54 research outputs found
A New Leptoceratopsid (Ornithischia: Ceratopsia) from the Upper Cretaceous of Shandong, China and Its Implications for Neoceratopsian Evolution
BACKGROUND: The ceratopsians represent one of the last dinosaurian radiations. Traditionally the only universally accepted speciose clade within the group was the Ceratopsidae. However, recent discoveries and phylogenetic analyses have led to the recognition of a new speciose clade, the Leptoceratopsidae, which is predominantly known from the Upper Cretaceous of North America. METHODOLOGY/PRINCIPAL FINDINGS: Here we report a new leptoceratopsid taxon, Zhuchengceratops inexpectus gen. et sp. nov., based on a partial, articulated skeleton recovered from the Upper Cretaceous Wangshi Group of Zhucheng, Shandong Province, China. Although Zhuchengceratops is significantly different from other known leptoceratopsids, it is recovered as a derived member of the group by our phylogenetic analysis. Furthermore, Zhuchengceratops exhibits several features previously unknown in leptoceratopsids but seen in ceratopsids and their close relatives, suggesting that the distribution of morphological features within ceratopsians is more complex than previously realized. CONCLUSION/SIGNIFICANCE: The discovery of Zhuchengceratops increases both the taxonomic diversity and the morphological disparity of the Leptoceratopsidae, providing further support for the hypothesis that this clade represents a successful radiation of horned dinosaurs in parallel with the Ceratopsidae in the Late Cretaceous. This documents a surprising case of the coexistence and radiation of two closely-related lineages with contrasting suites of jaw and dental features that probably reflect adaptation to different food resources
Low Serum Vitamin D Is Associated with Anti-Thyroid-Globulin Antibody in Female Individuals
Objectives. Some evidence has pointed out that vitamin D plays a significant role in reducing the incidence of autoimmune diseases, especially autoimmune thyroid diseases. The authors aimed to examine the relationship between circulating 25-hydroxyvitamin D and thyroid autoantibody in a population-based health survey of Xinjiang Chinese population. Subjects and Methods. A total of 1714 Chinese adults were analyzed. 25(OH)D, anti-thyroid antibodies, and thyroid function were measured. Results. The prevalence of vitamin D insufficiency was 28.3% in Hans and 9.3% in Uyghurs, and the prevalence of vitamin D deficiency was 61.6% in Hans and 87.6% in Uyghurs. Overall prevalence of TgAb positivity was 6.2% (0.9% males; 5.3% females). In female subjects, mean serum 25(OH)D levels were significantly lower in Hans and Uyghurs compared with males, and the difference was statistically significant. Importantly, after adjusting for age and ethnicity, a negative correlation (r=-0.121, P=0.014) was recognized between 25(OH)D and TgAb levels only in female subjects. Conclusion. Vitamin D insufficiency and deficiency are prevalent among Chinese adults. Low serum 25(OH)D is related to the presence of TgAb in females. The causal effect of low vitamin D level on thyroid autoimmunity should be studied further more
Inferring plantâplant interactions using remote sensing
Rapid technological advancements and increasing data availability have improved the capacity to monitor and evaluate Earth's ecology via remote sensing. However, remote sensing is notoriously âblindâ to fine-scale ecological processes such as interactions among plants, which encompass a central topic in ecology. Here, we discuss how remote sensing technologies can help infer plantâplant interactions and their roles in shaping plant-based systems at individual, community and landscape levels. At each of these levels, we outline the key attributes of ecosystems that emerge as a product of plantâplant interactions and could possibly be detected by remote sensing data. We review the theoretical bases, approaches and prospects of how inference of plantâplant interactions can be assessed remotely. At the individual level, we illustrate how close-range remote sensing tools can help to infer plantâplant interactions, especially in experimental settings. At the community level, we use forests to illustrate how remotely sensed community structure can be used to infer dominant interactions as a fundamental force in shaping plant communities. At the landscape level, we highlight how remotely sensed attributes of vegetation states and spatial vegetation patterns can be used to assess the role of local plantâplant interactions in shaping landscape ecological systems. Synthesis. Remote sensing extends the domain of plant ecology to broader and finer spatial scales, assisting to scale ecological patterns and search for generic rules. Robust remote sensing approaches are likely to extend our understanding of how plantâplant interactions shape ecological processes across scalesâfrom individuals to landscapes. Combining these approaches with theories, models, experiments, data-driven approaches and data analysis algorithms will firmly embed remote sensing techniques into ecological context and open new pathways to better understand biotic interactions
Experimental study on the electrical resistivity characteristics of sand under different testing conditions
Objective The results of laboratory tests on the electrical resistivity of sand are widely used in the interpretation of field electrical resistivity tomography. However, the influences of testing conditions and the field implementations of relationship curves between the electrical resistivity and properties of sand need further research. Methods First, the electrical resistivity test device was developed by using the two-electrode method. Then, the influences of current type, alternating current (AC) frequency, voltage and grain size of sand on the relationship between electrical resistivity and water saturation (Ď-Sr), as well as electrical resistivity and salinity of the pore water (Ď-n), were studied. Results The results showed that an AC current frequency of 10 Hz and an input voltage of 1 V were recommended to reduce the test error of resistance. There was a power function between the electrical resistivity and water saturation (Ď-Sr), as well as electrical resistivity and salinity of pore water (Ď-n), under AC and direct current (DC). As DC might cause an electrolysis reaction of the electrodes of the sand column under the high salinity of pore water, the AC electrical method was suggested. When the water saturation is greater than 50%, the electrical resistivity difference caused by the grain size of sand becomes small. Moreover, the electrical resistivity did not decrease significantly with increasing water saturation, which suggested that a relatively stable interface of the electrical resistivity might exist in the unsaturated zone with 50% saturation rather than in the water table. When the salinity of pore water is greater than 2 g/L, the electrical resistivity of all five types of saturated sands did not decrease obviously with increasing salinity. Conclusion Research results comfirm the electrical resistivity method easily distinguishes fresh water from brackish water but has difficulty further subdividing brackish water, salt water and brine
Effects of Pulsed Magnetic Field Melt Treatment on Grain Refinement of Al-Si-Mg-Cu-Ni Alloy Direct-Chill Casting Billet
Al-Si-Mg-Cu-Ni alloy is widely used in the manufacture of high-performance car engine parts. Coarse, dendritic α-Al and large primary Si are common in Al-Si-Mg-Cu-Ni alloy DC casting billet, which is harmful to the performance of the final product. In this paper, a pulsed magnetic field melt treatment technique was applied to the melt in the launder of a DC casting platform to modify the α-Al and primary Si in the billet. A transient numerical model was established to analyze the electromagnetic field, flow field and temperature field in the melt during the pulsed magnetic field treatment. The effect of the magnetic energy on the clusters in the melt was analyzed. We found that during the pulsed magnetic field melt treatment, the number of clusters close to the critical size was increased due to the cluster formation work being reduced by the magnetic energy, which facilitated nucleation and refined the solidification structure. Furthermore, the flow velocity increased, and temperature homogenized in the melt during the pulsed magnetic field melt treatment, which benefitted the clusters close to the critical size distributed and maintained in the melt uniformly. The experimental results show that the α-Al and primary Si were small and homogeneous following the pulsed magnetic field melt treatment. The size of α-Al and primary Si was reduced by 25.6–44.4% and 32.2–54.1%, respectively, in the billet center compared to the conventional process
Diffusion model simulation of odor pollutants in livestock and poultry farms based on environmental monitoring of the Internet of Things
Livestock pollution is one of the main sources of agricultural pollution, which has a negative impact on the global environment. Monitoring, simulation and early warning of major pollutants emitted from livestock production is of great significance for reducing agricultural pollution. Especially, real-time comprehensive monitoring and early warning of the concentration and distribution of harmful gases could improve the harm of livestock production to people, livestock itself and the environment, and increase the safety level of livestock production. This study focused on the perception and monitoring of the discharge status of livestock farming simulation technics, mainly to carry out Internet of Things-based monitoring of the main components of livestock culture pollutants, and to use odor gas air dispersion software âModOdorâ to simulate the spread of pollutants. This study was aimed to determine the characteristics of pollutant diffusion in typical farms, which could provide decision reference to odor hygienic buffer zone and minimum shelter distance to achieve the ecological and safety objectives of livestock farming
One-Pot Synthesis of 2,5-Diformylfuran from Fructose by Bifunctional Polyaniline-Supported Heteropolyacid Hybrid Catalysts
We report the preparation of bifunctional hybrid catalysts by supporting H3PMo12O40 (PMo12) heteropolyacid (HPA) on polyaniline (PAN) or formyl-functionalized PAN (F-PAN) for the “one-pot„ and “one-step„ synthesis of 2,5-diformylfuran (DFF) from fructose via 5-hydroxymethylfurfural (HMF) intermediate. We show that the PMo12 HPA is the main active species for both fructose dehydration and HMF oxidation owing to its Brønsted acidic and redox characters. However, the anchoring of PMo12 on PAN reduces the Brønsted acidity by acid–base interaction between protons in HPA and quinoid diimine structure in PAN, thereby reducing the dehydration performance. We demonstrate that the catalytic dehydration performance of the hybrid catalyst could be strengthened by grafting formyl groups on PAN before HPA anchoring. The highest DFF yield of 76.7% is obtained by conducting the “one-pot„ reaction over the 40-PMo12/F3-PAN catalyst at 413 K for 7 h in air, wherein the side-reactions of fructose or HMF degradation and HMF rehydration have been significantly reduced. This hybrid catalyst is reusable without significant activity loss, highlighting the designing of stable inorganic–organic hybrid catalysts for producing valuable hexose-derived platform chemicals
A Novel Workflow for Seasonal Wetland Identification Using Bi-Weekly Multiple Remote Sensing Data
Accurate wetland mapping is essential for their protection and management; however, it is difficult to accurately identify seasonal wetlands because of irregular rainfall and the potential lack of water inundation. In this study, we propose a novel method to generate reliable seasonal wetland maps with a spatial resolution of 20 m using a seasonal-rule-based method in the Zhalong and Momoge National Nature Reserves. This study used Sentinel-1 and Sentinel-2 data, along with a bi-weekly composition method to generate a 15-day image time series. The random forest algorithm was used to classify the images into vegetation, waterbodies, bare land, and wet bare land during each time period. Several rules were incorporated based on the intra-annual changes in the seasonal wetlands and annual wetland maps of the study regions were generated. Validation processes showed that the overall accuracy and kappa coefficient were above 89.8% and 0.87, respectively. The seasonal-rule-based method was able to identify seasonal marshes, flooded wetlands, and artificial wetlands (e.g., paddy fields). Zonal analysis indicated that seasonal wetland types, including flooded wetlands and seasonal marshes, accounted for over 50% of the total wetland area in both Zhalong and Momoge National Nature Reserves; and permanent wetlands, including permanent water and permanent marsh, only accounted for 11% and 12% in the two reserves, respectively. This study proposes a new method to generate reliable annual wetland maps that include seasonal wetlands, providing an accurate dataset for interannual change analyses and wetland protection decision-making
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