1,451 research outputs found

    On the evolution of decoys in plant immune systems

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    The Guard-Guardee model for plant immunity describes how resistance proteins (guards) in host cells monitor host target proteins (guardees) that are manipulated by pathogen effector proteins. A recently suggested extension of this model includes decoys, which are duplicated copies of guardee proteins, and which have the sole function to attract the effector and, when modified by the effector, trigger the plant immune response. Here we present a proof-of-principle model for the functioning of decoys in plant immunity, quantitatively developing this experimentally-derived concept. Our model links the basic cellular chemistry to the outcomes of pathogen infection and resulting fitness costs for the host. In particular, the model allows identification of conditions under which it is optimal for decoys to act as triggers for the plant immune response, and of conditions under which it is optimal for decoys to act as sinks that bind the pathogen effectors but do not trigger an immune response.Comment: 15 pages, 6 figure

    Sensing the heat: Climate change vulnerability and foreign direct investment inflows

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    We investigate whether climate change vulnerability determines foreign direct investment (FDI) inflows. We reason that multinational firms foresee a higher climate change vulnerability of host-country a locational disadvantage while making FDI allocation decisions. Utilizing annual data from 152 countries spanning the period 1996–2019 and employing the panel pooled ordinary least square regressions, we evidence that FDI inflows are lower in countries more vulnerable to climate change. We also observe that FDI inflows are only sensitive to climate-related risks in high- and middle-income countries, but not in low-income countries where the market size is a primary driver of FDI inflows. Moreover, we also find that host countries may weaken the adverse effects of climate change vulnerability on FDI inflows by strengthening the economic, institutional, and social environment

    Sparse Distribution Pattern Of Some Plant Species In Two Afromontane Rain Forests Of The Eastern Arc Mountains Of Tanzania

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    Mountain forests play major roles in biodiversity; containing many endemics and species of conservation concern. The diversity and distribution patterns of plants in mountain ecosystems are influenced by various environmental and anthropogenic factors that exhibit heterogeneity over space and time. This study analysed species diversity and distribution patterns on two afromontane rain forests of the eastern Arc Mountains of Tanzania in the west Usambaras and Ulugurus to assess any possible threats to biodiversity conservation in this region. A hundred sample plots (0.02 ha) were established on each of the two mountain ranges in such a way as to cover as much variations as possible from valley bottoms to ridge tops. The analysis was based on species importance values computed from the average of the relative basal area and relative density as well as species frequency. Using different diversity indices, the study showed that the mountains have high species diversity. Eighteen endemic species were identified in the Usambaras and thirty-two in the Ulugurus. These endemics are fairly shared between the two mountains and other mountain massifs of the Eastern Arc. Based on our analysis of species distribution, it was found that the proportion of sparsely (rarely) distributed species was over 30% and 49% for the woody species and total vascular plants, respectively. These findings are important in alerting on possible decline of biodiversity in the region and prompting the development of policies to address rare, threatened, and endangered plant species, which are non-existence in Tanzania. We suggest further surveys in the forests of the Eastern Arc Mountains to determine whether the apparently sparse distribution of some species may be found in reasonable abundances elsewhere and quantify the manner and type of use of the forest resources by surrounding local communities to determine their possible impacts on species distribution. TJFNC Vol. 75 2004: pp. 74-9
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