13 research outputs found

    Opuntia in México: Identifying Priority Areas for Conserving Biodiversity in a Multi-Use Landscape

    Get PDF
    BACKGROUND: México is one of the world's centers of species diversity (richness) for Opuntia cacti. Yet, in spite of their economic and ecological importance, Opuntia species remain poorly studied and protected in México. Many of the species are sparsely but widely distributed across the landscape and are subject to a variety of human uses, so devising implementable conservation plans for them presents formidable difficulties. Multi-criteria analysis can be used to design a spatially coherent conservation area network while permitting sustainable human usage. METHODS AND FINDINGS: Species distribution models were created for 60 Opuntia species using MaxEnt. Targets of representation within conservation area networks were assigned at 100% for the geographically rarest species and 10% for the most common ones. Three different conservation plans were developed to represent the species within these networks using total area, shape, and connectivity as relevant criteria. Multi-criteria analysis and a metaheuristic adaptive tabu search algorithm were used to search for optimal solutions. The plans were built on the existing protected areas of México and prioritized additional areas for management for the persistence of Opuntia species. All plans required around one-third of México's total area to be prioritized for attention for Opuntia conservation, underscoring the implausibility of Opuntia conservation through traditional land reservation. Tabu search turned out to be both computationally tractable and easily implementable for search problems of this kind. CONCLUSIONS: Opuntia conservation in México require the management of large areas of land for multiple uses. The multi-criteria analyses identified priority areas and organized them in large contiguous blocks that can be effectively managed. A high level of connectivity was established among the prioritized areas resulting in the enhancement of possible modes of plant dispersal as well as only a small number of blocks that would be recommended for conservation management

    An approach to support the Web User Interfaces evolution

    No full text
    Abstract. Currently, there is a growing group of Web 1.0 applications that is migrating towards Web 2.0 where their data and business logic could be maintained but their User Interface (UI) must be adapted. Our proposal facilitates the adaptation of existing Web 1.0 applications to Web 2.0, focusing on UIs and taking advantage of functionality already provided by legacy Web Models. In this paper we present, as an example, how to adapt applications already modelled with WebML to RUX-Model, a method that allows designing rich UIs for multi-device Web 2.0 UIs. One of our main goals in attending the workshop is discussing other potential adaptations for applications modelled with OOHDM, UWE or OO-H among others

    State-of-the Art and trends in the Systematic Development of Rich Internet Applications

    No full text
    Rich Internet Applications (RIAs) are widely adopted Web applications that add the richer interaction, presentation, and client-side computation capabilities of desktop applications to the Web. However, the evolution from Web applications towards RIAs comes at the cost of increased complexity in their development. For this reason, a wide variety of tools and technologies have been proposed in order to streamline their development effort. This paper investigates the current state of the art of the RIA development approaches. The review shows that the current industrial development practice lacks a comprehensive approach to RIA development, supporting all the development steps from the design to implementation, test and maintenance, and helping identifying correct design choices. This is in part due to the severe fragmentation of current RIA technologies that prevents the adoption of a commonly recognized set of best practices resulting in ad-hoc development processes. These aspects are in part treated by research methodologies and some innovative industrial solutions, but also these approaches present some limitations. The paper identifies future research directions for RIAs to fully support their development process and to support their design in a more comprehensive and systematic way, from both industrial and research perspectives

    Sulfidation extent of nanoscale zerovalent iron controls selectivity and reactivity with mixed chlorinated hydrocarbons in natural groundwater

    Get PDF
    Sulfidated nanoscale zerovalent iron (S-nZVI) exhibits low anoxic oxidation and high reactivity towards many chlorinated hydrocarbons (CHCs). However, nothing is known about S-nZVI reactivity once exposed to complex CHC mixtures, a common feature of CHC plumes in the environment. Here, three S-nZVI materials with varying iron sulfide (mackinawite, FeSm) shell thickness and crystallinity were exposed to groundwater containing a complex mixture of chlorinated ethenes, ethanes, and methanes. CHC removal trends yielded pseudo-first order rate constants (kobs) that decreased in the order: trichloroethene > trans-dicloroethene > 1,1-dichlorethene > trichloromethane > tetrachloroethene > cis-dichloroethene > 1,1,2-trichloroethane, for all S-nZVI materials. These kobs trends showed no correlation with CHC reduction potentials based on their lowest unoccupied molecular orbital energies (ELUMO) but absolute values were affected by the FeSm shell thickness and crystallinity. In comparison, nZVI reacted with the same CHCs groundwater, yielded kobs that linearly correlated with CHC ELUMO values (R2 = 0.94) and that were lower than S-nZVI kobs. The CHC selectivity induced by sulfidation treatment is explained by FeSm surface sites having specific binding affinities towards some CHCs, while others require access to the metallic iron core. These new insights help advance S-nZVI synthesis strategies to fit specific CHC treatment scenarios

    Ownership structure and accountability: the case of the privatization of the Spanish tobacco monopoly, 1887-96

    Get PDF
    This paper analyses the case of the privatization of the Spanish tobacco monopoly, focusing on the period between 1887 and 1896, which corresponds to the first leasing contract between the state and the Spanish Tobacco Company and it is concerned with two different issues. First, it deals with the effects of privatization on accountability.The main question examined is whether public and private ownership entail different approaches to the way in which managers are accountable to owners, and the impact this issue had on corporate reporting. Second, it is concerned with exploring the determinants of accounting disclosure. Here, the basic issue is to understand the factors shaping changes in corporate reporting during the period of study.Accounting History, Corporate Reporting, Privatization, Tobacco Monopoly, Spain,
    corecore