The emergence of Payment for Ecosystem Services （PES） concept has raised expectations that ecosystem conservation can be achieved through popular payments rather than through unpopular measures of command and contro...The emergence of Payment for Ecosystem Services （PES） concept has raised expectations that ecosystem conservation can be achieved through popular payments rather than through unpopular measures of command and control. A study on PES was conducted in Zomba Mountain Forest （ZMF） catchment area in southern Malawi between August and December 2009. The aim was to assess stakeholders＇ role that would promote payment for ecosystem services as a management tool. A purposive sampling was used to identify the respondents who were randomly sampled for interviews. The findings show that PES can be used as a management tool in ZMF as there are key stakeholders who benefit from the catchment area in terms of services. While there is moderate level of PES awareness among the community and other stakeholders, the current forest policy does not address PES which may derail implementation of a fully fledged PES arrangement. The study revealed that existing management challenges originate from inadequate funding that ZMF Reserve gets from government. However, this challenge offers opportunities to stakeholders through PES to contribute and participate in conserving ZMF for sustained flow of benefits.展开更多
An open source software （OSS） ecosystem refers to an OSS development community composed of many software projects and developers contributing to these projects. The projects and developers co-evolve in an ecosystem....An open source software （OSS） ecosystem refers to an OSS development community composed of many software projects and developers contributing to these projects. The projects and developers co-evolve in an ecosystem. To keep healthy evolution of such OSS ecosystems, there is a need of attracting and retaining developers, particularly project leaders and core developers who have major impact on the project and the whole team. Therefore, it is important to figure out the factors that influence developers＇ chance to evolve into project leaders and core developers. To identify such factors, we conducted a case study on the GNOME ecosystem. First, we collected indicators reflecting developers＇ subjective willingness to contribute to the project and the project environment that they stay in. Second, we calculated such indicators based on the GNOME dataset. Then, we fitted logistic regression models by taking as independent variables the resulting indicators after eliminating the most collinear ones, and taking as a dependent variable the future developer role （the core developer or project leader）. The results showed that part of such indicators （e.g., the total number of projects that a developer joined） of subjective willingness and project environment significantly influenced the developers＇ chance to evolve into core developers and project leaders. With different validation methods, our obtained model performs well on predicting developmental core developers, resulting in stable prediction performance （0.770, F-value）.展开更多
The terpenoids are one of the main types of secondary plant metabolization products,with wide distribution,structural diversity and chemical complexity.In this review,we introduce the types and distribution of terpeno...The terpenoids are one of the main types of secondary plant metabolization products,with wide distribution,structural diversity and chemical complexity.In this review,we introduce the types and distribution of terpenoids in higher plants,the ecological factors that affect the production of terpenoids,and importance of terpenoids in ecosystems.展开更多
文摘The emergence of Payment for Ecosystem Services （PES） concept has raised expectations that ecosystem conservation can be achieved through popular payments rather than through unpopular measures of command and control. A study on PES was conducted in Zomba Mountain Forest （ZMF） catchment area in southern Malawi between August and December 2009. The aim was to assess stakeholders＇ role that would promote payment for ecosystem services as a management tool. A purposive sampling was used to identify the respondents who were randomly sampled for interviews. The findings show that PES can be used as a management tool in ZMF as there are key stakeholders who benefit from the catchment area in terms of services. While there is moderate level of PES awareness among the community and other stakeholders, the current forest policy does not address PES which may derail implementation of a fully fledged PES arrangement. The study revealed that existing management challenges originate from inadequate funding that ZMF Reserve gets from government. However, this challenge offers opportunities to stakeholders through PES to contribute and participate in conserving ZMF for sustained flow of benefits.
基金This work is supported by the National Key Research and Development Program of China under Grant No. 2016YFB0800400, the National Basic Research 973 Program of China under Grant No. 2014CB340404, the National Natural Science Foundation of China under Grant Nos. 61572371, 61273216, and 61272111, the China Postdoctoral Science Foundation （CPSF） under Grant No. 2015M582272, the Natural Science Foundation of Hubei Province of China under Grant No. 2016CFB158, and the Fundamental Research Funds for the Central Universities of China under Grant No. 2042016kf0033.
文摘An open source software （OSS） ecosystem refers to an OSS development community composed of many software projects and developers contributing to these projects. The projects and developers co-evolve in an ecosystem. To keep healthy evolution of such OSS ecosystems, there is a need of attracting and retaining developers, particularly project leaders and core developers who have major impact on the project and the whole team. Therefore, it is important to figure out the factors that influence developers＇ chance to evolve into project leaders and core developers. To identify such factors, we conducted a case study on the GNOME ecosystem. First, we collected indicators reflecting developers＇ subjective willingness to contribute to the project and the project environment that they stay in. Second, we calculated such indicators based on the GNOME dataset. Then, we fitted logistic regression models by taking as independent variables the resulting indicators after eliminating the most collinear ones, and taking as a dependent variable the future developer role （the core developer or project leader）. The results showed that part of such indicators （e.g., the total number of projects that a developer joined） of subjective willingness and project environment significantly influenced the developers＇ chance to evolve into core developers and project leaders. With different validation methods, our obtained model performs well on predicting developmental core developers, resulting in stable prediction performance （0.770, F-value）.
文摘The terpenoids are one of the main types of secondary plant metabolization products,with wide distribution,structural diversity and chemical complexity.In this review,we introduce the types and distribution of terpenoids in higher plants,the ecological factors that affect the production of terpenoids,and importance of terpenoids in ecosystems.
