 51.2 µg/m(3) over the study period (Mar 2013 to Apr 2014), 46% higher than China's annual-mean PM2.5 standard of 35 µg/m(3). We estimated that more than 19.2 million people (98% of Beijing's population) are exposed to harmful level of long-term PM2.5 pollution. During 25% of the days with model data, the population-weighted mean PM2.5 exceeded China's daily PM2.5 standard of 75 µg/m(3). Predicted high-resolution daily PM2.5 maps are useful to identify pollution "hot spots" and estimate short- and long-term exposure. We further demonstrated that a good calibration of the satellite data requires a relatively large number of ground-level PM2.5 monitoring sites and more are still needed in Beijing.


Asunto(s)
Aerosoles/análisis , Fenómenos Ópticos , Material Particulado/análisis , Análisis Espectral , Beijing , Calibración , Humanos , Modelos Lineales , Modelos Teóricos , Tamaño de la Partícula , Análisis de Regresión , Reproducibilidad de los Resultados , Factores de Tiempo , Incertidumbre
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