构建“生命态”体育课堂的意义及策略

随着教学改革的不断深入,构建“生命态”体育课堂成了当前体育教学的主流。“生命态”课堂是从学生的生命发展出发,关注学生个体成长与能力生成,所有的教学活动都服务于学生生命成长,都是为了学生可持续发展提供支持。本文就以初中体育为内容,对其“生命态”课堂构建提供几点建议,旨在助力于初中体育教育的改革与创新。

Lead anthropogenic transfer and transformation in China

Information on lead redistribution and speciation changes in anthrosphere can help to analyze the whole lead cycle on the earth. Lead life cycle was traced based on the concepts of anthropogenic transfer and transformation. Lead transfer and the distribution of chemical species throughout the anthropogenic flow were identified in 2010 in China. The results show that 1.85 Mt lead ore was consumed(besides 1.287 Mt imported concentrated ore and 1.39 Mt lead scraps. After undergoing transformations, 3.53 Mt lead entered end services in chemical species of Pb, Pb O2 and PbSO4, altogether accounting for over 80% of the total lead products. Finally, 2.10 Mt ore was emitted into the environment in such species as PbSO4(26%), PbO(19%) and Pb(15%). Lead transfer begins in primary raw material sectors, and then transfers to manufacturing sectors. Lead provides services mainly in such industrial sectors as transportation, electrical power and buildings or construction.

Risk assessment of lead emissions from anthropogenic cycle

The risk assessment right from the source of emissions can effectively guide the pollution control. A model was established, consisting of four part： source estimation, environmental fate analysis, exposure analysis and risk assessment. The human health risk, ecological risk and total risk of lead emissions were assessed. The factors were estimated to indicate the environmental decrease and exposure probability. Of all the 1887 t emissions in China in 2010（quantified in the previous work）, it is turned out 1.3 t reached human bodies（0.9 mg/ca）, and 2.7 t reached the ecosystem. Lead mainly came from the Use stage for the source while lead causing risk mainly came from the Waste Management Recycling and Production stages. As for chemical forms, PbO contributed most to the human health risk and PbSO_4 contributed most to the ecological risk. PbSO_4, PbO and Pb altogether contributed 71% to the total risk, indicating these three chemicals should be taken priority for the risk management.

Effects of competitive interactions of different life forms submersed plants on biomass allocation in shallow lakes

Plant competition has been recognized as one of the most important factors influencing the soructure and function of lake ecosystems. Competition from plants of dissimilar growth form may have profound effects on shallow lakes＇. An experiment was conducted to investigate the effects of competitive interactions of submersed plants with dis- similar growth forms on the biomass allocations. Hydrilla verticitlata and Vallisneria natans were selected and were planted in a single-species monoculture and a mixed-species pattern, Results showed that the growth of E natans was＇ significantly affected by the tt, verticillata and caused a sharp reduction of biomass, but the root：shoot ratio of E ha- tans was not affected significantly and there was a minimal increase in mixture： while for H. verticillata, the biomass and the root：shoot ratio were not significantly changed by the competitive interactions ore natans, there was minimal increase of biomass and minimal decrease of the root：shoot ratio. These results may indicate that theplant which can develop a dense mat or canopy at the water surface would be a stronger competitor relative to the plant that depends more on light availability near the sediment.

Recovery of gonadal development in tiger puffer Takifugu rubripes after exposure to 17β-estradiol during early life stages

The aim of the present study was to investigate the long-term effects of 17l）-estradiol （E2） exposure on gonadal development in the tiger puffer （Taktfugu rubripes）, which has a genetic sex determination system of male homogametic XY-XX. Tiger puffer larvae were exposed to 1, 10 and 100 μg/L E2 from 15 to 100 days post-hatch （dph） and then maintained in clean seawater until 400 dph. Changes in sex ratio, gonadal structure and gonadosomatic index （GSI） were monitored at 100, 160, 270 and 400 dph. Sex-associated single nucleotide polymorphism （SNP） markers were used to analyze the genetic sex of samples, except those at 100 dph. Exposure had a positive effect on the conversion of genetically male gonads into phenotypically female gonads at 100 dph. However, gonads from 60% of genetic XY males in the 1-μg/L E2 group and 100% in the 10-μg/L E2 group developed intersexual gonads at 160 dph; gonads of all genetic XY males in the two treatment groups reverted to testis by 270 dph. While 38%, 57% and 44% of gonads of XY fish in the 100-gg/L E2 group reverted to intersexual gonads at 160, 270 and 400 dph, respectively, none reverted to testis after E2 treatment. In addition, E2 exposure inhibited gonadal growth of both genetic sexes, as indicated by the clear dose-dependent decrease in GSI at 270 and 400 dph. The results showed that exposure to E2 during the early life stages of tiger puffer disrupted gonadal development, but that fish recovered after migration to clean seawater. The study suggests the potential use of tiger puffer as a valuable indicator species to evaluate the effects of environmental estrogens on marine fish, thereby protecting valuable fishery resources.

The Ecological Crisis and the Principle of Relationality in African Philosophy

The way that humans think about the earth certainly affects the way that they relate and behave towards the earth and all its life forms. The various ideologies or worldviews that humanity has experienced such as dualism, capitalism, holism, animism, ubuntu, ukama, vital force, colonialism, and so forth are all different ways of thinking and relating to the earth. The paper argues that dualistic ways of thinking or viewpoints that radically separate the human as distinct from the earth are hostile to both human and earth flourishing. It further argues that the ecological crisis which has witnessed the destruction and pollution of the ecosystems and other devastations cannot be solved when humans continue to see the earth as an object for conquest and exploitation. Using a critical hermeneutics method, the paper affirms that the African principle of relationality can help in mitigating the environmental crisis. It finds and concludes that if this principle is radically practiced, a better environment will be created.

Improving Energy Efficiency in New Trawlers Fishing Gear in Mediterranean Sea

The objective of this work is to show the benefits of a new eco-systemic fishing gear installed in three bottom trawlers after one year using it. The study has been based on fuel consumption reduction for the three vessels and the catch in two of them. The new system minimizes the impact of the fishing gear on the seabed, with a reduction on the tow resistance. This generates significant fuel savings that improves the economical result of the fishery, helping the ship owners in the return of investment first, then in the future viability of the operation. Apart of the evident savings due to the fuel consumption reduction, in the long term, the ship owner will notice also savings on maintenance, both because the winches are towing with less tension （longer life for warps, brakes and hydraulic system） and the engine is running at low rpm＇s （longer life of the engine and between breakdowns）. The new fishing gear does not require any modification on the way that the fisherman is working, only replacing and/or modifying some parts or components of the fishing gear. The implementation is easy and the adjustments required could be done in a couple of days.

A generic methodological framework for accurately quantifying greenhouse gas footprints of crop cultivation systems

The greenhouse gas （GHG） footprint of an agricultural system is a measure of the climate change impact potential （CCIP） exerted by the formation of its product（s）, its accurate quantification is essential for determining the green value added tax of agricultural products for food markets, which in turn may drastically change the current patterns of food consumption and production towards a product life cycle oriented economy. This paper reviews the literature regarding GHG footprints of crop cultivation systems.The review concludes that few studies have fully considered the categories/ items of net GHG emissions from an investigated crop cultivation system, and thus probably led to biases in footprint estimation. Most studies to date have even neglected changes in the soil organic carbon stocks of ecosystems with annual crops, while process-oriented biogeochemical models so far have seldom been involved in GHG footprint quantification.To help with solving these problems or drawbacks, the authors propose a generic methodological framework for quantifying GHG footprints of crop cultivation systems free from grazing, which takes into account all direct/indirect GHG contributors within a ＇cradle-to-gate＇ life cycle. The authors then provide example values of some GHG emission factors, such as those from machinery operations and other agricultural inputs, extracted from the literature. In addition, direct measurements or model simulations of other major on-farm emission factors are emphasized. The need to further update this methodological framework in future studies, especially by adapting it to mixed crop-livestock production systems, is also indicated.

A Pioneering Low Carbon Material Database for Building Industry

Considering that buildings represent 40% of greenhouse gases and approximately 10% of global gross domestic product, the target the building industry has to accomplish is to get to a high quality and low carbon living, by reducing carbon emission by 2050, as said by Energy Performance of Buildings Directive. Considering these needs, designers, manufacturers and construction companies should be able to make use of web and design tools for collecting and inventorying a large variety of environmentally friendly materials, through a specific database that encloses low carbon certified products and eco-labeled ones. The eco-labels are internationally identified as the best tools to encourage the spread of green products and low carbon notions, even if in Europe, there is no specific tool to be used. The project called LoCaMat （Low Carbon Material Database） will act as the first Italian and European database that encompasses multiple data on certified green materials to be used for the construction sector, making buildings climate change resilient, ensuring an efficient use of energy and resources, getting to a complete life cycle assessment for buildings materials and components, encompassing, for the first time, green data and every kind of environmental specs for sustainable design and green practice.

Energy, Environment, Economic Life Cycle Assessment of Cassava-based Ethanol Used as Automotive Fuel in Guangxi Province, China

A life-cycle assessment (LCA) was carried out to compare the energy, environmental and economic impacts of converting cassava to fuel ethanol in Guangxi Province, China. The entire life cycle is a system that includes stages from cassava farming to ethanol fuel combustion. A computer-based model was developed to assess energy, environmental, and economic (EEE) life cycle implication of cassava-based ethanol fuel. The LCA results for fuel ethanol were compared to conventional gasoline (CG) as a base-line case. On the life-cycle bases, the use of cassava-based ethanol fuel in Guangxi may consume more energy but reduce greenhouse gas, VOC, and CO emissions. Life cycle cost results indicate that although fuel ethanol currently is not competitive compared to conventional gasoline, it has great potentials when there are subsidies and/or yields of cassava planting are improved. In terms of balancing the energy, environmental and economical, the introduction form of cassava-based ethanol fuel would be E10. The assessment results generated from this study provide an important reference for Guangxi policy makers to better understand the trade-offs among energy, environmental effects, and economics for the most effective using of regional energy resources.

A Data Assured Deletion Scheme in Cloud Storage

In order to provide a practicable solution to data confidentiality in cloud storage service,a data assured deletion scheme,which achieves the fine grained access control,hopping and sniffing attacks resistance,data dynamics and deduplication,is proposed.In our scheme,data blocks are encrypted by a two-level encryption approach,in which the control keys are generated from a key derivation tree,encrypted by an All-OrNothing algorithm and then distributed into DHT network after being partitioned by secret sharing.This guarantees that only authorized users can recover the control keys and then decrypt the outsourced data in an ownerspecified data lifetime.Besides confidentiality,data dynamics and deduplication are also achieved separately by adjustment of key derivation tree and convergent encryption.The analysis and experimental results show that our scheme can satisfy its security goal and perform the assured deletion with low cost.

Degradation process assessment of prestressed concrete continuous bridges in life-cycle

To accurately evaluate the degradation process of prestressed concrete continuous bridges exposed to aggressive environments in life-cycle,a finite element-based approach with respect to the lifetime performance assessment of concrete bridges was proposed.The existing assessment methods were firstly introduced and compared.Some essential mechanics problems involved in the degradation process,such as the deterioration of materials properties,the reduction of sectional areas and the variation of overall structural performance caused by the first two problems,were investigated and solved.A computer program named CBDAS(Concrete Bridge Durability Analysis System) was written to perform the above-metioned approach.Finally,the degradation process of a prestressed concrete continuous bridge under chloride penetration was discussed.The results show that the concrete normal stress for serviceability limit state exceeds the threshold value after 60 a,but the various performance indicators at ultimate limit state are consistently in the allowable level during service life.Therefore,in the case of prestressed concrete bridges,the serviceability limit state is more possible to have durability problems in life-cycle;however,the performance indicators at ultimate limit state can satisfy the requirements.

Insight into the reasons of leaf wax δD_(n-alkane) values between grasses and woods

Many studies have observed that leaf wax δDn-alkane values differed significantly between woods and grasses in modern plants, with grasses D-depleted by 40 %0-70 ‰. The reasons for the differences in leaf wax δDn-alkane values between woods and grasses, however, remain unclear. In this study, we measured the δD values of soil water （δDsw）, leaf water （δDlw）, and leaf wax n-alkane （δDn-alkane） for woods and grasses. We found no significant differences in the δD values of soil water （P = 0.82） and leaf water （P= 0.74） between the two life forms of plants. Therefore, the differences in leaf wax δDn-alkane values between woods and grasses may correlate with inherent properties of different plant life forms, such as leaf structures, biosynthetic processes, and leaf morphologies. Moreover, it is also possible that soil water with different 6Dsw at different depths utilized by woods and grasses may be responsible for some of the differences in leaf wax δDn-alkane values between the two life forms of plants, if woods mainly use soil water from the 〉100 cm depth, whereas grasses mainly use soil water from the 〈100 cm depth. The results of this work allow us to better understand the leaf wax δDn-alkane values of different plant life forms in a region.

Research on Ecological Protection and Restoration Measures in Altay Region based on the Coupling Perspective of the Mountains-Rivers-Forests-Farmlands-Lakes-Grasslands System

The adoption of both Nature-based Solutions(NbS)and a system perspective is a hot issue and an area in which there is much room for improvement in ecological protection and restoration.The study takes Altay region as an example,an area located in Xinjiang,China,which is an important ecological corridor of the national key functional area and the core area of the Belt and Road but has a fragile ecological environment and needs much enhancement in ecological protection and restoration.Guided by the concept of"mountains-rivers-forestsfarmlands-lakes-grasslands(MRFFLG)system is a life community",the coupling relationship of the various MRFFLG elements,the main ecological environmental problems and the integrated countermeasures for protection and restoration in Altay region have been analyzed in this study.The study shows that Altay region has a typical meta-ecosystem of mountain,oasis,and desert,and the connections by rivers and lakes make the ecosystem links within the region much closer.The interweaving of resource-environmental-ecological issues of the aquatic ecosystem,degradation of the quality of terrestrial ecosystems such as forests,grasslands and farmlands,the increased ecosystem fragmentation and ecological risks are the major ecological environmental issues in this region.This study takes the improvement of the ecosystem health and function in Altay region as the core goal of regional ecological protection and restoration.First,we establish a zoning governance pattern from the perspective of ecosystem integrity;second,we design governance strategies for different zones with the goal of synergistic improvements in the ecosystem functions;and finally,we clarify the key engineering tasks in different zones from the perspective of ecosystem services.Ecological conservation and restoration of the MRFFLG system is a prime example of the application and development of NbS in China.This paper constructs an analytical framework for identifying regional life communities,diagnosing ecological protection and restoration of zoning problems,and proposing classified solutions for ecological protection tasks for the protection of the MRFFLG system.This research will enrich the theory and technology for the protection and restoration of MRFFLG systems,and provide guidance for the practice of ecological protection and restoration in Altay region.

Limited ecological risk of insect-resistance transgene flow from cultivated rice to its wild ancestor based on life-cycle fitness assessment

Ecological impact caused by transgene flow from genetically engineered （GE） crops to their wild rela- tives is largely determined by the fitness effect brought by a transgene. To estimate such impact is critical for the eco- logical risk assessment prior to the commercialization of GE crops. We produced F1 and F2 hybrid descendants from crosses of two insect-resistant GE rice lines （Bt, Bt/CpT1） and their non-GE rice parent with a wild rice （Oryza ruff- pogon） population to estimate the transgenic fitness. Insect damages and life-cycle fitness of GE and non-GE crop- wild hybrid descendants as well as their wild parent were examined in a common-garden experiment. No significant differences in insect damages were observed between the wild rice parent and GE hybrid descendants under high- insect pressure. The wild parent showed significantly greater relative survival-regeneration ratios than its GE and non-GE hybrid descendants under both high- and low-in- sect pressure. However, more seeds were produced in GE hybrid descendants than their non-GE counterparts under high-insect pressure. Given that the introduction of Bt and Bt/CpT1 transgenes did not provide greater insect resistance to crop-wild hybrid descendants than their wild parent, we predict that transgene flow from GE insect-resistant rice to wild rice populations may not cause considerable ecolog- ical risks.

Comparative Life Cycle Assessment of Two Types of Truck Bumper Produced in the Algerian Auto Industry

Currently,the reduction of weight in automotive is a very important topic to reduce the air pollution.In this context,the purpose of the present paper is to analyze a real case study through a comparison of the environmental impacts between a conventional steel bumper and a polyester prototype.In the first part of this work,a door-to-door life-cycle assessment methodology was used throughout the study of the component manufacturing phase.The SimaPro 7.1 software is used to evaluate the impacts of both bumpers on the environment and health.The second part is devoted to dust analysis from the polyester workshop.The obtained results have allowed us to show the company that its choice of steel substitution by the polyester is advantageous for certain impacts including the impact of climate change,but unfortunately there may be,given the working conditions of the polyester workshop,a transfer of impact,since we will end up with a risk of health(irritations,cancers)for the workers.LCA has proven to be a very useful tool for validating a redesigned automotive component from an environmental point of view;from this case study,several recommendations were made for the company to design environmentally friendly components,and ecodesign should be introduced into the company’s procedures.

A dynamic influence model of social network hotspot based on grey system

The outbreak of hotspot in social network may contain complex dynamic genesis. Using user behavior data from hotspots in social network, we study how different user groups play different roles for a hotspot topic. Firstly, by analyzing users' behavior records, we mine group situation that promotes the hotspot.Several major attributions in a hotspot outbreak, such as individual, peer and group triggers, are defined formally according to the view-point of social identity, social interaction, retweet depth and opinion leader. Secondly,for the problem of the uneven and sparse data in each stage of hotspot topic's life cycle, we propose a dynamic influence model based on grey system to formalize the effect of different groups. Then the process of hotspot evolution driven by distinct crowd is showed dynamically. The experimental result confirms that the model is able not only to qualify users' influence on a hotspot topic but also to predict effectively an upcoming change in a hotspot topic.

Archaeal viruses-novel,diverse and enigmatic

Recent research has revealed a remarkable diversity of viruses in archaeal-rich environments where spindles, spheres, fila- ments and rods are common, together with other exceptional morphotypes never recorded previously. Moreover, their dou- ble-stranded DNA genomes carry very few genes exhibiting homology to those of bacterial and eukaryal viruses. Studies on viral life cycles are still at a preliminary stage but important insights are being gained especially from microarray analyses of viral transcripts for a few model virus-host systems. Recently, evidence has been presented for some exceptional archaeal- nspecific mechanisms for extra-cellular morphological development of virions and for their cellular extrusion. Here we sum- marise some of the recent developments in this rapidly developing and exciting research area.

Some limit theorems of killed Brownian motion

In this paper, we prove some limit theorems for killed Brownian motion during its life time. The emphases are on quasi-stationarity and quasi-ergodicity and related problems. On one hand, using an eigenfunction expansion for the transition density, we prove the existence and uniqueness of both quasi-stationary distribution (qsd) and mean ratio quasi-stationary distribution (mrqsd). The later is shown to be closely related to laws of large numbers (LLN) and to quasi-ergodicity. We further show that the mrqsd is the unique stationary distribution of a certain limiting ergodic diffusion process of the BM conditioned on not having been killed. We also show that a phase transition occurs from mrqsd to qsd. On the other hand, we study the large deviation behavior related to the above problems. A key observation is that the mrqsd is the unique minimum of certain large deviation rate function. We further prove that the limiting diffusion process also satisfies a large deviation principle with the rate function attaining its unique minimum at the mrqsd. These give interpretations of the mrqsd from different points of view, and establish some intrinsic connections among the above topics. Some general results concerning Yaglom limit, moment convergence and LLN are also obtained.