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Objective: Clinical characteristics of pediatric Guillain-Barré syndrome (GBS) have been extensively studied whereas scarcely been compared with those of adult GBS. Herein we compared the clinical features of GBS between pediatric and adult patients. Methods: We retrospectively collected the clinical data of 750 patients with GBS (541 adults and 209 children), and compared the clinical characteristics between children and adults. Results: Pain was a more frequent complaint in children (17.2% vs 9.6%, p < 0.01), who were also found with shorter interval from disease onset to nadir (6.3d vs 7.3d, p < 0.01) and higher incidence of bulbar dysfunction (22.0% vs 14.8%, p < 0.05). The disease severity in children was comparable with adults. In addition, a higher incidence of pediatric GBS was found in summer, especially in July and August (both p < 0.01). However, the incidence of antecedent infections of different seasons in adult and pediatric patients was comparable (p > 0.05). The clinical features of acute motor axonal neuropathy (AMAN) and acute inflammatory demyelinating polyneuropathy (AIDP) in children were overall comparable with adult ones (p > 0.05). Similar to adults, bulbar dysfunction (odds ratio [OR]: 4.621, 95% confidence interval [CI]: 1.240–17.218, p < 0.05) and lower nadir Medical Research Council (MRC) sum score (OR: 0.897, 95% CI: 0.855–0.941, p < 0.01) were also risk factors for mechanical ventilation in children. However, distinct from adult ones, autonomic dysfunction was significantly higher in mechanically ventilated childhood GBS (39.1% vs 8.8%, p < 0.01), which also served as a predictor for mechanical ventilation in pediatric GBS (OR: 70.415, 95% CI: 9.265–535.158, p < 0.01). As to the efficacy of intravenous immunoglobulin, insignificant difference was identified between children and adults. Conclusion: The clinical features of pediatric GBS differ from those of adults. Autonomic dysfunction is an independent risk factor for mechanical ventilation in pediatric patients. [ABSTRACT FROM AUTHOR]

The overall goal of this study was to understand carbon (C) stock dynamics in four different-aged Japanese larch ( Larix kaempferi) plantations in Northeast China that were established after clear-cutting old-growth Korean pine deciduous forests. Four Japanese larch plantations which were at 10, 15, 21, and 35 years old and an old-growth Korean pine deciduous forest which was 300 years old in Northeast China were selected and sampled. We compared the C pools of biomass (tree, shrub and herb), litterfall (LF), and soil organic carbon (SOC) among them. The biomass C stock of larch plantation at 10, 15, 21, and 35 years old was 26.8, 37.9, 63.6, and 83.2 Mg/ha, respectively, while the biomass C stock of the old-growth Korean pine deciduous forest was 175.1 Mg/ha. The SOC stock of these larch plantations was 172.1, 169.7, 140.3, and 136.2 Mg/ha respectively, and SOC stock of 170.4 Mg/ha in the control of old-growth forest. The biomass C stock increased with stand age of larch plantations, whereas SOC stock decreased with age, and C stock of LF did not change significantly ( P > 0.05). The increase of biomass C offset the decline of SOC stock with age, making total carbon stock (TCS) of larch plantations stable from stand ages of 10-35 years. The TCS in larch plantations was much smaller than that in the old-growth forest, suggesting that the conversion of old-growth forests to young larch plantations releases substantial C into the atmosphere. [ABSTRACT FROM AUTHOR]

Purpose: Conservation tillage can significantly affect the biological, chemical, and physical properties of soil. This study aimed to determine the effect of conservation tillage on the soil microbial community and respiration and on soil CO emissions. Materials and methods: In this study, the effects of 10 years of conservation tillage (no-till: NT and ridge tillage: RT) on soil CO fluxes and soil microbial communities were assessed in a black soil in Northeast China. Results and discussion: The annual soil CO emissions were higher under moldboard plow (MP) than under NT by 7.8 % ( P < 0.05). The average soil microbial respiration rate from RT was higher than that from MP by 11 % ( P < 0.05). Soil microbial respiration under NT (65 %) and RT (64 %) contributed more to soil CO emissions than MP (54 %). Total soil bacterial and fungal phospholipid fatty acids (PLFAs) were 1.6 times and 2.6 times greater under NT and RT, respectively, than under MP in the 0-5 cm layer, whereas they decreased by 21-47 % under NT and 26-41 % under RT in the 5-10, 10-20, and 20-30 cm layers. The F:B (the ratio of soil fungal PLFAs to bacterial PLFAs) varied with soil depth (0-10 cm) between conservation tillage (NT and RT) and MP. Conservation tillage induced the stratification of the soil microbial community on the vertical profile. Conclusions: RT increased soil microbial respiration, soil organic carbon (SOC) concentration, and soil microbial PLFAs at the 0-5 cm depth, whereas it did not influence the annual soil CO emissions compared to MP with a similar carbon input. These results suggested that RT might be an appropriate tillage practice for providing a better habitat for soil microbes and SOC sequestration in Northeast China. [ABSTRACT FROM AUTHOR]

To meet the demand for timber consumption, large areas of broadleaved secondary forests have been replaced by larch (Larix spp.) plantations in Northeast China. However, larch plantations face some serious problems, including soil fertility decline, acidification of surface runoff and low levels of biodiversity. Converting pure larch plantations into mixed larch-broadleaved forests would offer a potential solution to some of these issues. Two dominant broadleaved tree species of secondary forests (i.e. Juglans mandshurica and Fraxinus mandshurica), which have been successfully mixed with larch previously, were seeded in thinned pure larch stands to confirm the feasibility of converting even-aged pure larch plantation stands into uneven-aged mixed larch-broadleaved forests. Larch standswere treated with 100, 50 and 25 per cent thinning intensities to evaluate the effects of thinning on the persistence of seeds in two burial positions (under litter and in soil) and at two burial times (6 and 12 months), and on the seed germination at five burial positions (on top of litter, on top of soil, between litter and soil, in soil and in soil with littercoverage).We found that after 1-year burial, J. mandshurica and F. mandshurica seeds had aviability rate of82and10percent, respectively. Most seeds remained viableat25percent (91 percent for J. mandshurica,27per cent for F. mandshurica) and 50 per cent (90 per cent for J. mandshurica, 23 per cent for F. mandshurica) thinning treatments. Seeds of J. mandshurica andF. mandshurica buried in soil with littercover (21,38per cent)and in50per cent thinning treatments (16, 35 per cent) of larch plantation forests had significantly higher seed germination/ seedling survival rate, compared with other burial positions and thinning treatments. Regeneration results (seed persistence, seed germination and seedling survival) suggest that artificially converting larch plantations into larch-broadleaved mixed forests by thinning and adding seed sources of native broadleaved species is a potentially feasible practice. These results also provide new insights into the tending measures used in pure plantation management. [ABSTRACT FROM AUTHOR]

North China is regarded as a center of domestication for broomcorn millet (Panicum miliaceum) and foxtail millet (Setaria italica ssp. italica). The Neolithic Xinglonggou site (ca. 8000–7500 cal. BP) in the Liao River region has revealed the earliest macrobotanical evidence of domesticated millets in Northeast China, but controversy remains as to the importance of the millets in human diet. We employed an interdisciplinary approach involving analyses of starch grains, phytoliths, and usewear patterns to study a range of materials from Xinglonggou, including grinding stones, human dental calculus, and vegetative charcoal. The results demonstrate a broad spectrum of plant exploitation by the first farmers in Northeast China rather than dependence upon singular crops. Furthermore, three types of underground storage organs appear to be major staples, while millets were secondary to another early and important cultivated cereal, Job’s tears (Coix lacryma-jobi L.). Wild grasses and acorns also account for small portions of plants used. This study documents the northernmost and earliest occurrence of Job’s tears in temperate Northeast China, a species which may have originated in the subtropical regions. We argue that Job’s tears may have been one of the earliest domesticates in China along with millets. [ABSTRACT FROM AUTHOR]

Soil erosion in the Mollisol region of Northeast China is increasingly severe and directly affects national food security and sustainable development. However, few attempts have been made to create a clear distinction between the effects of rainfall and inflow on hillslope soil erosion. A laboratory study was conducted to discuss the roles and contributions of rainfall intensity and inflow rate to hillslope soil erosion and to fit equations based on variations of rainfall intensity and inflow rate (RI + IR) for soil erosion. A soil pan (8 m long, 1.5 m wide and 0.6 m deep and with an adjustable slope gradient of 0°-35°) was subjected to designed rainfall intensities (0, 50 and 100 mm h) and inflow rates (0, 50 and 100 mm h). The results showed that the effects of RI + IR treatments on hillslope soil loss were significantly greater than those on runoff. Furthermore, the effect of rainfall intensity on hillslope soil loss was significantly greater than the effect of inflow rate. Under the same total water supply, an increase in rainfall intensity resulted in greater average soil loss rates and stronger fluctuations in soil loss than an increase in the inflow rate. The occurrence of rill erosion significantly increased sediment transport capacity on the hillslope, which resulted in an increase in soil loss. Utilizing rainfall intensity and inflow rate, runoff and soil loss equations were generated and validated, and the performances of the two equations were satisfactory. Furthermore, it was determined that both equations are most applicable to the prediction of hillslope soil erosion under long rolling hillslope conditions. For the Mollisol region of Northeast China, the key factor affecting soil erosion on hillslopes is soil particle dispersion caused by rainfall. Therefore, taking measures to cover the soil, such as corn straw mulching, would effectively reduce rainfall erosivity and have significant positive effects on soil erosion prevention and control. [ABSTRACT FROM AUTHOR]

Northeast China is an intensive area of resource-exhausted city, which is facing the challenges of industry conversion and sustainable development. In order to evaluate the soil environmental quality influenced by mining activities over decades, the concentration and spatial distribution of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and Zinc (Zn) in surface soils (0-20cm) of a typical resource-exhausted city were investigated by analyzing 306 soil samples. The results showed that the average concentrations in the samples were 6.17 mg/kg for As, 0.19 mg/kg for Cd, 51.08 mg/kg for Cr, 23.27 mg/kg for Cu, 31.15 mg/kg for Ni, 22.17 mg/kg for Pb, and 54.21 mg/kg for Zn. Metals distribution maps produced by using the inverse distance weighted interpolation method and results revealed that all investigated metals showed distinct geographical patterns, and the concentrations were higher in urban and industrial areas than in farmland. Pearson correlation and principal component analysis showed that there were significant positive correlations (p<0.05) between all of the metals, and As, Cd, Cr, Mn, Ni, Pb, and Zn were closely associated with the first principal component (PC1), which explained 39.81% of the total variance. Cu and As were mainly associated with the second component (PC2). Based on the calculated Nemerow pollution index, percentage for slightly polluted (1

Replacing a rainfed cropping system with an irrigated one is widely assumed to be an effective measure for climate change adaptation. However, many agricultural impact studies have not necessarily accounted for the space-time variations in the water availability under changing climate and land use. Moreover, many hydrologic and agricultural assessments of climate change impacts are not fully integrated. To overcome this shortcoming, a tool that can simultaneously simulate the dynamic interactions between crop production and water resources in a watershed is essential. Here we propose the regional production and circulation coupled model (CROVER) by embedding the PRYSBI-2 (Process-based Regional Yield Simulator with Bayesian Inference version 2) large-area crop model into the global water resources model (called H08), and apply this model to the Songhua River watershed in Northeast China. The evaluation reveals that the model's performance in capturing the major characteristics of historical change in surface soil moisture, river discharge, actual crop evapotranspiration, and soybean yield relative to the reference data during the interval 1979-2010 is satisfactory accurate. The simulation experiments using the model demonstrated that subregional irrigation management, such as designating the area to which irrigation is primarily applied, has measurable influences on the regional crop production in a drought year. This finding suggests that reassessing climate change risk in agriculture using this type of modeling is crucial not to overestimate potential of irrigation-based adaptation. [ABSTRACT FROM AUTHOR]

This essay examines Japanese-Chinese arranged cross-border marriages and investigates the ways in which participants legitimate and render such marriages comprehensible in light of national and local histories. Marriageability in this context is produced not through conceptions of “exotic difference” but instead distinct discourses of “familiarity.” On the one hand, Chinese participants tactically narrate “blood ties” (xueyuan guanxi 血缘关系) to interpret current marriage migration as following relational bonds and thus a “natural” phenomenon. On the other hand, Japanese participants stress Chinese women's “familiarity” (shinkin kan 親近感) with Japan, a familiarity that is claimed to stem from positive historical ties forged by colonialism, and thus effaces Japanese wartime culpability. In short, multiple layered notions of familiarity, shaped by the colonial legacy in East Asia, are at work in rendering these transnational intimate relations possible. [ABSTRACT FROM PUBLISHER]

Flooding's impact on shallow groundwater is not well investigated. In this study, we analyzed changes in the depth and quality of a regional shallow aquifer in the 10.9 × 104 km2 Sanjiang Plain, Northeast China, following a large flood in the summer of 2013. Pre- (2008-2012) and post-flood records on groundwater table depth and groundwater chemistry were gathered from 20 wells across the region. Spatial variability of groundwater recharge after the flood was assessed and the changes in groundwater quality in the post-flood period were determined. The study found a considerable increase in the groundwater table after the 2013 summer flood across the region, with the largest (3.20 m) and fastest (0.80 m.s-1) rising height occurring in western Sanjiang Plain. The rising height and velocity gradually declined from the west to the east of the plain. For the entire region, we estimated an average recharge height of 1.24 m for the four flood months (June to September) of 2013. Furthermore, we found that the extreme flood reduced nitrate (NO3-) and chloride (Cl-) concentrations and electrical conductivity (EC) in shallow groundwater in the areas that were close to rivers, but increased NO3- and Cl- concentrations and EC in the areas that were under intensive agricultural practices. As the region's groundwater storage and quality have been declining due to the rapidly increasing rice cultivation, this study shows that floods should be managed as water resources to ease the local water shortage as well as shallow groundwater pollution. [ABSTRACT FROM AUTHOR]

To effectively manage water resources in agricultural production, it is necessary to understand the spatiotemporal variation of the water footprint (WF) and the influences of agricultural inputs. Employing spatial autocorrelation analysis and a geographically weighted regression (GWR) model, we explored the spatial variations of the WF and their relationships with agricultural inputs from 1998 to 2012 in Northeast China. The results indicated that: (1) the spatial distribution of WFs for the 36 major maize production prefectures was heterogeneous in Northeast China; (2) a cluster of high WFs was found in southeast Liaoning Province, while a cluster of low WFs was found in central Jilin Province, and (3) spatial and temporal differentiation in the correlations between the WF of maize production and agricultural inputs existed according to the GWR model. These correlations increased over time. Our results suggested that localized strategies for reducing the WF should be formulated based on specific relationships between the WF and agricultural inputs. [ABSTRACT FROM AUTHOR]

Rice farming in Northeast China is crucially important for China's food security and sustainable development. A key challenge is how to optimize nitrogen (N) management to ensure high yield production while improving N use efficiency and protecting the environment. Handheld chlorophyll meter (CM) and active crop canopy sensors have been used to improve rice N management in this region. However, these technologies are still time consuming for large-scale applications. Satellite remote sensing provides a promising technology for large-scale crop growth monitoring and precision management. The objective of this study was to evaluate the potential of using FORMOSAT-2 satellite images to diagnose rice N status for guiding topdressing N application at the stem elongation stage in Northeast China. Five farmers' fields (three in 2011 and two in 2012) were selected from the Qixing Farm in Heilongjiang Province of Northeast China. FORMOSAT-2 satellite images were collected in late June. Simultaneously, 92 field samples were collected and six agronomic variables, including aboveground biomass, leaf area index (LAI), plant N concentration (PNC), plant N uptake (PNU), CM readings and N nutrition index (NNI) defined as the ratio of actual PNC and critical PNC, were determined. Based on the FORMOSAT-2 imagery, a total of 50 vegetation indices (VIs) were computed and correlated with the field-based agronomic variables. Results indicated that 45% of NNI variability could be explained using Ratio Vegetation Index 3 (RVI3) directly across years. A more practical and promising approach was proposed by using satellite remote sensing to estimate aboveground biomass and PNU at the panicle initiation stage and then using these two variables to estimate NNI indirectly (R² = 0.52 across years). Further, the difference between the estimated PNU and the critical PNU can be used to guide the topdressing N application rate adjustments. [ABSTRACT FROM AUTHOR]

In conservation tillage systems, at least 30% of the soil surface was covered by crop residues which generally contain significant amounts of nitrogen (N). However, little is known about the multi-seasonal recoveries of the N derived from these crop residues in soil-crop systems, notably in northeastern China. In a temperate agro-ecosystem, 15N-labeled maize residue was applied to field surfaces in the 1st year (2009). From the 2nd to 4th year (2010-2012), one treatment halted the application of maize residue, whereas the soil in the second treatment was re-applied with unlabeled maize residue. Crop and soil samples were collected after each harvest, and their 15N enrichments were determined on an isotope ratio mass spectrometer to trace the allocation of N derived from the initially applied maize residue in the soil-crop systems. On average, 8.4% of the maize residue N was recovered in the soil-crop in the 1st year, and the vast majority (61.9%-91.9%) was recovered during subsequent years. Throughout the experiment, the cumulative recovery of the residue N in the crop increased gradually (18.2%-20.9%), but most of the residue N was retained in the soil, notably in the 0-10 cm soil layer. Compared to the single application, the sequential residue application significantly increased the recovery of the residue N in the soil profile (73.8% vs. 40.9%) and remarkably decreased the total and the initially applied residue derived mineral N along the soil profile. Our results suggested that the residue N was actively involved in N cycling, and its release and recovery in crop and soil profile were controlled by the decomposition process. Sequential residue application significantly enhanced the retention and stabilization of the initially applied residue N in the soil and retarded its translocation along the soil profile. [ABSTRACT FROM AUTHOR]

The estimation of annual maximum snow load is important for designing light-weight structures experiencing severe winter climate. The specified (basic) snow load in the Chinese design code is based on statistics of the return period values of ground snow load. The code tabulates the values for a few locations in a region. For example, values are only available at 31 sites for Heilongjiang Province with an area of more than 470,000 km, China. The snow load needs to be spatially interpolated for sites far away from the tabulated locations. However, the statistical justification of the selected probability distribution to model snow depth or load hazard is unclear and the preferred spatial interpolation technique is unknown. This study focuses on the extreme value analysis and spatial interpolation of the annual maximum snow depth and ground snow load using the records at 83 stations in Heilongjiang Province from 1981 to 2010. The statistical analysis results show that the use of the lognormal distribution rather than the Gumbel distribution for the annual maximum snow depth suggested in the code is preferred for most sites, and the application of the ordinary co-kriging is adequate for spatial interpolation of extreme snow depth. The results also show that the uncertainty in snowpack bulk density should not be neglected in estimating the extreme (ground) snow load for updating the snow load in Chinese design code. [ABSTRACT FROM AUTHOR]

The currently available studies on the green-up date were mainly based on ground observations and/or satellite data, and few model simulations integrated with wide coverage satellite data have been reported at large scale over a long time period (i.e., > 30 years). In this study, we combined phenology mechanism model, long-term climate data and synoptic scale remote sensing data to investigate the change in the green-up dates for Quercus mongolica over 33 weather stations in Northeast China and its climate-driven mechanism during 1962-2012. The results indicated that the unified phenology model can be well parameterized with the satellite derived green-up dates. The optimal daily mean temperature for chilling effect was between -27°C and 1°C for Q. mongolica in Northeast China, while the optimal daily mean temperature for forcing effect was above -3°C. The green-up dates for Q. mongolica across Northeast China showed a delayed latitudinal gradient of 2.699 days degree-1, with the earliest date on the Julian day 93 (i.e., 3th April) in the south and the latest date on the Julian day 129 (i.e., 9th May) in the north. The green-up date for Q. mongolica in Northeast China has advanced 6.6 days (1.3 days decade-1) from 1962 to 2012. With the prevailing warming in autumn, winter and spring in Northeast China during the past 51 years, the chilling effect for Q. mongolica has been weakened, while the forcing effect has been enhanced. The advancing trend in the green-up dates for Q. mongolica implied that the enhanced forcing effect to accelerate green-up was stronger than the weakened chilling effect to hold back green-up while the changes of both effects were caused by the warming climate. [ABSTRACT FROM AUTHOR]

A detailed analysis of the major ion chemistry, chemical weathering and CO consumption was conducted in the Songhua River basin, which is the largest basin with a draining area of 557 thousand km in Northeast China. The dataset used in this study included major ion concentrations came from 56 hydrological stations from the year of 1962 to 1984. The median of the total dissolved solid concentration of the Songhua River was 104.8 mg/L, about two times higher than the global average (65.0 mg/L), but lower than that of other Chinese Rivers. Prevalent ions were Na, Ca and HCO, and the average Ca/Na and Mg/Na molar ratios were 0.70 and 0.42, which were close to silicate weathering end-member. Long-term trend analysis by seasonal MK test showed that from 1962 to 1984, Ca, Na + K and HCO were significantly increasing, and the increasing rates calculated by linear fit slopes for Ca, Na + K and HCO ions were 0.22, 0.63 and 2.35 mg/year, respectively. An inverse model showed that the dissolved loads primarily came from rock weathering (91.5 %), including silicate weathering (66.4 %) and a small portion from carbonates (16.1 %) and evaporites (9.0 %). Other origins consisted of anthropogenic inputs (5.3 %) and atmospheric inputs (3.2 %). Average silicate and carbonate weathering rates were estimated as 4.03 and 1.76 t km year, and CO consumption rates of silicates and carbonates were 17.1 × 104 and 1.85 × 104 mol km year, respectively. These results are consistent with the lithologies of the study area, which mainly consisted of silicate rocks. [ABSTRACT FROM AUTHOR]

The aerosol optical depth (AOD), Angstrom exponent (Alpha), single scattering albedo (SSA), and volumes of aerosol size distributions were all retrieved from measurements made by a CE318 sunphotometer at four urban and industrial sites (Shenyang, Anshan, Benxi and Fushun) in Northeast China from 2009 to 2013. Values for direct radiative forcing (DRF) were then estimated using these measurements. For all four sites, the mean AOD appeared higher in the spring and summer, with the minimum occurring in the autumn. Conversely, the Alpha was lower in the spring but higher in the autumn and winter. The mean 440 nm SSA at the four sites varied from 0.81 to 0.87, indicating the highly spatial variability of aerosol optical properties. Frequent dust events resulted in a dominant contribution by coarse particles in spring, while fine particles were predominant during the summer. Mixtures of fine and coarse particles influenced aerosol optical properties in the autumn and winter. Results from this study provide useful information for the further understanding of retrieved aerosol optical properties and DRF in Northeast China. [ABSTRACT FROM AUTHOR]

To study the prediction of the anomalous precipitation and general circulation for the summer (June-July-August) of 1998, the Community Climate System Model Version 4.0 (CCSM4.0) integrations were used to drive version 3.2 of the Weather Research and Forecasting (WRF3.2) regional climate model to produce hindcasts at 60 km resolution. The results showed that the WRF model produced improved summer precipitation simulations. The systematic errors in the east of the Tibetan Plateau were removed, while in North China and Northeast China the systematic errors still existed. The improvements in summer precipitation interannual increment prediction also had regional characteristics. There was a marked improvement over the south of the Yangtze River basin and South China, but no obvious improvement over North China and Northeast China. Further analysis showed that the improvement was present not only for the seasonal mean precipitation, but also on a sub-seasonal timescale. The two occurrences of the Mei-yu rainfall agreed better with the observations in the WRF model, but were not resolved in CCSM. These improvements resulted from both the higher resolution and better topography of the WRF model. [ABSTRACT FROM AUTHOR]

Plastic film mulching (PM) has been widely used to improve maize (Zea mays L.) yields and water use efficiency (WUE) in Northeast China, but the effects of PM in a changing climate characterized by highly variable precipitation are not well understood. Six site-year field experiments were conducted in the dry and rainy years to investigate the effects of PM on maize growth, grain yield, and WUE in Northeast China. Compared to crops grown without PM treatment (control, CK), PM significantly increased the grain yield by 15-26% in the dry years, but no significant yield increase was observed in the rainy years. Yield increase in the dry years was mainly due to a large increase in dry matter accumulation pre-silking compared to the CK, which resulted from a greater dry matter accumulation rate due to the higher topsoil temperature and water content. As a result, the WUE of the crops that underwent PM (3.27 kg m-3) treatment was also increased by around 16% compared to the CK, although the overall evapotranspiration was similar between the two treatments. In the rainy years, due to frequent precipitation and scant sunshine, the topsoil temperature and water content in the field that received PM treatment was improved only at some stages and failed to cause higher dry matter accumulation, except at the 8th leaf stage. Consequently, the grain yield and WUE were not improved by PM in the rainy years. In addition, we found that PM caused leaf senescence at the late growth stage in both dry and rainy years. Therefore, in practice, PM should be applied cautiously, especially when in-season precipitation is taken into account. [ABSTRACT FROM AUTHOR]

The objective of this study is to optimize the river monitoring network in Taizihe River, Northeast China. The situation of the network and water characteristics were studied in this work. During this study, water samples were collected once a month during January 2009 - December 2010 from seventeen sites. Futhermore, the 16 monitoring indexes were analyzed in the field and laboratory. The pH value of surface water sample was found to be in the range of 6.83 to 9.31, and the average concentrations of NH4+-N, chemical oxygen demand (COD), volatile phenol and total phosphorus (TP) were found decreasing significantly. The water quality of the river has been improved from 2009 to 2010. Through the calculation of the data availability and the correlation between adjacent sections, it was found that the present monitoring network was inefficient as well as the optimization was indispensable. In order to improve the situation, the matter element analysis and gravity distance were applied in the optimization of river monitoring network, which were proved to be a useful method to optimize river quality monitoring network. The amount of monitoring sections were cut from 17 to 13 for the monitoring network was more cost-effective after being optimized. The results of this study could be used in developing effective management strategies to improve the environmental quality of Taizihe River. Also, the results show that the proposed model can be effectively used for the optimal design of monitoring networks in river systems. [ABSTRACT FROM AUTHOR]

Human activities are known to increase interference with runoff. Conversely, human activities related to utilizing and managing water resources are primarily determined by annual runoff processes dominated by precipitation distribution. With this view, the soil and water assessment tool was used to quantify human-induced annual runoff changes at different periods and under different patterns of precipitation in seven catchments in Northeast China. The conclusions are as follows. First, although human activities have distinct regional characteristics, an increase in reduced runoff is found for the catchments under investigation; human-induced runoff changes are more significant in the catchment where water resources are limited. Second, the interannual runoff distribution is significantly disturbed in the catchment with large reservoirs. Third, human-induced runoff changes are similar under all patterns of precipitation in the catchment where annual precipitation is less than 500 mm and intense human activities play a dominant role in runoff. Fourth, in general catchments, runoff changes more significantly during relatively drier years or years with uneven precipitation distribution. Finally, human-induced runoff change is related to both annual precipitation characteristics and operations of the reservoirs for catchments in which reservoirs played a significant role. [ABSTRACT FROM AUTHOR]

Habitat loss is one of the key factors underlying the decline of many waterbird species, including Siberian Crane (Grus leucogeranus), a threatened species worldwide. Wetlands are the primary stopover for many waterbirds and restoration of these wetlands involves both hydrological restoration and water resource management. To protect the stopover sites of Siberian Cranes, we collected Siberian Crane stopover numbers, meteorological and hydrological data, and remote sensing data from 2008 to 2011 in Momoge National Nature Reserve, one of the largest wetlands in northeastern China. A model was developed to estimate the suitability of Siberian Crane stopover sites. According to our results, the most suitable daily water level for Siberian Cranes between 2008 and 2012 occurred in the spring of 2008 and in the Scirpus planiculmis growing season and autumn of 2010. We suggest a season-dependent water management strategy in order to provide suitable conditions at Siberian Crane stopover sites. [ABSTRACT FROM AUTHOR]

The residents health risk of Pb, Cd and Cu exposure to street dust with different particle sizes (<100 and <63 μm) near Huludao Zinc Plant (HZP) was investigated in this study. The average concentrations of Pb, Cd and Cu in the <100-μm and <63-μm dust were 1,559, 178.5, 917.9 and 2,099, 198.4, 1,038 mg kg, respectively. It showed that smaller particles tended to contain higher element concentrations. Metals in dust around HZP decreased gradually from the zinc smelter to west and east directions. There was significantly positive correlation among Pb, Cd and Cu in street dust with different particle sizes. The contents of Pb, Cd and Cu in dust increased with decreasing pH or increasing organic matter. Non-carcinogenic health risk assessment showed that the health index (HI) for children and adult exposed to <63-μm particles were higher than exposed to <100-μm particles, which indicated that smaller particles tend to have higher non-carcinogenic health risk. Non-carcinogenic risk of Pb was the highest in both particle sizes, followed by Cd and Cu. HI for Pb and Cd in both particle sizes for children had exceeded the acceptable value, indicated that children living around HZP were experiencing the non-carcinogenic health risk from Pb and Cd exposure to street dust. [ABSTRACT FROM AUTHOR]

Soil organic matter plays a pronounced role in soil aggregation, showing a wide variation depending upon soil-management practices. This study was conducted to characterize organic-matter changes in aggregate fractions in response to land-use change and long-term fertilization. Two experimental sites were established for this study: Site 1 included grassland (GL) and bare land (BL); site 2 comprised three treatments under cropland: no fertilizer application (NF), nitrogen and phosphorus fertilizer application (NP), and NP amended with organic manure (NPM). There was significantly increased carbon (C) sequestration (P< 0.001) in particulate organic matter (POM) observed under grassland and NPM relative to other plots, especially in large macroaggregates, attributable to lack of disturbance and organic input. The protected coarse and fine POM-C together accounted for 15% on average of soil organic carbon, ranging from 10.1 to 18.6% for all plots. The enhanced correlation occurred between protected POM-C fractions and soil C stocks and soil aggregation (calculated as mean weight diameter, MWD) (P= 0.000) relative to other C fractions, indicating that the increases in POM fractions resulting from long-term vegetation restoration and organic amendment enhance soil aggregation and C sequestration in this black soil. In contrast, the significantly negative relationship between MWD and fine-to-coarse POM-C ratio implied that this ratio might account for the decreased soil aggregation. Principal component analysis (PCA) showed that three PCs accounted for 42.6, 25.7, and 11.8%, respectively, and together more than 80% of the total variance. The protected POMs with significantly greater positive PC1 loadings (>0.8), particularly for large macroaggregates, were highly sensitive to changes induced by land use and fertilizer-management practices, leading to the wide variations in soil properties. The interrelation of organic matter with soil aggregation helps us to better understand the mechanisms of C protection and restoration in this black soil in the context of soil degradation and climate change. [ABSTRACT FROM AUTHOR]

ABSTRACT Daily precipitation data from 34 weather stations in Northeast China from 1960 to 2008 are used to examine trends in the occurrence of dry days and prolonged dry episodes. Trends in the mean length and frequency of prolonged dry episodes, as well as the number of dry days within prolonged dry episodes ( DDPDE), are computed regionally and for individual stations at the threshold levels of 1 and 2 mm day−1. Regionally, the number of dry days is increasing in the summer half-year and decreasing in the winter half-year. DDPDE is significantly increasing in the summer half-year; the increased frequency of dry spells has the greatest effect. The mean length of prolonged dry episodes in the winter half-year has decreased significantly. Our results indicate that neither the frequency nor the mean length of prolonged dry episodes, alone, can adequately describe the short-term dry conditions of an area. Multiple characteristics of dry spells, including frequency, length, and the number of DDPDE should be considered. DDPDE is a function of both the frequency and length of dry episodes, but may be more influenced by one or the other characteristics of dry spells, depending on the season or region. [ABSTRACT FROM AUTHOR]

Crop residue resources may affect soil quality, global carbon balance, and stability of crop production, but also contribute to future energy security. This study was performed to evaluate the spatial and temporal variation in residue quantities of field crops in five provinces of North China ( NC) and three provinces of Northeast China ( NEC). The availability of biomass resources was derived from statistical data on crop yields for all crops on the provincial and even county level. We found that cereals - wheat, maize, and rice - were the biggest resource of crop residue feedstock. The ranking of these crops as a source of biomass for bioenergy is determined by the acreage in each region and the crop-specific yield. Annually, the average amount of total residue of 83.0 Mt (Mt = Mega tonnes) in NC (16.9 Million ha) comprised 76.6 Mt field residues and 6.4 Mt process residues on an air-dried basis. The average amount of total biomass residue of 105.7 Mt in NEC (19.8 Million ha) comprised 92.8 Mt field residues and 12.9 Mt process residues. Averaged for 2008, 2009, and 2010, the total standard coal equivalent ( SCE) in NC amounted to 46.4 Mt, which comprised 42.4 Mt field residues and of 3.9 Mt process residues. In NEC, the SCE value of 57.0 Mt comprised 49.7 Mt field residues and 7.4 Mt process residues. The temporal availability of field residues was mainly concentrated in the period between July and September, followed by the period between October and December. In the period between July and September, the amount of field residue available amounted to 40.9 and 53.1 Mt in NC and NEC, respectively. An accurate assessment of field residues may guide policy makers and industry to optimize the utilization of the crop residue resource. [ABSTRACT FROM AUTHOR]

Urban areas are key sources of reactive atmospheric nitrogen (N). Urban forests are moving towards a state of "N-saturation" due to N-deposition. However, the possible future-trend of inherent N-cycling in trees in response to urbanization-related N-deposition is not well known. With regard to the contradiction of current studies on the exogenous N-addition on endogenous N-retranslocation (NR) in the month- or season-long term, we treated 15-month old Changbai larch (Larixo lgensis Henry.) seedlings with ≤sup>15≤/sup>N-labeled ammonium sulfate supplied at rates of 0 (control), 30 (F30), 105 (F105), and 315 (F315) mg ≤sup>15≤/sup>N seedling≤sup>-1≤/sup> to simulate N-deposition at the accumulatively future amounts driven by urbanization. Seedlings were harvested nine days after treatment to determine their response of NR. Results revealed that N-deposition had a significant short-term effect on N-derived from plant (NDFP) in needles, wherein NDFP rose with the increase of ≤sup>15≤/sup>N-deposition intensity. In fine root (in diameter of 0-1 mm) NDFP in the F315 treatment was statistically higher than that in other treatments. There was a mean amount of 1.26 mg of N-retranslocated into needles, which accounted for 19% of total N-content. Results in the present study, together with the other ones we summarized, could be concluded that short-term NR in Changbai larch tended to increase in response to urbanization-related N-deposition. © 2014 Friends Science Publishers [ABSTRACT FROM AUTHOR]

A set of numerical experiments designed to analyze the oceanic forcing in spring show that the combined forcing of cold (warm) El Niño (La Niña) phases in the Niño4 region and sea surface temperature anomalies (SSTA) in the westerly drifts region would result in abnormally enhanced NorthEast Cold Vortex (NECV) activities in early summer. In spring, the central equatorial Pacific El Niño phase and westerly drift SSTA forcing would lead to the retreat of non-adiabatic waves, inducing elliptic low-frequency anomalies of tropical air flows. This would enhance the anomalous cyclone-anticyclone-cyclone-anticyclone low-frequency wave train that propagates from the tropics to the extratropics and further to the mid-high latitudes, constituting a major physical mechanism that contributes to the early summer circulation anomalies in the subtropics and in the North Pacific mid-high latitudes. The central equatorial Pacific La Niña forcing in the spring would, on the one hand, induce teleconnection anomalies of high pressure from the Sea of Okhotsk to the Sea of Japan in early summer, and on the other hand indirectly trigger a positive low-frequency East Asia-Pacific teleconnection (EAP) wave train in the lower troposphere. [ABSTRACT FROM AUTHOR]

Manure application is effective in promoting soil carbon sequestration, but its impact on N2O emission is not well understood. A field experiment was conducted in a maize-cultivated black soil in Northeast China with six treatments: inorganic fertilizer (NPK), 75% inorganic fertilizer N plus 25% pig (PM1) or chicken (CM1) manure N, 50% inorganic fertilizer N plus 50% pig (PM2) or chicken (CM2) manure N, and no N fertilizer (CK). Annual N2O emission significantly increased from 0.34 kg N ha−1 for CK to 0.86 kg N ha−1 for NPK and further to 1.65, 1.02, 1.17, and 0.93 kg N ha−1 for PM1, CM1, PM2, and CM2, respectively. A 15N tracing study showed that 71-79% of total N2O was related to nitrification at 30-70% water-filled pore space (WFPS), and heterotrophic nitrification contributed 49% and 25% to total N2O at 30% and 70% WFPS, respectively. In an incubation, N2O emission was only stimulated when nitrate and glucose were applied together at 60% WFPS, indicating that denitrification was carbon limited. PM had a stronger effect on denitrification than CM due to higher decomposability, and the lower N2O emission at higher manure application rate was associated with decreased mineral N supply. After compiling a worldwide database and establishing an empirical model that related N2O emissions (kg N ha−1) to precipitation ( Pr, m) and fertilizer N application rate ( Nr, kg N ha−1) (N2O = 1.533 Pr + 0.0238 Pr Nr), annual N2O emission from global-cultivated black soil applied with inorganic fertilizer N was estimated as 347 Gg N. Our results suggested that N2O emission from cultivated black soils in China was low primarily due to low precipitation and labile organic carbon availability, and would be stimulated by manure application; thus, increased N2O emission should be taken into consideration as applying manure increases soil organic carbon sequestration. [ABSTRACT FROM AUTHOR]

The Wudaogou Group in eastern Yanbian, Northeast China, plays a key role in constraining the timing and eastward termination of the Solonker–Xra Moron River–Changchun Suture, where the Palaeo-Asian Ocean closed. The Wudaogou Group consists of schist, gneiss, amphibolite, metasedimentary, and metavolcanic rocks, all of which underwent greenschist- to epidote–amphibolite-facies regional metamorphism, with some hornfels resulting from contact metamorphism. To determine the age of deposition, the timing and grade of metamorphism, and the tectonic setting of the Wudaogou Group, we investigated the petrography and geochronology of the metamorphic rocks in this group. Zircons from the metasedimentary rocks of this group can be divided into metamorphic zircons and detrital zircons of magmatic origin. U–Pb ages of metamorphic zircons dated by LA-ICP-MS vary from 249 ± 4 to 266 ± 4 Ma, approximating the age of regional metamorphism in the eastern Yanbian area. Detrital zircons yield U–Pb ages ranging from 253 ± 5 to 818 ± 5 Ma, and indicate that the provenance of the Wudaogou Group experienced four tectonic–thermal events between 818 and 253 Ma: Neoproterozoic (ca. 818–580 Ma), Cambro–Ordovician (ca. 500–489 Ma), Devonian–Carboniferous (ca. 422–300 Ma), and middle–late Permian (ca. 269–253 Ma). The youngest detrital zircon, with a U–Pb age of 253 ± 5 Ma, defines the maximum depositional age of the Wudaogou Group. The presence of the Cambro-Ordovician and Neoproterozoic detrital zircons implies that the source of the Wudaogou Group had an affinity with Northeast China, which leads us to conclude that the Solonker–Xra Moron River–Changchun Suture extends from Wangqing to Hunchun in eastern Yanbian, and that the Palaeo-Asian Ocean may have closed at the end of the Permian or Early Triassic period. [ABSTRACT FROM AUTHOR]

In this work, the variability of summer [June-August (JJA)] rainfall in northeast China is examined and its predictors are identified based on observational analyses and atmospheric modeling experiments. At interannual time scales, the summer rainfall anomaly in northeast China is significantly correlated with the rainfall anomaly over the Huang-Huai region (32°-38°N, 105°-120°E) in late spring (April-May). Compared with climatology, an earlier (later) rainy season in the Huang-Huai region favors a wet (dry) summer in northeast China. Also, this connection has strengthened since the late 1970s. In addition to the impact of the sea surface temperature anomaly (SSTA) in the tropical Indian Ocean, the local soil moisture anomalies caused by the rainfall anomaly in the Huang-Huai region in late spring generate summer general circulation anomalies, which contribute to the rainfall anomaly in northeast China. As a result, when compared with the SSTA, the rainfall anomaly in the Huang-Huai region in late spring can be used as another and even better predictor for the summer rainfall anomaly in northeast China. The results from atmospheric general circulation model experiments forced by observed SST confirm the diagnostic results to some extent, including the connection of the rainfall anomaly between the Huang-Huai region in April-May and northeastern China in JJA as well as the influence from SSTA in the tropical Indian Ocean. It is shown that eliminating the internal dynamical processes by using the ensemble mean intensifies the connection, implying that the connection of rainfall variation in the two different seasons/regions may be partially caused by the external forcing (e.g., SSTA in the tropical Indian Ocean). [ABSTRACT FROM AUTHOR]

This study investigated diarrheic broiler and layer chickens (<50 days; n = 14) and pigs of three age groups (preweaned <30 days, weaned ≈30 to 60 days, and growing >60 days; n = 64) for E. bieneusi genotypes in northeast China and evaluated the potential roles of chickens and pigs in zoonotic transmission of microsporidiosis. Two 45-day-old layer chickens in city Jixi, Heilongjiang province and one 23-day-old broiler chicken in city Songyuan, Jilin province were identified to harbor a human-pathogenic E. bieneusi genotype Henan-IV and a new genotype named CC-1, respectively, by nested PCR and sequence analysis of the ribosomal internal transcribed spacer (ITS). Eleven of 64 (17.2%) duodenal mucosal specimens from pigs in city Tianjin, city Tongliao of Inner Mongolia, cities Jilin and Songyuan of Jilin province, and cities Daqing, Harbin, and Suihua of Heilongjiang province, were positive for E. bieneusi, with the infection rates of weaned pigs (35%, 7/20) significantly higher than preweaned ones (3.6%, 1/28; P<0.05). Nucleotide sequences of the ITS were obtained from 6 pig specimens, belonging to 3 known genotypes CHN7, EbpC, and Henan-IV. That the previous reports have described the occurrence of genotypes EbpC and Henan-IV in humans and EbpC in wastewater in central China and the clustering of genotypes CC-1 and CHN7 into a major phylogenetic group of E. bieneusi genotypes with zoonotic potential indicated that chickens and pigs could be potential sources of human micorsporidiosis. To our knowledge, this is the first report describing the existence of zoonotic E. bieneusi genotypes in diarrheic chickens. [ABSTRACT FROM AUTHOR]

Assessments of the impacts of land use and land cover changes (LUCC) on the terrestrial carbon budget, atmospheric CO concentration, and CO-related climatic change are important to understand the environmental effects of LUCC and provide information about the effects of historical carbon emissions. Using regional land cover reconstructions from historical records, with a bookkeeping model, we estimated the carbon sink changes caused by historical cropland expansion in Northeast China during the past 300 years. The conclusions are as follows: (1) There was a dramatic land reclamation of cropland during the past 300 years in Northeast China. Approximately 26% of the natural land was cultivated, and 38% of the grassland and 20% of the forest and shrubland were converted to cropland. (2) The carbon emission induced by cropland expansion between 1683 and 1980 was 1.06-2.55 Pg C, and the estimation from the moderate scenario was 1.45 Pg C. The carbon emissions of the soil carbon pool was larger than that from the vegetation carbon pool and comprised more than 2/3 of the total carbon emissions. (3) The carbon emissions of the three provinces in Northeast China were different. Heilongjiang Province had the largest carbon emissions, and Jilin Province had the second largest emissions. (4) The primary source of carbon emissions was forest reclamation (taking 60% of the total emissions in the moderate scenario), the secondary source was grassland cultivation (taking 27%), and the tertiary sources were shrubland and wetland reclamation (taking 13%). Examination on the data accuracy revealed that the high-resolution regional land cover data allowed the carbon budget to be evaluated at the county level and improved the precision of the results. The carbon emission estimation in this study was lower than those in previous studies because of the improved land use data quality and various types of land use change considered. [ABSTRACT FROM AUTHOR]

Local actual evapotranspiration can be estimated with routinely measured meteorological variables using the Penman-Monteith model with surface resistance parameterized via the Katerji and Perrier approach (Agronomie 3(6):513-521, ; PM-KP model), or the nonlinear complementary relationship (CR) model proposed by Han et al. (Hydrol Process 26:3973-3981, ). A comparative study was carried out to evaluate the consistencies and differences of two models, as well as the performances of them for a cropland and grassland in northeast China. The departure of the actual evapotranspiration from the potential evaporation is described as a function of the ratio of the surface resistance to the aerodynamic resistance in the Penman-Monteith model, but the ratio of the aerodynamic term to the radiation term in the CR models. The two ratios are connected using a semi-empirical linear function by the Katerji and Perrier approach. The nonlinear CR model can be regarded as replacing the linear function by a power function after mathematical processing. On the other hand, the PM-KP model can be also considered as a CR-type model. On the daily basis at a maize cropland and degraded grassland in semiarid Northeast China, the nonlinear CR model with locally calibrated parameters performed better with data occupying all the growth stages, but the performances of the two models are similar during the early-, mid-, and late-season stages, respectively. On the half-hourly basis, the PM-KP model and the nonlinear CR model both performed well. It is deduced that on the daily basis the nonlinear CR model is more suitable for the cropland and grassland, but further comparisons are needed on the hourly basis. [ABSTRACT FROM AUTHOR]

The concentrations of four essential (Ca, Mg, Zn, and Cu) and two nonessential elements (Pb and Cd) in feathers and kidneys, livers, gut walls, and muscles of eight carcasses of migratory red-crowned cranes (Grus japonensis) from Zhalong Wetland, northeastern China, were examined. The concentrations of Cd in the feathers were between 0.4 mg kg−1dry weight (dw) and 3.1 mg kg−1dw, in the livers between 0.4 and 4.4 mg kg−1dw, the maximum of which exceeded a level considered to be environmental exposure risk (i.e., 3 mg kg−1dw in the liver or kidney). High Pb levels (0.4–3.2 mg kg−1dw, with an average of 1.8 mg kg−1) were also detected in livers, which exceeded a level considered toxicosis in birds (1.7 mg kg−1dw). Pb and Cd had the highest scores in principal component analysis. Relatively high Pb and Cd concentrations in the migratory cranes were thought to be associated with their habitat and prey. [ABSTRACT FROM PUBLISHER]

Ganglioside as a neurotrophic drug has been hitherto widely used in China, although Guillain-Barré syndrome (GBS) following intravenous ganglioside treatment was reported in Europe several decades ago. We identified 7 patients who developed GBS after intravenous use of gangliosides (ganglioside+ group) and compared their clinical data with those of 77 non-ganglioside-associated GBS patients (ganglioside− group) in 2013, aiming at gaining the distinct features of ganglioside-associated GBS. Although the mean age, protein levels in cerebrospinal fluid (CSF) and frequency of cranial nerve involvement were similar between the two groups, the Hughes Functional Grading Scale (HFGS) score and the Medical Research Council (MRC) sum score at nadir significantly differed (4.9±0.4 vs 3.6±1.0; 7.7±5.5 vs 36.9±14.5, both p<0.001), indicating a higher disease severity of ganglioside-associated GBS. A higher ratio of patients with ganglioside-associated GBS required mechanical ventilation (85.7% vs 15.6%, p<0.01). The short-term prognosis of ganglioside-associated GBS, as measured by the HFGS score and the MRC sum score at discharge, was poorer (4.3±0.5 vs 2.8±1.1; 17.3±12.9 vs 46.0±13.9, both p<0.001). All the patients in the ganglioside+ group presented an axonal form of GBS, namely acute motor axonal neuropathy (AMAN). When compared with the AMAN patients in the ganglioside− group, more severe functional deficits at nadir and poorer recovery after standard treatment were still prominent in ganglioside-associated GBS. Anti-GM1 and anti-GT1a antibodies were detectable in patients with AMAN while not in patients with the demyelinating subtype of GBS. The concentrations of these antibodies in patients with AMAN were insignificantly different between the ganglioside+ and ganglioside− groups. In sum, ganglioside-associated GBS may be a devastating side effect of intravenous use of gangliosides, which usually manifests a more severe clinical course and poorer outcome. [ABSTRACT FROM AUTHOR]

In this work, authors examine the variabilities of precipitation and surface air temperature (T2m) in Northeast China during 1948-2012, and their global connection, as well as the predictability. It is noted that both the precipitation and T2m variations in Northeast China are dominated by interannual and higher frequency variations. However, on interdecadal time scales, T2m is shifted significantly from below normal to above normal around 1987/1988. Statistically, the seasonal mean precipitation and T2m are largely driven by local internal atmospheric variability rather than remote forcing. For the precipitation variation, circulation anomalies in the low latitudes play a more important role in spring and summer than in autumn and winter. For T2m variations, the associated sea surface pressure (SLP) and 850-hPa wind (uv850) anomalies are similar for all seasons in high latitudes with significantly negative correlations for SLP and westerly wind anomaly for uv850, suggesting that a strong zonal circulation in the high latitudes favors warming in Northeast China. The predictability of precipitation and T2m in Northeast China is assessed by using the Atmospheric Model Inter-comparison Project type experiments which are forced by observed sea surface temperature (SST) and time-evolving greenhouse gas (GHG) concentrations. Results suggest that T2m has slightly higher predictability than precipitation in Northeast China. To some extent, the model simulates the interdecadal shift of T2m around 1987/1988, implying a possible connection between SST (and/or GHG forcing) and surface air temperature variation in Northeast China on interdecadal time scales. Nevertheless, the precipitation and T2m variations are mainly determined by the unpredictable components which are caused by the atmospheric internal dynamic processes, suggesting low predictability for the climate variation in Northeast China. [ABSTRACT FROM AUTHOR]

The spatial heterogeneity of soil nutrients influences crop yield and the environment. Previous research has focused mainly on the surface layer, with little research being carried out on the deep soil layers, where high root density is highly related to crop growth. In the study, 610 soil samples were collected from 122 soil profiles (0-60 cm) in a random-sample method. Both geostatistics and traditional statistics were used to describe the spatial variability of soil organic matter (SOM) and total nitrogen (TN) deeper in the soil profile (0-60 cm) with high root density from a typical Mollisol watershed of Northeast China. Also, the SOM and TN in farmland and forest (field returned to forest over 10 years) areas was compared. The spatial autocorrelations of SOM at 0-50 cm depth and TN at 30-60 cm depth were strong, and were mainly influenced by structural factors. Compared to farmland, SOM and TN were typically lower in the 0-30 cm depth of the forest areas, while they were higher in the 30-60 cm depth. As well, both SOM and TN decreased from the 0-20 cm layer to the 30-40 cm layer, and then discontinues, while they continuously decreased with increasing soil depth in the farmland. SOM and TN were typically higher at the gently sloped summit of the watershed and part of the bottom of the slope than at mid-slope positions at the 0-30 cm depth. SOM and TN were lower on the back slope at the 30-60 cm depth, but were higher at the bottom of the slope. Also, the spatial distribution of the carbon storage and nitrogen storage were all highest at the bottom of the slope and part of the summit, while they were lowest in most of back slope in depth of 0-60 cm, and mainly caused by soil loss and deposition. SOM at 0-60 cm and TN at 0-40 cm greater than the sufficiency level for crop growth (3.7-79.2 and 0.09-3.09 g kg, respectively) covered 99 % of the total area, yet for TN, over 35 % of the total area was less than the insufficiency level at the 40-60 cm depth. Generally, accurately predicting SOM and TN is nearly impossible when based only on soil loss by water, although the fact that variability is influenced by elevation, soil loss, deposition and steepness, was shown in this research. Nitrogen fertilizer and manure application were needed, especially in conjunction with conservation tillage in special conditions and specific areas such as the back slope, where soil loss was severe and the deep soil that lacked TN was exposed at the surface. [ABSTRACT FROM AUTHOR]

Background: The awareness, treatment and control of diabetes mellitus (DM) can effectively reflect on the social status of diabetes conditions. Although several researchers have investigated the awareness, treatment and control rates of diabetes mellitus in China, little is known about their association with risk factors. This study aims to examine the relationship between risk factors and awareness, treatment and control of diabetes mellitus in northeast China. Methods: A cross-sectional survey was conducted in 2012. Multistage stratified random cluster sampling design was used to select participants aged 18 to 79 years old. The analysis was based on a representative sample of 1,854 adult subjects. Multivariable logistic regression analysis was used to examine socio-demographic factors associated with the levels of awareness, treatment and control of diabetes mellitus. Results: The awareness, treatment, and control rates of diabetes mellitus were 64.1%, 52.9% and 44.2%, respectively. In the multivariable logistic regression analysis, family history of diabetes was significantly positively associated with awareness (OR, 2.145; 95% CI, 1.600–2.875) and treatment (OR, 2.021; 95% CI, 1.559–2.619) of diabetes mellitus, while negatively associated with control (OR, 0.671; 95% CI, 0.529–0.951). Cigarette smokers and alcohol drinkers were less likely than non-smokers and non-drinkers to be aware of their blood glucose levels (OR, 0.895, 0.614; 95% CI, 0.659–1.216, 0.446–0.844, respectively). Participants who frequently exercise were more likely to be aware of their diabetic conditions than people who never or rarely exercise (OR, 2.003; 95% CI, 1.513–2.651). Conclusions: We found that the awareness and treatment of diabetes mellitus were positively associated with age and were high in participants with a family history of diabetes and those who exercise frequently, but low for cigarette smokers and alcohol drinkers. Participants with a family history of diabetes had their diabetic condition poorly controlled. [ABSTRACT FROM AUTHOR]

Avian leukosis virus subgroup J (ALV-J), first isolated in 1989, preferentially infects meat-type birds. Chinese layer flocks have experienced outbreaks of this virus since 2008. To analyze the status of ALV-J infection in wild birds in China, 585 wild birds collected from three provinces of Northeast China from 2010 to 2012 were tested, and six ALV-J strains were isolated for the first time. Furthermore, the gp85 genes of the six strains were amplified, cloned, and sequenced. The results indicated that two different ALV-J strains coexisted in Chinese wild birds from 2010 to 2012. These results not only expand the epidemiological data available for ALV-J and provide necessary information for the further understanding of the evolution of ALV-J, but they also highlight the potential role of wild-bird migration in the spread of ALV-J. [ABSTRACT FROM AUTHOR]

The analysis of two historical time series of temperature and precipitation in Northeast China, spanning, respectively, 1870–2004 and 1841–2004, performed by continuous wavelet transform and other classical and advanced spectral methods, is presented here. Both variables show a particular trend and oscillations of about 85, 60, 35 and 20 years that are highly significant, with a phase opposition at the centennial scale and at the 20-year scale. The analysis of the four temperature series relative to single seasons shows that the 20-year cycle is typical of the summer monsoon season, while the 35-year cycle is most evident in winter. The cycles of ~60 years and longer are present in all seasons. The centennial variation of temperature and precipitation describes well the 1970–1980 transition between a period of relatively strong East Asian Summer Monsoon (EASM), corresponding to high precipitation and relatively cool temperatures in Northeast China, and a conditions of weak EASM (low precipitation and warm temperatures). The connection of the detected local variations with large-scale climatic variability is deduced from the comparison with different climatic records (Northern Hemisphere temperature, Pacific Decadal Oscillation and Atlantic Multidecadal Oscillation indexes). [ABSTRACT FROM AUTHOR]

The interannual variations of summer surface air temperature over Northeast China (NEC) were investigated through a month-to-month analysis from May to August. The results suggested that the warmer temperature over NEC is related to a local positive 500-hPa geopotential height anomaly for all four months. However, the teleconnection patterns of atmospheric circulation anomalies associated with the monthly surface air temperature over NEC behave as a distinguished subseasonal variation, although the local positive height anomaly is common from month to month. In May and June, the teleconnection pattern is characterized by a wave train in the upper and middle troposphere from the Indian Peninsula to NEC. This wave train is stronger in June than in May, possibly due to the positive feedback between the wave train and the South Asian rainfall anomaly in June, when the South Asian summer monsoon has been established. In July and August, however, the teleconnection pattern associated with the NEC temperature anomalies is characterized by an East Asia/Pacific (EAP) or Pacific/Japan (PJ) pattern, with the existence of precipitation anomalies over the Philippine Sea and the South China Sea. This pattern is much clearer in July corresponding to the stronger convection over the Philippine Sea compared to that in August. [ABSTRACT FROM AUTHOR]

A spring-composite index (s-CI) is proposed in this study that involves slightly altering the use of the accumulated precipitation from the composite index (CI) comparing the value with other three commonly used indices (standardized precipitation index, SPI; self-calibrated Palmer drought severity index, sc-PDSI; and CI). In addition, the spatial-temporal variation of the s-CI in the Songnen Plain (SNP) was investigated using the Mann-Kendall test and empirical orthogonal function (EOF) methods. The results indicated that the proposed s-CI could identify most drought events in 1990s and 2000s and performed relatively better than SPI, sc-PDSI, and CI in this region. Compared with the other three indices, the s-CI had a higher correlation with relative soil moisture in April and May. The recent spring droughts (2000s) were the most severe in April or May. The weather was drier in May compared with April in the 1980s, whereas the weather was wetter in May than in April in the 1960s and 1970s. Moreover, the spatial patterns of the first EOFs for both April and May indicated an obviously east-west gradient in the SNP, whereas the second EOFs displayed north-south drought patterns. The proposed index is particularly suitable for detecting, monitoring, and exploring spring droughts in the Songnen Plain under global warming. [ABSTRACT FROM AUTHOR]

Maize is one of the major cultivated crops of China, having a central role in ensuring the food security of the country. There has been a significant increase in studies of maize under interactive effects of elevated CO2 concentration ([CO2]) and other factors, yet the interactive effects of elevated [CO2] and increasing precipitation on maize has remained unclear. In this study, a manipulative experiment in Jinzhou, Liaoning province, Northeast China was performed so as to obtain reliable results concerning the later effects. The Open Top Chambers (OTCs) experiment was designed to control contrasting [CO2] i.e., 390, 450 and 550 µmol·mol−1, and the experiment with 15% increasing precipitation levels was also set based on the average monthly precipitation of 5–9 month from 1981 to 2010 and controlled by irrigation. Thus, six treatments, i.e. C550W+15%, C550W0, C450W+15%, C450W0, C390W+15% and C390W0 were included in this study. The results showed that the irrigation under elevated [CO2] levels increased the leaf net photosynthetic rate (Pn) and intercellular CO2 concentration (Ci) of maize. Similarly, the stomatal conductance (Gs) and transpiration rate (Tr) decreased with elevated [CO2], but irrigation have a positive effect on increased of them at each [CO2] level, resulting in the water use efficiency (WUE) higher in natural precipitation treatment than irrigation treatment at elevated [CO2] levels. Irradiance-response parameters, e.g., maximum net photosynthetic rate (Pnmax) and light saturation points (LSP) were increased under elevated [CO2] and irrigation, and dark respiration (Rd) was increased as well. The growth characteristics, e.g., plant height, leaf area and aboveground biomass were enhanced, resulting in an improved of yield and ear characteristics except axle diameter. The study concluded by reporting that, future elevated [CO2] may favor to maize when coupled with increasing amount of precipitation in Northeast China. [ABSTRACT FROM AUTHOR]

Many major biomes throughout the world are dominated by plants with clonal growth forms. While many recent studies have examined the effects of clonality on the growth of individual plants, relatively few studies have tested the community level effects of clonality as a function of environmental characteristics. By investigating six sand dune sites that have undergone different numbers of years of natural restoration constituting a succession sere, we quantified if the abundance and importance of clonal plants was related to successional age in the stressful environment of a semi-arid sand dune region in northeastern China. We expected that clonal plants would dominate at every stage of the succession sere. We also predicted that species diversity would decrease in later stages of the succession sere due to the extremely high proportion of clonal plants in the community. Our results showed that, through 45 years of succession, the total plant species richness and Shannon-Wiener diversity index continually increased. While the species number of clonal plants was consistently low during the succession, the importance of clonal plants increased gradually from none at 3 years to 49 % of the total, approximately equal to that of aclonal plants, at the 45-year site. Clonal plants with phalanx strategies were more important than guerillas at all ages in sand dune succession. At the beginning and early stages of sand dune succession, aclonal plants were more important than clonal plants, perhaps due to greater seed propagation. The distribution or arrangement of aclonal and clonal plants in the whole process of sand dune complemented each other. The results presented give new perceptions on the function of biodiversity in maintaining ecosystems. [ABSTRACT FROM AUTHOR]

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In this research, the linkage between late winter Bering Sea ice and maize/rice yields in northeastern China (NEC) is investigated. Results show that such ice influences NEC crop production and thus can be employed to predict harvest amounts. Further investigation reveals that positive anomalies of late winter sea ice cover can persist until spring and that spring sea ice can strengthen North Pacific Oscillation (NPO) positive-phase patterns, and vice versa. NPO significantly affects sea surface temperature (SST) over the North Pacific Ocean through sea-air interaction-in particular, in the Kuroshio region-that may persist until summer. In association with the positive SST anomalies, the polar vortex weakens and the western Pacific subtropical high strengthens, resulting in the convergence of southern and northern air masses over NEC. Moreover, both the southerly flow along the western flank of the western Pacific subtropical high and the easterly flow from the Japan Sea and the central Pacific region supply more water vapor transport; thus, an anomalous water vapor convergence center appears in NEC. With the anomalous updrafts, NEC exhibits positive precipitation anomalies. The greenhouse effect of water vapor results in an increase in minimum temperature, thereby leading to a decrease in diurnal temperature range (DTR). This increase in minimum temperature and decrease in DTR are primary factors favoring increases in rice and maize yields, respectively. [ABSTRACT FROM AUTHOR]