Leaf developmental stability of Platanus acerifolia under urban environmental stress and its implication as an environmental indicator

The developmental stability indices,leaf width based fluctuating asymmetry(FA1),and lateral vein length based directional asymmetry(RDA1)of Platanus acerifolia were studied.All the leaves were sampled from 14 sites that were categorized based on different urban environmental stress levels(UESL)in Shanghai metropolitan,China.Besides,foliar stomatal density and stomatal length were also studied as the subsidiary indices to test the availability of developmental stability indices as the indicator under a stressful environment.Results showed seasonal variation of FA1 and RDA1 existed among the 14 sites,but the data showed significant negative correlation between FA1 and UESL(FA1=0.029−0.0009UESL+0.0003UESL2,r=0.7665,P=0.0014).However,a similar trend was not found between RDA1 and UESL.Furthermore,the significant correlation among FA1 and leaf stomatal length and stomatal density implied they could be used as indicators of urban stress levels on a small scale.It seemed that RDA1 was possibly a normal parameter during leaf development but it was unavailable for use as an indicator of urban stresses.

Stability Through Development

Since its founding in 2000, the Forum on China-Africa Cooper ation （FOCAC） has without doubt become a world-class international platform with a track record of solid delivery results. China Africa traditional friendship and cooperation had had long trajectories before the establishment of the platform; but FOCAC not only re-engineered these ties in a more result-oriented fashion.

Effects of Region and Elevation on Adaptation of Leaf Functional Traits of an Invasive Plant Erigeron annuus in China

A key scientific challenge relating to the threat of invasive plants on agriculture at the region level is to understand their adaptation and evolution in functional traits.Leaf functional traits,related to growth and resource utilization,might lead to adaptation of invasive plants to the geographical barriers(region or elevation).In the field experiment,we discussed the effects of region and elevation on leaf functional traits on invasive plant Erigeron annuus in farmland habitats in China.We compared leaf size,coefficient of variation(CV)of leaf traits,and fluctuating asymmetry(FA)of E.annuus from three regions(east vs.center vs.west)and two leaf types(vegetative vs.reproductive leaf),and from nine elevations(980-2100 m)in the west region of China.Our results indicated region and leaf type influenced leaf functional traits,and leaf size was significantly higher and CV of leaf traits and FA in reproductive leaves were significantly lower in the east region than in the west and center regions.Elevation and leaf type affected leaf functional traits,and leaf size was significantly higher and CV of leaf traits in reproductive leaves were significantly lower in moderate elevation.E.annuus has higher leaf size and developmental stability(lower CV and FA)in the eastern region due to the longer adaptation period.Therefore,leaf functional traits play an important role in the adaptation of different longitudes and elevations.It can also facilitate the understanding of the invasiveness and adaptation of leaf traits of invasive plants in the agricultural ecosystem during their spread process in China.

The ecological context of bilateral symmetry of organ and organisms

A particular phenotype is generated through numerous networks of interactions from within the cell to the whole ecosystem. The level of the environmental noise and the ability of a given genotype to render different phenotypes under different environmental conditions, called phenotypic plasticity, determine survival or death at individual and/or population level. It is important to highlight that non-lethal environmental changes are important for generating genetic variability and promoting biological adaptations. However, when the level of environmental noise starts to be stressed, the developmental stability (DS) of the organism can be perturbed. The DS has been analysed through the symmetry deviations in organs or organisms with bilateral structure. The symmetry deviations occur due to inability to contain disorders from environmental or endogenous conditions during its development. This deviation is called fluctuating asymmetry (FA) when is a non-directional deviation in the symmetry of a bilateral structure normally distributed in a population. Low FA has been associated with greater DS. The analysis of FA has often been used to measure the effects of environmental perturbations. In this review, I discuss the concept of plant stress and phenotypic plasticity connecting both to the generation of an asymmetry phenotype, highlighting the usefulness of FA as an indicator of the level of stress which the organism is subjected to. Further, although this review explores mainly the connection between FA and stress in plants, the ecological context of symmetry in animals and plant-insect interaction is also discussed. Finally, I provided some methodologies used to detect symmetry variations in organs or organisms with bilateral structure.

Tourism Development and Well-Being:The Role of Population and Political Stability

This study's primary purpose was to explore the role of tourism development in enhancing well-being in a highly populated developing economy by focusing on the case study of Pakistan Several econometric techniques and approaches were used on annual time series data covering the 1990-2016 period to investigate the causal relationship of well-being with tourism development,political stability,economics,and population growth.The findings suggested that tourism development enhances economic growth and well-being,hence providing support for the tourism-led growth hypothesis However,population growth and political instability exhibited a negative relationship with well-being;in addition,the level of political stability determined tourism activities.Hence,this study is unique due to its specific focus on the role of political stability and tourism development in the enhancement of wellbeing in a highly populated developing economy Moreover,the practical implications of the study have been provided in light of the main findings.

The impact of China’s Consistent Stance on the Palestinian issue on the Embodiment of international pluralism

This study examined the impact of China’s firm position on the Palestinian issue on the embodiment of international multilateralism and strived to embody international multilateralism.And to clarify this effect,it is necessary first to highlight the depth of Chinese-Arab relations and common concern,such as China’s consistent position on the Palestinian issue and its quest to embody international pluralism in order to find appropriate solutions to the Palestinian issue in accordance with international law,then to focus on China’s consistent foreign policy towards the Middle East to promote stability and development with the success of the BRI in the region,and thirdly,to shed light on China’s stance on strengthening and materialising international cooperation to find appropriate solutions for the Palestinian issue,and finally,to focus attention on China’s diplomatic efforts to solve the Palestinian issue’a political solution based on international cooperation to implement the resolutions of international legitimacy’.This study relies on the historical method by tracing the historical sequence of events to reach the results that serve the subject of the study,as well as the descriptive analytical method,which is used to analyse information and events related to the subject of the study.The study concluded that the impact of China’s firm position on the Palestinian issue on the embodiment of international multilateralism is effective.Moreover,this study is a forward-looking survey of other studies aimed at anticipating the continuing impact of China’s firm stance on the Palestinian issue on the embodiment of international multilateralism,as it demonstrates seriousness and perseverance under the theme of’respect,mutual benefit and common destiny’in light of the challenges witnessed in the world today.