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Rain clusters are mesoscale disaster weather systems, and some of rain clusters have spiral structures. In this paper, a theoretical model of spiral rain cluster is established under pseudo-adiabatic approximation, and its horizontal structure equation is obtained. The study shows that the horizontal structure with spiral arm rain clusters has the following characteristics: at locations close enough to the center of the rain clusters, its shape is round and symmetrical; at locations far from the center, there may be spiral arms; the intensity of the vertical ascending motion of the rain cluster decreases with increasing distance from the center; and the vertical ascending motion is larger on the axis of the spiral arms of rain clusters. The conclusions obtained are consistent with not only the numerical results but also the observational facts. [ABSTRACT FROM AUTHOR]

Reference evapotranspiration (ET0) plays an important role in regional dry/wet conditions. Based on the Food and Agriculture Organization of the United (FAO) Penman-Monteith method and daily climate variables, ET0 was calculated for 21 stations in and around the Songnen Grassland, northeast China, during 1960-2014. The temporal and spatial variations of ET0 and precipitation (P) were analyzed in the annual, seasonal, and growing season (from April to October) time series using the Mann-Kendall test, Sen's slope estimator, and linear regression coupled with a break trend analysis. A sensitivity analysis was used to detect the key climate parameter contributing to ET0 change. By linear regression analysis on the relationship between ET0, P, and the aridity index (AI), the role of ET0 in determining regional wet/dry conditions was analyzed. Results show a higher ET0 in the southwest and a lower ET0 in the northeast, but P was opposite to that of ET0. Evident decreasing trends of ET0 in the annual, seasonal, and growing season time series were detected in almost the entire region by the trend analysis methods. For the entire region, the decreasing trend of ET0 can be linked to the relative humidity and maximum air temperature. The positive contribution of increasing temperature to ET0 was offset by the effect of the significantly decreasing relative humidity, wind speed, and sunshine duration at the 0.05 level during 1960-2014. In addition, the value of ET0 was higher in drought years and lower in wet years. [ABSTRACT FROM AUTHOR]

The development of the type II clustered regularly interspaced short palindromic repeats (CRISPR) system has resulted in the revolution of genetic engineering, and this technology has been applied in the genome editing of various species. However, there are no reports about target-specific genome editing in shrimp. In this research, we developed a microinjection method for the ridgetail white prawn Exopalaemon carinicauda and successfully applied CRISPR/Cas9 technology to the genome editing of E. carinicauda. Through coinjection of mRNA of Cas9 nuclease and gRNA specialized for E. carinicauda chitinase 4 (EcChi4), shrimps with indel mutations were obtained. Further analysis showed that the mutations could be transmitted to the next generation. This is the first time that site-specific genome editing has been successfully demonstrated in a decapod, and will further contribute to the study of functional genomics in decapods. [ABSTRACT FROM AUTHOR]

This study presents the methodology as well as a quantitative analysis of the influence of social and economic factors, namely GDP, population, economic growth rate, urbanization rate, and industrial structure on CO2 emissions as a result of energy consumption in the 101 counties of Inner Mongolia's industrial sector based on a geographically weighted regression model (GWR) and geographical information systems (GIS) from the perspectives of energy and environmental science. The results show significant differences in the measured CO2 emission levels among different counties. Utilizing the GWR method (which was tested on the smallest scale that has been published thus far), the relationship between CO2 emissions and these five explanatory variables produced an overall model fit of 99%. The GWR results showed that the parameters of variables in the GWR varied spatially, suggesting that the influencing factors had different effects on the CO2 emissions among the various counties. Overall, population, GDP, and urbanization rates positively affect CO2 emissions, industrial structure, and economic growth rate, and affect CO2 emissions both positively and negatively. We also characterize the fact that varying industrial structures and economic growth rates result in different effects on the CO2 emission of various regions. [ABSTRACT FROM AUTHOR]

Drought has an important influence on the hydrological cycle, ecological system, industrial and agricultural production, and social life. Based on the different time scales of characteristics of drought variability, the standardized precipitation evapotranspiration index (SPEI), a multi-timescale index with consideration of evaporation, was used in this study to estimate the spatial and temporal variability characteristics of drought. Climatic data from 15 meteorological stations across Horqin Sandy Land during 1964-2013 were used to calculate the SPEI of 1, 3, 6, and 12 months. In order to examine the relationship between droughts and other variables, 10 extreme climate indices were calculated based on the daily precipitation and maximum/mean/minimum temperature data of 15 meteorological stations, and linkages between SPEI-12 and atmosphere indices were established using by the cross wavelet transform method. The results indicated that the climate of Horqin Sandy Land had a tendency towards drought conditions, which is particularly apparent from the year 2000 onwards. During the study period, drought events were frequent in the region. Mild drought occurred in a quarter of the month, with that of moderate, severe, and extreme drought accounting for 0.11, 0.05, and 0.02 of the total months. The spatial trend of multi-timescale drought revealed that there was an increase in the severity of drought throughout Horqin Sandy Land, among which the magnitude in southern parts was larger than that of northern parts. The results also showed that the short time scale drought negatively correlated with precipitation extremes and positively correlated with temperature extremes. Furthermore, the long time scale drought (SPEI-12) was associated with atmosphere indices. Significant resonance periods were found between El Nino southern oscillation (ENSO), the East Asian summer monsoon index (EASMI), and SPEI-12. [ABSTRACT FROM AUTHOR]

Long-term remote sensing normalized difference vegetation index (NDVI) datasets have been widely used in monitoring vegetation changes. In this study, the NASA Global Inventory Modeling and Mapping Studies (GIMMS) NDVI3g dataset was used as the data source, and the dimidiate pixel model, intensity analysis, and residual analysis were used to analyze the changes of vegetation coverage in Inner Mongolia--from 1982 to 2010--and their relationships with climate and human activities. This study also explored vegetation changes in Inner Mongolia with respect to natural factors and human activities. The results showed that the estimated vegetation coverage exhibited a high correlation (0.836) with the actual measured values. The increased vegetation coverage area (49.2% of the total area) was larger than the decreased area (43.3%) from the 1980s to the 1990s, whereas the decreased area (57.1%) was larger than the increased area (35.6%) from the 1990s to the early 21st century. This finding indicates that vegetation growth in the 1990s was better than that in the other two decades. Intensity analysis revealed that changes in the average annual rate from the 1990s to the early 21st century were relatively faster than those in the 1980s-1990s. During the 1980s-1990s, the gain of high vegetation coverage areas was active, and the loss was dormant; in contrast, the gain and loss of low vegetation coverage areas were both dormant. In the 1990s to the early 21st century, the gains of high and low vegetation coverage areas were both dormant, whereas the losses were active. During the study period, areas of low vegetation coverage were converted into ones with higher coverage, and areas of high vegetation coverage were converted into ones with lower coverage. The vegetation coverage exhibited a good correlation (R² = 0.60) with precipitation, and the positively correlated area was larger than the negatively correlated area. Human activities not only promote the vegetation coverage, but also have a destructive effect on vegetation, and the promotion effect during 1982 to 2000 was larger than from 2001 to 2010, while, the destructive effect was larger from 2000 to 2010. [ABSTRACT FROM AUTHOR]

Spectral characteristics of CDOM (Chromophoric dissolved organic matter) in water columns are a key parameter for bio-optical modeling. Knowledge of CDOM optical properties and spatial discrepancy based on the relationship between water quality and spectral parameters in the Yinma River watershed with in situ data collected from highly polluted waters are exhibited in this study. Based on the comprehensive index method, the riverine waters showed serious contamination; especially the chemical oxygen demand (COD), iron (Fe), manganese (Mn), mercury (Hg) and dissolved oxygen (DO) were out of range of the contamination warning. Dissolved organic carbon (DOC) and total suspended matter (TSM) with prominent non-homogenizing were significantly high in the riverine waters, but chlorophyll-a (Chl-a) was the opposite. The ternary phase diagram showed that non-algal particle absorption played an important role in total non-water light absorption (>50%) in most sampling locations, and mean contributions of CDOM were 13% and 22% in the summer and autumn, respectively. The analysis of the ratio of absorption at 250–365 nm (E250:365) and the spectral slope (S275–295) indicated that CDOM had higher aromaticity and molecular weight in autumn than in summer, which is consistent with the results of water quality and the CDOM relative contribution rate. Redundancy analysis (RDA) indicated that the environmental variables OSM (Organic suspended matter) had a strong correlation with CDOM absorption, followed by heavy metals, e.g., Mn, Hg and Cr6+. However, for the specific UV absorbance (SUVA254), the seasonal values showed opposite results compared with the reported literature. The potential reasons were that more UDOM (uncolored dissolved organic matter) from human sources (wastewater effluent) existed in the waters. Terrigenous inputs simultaneously are in relation to the aCDOM(440)-DOC relationship with the correlation coefficient of 0.90 in the summer (two-tailed, p < 0.01), and 0.58 in the autumn (two-tailed, p < 0.05). Spatial distribution of the CDOM parameters exhibited that the downstream regions focused on dry land have high CDOM molecular weight and aromatic hydrocarbon. Partial sampling locations around the cities or countries generally showed abnormal values due to terrigenous inputs. As a bio-optical model parameter, the spectral characteristic of CDOM is helpful in adjusting the derived algorithms in highly polluted environments. The study on organic carbon and pollutants in highly polluted waters had an important contribution to global carbon balance estimation and water environment protection. [ABSTRACT FROM AUTHOR]

Spectral characteristics of optically active constituents (OACs) in waters are key parameters of biooptical modeling. Comparative analyses about the differences of optical characteristics and composition between riverine and reservoir waters in the second Songhuajiang River tributaries were conducted, and the influencing factors impacting on chromophoric dissolved organic matter (CDOM) and organic carbon (DOC) were examined based on the absorption properties. Dissolved organic carbon (DOC) and total suspended matter (TSM) were significantly higher in the riverine waters, and chlorophyll-a (Chl-a) was opposite. The relationship between the CDOM absorption coefficient at specific wavelength and DOC concentration both in the riverine and reservoir waters exhibited a positive correlation (r = 0.90, p< 0.01). The close relationship between Chl-a concentration and CDOM absorption confirmed a small amount of phytoplankton absorption to total absorption in the individual samplings. Analysis of absorption ratio (E250:365), specific UV absorbance (SUVA254), and spectral slope ratio (Sr) indicated that CDOM in riverine waters had lower aromaricity, molecular weight, and vascular plant contributions than in reservoir waters. Furthermore, non-algal particles played an important role in the total non-water absorption for riverine waters, and CDOM was dominant in the reservoir waters. This indicated that the Yinma River watershed was strongly influenced by the artificial discharge. As a parameter of the bio-optical model, the spectral characteristics of CDOM could help to adjust derived algorithms based on remote sensing and to estimate the dissolved organic carbon flux. [ABSTRACT FROM AUTHOR]

Studying the influencing factors of carbon dioxide emissions is not only practically but also theoretically crucial for establishing regional carbon-reduction policies, developing low-carbon economy and solving the climate problems. Therefore, we used a geographical detector model which is consists of four parts, i.e., risk detector, factor detector, ecological detector and interaction detector to analyze the effect of these social economic factors, i.e., GDP, industrial structure, urbanization rate, economic growth rate, population and road density on the increase of energy consumption carbon dioxide emissions in industrial sector in Inner Mongolia northeast of China. Thus, combining with the result of four detectors, we found that GDP and population more influence than economic growth rate, industrial structure, urbanization rate and road density. The interactive effect of any two influencing factors enhances the increase of the carbon dioxide emissions. The findings of this research have significant policy implications for regions like Inner Mongolia. [ABSTRACT FROM AUTHOR]

In this paper, we purified two native chitinases from the hepatopancreas of the ridgetail white prawn Exopalaemon carinicauda by using ion-exchange resin chromatography (IEC) and gel filtration. These two chitinases, named EcChi1 and EcChi2, were identified by chitinolytic activity assay and LC-ESI-MS/MS. Their apparent molecular weights were 44 kDa and 65 kDa as determined by sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The specific activity of EcChi1 and EcChi2 was 1305.97 U·mg−1 and 28.69 U·mg−1. The optimal temperature and pH of EcChi1 were 37 °C and pH 4.0, respectively. Co2+, Fe3+, Zn2+, Cd2+, and Cu2+ had an obvious promoting effect upon chitinase activity of EcChi1. For colloidal chitin, the Km and Vmax values of EcChi1 were 2.09 mg·mL−1 and 31.15 U·mL−1·h−1. [ABSTRACT FROM AUTHOR]

Compelling evidence for naturally occurring immunosurveillance against malignancies informs and justifies some current approaches toward cancer immunotherapy. However, some types of immune reactions have also been shown to facilitate tumor progression. For example, our previous studies showed that although experimental tumor growth is enhanced by low levels of circulating antibodies directed against the nonhuman sialic acid N-glycolyl-neuraminic acid (Neu5Gc), which accumulates in human tumors, growth could be inhibited by anti-Neu5Gc antibodies from a different source, in a different model. However, it remains generally unclear whether the immune responses that mediate cancer immunosurveillance vs. those responsible for inflammatory facilitation are qualitatively and/or quantitatively distinct. Here, we address this question using multiple murine tumor growth models in which polyclonal antibodies against tumor antigens, such as Neu5Gc, can alter tumor progression. We found that although growth was stimulated at low antibody doses, it was inhibited by high doses, over a linear and remarkably narrow range, defining an immune response curve (IRC; i.e., inverse hormesis). Moreover, modulation of immune responses against the tumor by altering antibody avidity or by enhancing innate immunity shifted the IRC in the appropriate direction. Thus, the dualistic role of immunosurveillance vs. inflammation in modulating tumor progression can be quantitatively distinguished in multiple model systems, and can occur over a remarkably narrow range. Similar findings were made in a human tumor xenograft model using a narrow range of doses of a monoclonal antibody currently in clinical use. These findings may have implications for the etiology, prevention, and treatment of cancer. [ABSTRACT FROM AUTHOR]

In this paper, an Urban Light Index (ULI) is constructed to facilitate analysis and quantitative evaluation of the process of urbanization and expansion rate by using DMSP/OLS Nighttime Light Data during the years from 1992 to 2010. A unit circle urbanization evaluation model is established to perform a comprehensive analysis of the urbanization process of 34 prefecture-level cities in Northeast China. Furthermore, the concept of urban light space is put forward. In this study, urban light space is divided into four types: the core urban area, the transition zone between urban and suburban areas, suburban area and fluorescent space. Proceeding from the temporal and spatial variation of the four types of light space, the pattern of morphologic change and space-time evolution of the four principal cities in Northeast China (Harbin, Changchun, Shenyang, Dalian) is analyzed and given particular attention. Through a correlation analysis between ULI and the traditional urbanization indexes (urban population, proportion of the secondary and tertiary industries in the regional GDP and the built-up area), the advantages and disadvantages as well as the feasibility of using the ULI in the study of urbanization are evaluated. The research results show that ULI has a strong correlation with urban built-up area (R² = 0.8277). The morphologic change and history of the evolving urban light space can truly reflect the characteristics of urban sprawl. The results also indicate that DMSP/OLS Nighttime Light Data is applicable for extracting urban space information and has strong potential to urbanization research. [ABSTRACT FROM AUTHOR]

This paper describes the long-term effects on vegetation following the catastrophic fire in 1987 on the northern Great Xing'an Mountain by analyzing the AVHRR GIMMS 15-day composite normalized difference vegetation index (NDVI) dataset. Both temporal and spatial characteristics were analyzed for natural regeneration and tree planting scenarios from 1984 to 2006. Regressing post-fire NDVI values on the pre-fire values helped identify the NDVI for burnt pixels in vegetation stands. Stand differences in fire damage were classified into five levels: Very High (VH), High (H), Moderate (M), Low (L) and Slight (S). Furthermore, intra-annual and inter-annual post-fire vegetation recovery trajectories were analyzed by deriving a time series of NDVI and relative regrowth index (RRI) values for the entire burned area. Finally, spatial pattern and trend analyses were conducted using the pixel-based post-fire annual stands regrowth index (SRI) with a nonparametric Mann-Kendall (MK) statistics method. The results show that October was a better period compared to other months for distinguishing the post- and pre-fire vegetation conditions using the NDVI signals in boreal forests of China because colored leaves on grasses and shrubs fall down, while the leaves on healthy trees remain green in October. The MK statistics method is robustly capable of detecting vegetation trends in a relatively long time series. Because tree planting primarily occurred in the severely burned area (approximately equal to the Medium, High and Very High fire damage areas) following the Daxing'anling fire in 1987, the severely burned area exhibited a better recovery trend than the lightly burned regions. Reasonable tree planting can substantially quicken the recovery and shorten the restoration time of the target species. More detailed satellite analyses and field data will be required in the future for a more convincing validation of the results. [ABSTRACT FROM AUTHOR]

This study presents the methodology and procedure for risk analysis, assessment, and regionalization of snow disasters in grassland regions, supported by geographical information systems (GIS) and technology of natural disaster risk assessment from the viewpoints of climatology, geography, disaster science, and environmental science. Based on the standard formulation of natural disaster risk, the composite Grassland Snow Disaster Risk Index (GSDRI) combined the hazard of grassland snow, the exposure of the region, the vulnerability, and emergency response and recovery capability (management ability) for grassland snow disasters in the region were developed by using Analytic Hierarchy Process (AHP) and Weighted Comprehensive Method (WCM). The GSDRI was developed to compare the relative risk of economic and life loss in different counties of Xilingol. It can also be used to compare different relative contributions such as meteorological triggering factor, and natural and socioeconomic factors. The result shows that the risk degrees of the grassland snow disaster in Xilingol increases gradually from southwest to northeast. The information obtained from field investigation and interviews in relation to results compiled were statistically evaluated. The results obtained in this study are specifically intended to support local and national governmental agencies in grassland snow disaster management. [ABSTRACT FROM AUTHOR]

Cathepsin B is one of the most important proteolytic enzymes involved in the nutrient metabolism of clam Meretrix meretrix. The recombinant fusion protein GST-MmeCB (rGST-MmeCB) was obtained at a high level from Escherichia coli and identified using LC-ESI-MS/MS. The GST tag was cleaved from rGST-MmeCB, and the resulting recombinant MmeCB (rMmeCB) was able to degrade the selective substrate carbobenzoxy- l-arginyl- l-arginyl-7-amino-4-trifluoromethylcoumarin (Z-Arg-Arg-AFC) in vitro. The kinetic parameters of the rMmeCB were calculated as follows: K, V and k are 6.11 μM, 0.0174 μM min and 277.57 s, respectively. Rabbit anti-rGST-MmeCB polyclonal antibodies was prepared and used to analyze the tissue distribution of MmeCB protein in M. meretrix. The results showed that the highest level of cathepsin B was found in the digestive gland and moderate levels were found in gill and mantle. Similar expression patterns were found at the mRNA level as detected by real time PCR. Further analysis showed that starvation caused a slight increase in MmeCB protein synthesis in the digestive gland, while refeeding after starvation caused an apparent increase in MmeCB synthesis in digestive gland, gill and mantle. Real time PCR analysis showed that MmeCB mRNA in digestive gland was significantly up-regulated by starvation and returned to normal level after the starved clams were refed. Together, these results indicated that cathepsin B is probably involved in the nutrient digestion of M. meretrix. [ABSTRACT FROM AUTHOR]

Abstract  GRP78 (78 kDa glucose-regulated protein), also known as BiP (immunoglobulin heavy-chain-binding protein), is an essential regulator of endoplasmic reticulum (ER) homeostasis because of its multiple functions in protein folding, ER calcium binding, and controlling of the activation of transmembrane ER stress sensors. In this report, we cloned the full length cDNA of GRP78 (FcGRP78) from Chinese shrimp Fenneropenaeus chinensis. This cDNA revealed a 2,325 bp with 1,968 bp open reading frame encoding 655 amino acids. This is the first reported GRP78 gene in Crustacea. The deduced amino acid sequence of FcGRP78 shared high identity with previously reported insect GRP78s: 86, 87 and 85% identity with GRP78s of Drosophila melanogaster, Aedes aegypti and Bombyx mori, respectively. Northern blot analysis shows that FcGRP78 is ubiquitously expressed in tissues of shrimp. Heat shock at 35°C significantly enhanced the expression of FcGRP78 at the first hour, reached the maximum at 4 h post heat shock, dropped after that and resumed to the normal level until 48 h of post recovery at 25°C. Additionally, differential expression of FcGRP78 was detected in haemocytes, hepatopancreas and lymphoid organ when shrimp were challenged by white spot syndrome virus (WSSV). We inferred that FcGRP78 may play important roles in chaperoning, protein folding and immune function of shrimp. [ABSTRACT FROM AUTHOR]

A gene encoding a chitosanase ( mschito) was cloned from Microbacterium sp. OU01. The ORF consists of 801 bp which encoded a polypeptide of 266 amino acid residues. The deduced amino acid sequence shows 98% identity to that of the chitosanase reported in Pseudomonas sp. A-01. In addition, the fusion protein containing MSCHITO was expressed in E. coli and purified using Ni-NTA affinity chromatography. The purified rMSCHITO protein degraded the chitosan (the degree of deacetylation of 99%) and produced a mixture of chitooligosaccharides. The MSCHITO is thus an endo-chitosanase. [ABSTRACT FROM AUTHOR]

A crustin-like protein (CruFc) from Fenneropenaeus chinensis was expressed in Pichia pastoris and then purified to electrophoretic homogeneity on a Sephacryl S-100 column with a band corresponding to the expected one (13 kDa) shown by 15% SDS-PAGE. Western blot indicated that the rCruFc specifically reacted with polyclonal rabbit anti- Fenneropenaeus chinensis CruFc. Production in a 5 l bioreactor gave 237 mg rCruFc/l. Antimicrobial assay revealed that 4 μM rCruFc inhibited growth of Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

Two extracellular chitosanases (ChiX and ChiN) were extracted from Microbacterium sp. OU01 with Mr values of 81 kDa (ChiX) and 30 kDa (ChiN). ChiN was optimally active at pH 6.2 and 50°C and ChiX at pH 6.6 and 60°C (assayed over 15 min). Both the activities increased with the degree of deacetylation (DDA) of chitosan. ChiN hydrolyzed oligomers of glucosamine (GlcN) larger than chitopentaose, and chitosan with 62–100% DDA; but ChiX acted on chitosan and released GlcN. Hydrolysis of chitosan with 99% DDA by ChiN released chitobiose, chitotriose and chitotetraose as the major products. [ABSTRACT FROM AUTHOR]

This work investigated the distribution, partitioning, and ecological risks of 16 polycyclic aromatic hydrocarbons (PAHs) in water and sediment of the Yinma River Basin in China in normal, wet, and dry seasons. Sixteen PAHs were analyzed in 17 paired sets of water and sediment samples collected from the study area. The concentrations of PAHs in water and sediment showed spatial-temporal variations, the concentrations in water ranged from 167.6 to 373.9 ng/L with a mean value of 227.9 ng/L in the normal season, from 186.0 to 386.9 ng/L with a mean value of 281.6 ng/L in the wet season, and ranged from 147.0 to 315.9 ng/L with an average value of 218.6 ng/L in the dry season, while concentrations in sediment varied from 895.6 to 2,518.2 ng/g with a mean value of 1,739.4 ng/g in the normal season, from 1,233.0 to 4,763.0 ng/g with a mean value of 2,122.6 ng/g in the wet season, and ranged from 914.2 to 5,678.5 ng/g with an average value of 1,943.7 ng/g in the dry season. Partitioning of PAHs in water and sediment was studied and the result showed that PAHs tend to absorb in sediment. Ecological risk assessments were conducted based on the species-sensitivity distribution (SSD) model, with results suggesting that ecological risks of individual PAHs in water and sediment were little, and the multiple congeners of PAHs in sediment from some sampling sites had ecological risks. Primary sources of 16 PAHs in water and sediment were identified with isomer ratios, and results indicated that primary sources of PAHs in water were identified as a mixture pattern of petroleum and combustion sources, and in sediment were identified as a mixture pattern of petroleum and grass, wood and coal combustion sources. [ABSTRACT FROM AUTHOR]

Geological disaster causes loss of lives and damage to man-made and natural stuctures. In this paper, a coupling method with optimal combination weighing law and extension model was established. Based on dynamic impact factors such as forest coverage, annual average rainfall, topography and gemorphogy, geologic structure, and type of rock and soil, the amount of disaster points and human engineering activities, we chose Jilin Province in China as the case study area. We made a spatial analysis and drew a geological disaster susceptibility zonation map using GIS technology. In addition, we established a geological disaster forecast and early-warning model. The results are as follows: 1) the couple method is an innovative and significant exploration, 2) geological disaster susceptibility zones in Jilin Province were divided into four areas, and 3) the forecasting and early warning model has a relatively high accuracy of forecast and early warning. [ABSTRACT FROM AUTHOR]

Neutrophil entry into the lung tissues is a key step in host defense to bacterial and yeast infections, but if uncontrolled can lead to severe tissue damage. Here, we demonstrate for the first time that sialic acid. binding Ig-like lectin E (siglec-E) functions to selectively regulate early neutrophil recruitment into the lung. In a model of acute lung inflammation induced by aerosolized lipopolysaccharide, siglec-E-deficient mice exhibited exaggerated neutrophil recruitment that was reversed by blockade of the β2 integrin, CD11b. Siglec-E suppressed CD11b "outside-in" signaling, because sigtec-E-deficient neutrophils plated on the CD11b ligand fibrinogen showed exaggerated phosphorylation of Syk and p38 mitogen-activated protein kinase. Sialidase treatment of fibrinogen reversed the suppressive effect of siglec-E on CD11b signaling, suggesting that sialic acid recognition by siglec-E is required for its inhibitory function. Siglec-E in neutrophils was constitutively associated with the tyrosine phosphatase SHP-1 and may therefore function to constitutively dampen inflammatory responses of neutrophils. These data reveal that siglec-E is an important negative regulator of neutrophil recruitment to the lung and β2. [ABSTRACT FROM AUTHOR]