A Dendroclimatic Study of Relic Picea meyeri in Inner Mongolian Steppe

Dendroclimatic methods were used to investigate the fundamental relationships between the temperature variables and the growth of climatically relic Picea meyeri Rehd. et Wils. on sandy land of Inner Mongolian grasslands in the Xilin River Basin. The annual mean temperature and accumulated temperature (above 5 ℃, 10 ℃) respectively showed no significant correlation with the spruce growth relative to summer mean temperature, which displayed strong coherence with tree growth ( P <0.01). The mean temperature in May showed significantly negative correlation with spruce growth ( P <0.05). Furthermore, it was revealed that the negative influence of May temperature was due to monthly mean maximum temperature ( T max ) ( P <0.01) other than monthly mean minimum temperature ( T min ) values ( P <0.1), which indicated that the use of T min and T max separately can allow much more insights on the temperate influence. In addition, extreme maximum temperature in May and June might impose the most detrimental influence on tree growth in semi_arid Inner Mongolian grassland. The analysis of the recorded meteorological data demonstrated that the increases in temperature were synchronous with slight decreases in precipitation in the growing season, which suggested that P. meyeri may reduce growth due to temperature_induced drought. On the other hand, the analysis for decadal periods explored that trees appeared to reduce the sensitivity to the warming, and consequently increased sensitivity to rainfall. This may serve as a baseline for more accurate predictions of the potential impacts of altered climate regimes on tree growth.

1例白喉棒状杆菌的鉴定

白喉棒状杆菌,是棒状杆菌属中对人类有重要致病作用的病原菌,主要侵犯咽部形成灰白色假膜,能产生强烈的外毒素,通过血液循环将毒素扩散、引起多种器官病变。我院从1患儿咽部分离出白喉棒状杆菌。

Population structure analysis and determination of neurotoxin content in a set of grass pea (Lathyrus sativus L.) accessions of Bangladesh origin

Grass pea(Lathyrus sativus L.) is a crop that is considered one of the more resilient to climate change. With protein-rich seeds and leaves, it has strong potential as human food as well as animal feed and fodder. However, genetic improvement in this crop remains stagnant owing to the poor characterization of its genetic resources. In this study, we characterized 118 accessions of grass pea with 18 EST-SSR markers. A total of 118 accessions, 101 of L. sativus(100 cultivated accessions from Bangladesh and one wild accession) and 17 wild accessions of other Lathyrus species, were used. A total of 67 alleles were detected, with an average of 3.72 alleles per locus and average polymorphism information content of 0.52. A dissimilarity matrix was formed and hierarchical cluster analysis performed using the UPGMA method grouped genotypes into four main clusters. Cluster analysis based on the genetic dissimilarity revealed a clear grouping of the 100 cultivated and 18 wild accessions into four main groups. Group I consisted of 20 accessions with high β-N-oxalyl-L-α,β-diaminopropionic acid(β-ODAP) concentration. Of these 20 accessions, 17 were wild accessions. Only one wild accession(L. cicera) was clustered in group II, which contained 35 accessions. Most of the group II accessions contained low β-ODAP. Group III was represented by 34 accessions, many of them with high β-ODAP. Group IV consisted of 29 accessions, a few of which had very high β-ODAP concentrations. Analysis of molecular variance of the microsatellite data showed significantly higher values of molecular variance between(83%) than within(17%) populations. These characterized accessions will be useful in grass pea breeding programs.

Impact of Vibrio parahaemolyticus and white spot syndrome virus(WSSV)co-infection on survival of penaeid shrimp Litopenaeus vannamei

White spot syndrome virus(WSSV) is an important viral pathogen that infects farmed penaeid shrimp, and the threat of Vibrio parahaemolyticus infection to shrimp farming has become increasingly severe. Viral and bacterial cross or superimposed infections may induce higher shrimp mortality. We used a feeding method to infect L itopenaeus vannamei with WSSV and then injected a low dose of V. parahaemolyticus(WSSV+Vp), or we fi rst infected L. vannamei with a low-dose injection of V. parahaemolyticus and then fed the shrimp WSSV to achieve viral infection(Vp+WSSV). The effect of V. parahaemolyticus and WSSV co-infection on survival of L. vannamei was evaluated by comparing cumulative mortality rates between experimental and control groups. We also spread L. vannamei hemolymph on thiosulfate citrate bile salt sucrose agar plates to determine the number of V ibrio, and the WSSV copy number in L. vannamei gills was determined using an absolute quantitative polymerase chain reaction(PCR) method. L v My D88 and Lvakt gene expression levels were detected in gills of L. vannamei by real-time PCR to determine the cause of the different mortality rates. Our results show that(1) the cumulative mortality rate of L. vannamei in the WSSV+Vp group reached 100% on day 10 after WSSV infection, whereas the cumulative mortality rate of L. vannamei in the Vp+WSSV group and the WSSV-alone control group approached 100% on days 11 and 13 of infection;(2) the number of Vibrio in the L. vannamei group infected with V. parahaemolyticus alone declined gradually, whereas the other groups showed signifi cant increases in the numbers of Vibrio( P <0.05);(3) the WSSV copy numbers in the gills of the WSSV+Vp, Vp+WSSV, and the WSSV-alone groups increased from 10 5 to 10 7 /mg tissue 72, 96, and 144 h after infection, respectively. These results suggest that V. parahaemolyticus infection accelerated proliferation of WSSV in L. vannamei and vice versa. The combined accelerated proliferation of both V. parahaemolyticus and WSSV led to massive death of L. vannamei.

Shrimp arginine kinase being a binding protein of WSSV envelope protein VP31

Viral entry into the host is the earliest stage of infection in the viral life cycle in which attachment proteins play a key role. VP31(WSV340/WSSV396), an envelope protein of white spot syndrome virus(WSSV), contains an Arg-Gly-Asp(RGD) peptide domain known as a cellular attachment site. At present, the process of VP31 interacting with shrimp host cells has not been explored. Therefore, the VP31 gene was cloned into p ET30a(+), expressed in Escherichia coli strain BL21 and purifi ed with immobilized metal ion affi nity chromatography. Four gill cellular proteins of shrimp( Fenneropenaeus c hinensis) were pulled down by an affi nity column coupled with recombinant VP31(r VP31), and the amino acid sequences were identifi ed with MALDI-TOF/TOF mass spectrometry. Hemocyanin, beta-actin, arginine kinase(AK), and an unknown protein were suggested as the putative VP31 receptor proteins. SDS-PAGE showed that AK is the predominant binding protein of VP31. An i n vitro binding activity experiment indicated that recombinant AK's(r AK) binding activity with r VP31 is comparable to that with the same amount of WSSV. These results suggested that AK, as a member of the phosphagen kinase family, plays a role in WSSV infection. This is the fi rst evidence showing that AK is a binding protein of VP31. Further studies on this topic will elucidate WSSV infection mechanism in the future.

Coupling Relationship Between Summer Microclimate and Spatial Layout of Street Canyons in the White Stupa Temple Area of Beijing

With the rapid urbanization, many high-rise buildings and new districts have been built continuously. However, the old town of cities has gradually been forgotten by people and its environment is becoming increasingly harsh. The old town usually has diversified space and function. As an important part of the old town, the street canyon that is closely related to human settlements is a public space where people communicate and do activities. Therefore, research on microclimate-based improvement of the street canyon in the old town is of great significance. Six typical street canyons in the White Stupa Temple area of Beijing were selected for research to explore spatial characteristics of the street canyon. Microclimate factors such as temperature, humidity, wind speed, and solar radiation were measured on the spot in summer. These factors were combined with two microclimate assessment indexes of physiological equivalent temperature(PET) and wet bulb globe temperature(WBGT) to evaluate the microclimate of the street canyon. In the analysis of the measured data, the mean value comparison method was used to analyze the average values of the microclimate factors in different time periods. Spatial layout of microclimate included the orientation of the canyon, the ratio of the canyon height to canyon width, and green coverage of the canyon, and an in-depth study was made on the coupling relationship between the spatial layout and the microclimate of the canyon. Research results can provide an optimization strategy for the transformation design of the street canyon in White Stupa Temple area, and provide a scientific reference for the research on spatial layout and microclimate improvement in the old town, so as to improve the living quality of residents in the old town.

Spatial and temporal variation of daytime and nighttime MODIS land surface temperature across Nepal

Land surface temperature(LST)is an important variable for assessing climate change and related environmental impacts observed in recent decades.Regular monitoring of LST using satellite sensors such as MODIS has the advantage of global coverage,including topographically complex regions such as Nepal.In order to assess the climatic and environmental changes,daytime and nighttime LST trend analysis from 2000 to 2017 using Terra-MODIS monthly daytime and nighttime LST datasets at seasonal and annual scales over the territory of Nepal was performed.The magnitude of the trend was quantified using ordinary linear regression,while the statistical significance of the trend was identified by the Modified Mann—Kendall test.Our findings suggest that the nighttime LST in Nepal increased more prominently compared to the daytime LST,with more pronounced warming in the pre-monsoon and monsoon seasons.The annual nighttime LST increased at a rate of 0.05 K yr-1(p<0.01),while the daytime LST change was statistically insignificant.Spatial heterogeneity of the LST and LST change was observed both during the day and the night.The daytime LST remained fairly unchanged in large parts of Nepal,while a nighttime LST rise was dominant all across Nepal in the pre-monsoon and monsoon seasons.Our results on LST trends and their spatial distribution can facilitate a better understanding of regional climate changes.

Spatio-temporal Variation of Arctic Sea Ice in Summer from 2003 to 2013

The variation in Arctic sea ice has significant implications for climate change due to its huge influence on the global heat balance. In this study, we quantified the spatio-temporal variation of Arctic sea ice distribution using Advanced Microwave Scanning Radiometer(AMSR-E) sea-ice concentration data from 2003 to 2013. The results found that, over this period, the extent of sea ice reached a maximum in 2004, whereas in 2007 and 2012, the extent of summer sea ice was at a minimum. It declined continuously from 2010 to 2012, falling to its lowest level since 2003. Sea-ice extent fell continuously each summer between July and mid-September before increasing again. It decreased most rapidly in September, and the summer reduction rate was 1.35 × 10~5 km^2/yr, twice as fast as the rate between 1979 and 2006, and slightly slower than from 2002 to 2011. Area with >90% sea-ice concentration decreased by 1.32 × 10~7 km^2/yr, while locations with >50% sea-ice concentration, which were mainly covered by perennial ice, were near the North Pole, the Beaufort Sea, and the Queen Elizabeth Islands. Perennial Arctic ice decreased at a rate of 1.54 × 10~5 km^2 annually over the past 11 years.

Effects of Nitrogen Deposition on Tundra Vegetation Undergoing Invasion by Deyeuxia angustifolia in Changbai Mountains

In recent years, herbaceous species such as Deyeuxia angustifolia （Kom.） Y. L. Chang has invaded alpine tundra regions of the western slope of the Changbai Mountains. Because atmospheric nitrogen deposition is predicted to increase under a warming climate and D. angustifolia is sensitive to nitrogen addition, field experiments were conducted from 2010 to 2013 to determine the effect of increased nitrogen deposition on the mechanisms of D. angustifolia invasion. The goal of this study is to evaluate the impact of increased nitrogen deposition on the changes in alpine tundra vegetation （consisting mostly of Rhododendron chrysanthum Pall. and Vaccinium uliginosum Linn.）. The results showed that： 1） simulated nitrogen deposition affected overall characteristics and structure of R. chrysanthum and E uliginosum communities and had a positive impact on the growth of tundra vegetation invaded by 1）. angustifolia; 2） R. chrysanthum was more resistant to invasion by D. angustifolia than V.. uliginosum; 3） simulated nitrogen deposition could improve the growth and enhance the competitiveness of D. angustifolia, which was gradually replacing R. chrysanthum and V. uliginosum and might become the dominant species in the system in future, transforming alpine tundra into alpine meadow in the Chanebai Mountains.

Extracting Vegetation Phenology Metrics in Changbai Mountains Using an Improved Logistic Model

Remotely sensing images are now available for monitoring vegetation dynamics over large areas.In this paper,an improved logistic model that combines double logistic model and global function was developed.Using this model with SPOT/NDVI data,three key vegetation phenology metrics,the start of growing season (SOS),the end of growing season (EOS) and the length of growing season (LOS),were extracted and mapped in the Changbai Mountains,and the relationship between the key phenology metrics and elevation were established.Results show that average SOS of forest,cropland and grassland in the Changbai Mountains are on the 119th,145th,and 133rd day of year,respectively.The EOS of forest and grassland are similar,with the average on the 280th and 278th,respectively.In comparison,average EOS of the cropland is relatively earlier.The LOS of forest is mainly from the 160th to 180th,that of the grassland extends from the 140th to the 160th,and that of cropland stretches from the 110th to the 130th.As the latitude increases for the same land cover in the study area,the SOS significantly delays and the EOS becomes earlier.The SOS delays approximately three days as the elevation increases 100 m in the areas with elevation higher than 900 m above sea level (a.s.l.).The EOS is slightly earlier as the elevation increases especially in the areas with elevation below 1200 m a.s.l.The LOS shortens approximately four days as the elevation increases 100 m in the areas with elevation higher than 900 m a.s.l.The relationships between vegetation phenology metrics and elevation may be greatly influenced by the land covers.Validation by comparing with the field data and previous research results indicates that the improved logistic model is reliable and effective for extracting vegetation phenology metrics.

《黄帝内经》带下病探微

带下病指女性白带的量、色、质、味异常,早在《黄帝内经》就有带下及带下病详细的论述。秦汉时期有不同称谓,隋代《诸病源候论》基本固定病名。广义 "带下" 即妇女疾病总称;狭义 "带下"指女性阴中流出的液体,亦称白带,有生理性的,也有病理性的,狭义 "带下" 之名,始见《神农本草经》。《内经》中详细记载 "带下" 的来源、作用:为女性体内之精华物质,与入骨孔补益脑髓的物质同源。白带量过多则为病,即《内经》中之"淫"病,为阴阳不和,肾虚无摄;怵惕思虑,神伤恐惧;脾邪传肾,少腹疝瘕;暴食不洁,升降失常。淫之重症有四逆、五逆之说,均指病势深重,积重难返。白淫,男女皆可有,男子随溲而下,溺中若有精之状,即后世所言"白浊";女子则下于阴中,即后世所言之"带下"。《灵枢·五色》"有润如膏状",未述及 "带下" 之颜色及性状。《神农本草经》中论述了赤、白之分。老官山汉墓出土竹简涉及白带颜色、质地及气味。《诸病源候论》根据白带颜色分成"五色带"。傅山归纳总结"五色带",并给出相应的病机及治疗。

Differentially Expressed Serum Protein Profiling in Esophageal Squamous Cell Carcinoma Patients with Different Chinese Medicine Syndromes

Objective:Esophageal carcinoma is the eighth most common malignant tumor and ranked the sixth cause of death in the worldwide careinoma.To find out effective serum markers for early diagnosis and targeted treatment is important to improve esophageal carcinoma survival rate.The aim of this study was to screen differ-entially expressed serum protein profiling in esophageal squamous cell careinoma(ESCC)patients with differ-ent Chinese medicine syndrome and establish ESCC syndrome diagnosis model,to explore the signifcance of ESCC serum differential protein in traditional Chinese medicine(TCM)syndrome diagnosis and provide exper-imental and theoretical basis for the diagnosis,clinical treatment of ESCC.Methods:Serum specimens of 80 ES-CC patients with different syndrome and 20 healthy people were selected according to distribution of their sex and age.Magnetic beads based weak cation exchange combined w ith matrix-assist ed laser desorption/ionization time-of-flight mass spectrometry prot eomic technology and Autoflex Analysis and ClinProTools software were applied to screen differentially expressed serum protein profiling.Then establishing each syndrome group diag-nosis model and verifying with new samples to evaluate the diagnosis value of each syndrome group diagnosis model.Results:18 significantly differential expression protein peaks were screened between the whole ESCC patients sera and the healthy control group.Compared with normal control group,among which,ten were signif-cant down-regulation with m/z values of4210,4267,4054,4248,2106,4091,2991,5337,3952,822,and eight were significant up-regulation with m/z values of 2900,2883,1467,1617,2862,2600,895,811.There were 16,12,11,15 differentially expressed protein peaks in phlegm and qi stagnat ion syndrome(Group P),fluid insufficiency and heat agglomeration syndrome(Group F),blood stasis syndrome(Group B),qi and yang deficiency syndrome(Group Q),respectively.Protein with m/z of4210,4091,4054 and 5337 presen-ted obviously low expression in all syndrome groups,while protein with m/z of2883,1617 presented obvious-y high expression.Protein with m/z of 4644 is an obvious and significative biomarker in the comparison of dif-ferent syndrome of ESCC.Establishing ESCC each syndrome serum different ial protein profiling diagnosis mod-el showed that the specificity and veracity in four syndrome groups were all≥80.00%.Conclusion:Our study achieved differentially expressed protein profiling in ESCC patients with different TCM syndromes,established relatively high sensitivity and specificity of different syndrome of ESCC serum differential protein profiling diag-nosis model,which implied the screened syndrome related serum differential expression protein in TCM syn-drome differentiation and diagnosis had great clinical meaning,could be the assistant diagnosis biomarker of ESCC.

Effects of Acupuncture on Humoral Immunologic Function and Trace Elements in 20 Cases of Behcet's Disease

Acupuncture therapy could normalize both increased light chain K value of IgM and lowered trace element Zn content in patients with Behcet's disease with statistically significant differences,suggesting that acupuncture therapy can elevate humoral immunologic function and improve metabolism of the trace element in these patients.

Stable isotope paleohydrology and chemostratigraphy of the Albian Wayan Formation from the wedge-top depozone,North American Western Interior Basin

Understanding of the role of atmospheric moisture and heat transport in the climate system of the Cretaceous greenhouse world represents a major challenge in Earth system science. Stable isotopic paleohydrologic data from mid-Cretaceous paleosols in North America, from paleoequatorial to paleoArctic latitudes, have been used to constrain the oxygen isotope mass balance of the Albian hydrologic cycle. Over the range from 40°-50°N paleolatitude, sideritic paleosols predominate, indicating paleoenvironments with positive precipitation-evaporation （P-E） balances. Local exceptions occur on leeward side of the Sevier Orogen, where calcic paleosols in the wedge-top depozone record paleoenvironments with negative P-E balances in the orographic rain shadow. Stratigraphic sections in the Wayan Formation of Idaho （WF） were sampled from the wedge-top depozone. The units consist of stacked m-scale mudstone paleosols separated by m-scale sandstone-siltstone beds. Sections were sampled for organic carbon isotope profiles, and B-horizons from 6 well-developed paleosols were sampled for detrital zircons to determine maximum depositional ages. The first of these from the WF has produced a U-Pb concordia age of 101.0±1.1 Ma. This same WF section has produced a stratigraphic trend of upwardly decreasing δ18C values ranging from -24‰ upwards to -27‰ VPDB, suggesting correlation to the late Albian C15 C-isotope segment. Pedogenic carbonates from the WF principally consist of micritic calcite, with carbon-oxygen isotope values that array along meteoric calcite lines （MCLs） with δ18O values that range from -9.47‰ up to -8.39‰ VPDB. At approximately 42°N paleolatitude, these MCL values produce calculated paleoprecipitation values of-8.12‰ to -7.04‰ VSMOW, a range that is consistent with the estimates produced from other proxies at the same paleolatitudes across North America. These results indicate that despite the orographic rain shadow effect, the processes of meridional atmospheric moisture transport in this locale were similar to those in more humid mid-latitude paleoenvironments elsewhere in the continent.

Zika Virus Baculovirus-Expressed Virus-Like Particles Induce Neutralizing Antibodies in Mice

The newly emerged mosquito-borne Zika virus(ZIKV) strains pose a global challenge owing to its ability to cause microcephaly and neurological disorders. Several ZIKV vaccine candidates have been proposed, including inactivated and live attenuated virus vaccines, vector-based vaccines, DNA and RNA vaccines. These have been shown to be efficacious in preclinical studies in mice and nonhuman primates, but their use will potentially be a threat to immunocompromised individuals and pregnant women. Virus-like particles(VLPs) are empty particles composed merely of viral proteins, which can serve as a safe and valuable tool for clinical prevention and treatment strategies. In this study, we used a new strategy to produce ZIKV VLPs based on the baculovirus expression system and demonstrated the feasibility of their use as a vaccine candidate. The pre-membrane(prM) and envelope(E) proteins were co-expressed in insect cells and selfassembled into particles similar to ZIKV. We found that the ZIKV VLPs could be quickly and easily prepared in large quantities using this system. The VLPs were shown to have good immunogenicity in immunized mice, as they stimulated high levels of virus neutralizing antibody titers, ZIKV-specific IgG titers and potent memory T cell responses. Thus, the baculovirus-based ZIKV VLP vaccine is a safe, effective and economical vaccine candidate for use against ZIKV.

Clay mineralogy of the first and second members of the Nenjiang Formation, Songliao Basin: Implications for paleoenvironment in the Late Cretaceous

The first and second members ofthe Nenjiang Formation （K2n1＋2） in the Songliao Basin, northeast China, are an interval of dark-colored mudstone. Paleoenvironmental studies of these strata are useful for understanding the terrestrial environment under a greenhouse climate and hydrocarbon accumulation in lake basins. In this study, clay mineralogy of the K2n1＋2 from four borehole or outcrop sections is investigated to understand terrestrial paleoenvironment during the depositional period in the Late Cretaceous. In the mudstone samples, smectite and illite are the predominant clay minerals, and were derived from weathering of parent rocks in a temperate, sub-humid to sub-arid climate; kaolinite and chlorite are minor clay species. The difference in the clay-mineral assemblages between the eastern and western margins of the basin was primarily controlled by provenance lithology, and the high smectite content in the western basin resulted from alteration of volcanic rocks exposed in the Greater Xing＇an Range area. The increasing illite content and ratio of illite/smectite percentages in the upper part of the first member of the Nenjiang Formation indicate paleoenvironmental change. This temporal change in the clay-mineral composition was primarily caused by a regionally cooler and drier paleoclimate, consistent with previous paleoenviroumental reconstructions.

Coupling the Occurrence of Correlative Plant Species to Predict the Habitat Suitability for Lesser White-fronted Goose (Anser erythropus) under Climate Change: A Case Study in the Middle and Lower Reaches of the Yangtze River

Climate change and human activities influence species biodiversity by altering their habitats. This paper quantitatively analyzed the effects of climate change on a migratory bird. The Lesser White-fronted Goose(LWfG), a species which migrates via the middle and lower reaches of the Yangtze River region, is an herbivorous species of high ecological value. It is an endangered species threatened by climate change and human activities, so comprehensive information about its distribution is required. To assess the effectiveness of conservation of the LWfG under climate change, both climate variables and human activities are often used to predict the potential changes in the distribution and habitat suitability for LWfG. In this work, the current scenario and the Global Circulation Models(GCMs) climate scenarios were used to simulate the future distribution of the species. However, besides climate change and human activities, the spatial pattern of plants surrounding the wetland is also known to be closely related to the distribution of LWfG. Therefore, the distribution model results of six plant species related to LWfG’s diet selection were used as environment variables to reflect the changes of suitable LWfG habitat. These environmental variables significantly improved the model’s performance for LWfG, since the birds were clearly influenced by the plant distribution factors. Meanwhile, the suitable habitat area decreases by 2070 in GCM models under two representative concentration pathways scenarios(RCP2.6 and RCP8.5). More appropriate management and conservation policies should be taken to adapt to future climate change. These adjustments include modifications of the size, shape and use of the conservation area for this species.

Clay mineral assemblages at IODP Site U1340 in the Bering Sea and their paleoclimatic significance

Clay mineral assemblages and crystallinities in sediments from IODP Site 1340 in the Bering Sea were analyzed in order to trace sediment sources and reconstruct the paleoclimatic history of the Bering Sea since Pliocene （the last -4.3 Ma）. The re- sults show that clay minerals at Site U1340 are dominated by illite, with a moderate amount of smectite and chlorite, and minor kaolinite. Sediment source studies suggest that the clay mineral assemblages and their sources in the studied core are controlled primarily by the climate conditions. During the warm periods, clay minerals originated mainly from the adjacent Aleutian Is- lands, and smectite/（illite＋chlorite） ratios increased. During the cold periods, clay minerals from the Alaskan region distinctly increased, and smectite/（illite＋chlorite） ratios declined. Based on smectite/（illite＋chlorite） ratios and clay mineral crystallinities the evolutionary history of the paleoclimate was revealed in the Bering Sea. In general, the Bering Sea was characterized by warm and wet climate condition from 4.3 to 3.94 Ma, and then cold and dry condition associated with the enhanced volcanism from 3.94 to 3.6 Ma. Thereafter, the climate gradually became cold and wet, and then was dominated by a cold and dry condi- tion since 2.74 Ma, probably induced by the intensification of the Northern Hemisphere Glaciation. The interval from 1.95 to 1.07 Ma was a transitional period of the climate gradually becoming cold and wet. After the middle Pleistocene transition （1.07 to 0.8 Ma）, the Bering Sea was governed mainly by cold and wet climate with several intervals of warm climate at -0.42 Ma （MIS 11）, -0.33 Ma （MIS 9） and ~0.12 Ma （MIS 5）, respectively. During the last 9.21 ka （the Holocene）, the Bering Sea was characterized primarily by relatively warm and wet climatic conditions.

Late Cretaceous palynology and paleoclimate change:Evidence from the SK1(South) core, Songliao Basin, NE China

Cretaceous climate was warmer than today.The Songliao Basin contains one of the most important Late Cretaceous non-marine deposits in China for the research of the paleoenvironment and paleoclimate.This research is based on core samples from the SK1(S)borehole.The strata sampled are the upper part of the Quantou Formation to member 2 of the Nenjiang Formation,where spores,pollen,dinoflagellates,and other microfossils are abundantly preserved.Based on analysis of the spores and pollen fossils from the core samples,the following six fossil assemblage zones have been recognized in ascending order:The Cicatricosisporites-Cyathidites-Pinuspollenites,Schizaeoisporites-Cyathidites-Classopollis,Cyathidites-Schizaeoisporites,Schizaeoisporites-Cyathidites-Proteacidites,Proteacidites-Cyathidites-Dictyotriletes,and the Lythraites-Callistipollenites-Schizaeoisporites zones.The six fossil zones range from the late Cenomanian to early Campanian.The Late Cretaceous dinoflagellate cysts in the Songliao Basin are of high abundance and low diversity.Specific phytoplankton types reflect salinity changes of the Songliao Lake.Paleoecology of the dinoflagellates suggests that sediments of members 2 and 3 of the Yaojia Formation(K2y2+3)were deposited in a freshwater environment,whereas members 2 and 3 of the Qingshankou Formation(K2q2+3)and members 1 and 2 of the Nenjiang Formation(K2n1+2)were deposited in freshwater to brackish water environments.Combined with the paleoecology of dinoflagellates and the palynomorph biozones,valuable information of the paleoclimate was provided.The quantitative analyses of spores and pollen fossils,such as vegetation type,climate type,and humidity type,diversity and dominance,indicate a relatively sub-humid,mid-subtropical paleoclimate,with slight climatic fluctuation and/or temporal change.