Zonal Distribution Research Articles

Temporal and spatial distributions of precipitation on the Huang-Huai-Hai Plain during 1960–2019, China

AbstractThe Huang-Huai-Hai Plain is an important commercial grain production base in China. Understanding the temporal and spatial variations in precipitation can help prevent drought and flood disasters and ensure food security. Based on the precipitation data for the Huang-Huai-Hai Plain from 1960 to 2019, this study analysed the spatiotemporal distribution of total precipitation at different time scales using the Mann–Kendall test, the wavelet analysis, the empirical orthogonal function (EOF), and the centre-of-gravity model. The results were as follows: (1) The winter precipitation showed a significant upward trend on the Huang-Huai-Hai Plain, while other seasonal trends were not significant. (2) The precipitation on the Huang-Huai-Hai Plain shows a zonal decreasing distribution from southeast to northwest. (3) The application of the EOF method revealed the temporal and spatial distribution characteristics of the precipitation field. The cumulative variance contribution rate of the first two eigenvectors reached 51.5%, revealing two typical distribution fields, namely a ‘global pattern’ and a ‘north-south pattern’. The ‘global pattern’ is the decisive mode, indicating that precipitation on the Huang-Huai-Hai Plain is affected by large-scale weather systems. (4) The annual precipitation barycentres on the Huang-Huai-Hai Plain were located in Jining city and Taian city, Shandong Province, and the spatial distribution pattern was north-south. The annual precipitation barycentres tended to move southwest, but the trend was not obvious. The annual precipitation barycentre is expected to continue to shift to the north in 2020.

Implication of Tidal Forcing Effects on the Zonal Variation of Solstice Equatorial Plasma Bubbles

AbstractEquatorial plasma bubbles (EPBs) are plasma depletions that can occur in the nighttime ionospheric F region, causing scintillation in satellite navigation and communications signals. Past research has shown that EPB occurrence rates are higher during the equinoxes in most longitude zones. An exception is over the central Pacific and African sectors, where EPB activity has been found to maximize during solstice. Tsunoda et al. (2015) hypothesized that the solstice maxima in these two sectors could be driven by a zonal wavenumber 2 atmospheric tide in the lower thermosphere. In this study, we utilize satellite observations to examine evidence of such a wave‐2 feature preconditioning the nighttime ionosphere to favor higher EPB growth rates over these two regions. We find the postsunset total electron content (TEC) observed by FORMOSAT‐3/COSMIC (Constellation Observing System for Meteorology, Ionosphere, and Climate) during boreal summer from 2007 to 2012 exhibits a wave‐2 zonal distribution, consistent with elevated vertical plasma gradients favorable for EPB formation. Numerical experiments are also carried out to determine whether such an ionospheric wave‐2 can be produced as a result of vertical coupling from atmospheric tides with zonal wavenumber 2 in the local time frame. We find that forcing from these tidal components produced increases in the Rayleigh‐Taylor growth rate over both sectors during solar maximum and minimum, as well as wave‐2 modulations on vertical ion drift, ion flux convergence, and nighttime TEC. Our results are consistent with the aforementioned hypothesis over both regions with vertical coupling effects from atmospheric tides preconditioning the nighttime ionosphere to favor higher EPB growth rates.

The effect of heavy metal pollution on urban ecosystem and the evaluation of different land classifications; in Bingöl city/Turkey

PurposeOne of the problems that urbanization creates on the ecosystem is the increase of heavy metal accumulation of the urban lands. Due to constant urbanization and industrialization in many parts of the world, metals are constantly spreading to the environment and pose a great threat to human health. The purpose of the study is to determine the effect of heavy metal accumulation values of the lands located in Bingöl city center on the urban ecosystem by examining them in terms of zonal and land-use classification.Design/methodology/approachThe research was conducted on 30 samples taken from five zones and six land-use classes (traffic area-TA, school area-SA, commercial-industry area-CA, green space-GS, residential area-RA and open space-OS). Heavy metal deposits of soil samples were determined in accredited laboratories using the Inductively Coupled Plasma – Mass Spectrometer (ICP-MS) and Atomic Absorption Spectrometer (AAS) device. The study employed the SPSS program for statistical analysis of laboratory results, and ArcGIS Pro programs were used to determine spatial pollution distribution.FindingsAlthough the heavy metal contents of soil samples pose no problems in terms of national and international standards, a number of zones carry risks for the future. In the analyzes, traffic and settlement area soils in terms of land-use classifications and Zone 5 soils in terms of zonal distribution were determined as ecologically risky areas.Originality/valueThe study provided suggestions on what should be done to use the results of the research in planning the physical development of the city.

Optimal heterogeneous search and rescue asset location modeling for expected spatiotemporal demands using historic event data

The United States Coast Guard is charged with coordinating all search and rescue missions in maritime regions within the United States’ purview. Given the size of the Pacific Ocean and limited available resources, the service seeks to posture its fleet of organic assets to reduce the expected response time for such missions. Leveraging 7.5 years of historic event records for the region of interest, we demonstrate a two-stage solution approach. In the first stage, we develop a stochastic zonal distribution model to evaluate spatiotemporal trends for emergency event rates and response strategies. In the second stage, results from the aforementioned analysis enable parameterization of a bi-objective MILP to identify the best locations to station limited heterogeneous search and rescue assets. This research models both 50th and 75th percentile forecast demands across both the set of current homeports, and a larger set of feasible basing locations. Results provide a minimum 9.6% decrease in expected response time over current asset basing. Our analysis also reveals that positioning assets to respond to 75th percentile demands sacrifices, at most, 2.5% in response time during median demand months, whereas positioning for median demand results in operationally inadequate response capability when 75th percentile demands are encountered.

Spatiotemporal Variations and Risk Analysis of Chinese Typhoon Disasters

Typhoons are a product of air-sea interaction, which are often accompanied by high winds, heavy rains, and storm surges. It is significant to master the characteristics and pattern of typhoon activity for typhoon warning and disaster prevention and mitigation. We used the Kernel Density Estimation (KDE) index as the hazard index; the probability of exceeding, or reaching, return period or exceeding a certain threshold was used to describe the probability of hazard occurrence. The results show that the overall spatial distribution of typhoon hazards conforms to a northeast-southwest zonal distribution, decreasing from the southeast coast to the northwest. Across the six typical provinces of China assessed here, data show that Hainan possesses the highest hazard risk. Hazard index is relatively high, mainly distributed between 0.005 and 0.015, while the probability of exceeding a hazard index greater than 0.015 is 0.15. In light of the four risk levels assessed here, the hazard index that accounts for the largest component of the study area is mainly distributed up to 0.0010, all mild hazard levels. Guangdong, Guangxi, Hainan, Fujian, Zhejiang, and Jiangsu as well as six other provinces and autonomous regions are all areas with high hazard risks. The research results can provide important scientific evidence for the sustainable development of China’s coastal provinces and cities. The outcomes of this study may also provide the scientific basis for the future prevention and mitigation of marine disasters as well as the rationalization of related insurance.

Evaluation of the Performance of CMIP5 Models to Simulate Land Surface Air Temperature Based on Long-Range Correlation

The daily average land surface air temperature (SAT) simulated by 8 CMIP5 models historical experiments and that from NCEP data during 1960–2005, are used to evaluate the performance of the CMIP5 model based on detrended fluctuation analysis (DFA) method. The DFA results of NCEP data show that SAT in most regions of the world exhibit long-range correlation. The scaling exponents of NCEP SAT show the zonal distribution characteristics of larg in tropics while small in medium and high latitudes. The distribution characteristics of the zonal average scaling exponents of CMCC-CMS, GFDL-ESM2G, IPSL-CM5A-MR are similar to that of NCEP data. From the DFA errors of model-simulated SAT, the performance of IPSL-CM5A-MR is the best among the 8 models throughout the year, the performance of FGOALS-g2 is good in spring and summer, GFDL-ESM2G is the best in autumn, CNRM-CM5 and CMCC-CMS is good in winter. The scaling exponents of model-simulated SAT are closer to that of NCEP data in most areas of the mid-high latitude on the northern hemisphere. However, simulations of SAT in East Asia and Central North American are generally less effective. In spring, most models have better performance in Siberian (SIB), Central Asia (CAS) and Tibetan (TIB). SAT in Northern Europe area are well simulated by most models in summer. In autumn, areas with better performance of most models are Mediterranean, SIB and TIB regions. In winter, SAT in Greenland, SIB and TIB areas are well simulated by most models. Generally speaking, the performance of CMIP5 models for SAT on global continents varies in different seasons and different regions.

Semi‐Monthly Lunar Tide Oscillation of foF2 in Equatorial Ionization Anomaly (EIA) Crests During 2014–2015 SSW

AbstractWe investigate the ionospheric responses to the 2014–2015 sudden stratospheric warming (SSW) event in winter and summer hemisphere by using ionosondes distributed in Equatorial Ionization Anomaly (EIA) crests. Daily mean value of foF2 at each station shows obvious semimonthly lunar tide (∼14.5‐day period) modulation from lower to higher latitude in both hemispheres during SSW period. Besides, lunar tide modulation in summer hemisphere is later than that in winter hemisphere, which can be explained by the planetary wave penetrating across the equator from winter to summer hemisphere. In addition, lunar semidiurnal tide extracted from foF2 presents evident enhancement after warming onset. Our results demonstrate the quasi 16‐day periodic oscillations in F region of EIA crests are caused by the enhanced lunar tide in dynamo wind of mesosphere and lower thermosphere region, which is due to the disturbances in the zonal mean wind distribution in connection with SSW.

Ecological Optimization of Spatial Patterns of Water Conservancy landscape in Qilian Mountains based on land processes: a case study of Zamu River Basin in Upper Shiyang River Basin

Based on the relation of the ecological landscape to its ecological function, this paper takes Zamu river basin in upper Shiyang river as an example, which located in the cold region of Qilian Mountains in northwestern of China. With the use of the remote sensing data, the spatial information processing technology of GIS, suitability evaluation with the overall optimization of land use patter is applied to ascertain the function zoning and ecological pattern components of land use, to develop approaches to the ecological optimization of the spatial pattern of water conservation landscape in the mountains region. The results show that: With Zamu river basin as the research object, based on the source of the water conservation ecological landscape of frozen soil and water conservation forest, considering the zonal distribution of the frozen soil and water conservation forests in order to classification of factors such an slope, elevation, vegetation cover type and so on, we divided Zamu river valley into five ecological function regions. There are the water conservation core, water conservation buffer, water conservation excessive area, water conservation area and human development and utilization of the edge area. Also we put forward the countermeasures for protecting the each function.

How histopathologic changes in pediatric nonalcoholic fatty liver disease influence in vivo liver stiffness

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in children and adolescents. About 30% of patients with NAFLD progress to the more severe condition of nonalcoholic steatohepatitis (NASH), which is typically diagnosed using liver biopsy. Liver stiffness (LS) quantified by elastography is a promising imaging marker for the noninvasive assessment of NAFLD and NASH in pediatric patients. However, the link between LS and specific histopathologic features used for clinical staging of NAFLD is not well defined. Furthermore, LS data reported in the literature can vary greatly due to the use of different measurement techniques. Uniquely, time-harmonic elastography (THE) based on ultrasound and magnetic resonance elastography (MRE) use the same mechanical stimulation, allowing us to compare LS in biopsy-proven NAFLD previously determined by THE and MRE in 67 and 50 adolescents, respectively. In the present work, we analyzed the influence of seven distinct histopathologic features on LS, including septal infiltration, bridging fibrosis, pericellular fibrosis, hepatocellular ballooning, portal inflammation, lobular inflammation, and steatosis. LS was highly correlated with periportal and lobular fibrosis as well as hepatocellular ballooning while no independent association was found for inflammation and steatosis. Based on this analysis, we propose a composite elastography score (CES) which includes the four key histopathologic features identified as mechanically relevant. Interestingly, CES-relevant histopathologic features were associated with zonal distribution patterns of pediatric NAFLD.Mechano-structural changes associated with NAFLD progression can be histopathologically staged using the CES, which is easily determined noninvasively based on LS measured by time-harmonic elastography.

Phragmites australis makes valuable floating mat biotopes under oligotrophic conditions

To understand the mechanism of how Phragmites australis makes valuable floating mat biotopes under oligotrophic conditions, we investigated the environmental (water chemistry) and vegetational characteristics (growth, plant species richness, and floristic composition) of a floating mat consisting of three main mat-forming species with a zonal distribution (P. australis on the land side of the floating mat, Zizania latifolia on the middle area, and Typha angustifolia on the water side). Although they showed relatively low growth in the floating mat, compared to those in land-based wetlands, P. australis grew better than other mat-forming species in terms of shoot height and biomass production. Specifically, P. australis made more below-ground parts (593 ± 38 g/m2) than other mat-forming species (Z. latifolia, 100 ± 10 g/m2; T. angustifolia, 167 ± 8 g/m2) and more companion species were found in P. australis-dominated plots (8.5 ± 1.0 species/m2) than other plots (Z. latifolia-dominated plots, 2.7 ± 0.6 species/m2; T. angustifolia-dominated plots, 1.0 ± 0.0 species/m2). The larger amount of below-ground P. australis parts could contribute to thicker and denser mat structures, possibly providing more favorable habitats for neighboring plant species, thus facilitating more companion species within the P. australis-dominated area of the mat.

Geometric mapping of the eye lens and its epithelium reveals changes that accompany emmetropia

PurposeTo investigate changes in both lens shape and the epithelial distribution as emmetropia is established in C57Bl6J mice between postnatal weeks 4 to 6.MethodsWe used a computational approach to produce geometrical maps of the mouse lens and its epithelium. Conveniently our approach ulitises data collected from intact lenses imaged using a conventional laser scanning confocal microscope. It delivers cartesian coordinates for every epithelial cell in the lens epithelium. We chose to investigate lenses during postnatal weeks 4 to 6, a time during lens development when emmetropia is established in this inbred strain of mice (Tkatchenko et al., 2010).ResultsGeometric mapping standardises the measurement and analysis of lens epithelial cell densities. Emmetropia is established in C57Bl6J inbred mice, but many other strains exhibit considerable refractive error (Tkatchenko et al., 2019). The eye lens plays its part in the development and establishment of emmetropia in mice (Tkatchenko et al., 2010; Pardue et al., 2013). We record a change in the shape of the eye lens from a spheroid to a lentoid shape between postnatal weeks 4 and 6. The distribution of the epithelial cells in the lens epithelium also changes from a non‐zonal to a zonal distribution, with characteristics that typify the epithelia of adult animals. We correlate these observations regarding lens geometry with genetic mutations in lens cytoskeletal proteins found in those strains that present with refractive error, but which are absent from C57Bl6J (Sandilands et al., 2004). We discuss the potential significance of these observations in the context of the mechanistic basis of the lens contribution to emmetropia.ConclusionsThe development of emmetropia in the C57Bl6J inbred strain of mice correlates with changes in epithelial cell organisation and changes in lens geometry, which when combined with strain‐specific genetic differences offer a mechanistic understanding involving the lintermediate filament cytoskeleton.Pardue, M. T., et al., (2013) Exp Eye Res, 114, 96–105.Sandilands, A., et al (2004). Eye Res. 78, 109–123.Tkatchenko, T. V. et al. (2019). BMC Medical Genomics, 12, 1–24.Tkatchenko, T. V., Shen, Y. and Tkatchenko, A. V. (2010) Invest Ophth Vis Sci, 51, 21–27. https://doi.org/10.1167/iovs.08‐2767

Геоинформационное обеспечение изучения размещения зарубежных ТНК в глобальных городах

The article discusses the experience of assessing the location of foreign TNCs in global cities as a significant factor in the field of environmental, economic and social aspects of sustainable development of urban areas. A number of initial theoretical models are proposed from the standpoint of the center-peripheral approach and a conceptual scheme of geoinformation and cartographic support of the study is presented, the main stages of its implementation are revealed. The databases of the European Commission’s Joint Research Center (GHS Urban Center Database, GHS-UCDB) and (GHS Functional Urban Areas, GHS-FUA) were used to get an idea of the real models of the intracity location of large business in the delimitation of the boundaries of agglomerations and their separate zones. To determine the composition of TNC divisions, Forbes 2000 data for 2020 and information from corporate websites on the branch network with geographic reference from the Craft.co reference service were used. In total, 55 global cities of the alpha group and more than 12 thousand foreign branches of TNCs were involved in the analysis. The processing and systematization of the obtained data was carried out using the object-relational database management system (RDBMS) PostgreSQL and the PostGIS extension. The visualization of the research results based on the consolidation of tabular data and spatial relationships using QGIS. Comparative analysis showed the effectiveness of the developed technique. As a result of its application, the overall scale of the presence of big business in the global cities of the alpha group and a significant gap between leaders and outsiders were determined. The absence of a universal model for the zonal distribution of TNCs in the urban space was revealed, the basic invariants of which were visualized using the example of a number of centers. The presented developments can contribute to the development of the direction of microgeographic research in geo-urban studies. In practice, the methodology can be useful for modernizing the assessment of the quality of the urban environment and the conditions for its formation as part of the implementation in the Russian Federation of the national project “Housing and Urban Environment”.

Vegetative structure and zonal distribution of true mangroves in Shwe-Thaung-Yan coastal areas, Myanmar

The survey was conducted in the mangrove forests around the Magyi and Utto Creeks at Shwe-Thaung-Yan coastal areas in Ayeyarwady Delta region, April 2018. Transect lines were laid as lower, middle and upper, and quadrate plots based on Point Center Quarter Method (PCQM) P-DATA PRO were used. A total of 15 species of true mangrove was recorded. Rhizophora apiculata and Bruguiera gymnorhiza are the most dominant and distributed species in the study area. Followed by Bruguiera sexangulata, Cerop tagal and Rhizophora mucronata then remaining species. Zonation pattern of mangroves species as lower, middle, upper was also examined in study areas. Among than 1 species in Near Threaten (NT), 1 species in Critically Endangered (CR), 1 species in Endangered (EN) and remaining species are Least Concern (LC) had been considered according with IUCN red list. The environmental parameters such as water salinity and temperature, soil salinity, soil temperature and soil pH of study area were also recorded.

Effects of rock block content and confining pressure on dynamic characteristics of soil-rock mixtures

Soil-rock mixture (S-RM) is a complex geo-material characterized by competent rock inclusions floating in a weaker soil matrix structure. The mechanical performances of it are significantly controlled by the interaction and properties of rock blocks and the external environment. In this study, experiments on S-RM were conducted through a large-scale triaxial apparatus for investigating the effects of rock block content and confining pressure on the dynamic characteristics of them. The features of the axial stress and strain time-histories of S-RM were analyzed. The reductions of the maximum shear modulus and the dynamic shear modulus ratio were investigated. The increase in the damping ratio was explored. And the effects of rock block content and confining pressure on the dynamic characteristics of S-RM were discussed in detail. Results indicate that there is an approximately linear relationship between the maximum shear modulus and the rock block content while an approximately exponential relationship between the maximum shear modulus and the confining pressure. The distribution of the dynamic shear modulus ratio of S-RM takes on a low dispersion at the same normalized shear strain. The unnormalized/normalized damping ratio of S-RM is increasing with the shear strain and takes on a feature of zonal distribution as a whole. Both the dynamic shear modulus ratio and the normalized damping ratio of S-RM could be evaluated by a function of normalized shear strain. The four-parameter formulas for the dynamic characteristics of S-RM were introduced for all practical purposes in the final. The results of this study can provide a reference to further understand the dynamics performance and the parameter determination of S-RM and other similar geo-materials.

Карта растительности Норского заповедника (Амурская область)

The Norsky State Nature Reserve is located in Selemdzhinsky district of the Amurskaya oblast. Its area is 211 168 ha. Currently the flora of the Norsky Nature Reserve is studied in details. A species list has been published and an analysis of the flora has been made (Starchenko, Chuvasheva, 1993; Veklich, 2009). The vegetation cover is poorly studied; so far no geobotanical map of the Reserve has been compiled. Only the overview map (scale 1 : 2 500 000) of the vegetation of the Amur basin (1969) gives an idea of the vegetation as a whole. The climatic characteristics of the territory and the complex relief determine the diversity of plant habitats and their communities. The climate of the Norsky Reserve is continental with monsoon features and even ultracontinental (after A. I. Kaigorodov (1955). The modern relief of the Reserve includes wide floodplains of Nora and Selemdzha rivers, accumulative delta-terraces plain, Norskaya accumulative denudation plain (Geomorphologiya..., 1973) and hills. According to the latest botanical and geographical zoning of the Amurskaya oblast, the Norsky Reserve belongs to the Mamynskiy and Ulmsko-Aldikonskiy districts of the Turan-Mamyn province of the Manchurian subdistrict of the East Asian area (Borisova,Starchenko, 2018). The province belongs to southern taiga with some elements of nemoral forests (Quercus mongolica, Tilia amurensis and etc.) along the valleys of Selemdzha River and its major tributaries. The southern taiga includes different larch forests (often disturbed), derived birch-larch forests with Pinus sylvestris, Picea ajanensis and Abies nephrolepis. The presence of nemoral species in forest cenoses increases in the direction from north to south. A province peculiarity is the wide distribution of larch peatmoss forests, swamps and wet meadows. The scientific-reference typological map of vegetation on a medium scale (1 : 300 000) was compiled for the Norsky Nature Reserve for the first time. It shows spatial patterns of vegetation distribution in connection with the natural features of the territory (Fig. 5). The vegetation map legend is based on an ecologic and phytocoenotic classification. A zonal distribution of plant communities is presented in the legend. Plant communities are divided into some categories: dark-coniferous, light-coniferous and derived forests, which are represented as formations. The main cartographic units are groups of associations and their various combinations. The legend shows the vegetation of floodplains, rocks, and disturbed areas. Vegetation divisions are represented on the vegetation map by seventeen colors and one extra scale sign. All symbols have their own serial number, which is marked in the map legend. The largest areas on the territory of the Reserve are occupied by larch forests — 42 % (Fig. 6). The forested territory as a whole occupies 36.5 %, of which the largest areas are rhododendron larch (9.7 %) and floodplain (9.5 %) forests. Ledum larch and moss-shrub forests occupy 5.7 %. Larch mixed-grass-shrub forests cover some small areas (2.0 %). Sub-taiga larch forests with nemoral grasses and often with oak and black birch trees occupy 0.6 %. Pine and larch-pine forests extend 1.3 % of the Reserve’s area. Fir-spruce forests on watersheds have limited distribution — about 1 %. They are a chain of ecologic-dynamic series on floodplain occupying 2.7 % of the Reserve’s area. To conclude, the vegetation cover of the Norsky Nature Reserve reflects the zonal and provincial features of the territory.

Hepatic sinusoids versus central veins: Structures, markers, angiocrines, and roles in liver regeneration and homeostasis.

The blood circulates through the hepatic sinusoids delivering nutrients and oxygen to the liver parenchyma and drains into the hepatic central vein, yet the structures and phenotypes of these vessels are distinctively different. Sinusoidal endothelial cells are uniquely fenestrated, lack basal lamina and possess organelles involved in endocytosis, pinocytosis, degradation, synthesis and secretion. Hepatic central veins are nonfenestrated but are also active in synthesis and secretion. Endothelial cells of sinusoids and central veins secrete angiocrines that play respective roles in hepatic regeneration and metabolic homeostasis. The list of markers for identifying sinusoidal endothelial cells is long and their terminologies are complex. Further, their uses vary in different investigations and, in some instances, could be confusing. Central vein markers are fewer but more distinctive. Here we analyze and categorize the molecular pathways/modules associated with the sinusoid-mediated liver regeneration in response to partial hepatectomy and chemical-induced acute or chronic injury. Similarly, we highlight the findings that central vein-derived angiocrines interact with Wnt/β-catenin in perivenous hepatocytes to direct gene expression and maintain pericentral metabolic zonation. The proposal that perivenous hepatocytes behave as stem/progenitor cells to provoke hepatic homeostatic cell renewal is reevaluated and newer concepts of broad zonal distribution of hepatocyte proliferation in liver homeostasis and regeneration are updated. Thus, this review integrates the structures, biology and physiology of liver sinusoids and central veins in mediating hepatic regeneration and metabolic homeostasis.

Last exposure process of the Larsemann Hills and adjacent area, East Antarctica, based on bedrock exposure ages

The East Antarctic Ice Sheet (EAIS) is the largest glacial system in the world, and the evolution history of the EAIS strongly affects global climate change. As one of the most extensive ice-free areas in coastal East Antarctica, the Larsemann Hills represent an important site for understanding the glacial evolution of East Antarctica. Generally, the last exposure process in the Larsemann Hills was considered to occur in the last glacial period. However, the initial time of the last exposure process in the Larsemann Hills remains unclear. This study presents the 10Be exposure ages of eight bedrock samples with glacial striae, which means that the original uneroded surfaces are preserved, from the Larsemann Hills and neighboring areas. The 10Be exposure ages ranging from 70.7 ± 4.7 to 13.5 ± 1.2 ka indicate that the Larsemann Hills have become ice-free since MIS4. The 10Be exposure ages with the characteristics of zonal distribution in the E–W direction and ages generally change from north to south, which reveals the combination of glacial retreat and topography differences. The activity of the ice sheet in the Larsemann Hills did not respond to the Last Glacial Maximum (LGM). In contrast, the deglaciation in the Larsemann Hills occurred as a diachronous process during the global last glacial periods, which began long before the LGM and lasted after the LGM. According to the exposure ages in the Larsemann Hills and the distance from the edge of the ice sheet, the average glacial retreat rate since MIS4 has been 71.57 m/ka.

Characteristics of bacterial biodiversity and community structure in non-rhizosphere soils along zonal distribution of plants within littoral wetlands in inner Mongolia, China

The littoral ecotone between land and lake makes an important part of the lake ecosystem which provide essential ecosystem services for human society. In this paper, the littoral wetland zone of Balagasi Lakeshore, Inner Mongolia, China and steppe being adjacent to was taken as the research object to discuss the characteristics of bacterial diversity and community structure in non-rhizosphere soils along zonal distribution of plants in the arid area. From the sediment of the exposed lakebed to the landward, according to the distribution of plant communities (Phragmites australis, Kalidium foliatum, Achnatherum splendens, Reaumuria songarica and Stipa klemenzii), the relationship between plant communities and soil physical and chemical factors were analysed. The Illumina HiSeq high-throughput sequencing method was used to measure bacterial community diversity and composition in their non-rhizosphere soils along the zonal distribution of plant. The results showed that the distribution of plant communities in the littoral zone of Balagasi Lake was mainly affected by soil bulk density, pH, TP, AP, TOC and TN. Meanwhile, the distribution of bacterial communities in non-rhizosphere soils was mainly affected by water content, salinity, AP, TOC, TP of soils. The communities of Achnatherum splendens, Reaumuria songarica, Stipa klemenzii were negatively correlated with pH, water content and nutrient content, while the Phragmites australis was opposite. There was a positive correlation between the Kalidium foliatum community and soil nutrient content. The species diversity of soil bacteria was the lowest in lakebed sediment. There was a significant negative correlation between Acidobacteria∖Verrucomicrobia∖Actinobacteria and soil salinity, so in the three sample groups near the lakebed area (lakebed sediment, Phragmites australis community, Kalidium foliatum community), the relative abundance of which was lower than slope and landward terrace. However, the relative abundance of Proteobacteria was opposite. Bacteroidetes was positively correlated with soil nutrients, and its relative abundance was the highest in the non-rhizosphere soil of Kalidium foliatum community with the highest soil nutrients.

Cranial synchondroses of primates at birth.

Cranial synchondroses are cartilaginous joints between basicranial bones or between basicranial bones and septal cartilage, and have been implicated as having a potential active role in determining craniofacial form. However, few studies have examined them histologically. Using histological and immunohistochemical methods, we examined all basicranial joints in serial sagittal sections of newborn heads from nine genera of primates (five anthropoids, four strepsirrhines). Each synchondrosis was examined for characteristics of active growth centers, including a zonal distribution of proliferating and hypertrophic chondrocytes, as well as corresponding changes in matrix characteristics (i.e., density and organization of Type II collagen). Results reveal three midline and three bilateral synchondroses possess attributes of active growth centers in all species (sphenooccipital, intrasphenoidal, presphenoseptal). One midline synchondrosis (ethmoseptal) and one bilateral synchondrosis (alibasisphenoidal synchondrosis [ABS]) are active growth centers in some but not all newborn primates. ABS is oriented more anteriorly in monkeys compared to lemurs and bushbabies. The sphenoethmoidal synchondrosis (SES) varies at birth: in monkeys, it is a suture-like joint (i.e., fibrous tissue between the two bones); however, in strepsirrhines, the jugum sphenoidale is ossified while the mesethmoid remains cartilaginous. No species possesses an SES that has the organization of a growth plate. Overall, our findings demonstrate that only four midline synchondroses have the potential to actively affect basicranial angularity and facial orientation during the perinatal timeframe, while the SES of anthropoids essentially transitions toward a "suture-like" function, permitting passive growth postnatally. Loss of cartilaginous continuity at SES and reorientation of ABS distinguish monkeys from strepsirrhines.

Assessment of copper accumulation in archived liver specimens from cats.

The aim of this study was to assess hepatic copper concentrations and zonal distribution in cat liver specimens. For this study, 121 archived, formalin-fixed, paraffin-embedded liver specimens from cats were used. Tissue sections were stained for copper with rhodanine and scored from 0 (no copper accumulation) to 5 (panlobular copper accumulation). The tissue specimens were then deparaffinized and hepatic copper concentrations were measured using flame atomic absorption spectroscopy. Tissue samples were categorized into four groups based on histopathologic findings: (1) no significant histopathologic hepatic changes (n = 66); (2) hepatic steatosis (n = 18); (3) inflammatory or infectious disease (n = 24); and (4) neoplasia (n = 13). Of the 121 specimens, 13 (11%) stained positive for copper, with three having a score ⩾3. Thirty-seven specimens (31%) had copper concentrations above the reference interval ([RI] <180 µg/g dry weight liver). Copper concentrations in cats with hepatic inflammatory or infectious disease were significantly higher than cats with hepatic steatosis (P = 0.03). Copper-staining score and concentration were positively correlated (rs = 0.46, P <0.001). Despite the fact that 31% of specimens had copper concentrations above the RI, only 11% showed positive copper staining and only 2.5% had a score ⩾3. Our findings suggest that hepatic copper concentrations greater than the upper limit of the RI are relatively common in cats. Further studies to determine the factors that influence hepatic copper staining in cats and to establish contemporary RIs for hepatic copper in healthy cats are warranted.