Plant Species Rather Than Climate Greatly Alters the Temporal Pattern of Litter Chemical Composition During Long-Term Decomposition

A feedback between decomposition and litter chemical composition occurs with decomposition altering composition that in turn influences the decomposition rate. Elucidating the temporal pattern of chemical composition is vital to understand this feedback, but the effects of plant species and climate on chemical changes remain poorly understood, especially over multiple years. In a 10-year decomposition experiment with litter of four species (Acer saccharum, Drypetes glauca, Pinus resinosa, and Thuja plicata) from four sites that range from the arctic to tropics, we determined the abundance of 11 litter chemical constituents that were grouped into waxes, carbohydrates, lignin/tannins, and proteins/peptides using advanced 13C solid-state NMR techniques. Decomposition generally led to an enrichment of waxes and a depletion of carbohydrates, whereas the changes of other chemical constituents were inconsistent. Inconsistent convergence in chemical compositions during decomposition was observed among different litter species across a range of site conditions, whereas one litter species converged under different climate conditions. Our data clearly demonstrate that plant species rather than climate greatly alters the temporal pattern of litter chemical composition, suggesting the decomposition-chemistry feedback varies among different plant species

Soil Abiotic Properties and Plant Functional Traits Mediate Associations Between Soil Microbial and Plant Communities During a Secondary Forest Succession on the Loess Plateau

In the context of secondary forest succession, aboveground-belowground interactions are known to affect the dynamics and functional structure of plant communities. However, the links between soil microbial communities, soil abiotic properties, plant functional traits in the case of semi-arid and arid ecosystems, are unclear. In this study, we investigated the changes in soil microbial species diversity and community composition, and the corresponding effects of soil abiotic properties and plant functional traits, during a ≥150-year secondary forest succession on the Loess Plateau, which represents a typical semi-arid ecosystem in China. Plant community fragments were assigned to six successional stages: 1–4, 4–8, 8–15, 15–50, 50–100, and 100–150 years after abandonment. Bacterial and fungal communities were analyzed by high-throughput sequencing of the V4 hypervariable region of the 16S rRNA gene and the internal transcribed spacer (ITS2) region of the rRNA operon, respectively. A multivariate variation-partitioning approach was used to estimate the contributions of soil properties and plant traits to the observed microbial community composition. We found considerable differences in bacterial and fungal community compositions between the early (S1–S3) and later (S4–S6) successional stages. In total, 18 and 12 unique families were, respectively, obtained for bacteria and fungi, as indicators of microbial community succession across the six stages. Bacterial alpha diversity was positively correlated with plant species alpha diversity, while fungal diversity was negatively correlated with plant species diversity. Certain fungal and bacterial taxa appeared to be associated with the occurrence of dominant plant species at different successional stages. Soil properties (pH, total N, total C, NH4-N, NO3-N, and PO4-P concentrations) and plant traits explained 63.80% and 56.68% of total variance in bacterial and fungal community compositions, respectively. These results indicate that soil microbial communities are coupled with plant communities via the mediation of microbial species diversity and community composition over a long-term secondary forest succession in the semi-arid ecosystem. The bacterial and fungal communities show distinct patterns in response to plant community succession, according to both soil abiotic properties and plant functional traits

5G Internet of Things: A survey

© 2018 The existing 4G networks have been widely used in the Internet of Things (IoT) and is continuously evolving to match the needs of the future Internet of Things (IoT) applications. The 5G networks are expected to massive expand today's IoT that can boost cellular operations, IoT security, and network challenges and driving the Internet future to the edge. The existing IoT solutions are facing a number of challenges such as large number of connection of nodes, security, and new standards. This paper reviews the current research state-of-the-art of 5G IoT, key enabling technologies, and main research trends and challenges in 5G IoT

The capacities of institutions for the integration of ecosystem services in coastal strategic planning: The case of Jiaozhou Bay

This paper explains how the practice of integrating ecosystem-service thinking (i.e., ecological benefits for human beings) and institutions (i.e., organisations, policy rules) is essential for coastal spatial planning. Adopting an integrated perspective on ecosystem services (ESs) both helps understand a wide range of possible services and, at the same time, attune institution to local resource patterns. The objective of this paper is to identify the extent to which ESs are integrated in a specific coastal strategic planning case. A subsequent objective is to understand whether institutions are capable of managing ESs in terms of uncovering institutional strengths and weaknesses that may exist in taking ESs into account in existing institutional practices. These two questions are addressed through the application of a content analysis method and a multi-level analysis framework on formal institutions. Jiaozhou Bay in China is used as an illustrative case. The results show that some ESs have been implicitly acknowledged, but by no means the whole range. This partial ES implementation could result from any of four institutional weaknesses in the strategic plans of Jiaozhou Bay, namely a dominant market oriented interest, fragmented institutional structures for managing ESs, limited ES assessment, and a lack of integrated reflection of the social value of ESs in decision-making. Finally, generalizations of multi-level institutional settings on ES integration, such as an inter-organisational fragmentation and a limited use of ES assessment in operation, are made together with other international case studies. Meanwhile, the comparison highlights the influences of extensive market-oriented incentives and governments' exclusive responsibilities on ES governance in the Chinese context

Understanding High Saving Rate in China

This paper presents a detailed analysis of the Chinese saving rate based on the flow of funds data. It finds that the most widely adopted view of precautionary saving, which is regarded as the top reason for maintaining a high saving rate in China, is misleading because this conclusion is drawn from the household survey data. In fact, the household saving rate has declined dramatically since the mid-1990s, as is observed from the flow of funds framework. The high national saving rate is attributed to the increasing shares of both government and corporation disposable incomes. Insufficient consumption demand is caused by the persistent decrease in percentage share of household to national disposable income. Government- directed income redistribution urgently needs to be improved to accelerate consumption, which in turn would make the Chinese economy less investment-led and help to reduce the current account surplus. Copyright The official journal of The Institute of World Economics and Politics, Chinese Academy of Social Sciences (CASS) 2007.

Preparation and Property Study of Organosilicon Antisticking Coatings

In this article, an organosilicon antisticking coating was synthesized from vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst. Firstly, the methyl vinyl MQ (mono and quad) silicone resin was added. When the silicone content was 30 wt.%, the shore hardness and tensile strength increased to about 27.4% and 115.9%, respectively. Furthermore, nano-SiO2 powder was added to further improve its antisticking property. This was due to the change of the surface roughness, which could greatly improve the antisticking performance. When the nano-SiO2 powder content was 2 wt.%, the surface free energy and antisticking force were the lowest and the antisticking effect was the best as well and the mechanical properties of silicone rubber had been improved

Molecular dynamics study on the kinematic viscosity, density and structure of fuel blends containing n-decane and biofuel compound of ethyl decanoate or ethyl dodecanoate

Bio-aviation fuel is blend consisting of aviation kerosene and biofuels, which is a clean renewable energy and has gained considerable attention in recent years. However, numerical studies on the thermophysical properties of bio-aviation fuel containing fatty acid esters are still limited. In this paper, the kinematic viscosity and density of fuel blends containing n-decane and biofuel compound of ethyl decanoate or ethyl dodecanoate are investigated by molecular dynamics (MD) method, and the calculated viscosities are compared with those by a theoretical model of UNIFAC-VISCO (UV). The MD results applying with a PCFF force field (FF) can reproduce the experimental data for the fuel blends very well in comparison with both the COMPASS FF and the UV model. In addition, to link the variety of molecular structure to the changes of their thermophysical properties, local structures of n-decane and ethyl decanoate in mixture are systematically analyzed. It illustrates that a decreasing end-to-end length of molecular chains combined with the growing intermolecular distance leads to the reduction of the kinematic viscosity of fuel blends with the increasing of temperature. This work provides a baseline to help understand the thermophysical properties of esters and their based bio-aviation kerosene surrogates

Climate Change Effects on Southern Subtropical and Tropical Tree Species in Ganzhou City, China

Aims: To confirm climate warming changes that have taken place in Gannan Arboretum and Ganzhou City by the expect success of introduced tropical tree species as a response to climatic warming scenarios. Study Design: Cross-sectional study. Study Site and Duration: Survey and observational sites were located in 1) Gannan Arboretum and 2) Ganzhou City, Jiangxi Province, China. The survey and observations of introduced tree species were conducted from October, 2009, to November, 2010. Additional growth records were obtained for a period prior to and including the 1970s to assist in the investigation. Methodology: 1) The meteorological data (1951–2009) record was used to analyse climatic change patterns. 2) Growth and development of introduced tree species were examined to evaluate effects of introduction. 3) Climate zone attributes of introduced tree species were determined in order to establish place of origin. Effects of introduced tree species were coupled with climatic change scenario data to analyze associative relationships. Results: 1) A trend in climate warming has been evident in Ganzhou City since the1950s. Based on metrological records from 1951 to 2009, a steady rise in annual average temperature has occurred in the region, increasing from 0.2ºC to 0.3ºC each 20 year period. This trend has been especially evident by changes to average temperature during the coldest month (January) as well as changes in annual minimum temperatures. 2) According to observations and measurements, 39 introduced tropical tree species have successfully established themselves in the Ganzhou region through natural domestication. Among these, 24 tree species were considered basically successful with normal growth patterns while the remaining 15 species achieved preliminary success. 3) Stem analysis data on the five primary introduced tree species indicate that growth patterns were normal and vigorous, suggesting that these tropical tree species have successfully established themselves. It was therefore determined that the successful northward migration of the 39 tree species investigated was chiefly the result of a climate warming trend taking place in the region

Climate Change Effects on Southern Subtropical and Tropical Tree Species in Ganzhou City, China

Aims: To confirm climate warming changes that have taken place in Gannan Arboretum and Ganzhou City by the expect success of introduced tropical tree species as a response to climatic warming scenarios. Study Design: Cross-sectional study. Study Site and Duration: Survey and observational sites were located in 1) Gannan Arboretum and 2) Ganzhou City, Jiangxi Province, China. The survey and observations of introduced tree species were conducted from October, 2009, to November, 2010. Additional growth records were obtained for a period prior to and including the 1970s to assist in the investigation. Methodology: 1) The meteorological data (1951–2009) record was used to analyse climatic change patterns. 2) Growth and development of introduced tree species were examined to evaluate effects of introduction. 3) Climate zone attributes of introduced tree species were determined in order to establish place of origin. Effects of introduced tree species were coupled with climatic change scenario data to analyze associative relationships. Results: 1) A trend in climate warming has been evident in Ganzhou City since the1950s. Based on metrological records from 1951 to 2009, a steady rise in annual average temperature has occurred in the region, increasing from 0.2ºC to 0.3ºC each 20 year period. This trend has been especially evident by changes to average temperature during the coldest month (January) as well as changes in annual minimum temperatures. 2) According to observations and measurements, 39 introduced tropical tree species have successfully established themselves in the Ganzhou region through natural domestication. Among these, 24 tree species were considered basically successful with normal growth patterns while the remaining 15 species achieved preliminary success. 3) Stem analysis data on the five primary introduced tree species indicate that growth patterns were normal and vigorous, suggesting that these tropical tree species have successfully established themselves. It was therefore determined that the successful northward migration of the 39 tree species investigated was chiefly the result of a climate warming trend taking place in the region

Treatment of Large and Complicated Scalp Defects with Free Flap Transfer

Background. Large scalp defects, especially those complicated by calvarial defects, titanium mesh exposure, or cerebrospinal fluid (CSF) leak, pose a challenge for the neurosurgeon and plastic surgeon. Here, we describe our experience of reconstructing the complex scalp defect with free flap transfer. Methods. From October 2012 to September 2017, 8 patients underwent free flap transfer for the reconstruction of the scalp or complicated scalp and calvarial defects. Five patients presented with scalp tumor and the other 3 patients with scalp necrosis or ulceration (2 patients with titanium plate exposure). Seven anterolateral thigh flaps and one radial forearm flap were harvested and employed. The clinical data, including defect characteristics, flap type, complications, and outcomes, were recorded and analyzed. Results. Five patients were pathologically diagnosed with malignant tumor, and 3 of them were given further radiotherapy. For the 2 patients with exposure of titanium plate, no titanium plate was removed. For the patient with scalp necrosis after decompressive craniectomy accompanied by CSF leakage, the CSF leak was stopped after reconstruction. The size of the flaps ranged from 3 to 14 cm in width and 4 to 18 cm in length. No flap failure occurred in these cases. From follow-up to the present, no ulceration or necrosis occurred. Conclusions. Free flap transfer is an ideal method for the reconstruction of large, complicated scalp defects with a one-stage operation. The anterolateral thigh flap is favored because of its durability, adjustability, water tightness, and infection prevention