Search

The impact of tectonics, volcanism and climate in controlling temporal and spatial variations in rift‐basin sedimentation is still poorly understood. Here, we tackle this issue by the analysis of mid‐Cretaceous sediments deposited in the Songliao Basin, northeastern China. We present new zircon U–Pb, apatite fission‐track and trace‐element data from the northeastern basin, which are discussed within the framework of the published geochronology dataset. Our results reveal a major provenance change from syn‐rift tectonic extension to post‐rift thermal subsidence at ~103 Ma. During the syn‐rift stage, the detrital inputs were dominantly from transverse rivers sourced from the surrounding mountains including graben shoulders and volcanoes. During the post‐rift stage and coeval thermal subsidence, the basin sedimentation was controlled by coexisting transverse and axial drainage systems sourced from uplifting regions in the south. We conclude that tectonics, not climate, exerted a major control in sediment provenance change in the mid‐Cretaceous Songliao Basin. [ABSTRACT FROM AUTHOR]

Permian magmatism occurred widely in the Tarim basin and adjacent areas of NW China, resulting in the emplacement of numerous carbonatite plutons and alkaline rock intrusions, which are likely to have been derived from mantle sources. In addition, at least one large igneous province (LIP) can be recognized in NW China; namely, the ca. 270–290 Ma Tarim LIP, and it can be inferred that the peak age of magma activity is ~ 280 Ma. Therefore, the mantle plume is limited spatially within southern Tianshan and the Tarim Basin and temporally in the Early Permian. Age and field evidence suggest a spatial and temporal relationship between the carbonatites and alkaline rocks within the Tarim LIP, and their genesis is related to the Tarim mantle plume. In this paper, we direct our attention to the mineral assemblages that are related to carbonatites and alkaline rocks which host REE deposits (Wajilitag, Boziguoer) in the northern Tarim Craton. Alkaline rocks typically are related to rifts and/or extensional tectonics, and we suggest that these magmatic and metallogenic events occurred during an extensional regime, possibly related to the Tarim mantle plume event that affected much of South Tianshan during the Permian. [ABSTRACT FROM AUTHOR]

The Tianyu Cu‐Ni sulfide deposit occurs in the north margin of the Central Tianshan Arc in East Tianshan orogenic belt, Xinjiang, NW China. The intrusions consist of gabbro, peridotite, and olivine pyroxenite. The peridotite and pyroxenite are the main host rock for the Cu‐Ni ores. Rhenium and osmium isotopic analyses of Ni‐ and Cu‐bearing sulfide minerals from the deposit have been used to determine the source of osmium, and by inference, the sources of ore metals. Sulfide ore samples have Os and Re concentrations varying in the ranges 1.85 to 4.58 ppb and 93.56 to 146.00 ppb, respectively. An initial 187Os/188Os ratio ranges from 0.86 to 1.23 for the ores and the γOs values from 592 to 2227. Osmium isotopic data suggest that the Tianyu intrusion and associated Cu‐Ni mineralization has derived from crustal‐contaminated mantle melts. The intrusions early show island‐arc geochemical signatures, which indicate that the Hulu mafic–ultramafic intrusions, along with the Cu‐Ni deposit, formed as a result of subduction of oceanic crust in the Early Permian. [ABSTRACT FROM AUTHOR]

While spatial heterogeneity of riverine nitrogen (N) loading is predominantly driven by the magnitude of basin‐wide anthropogenic N input, the temporal dynamics of N loading are closely related to the amount and timing of precipitation. However, existing studies do not disentangle the contributions of heavy precipitation versus non‐heavy precipitation predicted by future climate scenarios. Here, we explore the potential responses of N loading from the Mississippi Atchafalaya River Basin to precipitation changes using a well‐calibrated hydro‐ecological model and Coupled Model Intercomparison Project Phase 5 climate projections under two representative concentration pathway (RCP) scenarios. With present agricultural production and management practices, N loading could increase up to 30% by the end of the 21st century under future climate scenarios, half of which would be driven by heavy precipitation. Particularly, the RCP8.5 scenario, in which heavy precipitation and drought events become more frequent, would increase N loading disproportionately to projected increases in river discharge. N loading in spring would contribute 41% and 51% of annual N loading increase under the RCP4.5 and RCP8.5 scenarios, respectively, most of which is related to higher N yield due to increases in heavy precipitation. Anthropogenic N inputs would be increasingly susceptible to leaching loss in the Midwest and the Mississippi Alluvial Plain regions. Our results imply that future climate change alone, including more frequent and intense precipitation extremes, would increase N loading and intensify the eutrophication of the Gulf of Mexico over this coming century. More effective nutrient management interventions are needed to reverse this trend. Plain Language Summary: Future climate change is expected to alter nutrient transport from land to rivers, which will have impacts on coastal ecosystems. The impacts of future precipitation changes on nitrogen (N) loading, however, remain unclear. Based upon a well‐tested hydro‐ecological model, this study separates the roles of future heavy precipitation, non‐heavy precipitation, and no‐precipitation days in affecting N leaching loss and predicts the changes in N loading to the Gulf of Mexico. N loading is projected to increase by 30% under two climate scenarios (RCP4.5 and RCP8.5) by the end of the 21st century, half of which is likely driven by heavy precipitation. Future increases in spring heavy precipitation likely result in higher N leaching loss and enhance N loading. Our results indicate that more effective nutrient reduction efforts will be needed to reach the reduction goals of N loading and hypoxia extent in the Gulf of Mexico. Key Points: We examine the responses of nitrogen (N) loading from the Mississippi Atchafalaya River Basin (MARB) to future climate changesN loading from the MARB could increase by 30% under future climate scenarios, and half of the increase would be driven by heavy precipitationAnthropogenic N input would be increasingly susceptible to leaching loss in the Midwest and Mississippi Alluvial Plain under future climate [ABSTRACT FROM AUTHOR]

The atmospheric concentration of nitrous oxide (N2O) has increased by 23% since the pre‐industrial era, which substantially destructed the stratospheric ozone layer and changed the global climate. However, it remains uncertain about the reasons behind the increase and the spatiotemporal patterns of soil N2O emissions, a primary biogenic source. Here, we used an integrative land ecosystem model, Dynamic Land Ecosystem Model (DLEM), to quantify direct (i.e., emitted from local soil) and indirect (i.e., emissions related to local practices but occurring elsewhere) N2O emissions in the contiguous United States during 1900–2019. Newly developed geospatial data of land‐use history and crop‐specific agricultural management practices were used to force DLEM at a spatial resolution of 5 arc‐min by 5 arc‐min. The model simulation indicates that the U.S. soil N2O emissions totaled 0.97 ± 0.06 Tg N year−1 during the 2010s, with 94% and 6% from direct and indirect emissions, respectively. Hot spots of soil N2O emission are found in the US Corn Belt and Rice Belt. We find a threefold increase in total soil N2O emission in the United States since 1900, 74% of which is from agricultural soil emissions, increasing by 12 times from 0.04 Tg N year−1 in the 1900s to 0.51 Tg N year−1 in the 2010s. More than 90% of soil N2O emission increase in agricultural soils is attributed to human land‐use change and agricultural management practices, while increases in N deposition and climate warming are the dominant drivers for N2O emission increase from natural soils. Across the cropped acres, corn production stands out with a large amount of fertilizer consumption and high‐emission factors, responsible for nearly two‐thirds of direct agricultural soil N2O emission increase since 1900. Our study suggests a large N2O mitigation potential in cropland and the importance of exploring crop‐specific mitigation strategies and prioritizing management alternatives for targeted crop types. [ABSTRACT FROM AUTHOR]

Spatiotemporal patterns of crop nitrogen (N) budget have important implications for agricultural N management and environmental policy. Previous studies examined crop N budget in different countries but often overlooked cross‐crop differences at sub‐national scales. In this study, we synthesize multiple databases to examine the N budget of eight major crops in the United States at the county scale during 1970–2019. Our analyses show that national crop N use efficiency (NUE) increased from 0.55 kg N kg−1 N in the 1970s to 0.65 kg N kg−1 N in the 2010s. Four out of eight crops such as corn, rice, cotton, and sorghum demonstrated an increasing NUE trend during the study period, whereas the other crops overall presented a declining NUE trend. Nationwide, about 41% of the total N input was not used by these crops (i.e., N surplus) over the study period, of which temporal variation was mainly driven by corn due to its large planting area and high N input. The national N surplus first increased in the 1970s and remained relatively stable till the 2000s. Since the early 2010s, however, N surplus began to decline and approached the levels in the early 1970s—an encouraging development that may lead to decreased N pollution to the environment. The hotspots of national N surplus coincided with corn‐ and rice‐producing counties. The sub‐national variations and temporal dynamics in crop N budget revealed in this study highlight the urgent need to understand the farm‐level crop N balance and the dominant factors controlling crop NUE for mitigating N pollution. Key Points: We synthesized county‐level crop nitrogen (N) budget data of eight major crops in the United States during 1970–2019The national crop nitrogen use efficiency (NUE) increased from 0.55 kg N kg−1 N in the 1970s to 0.65 kg N kg−1 N in the 2010s, with an average NUE of 0.59 kg N kg−1 NN surplus accounted for 41% (27%–55%) of the national total N input, with a significant decline detected during the recent decade [ABSTRACT FROM AUTHOR]

Recombinant lysostaphin has been used for the treatment of cow endometritis and mastitis in China. To our knowledge, no scientific effort has been made to evaluate the efficacy of lysostaphin in sows with clinical endometritis. Lysostaphin, loaded in effervescent tablets that were completely foamed and dissolved within 30 min in the presence of water or body fluids and released active lysostaphin, were administered vaginally on endometritis sows in this study. The clinical recovery, bacterial clearance and reproductive performance of sows with endometritis were investigated. We found that the 400U dosage (400U lysostaphin/pill/time, repeat once on the third day, a total of two times, with 10% oxytetracycline uterine injection as a control) is the most effective treatment. Staphylococcus aureus was the most prevalent finding (34%, n = 188), followed by Streptococcus (32%, n = 181), Escherichia coli (19%, n = 104) and other bacilli (15%, n = 83) before treatment by drugs. Administration of lysostaphin resulted in an extremely significant (p <.01) reduction in S. aureus (0.18 ± 0.25 from 4.57 ± 0.33) and Streptococcus (0.11 ± 0.14 from 3.88 ± 0.29), as well as a significant (p <.05) reduction in E. coli (0.55 ± 0.42 from 3.11 ± 0.14). Mixed infections (83%) were predominant before treatment, in contrast to single infections (61%) after treatment. Large‐scale trials were conducted to verify the clinical efficacy of lysostaphin on sow endometritis. The average cure rate of 400u lysostaphin on sow endometritis(82.5%) was higher than the antibiotic group(72.17%). In addition, our results revealed that intravaginal administration of lysostaphin had no adverse effect on the reproductive performance of sows. Thus, this lysostaphin has potential application value as a new method alternative to antibiotics to treat endometritis in sows. [ABSTRACT FROM AUTHOR]

The increasing demands of food and biofuel have promoted cropland expansion and nitrogen (N) fertilizer enrichment in the United States over the past century. However, the role of such long-term human activities in influencing the spatiotemporal patterns of ammonia (NH 3) emission remains poorly understood. Based on an empirical model and time-series gridded datasets including temperature, soil properties, N fertilizer management, and cropland distribution history, we have quantified monthly fertilizer-induced NH 3 emission across the contiguous US from 1900 to 2015. Our results show that N-fertilizer-induced NH 3 emission in the US has increased from <50 Gg N yr -1 before the 1960s to 641 Gg N yr -1 in 2015, for which corn and spring wheat are the dominant contributors. Meanwhile, urea-based fertilizers gradually grew to the largest NH 3 emitter and accounted for 78 % of the total increase during 1960–2015. The factorial contribution analysis indicates that the rising N fertilizer use rate dominated the NH 3 emission increase since 1960, whereas the impacts of temperature, cropland distribution and rotation, and N fertilizer type varied among regions and over periods. Geospatial analysis reveals that the hot spots of NH 3 emissions have shifted from the central US to the Northern Great Plains from 1960 to 2015. The increasing NH 3 emissions in the Northern Great Plains have been found to closely correlate to the elevated NH 4+ deposition in this region over the last 3 decades. This study shows that April, May, and June account for the majority of NH 3 emission in a year. Interestingly, the peak emission month has shifted from May to April since the 1960s. Our results imply that the northwestward corn and spring wheat expansion and growing urea-based fertilizer uses have dramatically altered the spatial pattern and temporal dynamics of NH 3 emission, impacting air pollution and public health in the US. [ABSTRACT FROM AUTHOR]

Future crop yield increases are unlikely to keep pace with the dietary needs of a global human population expected to reach nine billion by 2050. This study used United States Department of Agriculture county‐level yield data and autoregressive moving‐average models to examine how changes in maize (Zea mays L.), soybean (Glycine max L.), and winter wheat (Triticum aestivum L.) yields, temporal variability in yields, and yield gaps have varied across space and time from 1970–2017. The majority of county‐level yields have increased linearly, although the increases in wheat lag behind corn and soybean. Where trends were nonlinear, accelerating yields were found in more mesic regions east of the Great Plains, and decelerating yields were found in the drier central and western United States. Mean crop yields were positively correlated with rate of yield increase and negatively correlated with interannual variability. Hotspots were identified in Minnesota, Iowa, Illinois, Nebraska, and some West Coast states where crop yields are currently the largest, have the lowest yield gaps, and since 1970, have had the highest rates of change and/or are experiencing an acceleration of annual yield gains. Across all crop types, the counties with the lowest average yields, highest yield gaps, lowest rates of yield increase over time, and/or deceleration in yield increases were predominantly found in the central United States, including the Dakotas, Kansas, Oklahoma, and Texas. Regions of greatest performance generally have fertile soils, plentiful growing season rainfall, and optimal growing season length and temperatures, or are benefitting from irrigation. [ABSTRACT FROM AUTHOR]

The Altai‐Junggar‐Tianshan collage in southern Altaids is an important metallogenic domain in Central Asia that contain world‐class copper‐iron‐nickel deposits. As an accretionary‐type metallogenic system, the metallogenic processes of the Altai‐Junggar‐Tianshan collage is essential in understanding the genetic mechanism of ore deposits in general. Here in this paper we present a brief introduction to the project on the western part of the Southern Altaids, entitled "The deep structure and metallegenic processes of the North China accretionary metallogenic systems". This project mainly focuses on the deep structure and metallogenic background of the Altai‐Junggar‐Tianshan collage by integrated studies from field geology, structural mapping, geochemistry and geophysical exploration. Multiple new geological and geophysical methods will be applied to make transparency of the Kalatongke and Kalatage ore clusters. This will update our understanding of the geodynamic processes of metallogenesis and lead to the development and foundation of new metallogenic theories in accretionary orogens. [ABSTRACT FROM AUTHOR]

A great number of magmatic Cu‐Ni deposits (including Kalatongke in Xinjiang and Hongqiling in Jilin) are distributed over a distance of almost 3000 km across the Tianshan‐Xingmeng Orogenic Belt, from Tianshan Mountains in Xinjiang in the west, to Jilin in eastern China in the east. These deposits were formed during a range of magmatic episodes from the Devonian to the Triassic. Significant magmatic Cu‐Ni‐Co‐PGE deposits were formed from the Devonian period in the Nalati arc (e.g. Jingbulake Cu‐Ni in Xinjiang), Carboniferous period in the Puerjin‐Ertai arc (e.g. Kalatongke Cu‐Ni‐Co‐PGE in Xinjiang), Carboniferous period in the Dananhu‐Touquan arc (e.g. Huangshandong, Xiangshan and Tulaergen in estern Tianshan, Xinjiang) to Triassic period in the Hulan arc (e.g. Hongqiling Cu‐Ni in Jilin). In addition to the overall tectonic, geologic and distribution of magmatic Cu‐Ni deposits in the Tianshan‐Xingmeng Orogenic Belt, the metallogenic setting, deposit geology and mineralization characteristics of each deposit mentioned above are summarized in this paper. Geochronologic data of Cu‐Ni deposits indicate that, from west to east, the metallogenic ages in the Tianshan‐Xingmeng Orogenic Belt changed with time, namely, from the Late Caledonian (∼440 Ma), through the Late Hercynian (300–265 Ma) to the Late Indosinian (225–200 Ma). Such variation could reflect a gradual scissor type closure of the paleo Asian ocean between the Siberia Craton and the North China Craton from west to east. [ABSTRACT FROM AUTHOR]

Spatial variation and temporal trajectory of crop nitrogen use efficiency (NUE) have important implications for nitrogen management and environmental conservation. Previous studies have examined cross‐nation divergences in crop NUE but often overlooked its spatial heterogeneity and cross‐crop differences at subnational scales. We examined the relationship between state‐level NUE and nitrogen fertilizer use for two major fertilizer‐consuming crops, corn and winter wheat, which account for over half of national N fertilizer use in the United States. Since 1970, as N fertilizer use rates have changed, the responses of crop yield and NUE have exhibited large temporal and spatial variations. It is evident that NUE of corn begins to decline when N fertilizer application rate exceeds ~150 kg N ha−1 yr−1, and that yield response of winter wheat slows down with annual N fertilizer input above ~50 kg N ha−1 yr−1. State‐level NUE in both crops has risen in recent decades, which could potentially reduce N loss from agricultural production. Across the United States, some major corn‐producing states demonstrate a shift from an increasing trend of NUE during the period 1970 to 1999 to a decreasing trend after 2000, whereas winter wheat‐producing states present an opposite pattern. Furthermore, this study indicates that annual dynamics of N surplus in corn is closely tied with grain yields, while that in winter wheat significantly correlates with N fertilizer input. A larger proportion of N loss would be anticipated if no further increase in corn yield was obtained or fertilizer use kept rising in winter wheat. Plain Language Summary: There have been growing concerns about a mismatch between agricultural nitrogen supply and crop nitrogen demand. To reduce nitrogen pollution from cultivation, it is essential to know how nitrogen use efficiency (NUE) of crops has changed over space and time, and how far we are from their potentials. Here we examined the NUE patterns in two major fertilizer‐consuming crops across the United States since 1970. Despite large spatial variations, we found that NUE in corn and winter wheat has improved in recent decades, potentially reducing nitrogen loss. We also identified a turning point of nitrogen fertilizer use rate for each crop, above which NUE begins to decline or yield response slows down. In addition, our study shows that nitrogen demand and supply play different roles between crops in regulating nitrogen surplus. Key Points: Responses of yield and N use efficiency to N fertilizer input exhibit different trajectories between corn and winter wheat and vary across the statesState‐level NUE of corn and winter wheat has improved in recent decades, but peak NUE occurs at a medium level of N fertilizer inputInterannual variations in N surplus at a national scale are closely tied with grain yields in corn and with N fertilizer use rate in winter wheat [ABSTRACT FROM AUTHOR]

Paleoclimate records identified a severe drought lasting approximately a decade on the Mongolian Plateau during the 2000s, the severity of which was only exceeded by a single drought during the last two millennia. Under high‐emission scenarios, arid and semiarid areas are projected to continue to experience a drying trend over the coming decades; therefore, understanding how ecosystems respond to long‐lasting drought has global implications. Here we used a process‐based ecosystem model to examine the interannual and intra‐annual variations in net ecosystem productivity in response to climate extremes across the Mongolian Plateau. We find that the recent‐decade drought caused Mongolian terrestrial ecosystems to shift from a carbon (C) sink to a C source, canceling 40% of climate‐induced C accumulation over the entire twentieth century. Our study details a shortened C sequestering season, increased summer C source, and accelerated C depletion during the 2000s drought. Plain Language Summary: Multiple lines of evidence have shown detrimental effects of drought events on ecosystem production and carbon dynamics, but it remains uncertain how arid and semiarid ecosystems respond to long‐lasting drought. Here we reveal that a severe drought during the first decade of the 2000s on the Mongolian Plateau considerably weakened C sequestration capacity and accelerated C depletion. This work has broad implications for understanding impacts of persistent droughts on terrestrial C dynamics as a drying trend, in many arid and semiarid areas, is projected to continue over the coming decades. Key Points: The recent decade (2000–2009) has been identified as one of the driest periods on the Mongolian Plateau over the most recent ~2,000 yearsThis long‐duration drought shortened the C sequestration season, increased the summer C source, and led to a net annual C releaseThe NEP amplitude in this dry decade increased due to reduced C uptake and increased C emissions, implying an accelerated C depletion [ABSTRACT FROM AUTHOR]

Abstract: The first carbonatite dyke at Bayan Obo is well exposed on the surface for a length and width of approximately 60 m and 1.1–1.5 m, respectively. Along its strike, the fenitized H1 (Qs) and H2 (Cs) quartzite is replaced by Na‐amphiboles, aegirines, and alkali‐feldspars, intermittently stretching as far away as 800 m in length. Based on petrographical characteristics, the dyke's fenitized wall rocks are divisible into different zones: (1) outer, (2) middle, and (3) inner. The outer zone is 5–17 m from the NW margin of the dyke. The middle zone is located at 3.5–5 m from the NW margin of the dyke. The inner contact zone is located between direct contact with the dyke and 3.5 m from the dyke. In the outer zone, upon visual examination, no evidence of outcrop fenitization was found and the major elemental rock composition is nearly identical to the unaltered H1 and H2 lithologies. In the thin sections, however, small amounts of Na‐amphibole and phlogopite are present. Despite relatively poor development throughout the 5 m of fenitization, the wall rocks have retained at least a small geochemical signature comparable to the original sedimentary protolith. The fenites occurring in the inner zone exhibit distinct variations, not only for the sharp contact at the outcrop scale, but also for variations in major, rare earth elements (REE), and trace elements and Sm‐Nd isotope composition. The wall rocks within 3.5 m have undergone strong fenitization, inheriting the geochemical signature derived from the carbonatite dyke. Fenitization in the middle zone was not as strong, at least compared to the inner zone, but was stronger than the outer zone. Compared to some trace elements and REEs, the major elements are relatively immobile during fenitization. The Sm‐Nd isotope data for the carbonatite dyke and the adjacent fenitized wall rocks, where the Sm and Nd originate solely from the dyke, plots as a six‐point isochron with an age of 1308±56 Ma. This age is identical to that of ore‐bearing dolomite carbonatite and the related ore‐forming events, indicating that there may be a petrogenetic link between the two. Based on Sr and Nd isotope compositional data, the first carbonatite dyke may be derived from an enriched mantle. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to evaluate the clinical outcome of tibial pilon fractures treated with arthroscopy and assisted reduction with an external fixator. Methods: Thirteen patients with tibial pilon fractures underwent assisted reduction for limited lower internal fixation with an external fixator under arthroscopic guidance. The weight-bearing time was decided on the basis of repeat radiography of the tibia 3 months after surgery. Postoperative ankle function was evaluated according to the Mazur scoring system. Results: Healing of fractures was achieved in all cases, with no complications such as severe infection, skin necrosis, or an exposed plate. There were 9 excellent, 2 good, and 2 poor outcomes, scored according to the Mazur system. The acceptance rate was 85%. Conclusion: Arthroscopy and external fixator-assisted reduction for the minimally invasive treatment of tibial pilon fractures not only produced less trauma but also protected the soft tissues and blood supply surrounding the fractures. External fixation could indirectly provide reduction and effective operative space for arthroscopic implantation, especially for AO type B fractures and partial AO type C1 fractures. [ABSTRACT FROM AUTHOR]

Future extreme precipitation (EP, daily rainfall amount over certain thresholds) is projected to increase with global climate change; however, its effect on groundwater recharge has not been fully explored. This study specifically investigates the spatiotemporal dynamics of groundwater recharge and the effects of extreme precipitation (daily rainfall amount over the 95th percentile, which is tagged by ranking the percentiles in each season for a base period) on groundwater recharge from 1950 to 2010 over the Northern High Plains (NHP) Aquifer using the Soil Water Balance Model. The results show that groundwater recharge significantly ( p < 0.05) increased in the eastern NHP from 1950 to 2010, where the highest annual average groundwater recharge occurs compared to the central and the western NHP. In the eastern NHP, 45.1% of the annual precipitation fell as EP, which contributed 56.8% of the annual total groundwater recharge. In the western NHP, 30.9% of the annual precipitation fell as extreme precipitation, which contributed 62.5% of the annual total groundwater recharge. In addition, recharge by extreme precipitation mainly occurred in late spring and early summer, before the maximum evapotranspiration rate, which usually occurs in mid-summer until late fall. A dry site in the western NHP and a wet site in the eastern NHP were analysed to indicate how recharge responds to EP with different precipitation regimes. The maximum daily recharge at the dry site exceeded the wet site when there was EP. When precipitation fell as non-extreme rainfall, most recharge was less than 5 mm at both the dry and wet sites, and the maximum recharge at the dry site became lower than the wet site. This study shows that extreme precipitation plays a significant role in determining groundwater recharge. © 2016 The Authors Hydrological Processes Published by John Wiley & Sons Ltd. [ABSTRACT FROM AUTHOR]

In the aftermath of the severe droughts and floods at the end of the 20th century, the Chinese government launched several ecological restoration projects, including the Natural Forest Protection Program in 1998 and the Grain-for-Green Program in 1999, to promote afforestation and reforestation to reduce surface runoff and consequent soil erosion nationwide. However, it is still unclear how vegetation has changed in southern China since the launch of these programs. In this study, we used the MODIS Enhanced Vegetation Index (EVI) to analyze the vegetation cover dynamics in southern China from 2000 to 2009 and evaluate the resulting effects of controlling soil erosion. Our observations indicate that 5.3% of the study area significantly increased and 0.98% significantly decreased in EVI value (p < 0.05). The spring EVI had largest increase in space. The conversions of croplands on steep slopes to forests resulting from national policies led to significant increases in EVI. The increase in EVI was not driven by annual average temperature and annual precipitation. By referencing ecological restoration statistical data and field observations, we showed that ecological restoration programs significantly improved vegetation cover in southern China. Increase in the area of farmland-converted forestlands has reduced soil erosion based upon monitoring sediment yields at hydrologic stations in the Yangtze River. This study displays the spatial patterns of trend in vegetation growth since the beginning of the 21st century in southern China and highlights the important role of China’s afforestation program. [ABSTRACT FROM AUTHOR]

In this work, a lysostaphin-loaded, control-released, self-setting and injectable porous bone cement with efficient protein delivery was prepared by a novel setting method using hydroxyapatite/chitosan (HA/CS) composite scaffold. The cement samples were made through cementitious reactions by mixing solid powder, a mixture of HA/CS composite particles, lysostaphin, Ca(OH)2, CaCO3 and NaHCO3, with setting liquid containing citric acid, acetic acid, NaH2PO4, CaCl2 and poloxamer. The setting parameters of the cement samples were determined. The results showed that the final setting time was 96.6±5.2 min and the pH value increased from approximately 6.2 to nearly 10 during the setting process and the porosity was 34% at the end. And the microstructure and composition were detected by scanning electron microscopy (SEM), x-ray diffraction and Fourier transform-infrared spectroscopy. For the release behavior of lysostaphin loaded in the cement sample, the in vitro cement extract experiment indicated that about 94.2±10.9% of the loaded protein was released before day 8 and the in vivo Qdot 625 fluorescence tracking experiment showed that the loaded protein released slower than the free one. Then the biocompatibility of the cement samples was evaluated using the methylthiazol tetrazolium assay, SEM and hematoxylin-eosin staining, which suggested good biocompatibility of cement samples with MC 3T3-E1 cells and subcutaneous tissues of mice. Finally the antibacterial activity assay indicated that the loaded lysostaphin had good release ability and strong antibacterial enzymatic activity against methicillin-resistant Staphylococcus aureus. Collectively, all the results suggested that the lysostaphin-loaded self-setting injectable porous bone cement released the protein in a controlled and effective way and the protein activity was well retained during the setting and releasing process. Thus this bone cement can be potentially applied as a combination of artificial bone substitute and controlled-release system for delivery of lysostaphin to treat bone defects and infections. [ABSTRACT FROM AUTHOR]

One of the most largest known and important metallogenic provinces in China is East Tianshan, where seven major types of Late Paleozoic metal deposits have been recognized: (1) porphyry-type Cu-Mo-(Au) ore deposits, (2) volcanic Fe-Cu deposits, (3) orogenic lode gold deposits, (4) magmatic Cu-Ni sulfide deposits, (5) epithermal gold deposits, (6) volcanic hydrothermal Cu deposits, and (7) skarn Cu-Ag deposits. Tectonically, the development of these Late Paleozoic metal mineral deposits was closely associated with the subduction and closure of the ancient Tianshan ocean intervening between the Tarim craton and the Junggar-Kazakhstan block. In the Late Devonian to Early Carboniferous, the northern margin of the Tarim craton existed as a passive-type continental margin, whereas the ancient Tianshan ocean was subducted beneath the southern margin of the Junggar-Kazakhstan block, resulting in the formation of the Dananhu-Tousuquan magmatic arc and associated porphyry-type Cu-Mo-(Au) deposits. In the Middle Carboniferous, the ancient Tianshan ocean began to subduct beneath the northern margin of the Tarim craton, leading to the formation of the Aqishan-Yamansu magmatic arc and associated volcanic Fe-Cu deposits. In the Late Carboniferous, the ancient Tianshan ocean was closed, and a continent-arc collision occurred, leading to the formation of the Tianshan orogen. Following the collision was an extensional event, which was associated with the emplacement of large amounts of ultramafic-mafic complexes and the formation of a number of large- to medium-scale magmatic copper-nickel ore deposits along the Kangger suture zone. In the Early Permian, East Tianshan entered into a post-collision stage, associated with the widespread emplacement of granitoid bodies and eruption of within-plate volcanism, which led to the formation of volcanic hydrothermal copper deposits, skarn-type Cu-Ag deposits, post-orogenic gold deposits, and epithermal gold deposits in East Tianshan. [ABSTRACT FROM AUTHOR]

The Daheishan Mo deposit is located in the eastern part of the Central Asian Orogenic Belt, NE China. Rhenium and osmium isotopes of molybdenites from the Daheishan deposit were used to determine the age of mineralization. Rhenium concentrations in molybdenite samples are between 17 and 30μg g−1. Analysis of seven molybdenite samples yields an isochron age of 168.0 ± 4.4 Ma (2σ). Based on the geological history and spatial-temporal distribution of the granitoids, it is proposed that the Mo deposits in eastern China were related to the subduction of the Paleo-Pacific plate during Jurassic time. [ABSTRACT FROM AUTHOR]

The Hongqiling Cu- Ni sulfide deposit in central Jilin Province is located in the eastern part of the Central Asian Orogenic Belt. Rhenium and osmium isotopes in sulfide minerals from the deposit are used to determine the timing of mineralization and the source of osmium, and ore metals. Sulfide ore samples have osmium and rhenium concentrations of 0.28-1.07 ppb and 2.39-13.17 ppb, respectively. Ten analyses yield an isochron age of 223 ± 9 Ma, indicating that the Cu- Ni sulfide deposit in the area formed in the Triassic. The initial 187Os/ 188Os ratio is around 0.295 ± 0.019 ( MSWD = 1.14) and the δ34S values of sulfide ores vary from −1.50 to +3.00‰. These data indicate that the mineralizing materials were derived mainly from a mantle with some quantities of crustal components introduced into the rock-forming and ore-forming systems during mineralization and magmatic emplacement. [ABSTRACT FROM AUTHOR]

The Tianshan–Xingmeng molybdenum belt is part of a larger E–W-trending metallogenic belt in northern China. Most of these molybdenum deposits occur as porphyry or porphyry-skarn type, but there are also some vein-type deposits. Following systematic Re-Os dating of molybdenite from four deposits and comparisons with two previously dated deposits, we conclude that molybdenum mineralization in the Tianshan–Xingmeng Orogenic Belt resulted from hydrothermal activity linked to the emplacement of granitoid stocks. Three pulses of granitoid magmatism and Mo mineralization have been recognized in this study, corresponding to tectonic events in the Tianshan–Xingmeng Orogenic Belt. We identify five distinct stages of Mo mineralization events in the Tianshan–Xingmeng Orogenic Belt: 320–250 Ma, 250–200 Ma, 190–155 Ma, 155–140 Ma, and 140–120 Ma. Late Palaeozoic (320–250 Ma) Mo mineralization was closely related to closure of the Palaeo-Asian Ocean and collision between the Siberia and Tarim cratons. Triassic (250–200 Ma) Mo mineralization occurred in a post-collisional tectonic setting. The Early–Middle Jurassic (190–155 Ma) Mo mineralization was related to subduction of the Palaeo-Pacific Ocean on the eastern Asian continental margin, whereas in the Erguna block, the Mo mineralization events were associated with the subduction of the Mongol–Okhotsk Ocean. From 155 to 120 Ma, large-scale continental extension occurred in the Tianshan–Xingmeng Orogenic Belt and surrounding regions. However, the Late Jurassic (150–140 Ma) Mo mineralization events in these areas evolved in a post-orogenic extensional environment of the Mongol–Okhotsk Ocean subduction system. The Early Cretaceous (140–120 Ma) Mo mineralization occurred under the combined effects of the closure of the Mongol–Okhotsk Ocean and subduction of the Palaeo-Pacific Ocean. [ABSTRACT FROM PUBLISHER]

During late Palaeozoic time, extensive magmatism and associated ore deposits were developed in the eastern Tianshan orogenic belt (ETOB), Northwest China, which is part of the Central Asian Orogenic Belt. To understand the petrogenesis of the intrusions in this area, we performedin situzircon U–Pb and Hf isotopic analyses on the Tuwu–Yandong (TW–YD) stocks and the Xianshan, Hulu, Luodong, and Poshi batholiths. Two major suites of intrusive rocks have been recognized in the ETOB: (1) 338–339 Ma plagiogranite porphyries and 265–300 Ma ultramafic and mafic rocks, of which the former are associated with 323 Ma porphyry Cu–Mo deposits and have enriched radiogenic Hf isotopic compositions (ϵHf(t) = +11.5 to +15.6), which were derived from a depleted mantle source, whereas the latter are associated with 265–300 Ma magmatic Ni–Cu deposits and have variable Hf isotopic compositions (ϵHf(t) = −10.3 to +14.3), indicating an origin via the hybridization of depleted mantle magma and variable amounts of ancient lower-crustal components. The proposed magma sources, combined with the geochemical differences between these two suites of intrusive rocks, indicate that in the lower to middle Carboniferous, a N-dipping subduction zone beneath the Dananhu arc triggered the emplacement of granitic porphyries in the Tousuquan and Dananhu island arc belt in the east Tianshan, leading to the formation of the TW and YD porphyry Cu–Mo deposits. In the Upper Carboniferous to Lower Permian, large mafic–ultramafic complexes were emplaced during the closure of the ancient Tianshan Ocean, resulting in the formation of several magmatic Cu–Ni sulphide deposits. [ABSTRACT FROM AUTHOR]

Methicillin-resistant Staphylococcus aureus (MRSA) have become increasingly prevalent as nosocomial pathogens, especially in burn patients, which is the leading cause of their death. A drug delivery system of chitosan-collagen hydrogel incorporated with lysostaphin (CCHL) based on the lysostaphin gauze was developed for MRSA infected burn wounds. CCHL scaffold consisted of numerous interconnected sphericles and tubular bodies with an average diameter of 100--200 µµm, 20--60-fold swelling, high water retention capacity, and cell proliferation properties. The minimal inhibitory concentration of CCHL was 0.053 U/mL. By the second week after its application on MRSA infected third-degree burn wounds, no bacteria could be detected and the burn wounds had started healing. Therefore, CCHL should be studied further as a promising candidate of burn treatment dressing against MRSA infections for clinics. [ABSTRACT FROM AUTHOR]

Nasal colonization of Staphylococcus aureus ( S.aureus) is known as a significant risk factor for nosocomial infections, and clearance of its nasal colonization greatly reduces the risk. In the present study the preparation and characterizations of the chitosan-o/w cream incorporated with lysostaphin (CCL) were described. It showed that the concentration of incorporated lysostaphin had a direct relationship with its release behavior from the cream. It was rapid at 2 and 3.5 mg lysostaphin/g cream and of a more sustained pattern at 5 mg lysostaphin/g cream. Efficacy of lysostaphin released from the CCL cream to inhibit S.aureus growth was higher than that of lysostaphin delivery routinely treated, as demonstrated by the reduction of the mucociliary transport rate (MTR) in contrast to the control graphite particles ( p < 0.05). Therefore, it is concluded that drug delivery by the CCL holds its potential as a local nasal anti- S.aureus infection. [ABSTRACT FROM AUTHOR]