80 research outputs found

    It’s all in the crystals


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    Protein surface engineering is increasingly used as a routine tool to enhance the crystallization propensity of proteins. Future possibilities include the use of multi-site protein variants, rational modulation of solubility and the development of strategies to tackle membrane proteins

    Primary succession and its driving variables – a sphere-spanning approach applied in proglacial areas in the upper Martell Valley (Eastern Italian Alps)

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    Climate change and the associated glacier retreat lead to considerable enlargement and alterations of the proglacial systems. The colonisation of plants in this ecosystem was found to be highly dependent on terrain age, initial site conditions and geomorphic disturbances. Although the explanatory variables are generally well understood, there is little knowledge on their collinearities and resulting influence on proglacial primary succession. To develop a sphere-spanning understanding of vegetation development, a more interdisciplinary approach was adopted. In the proglacial areas of FĂŒrkeleferner, Zufallferner and Langenferner (Martell Valley, Eastern Italian Alps), in total 65 plots of 5×2 m were installed to perform the vegetation analysis on vegetation cover, species number and species composition. For each of those, 39 potential explanatory variables were collected, selected through an extensive literature review. To analyse and further avoid multicollinearities, 33 of the explanatory variables were clustered via principal component analysis (PCA) to five components. Subsequently, generalised additive models (GAMs) were used to analyse the potential explanatory factors of primary succession. The results showed that primary succession patterns were highly related to the first component (elevation and time), the second component (solar radiation), the third component (soil chemistry), the fifth component (soil physics) and landforms. In summary, the analysis of all explanatory variables together provides an overview of the most important influencing variables and their interactions; thus it provides a basis for the debate on future vegetation development in a changing climate.</p

    A candidate ion-retaining state in the inward-facing conformation of sodium/galactose symporter: Clues from atomistic simulations

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    The recent Vibrio parahaemolyticus sodium/galactose (vSGLT) symporter crystal structure captures the protein in an inward-facing substrate-bound conformation, with the sodium ion placed, by structural alignment, in a site equivalent to the Na2 site of the leucine transporter (LeuT). A recent study, based on molecular dynamics simulations, showed that the sodium ion spontaneously leaves its initial position diffusing outside vSGLT, toward the intracellular space. This suggested that the crystal structure corresponds to an ion-releasing state of the transporter. Here, using metadynamics, we identified a more stable Na+ binding site corresponding to a putative ion-retaining state of the transporter. In addition, our simulations, consistently with mutagenesis studies, highlight the importance of D189 that, without being one of the NA(+)-coordinating residues, regulates its binding/release

    Probabilistic fire spread forecast as a management tool in an operational setting

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    Background: An approach to predict fire growth in an operational setting, with the potential to be used as a decision-support tool for fire management, is described and evaluated. The operational use of fire behaviour models has mostly followed a deterministic approach, however, the uncertainty associated with model predictions needs to be quantified and included in wildfire planning and decision-making process during fire suppression activities. We use FARSITE to simulate the growth of a large wildfire. Probabilistic simulations of fire spread are performed, accounting for the uncertainty of some model inputs and parameters. Deterministic simulations were performed for comparison. We also assess the degree to which fire spread modelling and satellite active fire data can be combined, to forecast fire spread during large wildfires events. Results: Uncertainty was propagated through the FARSITE fire spread modelling system by randomly defining 100 different combinations of the independent input variables and parameters, and running the correspondent fire spread simulations in order to produce fire spread probability maps. Simulations were initialized with the reported ignition location and with satellite active fires. The probabilistic fire spread predictions show great potential to be used as a fire management tool in an operational setting, providing valuable information regarding the spatial–temporal distribution of burn probabilities. The advantage of probabilistic over deterministic simulations is clear when both are compared. Re-initializing simulations with satellite active fires did not improve simulations as expected. Conclusion: This information can be useful to anticipate the growth of wildfires through the landscape with an associated probability of occurrence. The additional information regarding when, where and with what probability the fire might be in the next few hours can ultimately help minimize the negative environmental, social and economic impacts of these firesinfo:eu-repo/semantics/publishedVersio

    Monitoring holopelagic Sargassum spp. along the Mexican Caribbean coast: understanding and addressing user requirements for satellite remote sensing

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    Massive influxes of holopelagic Sargassum spp. (Sargassum natans and S. fluitans) have been causing major economic, environmental and ecological problems along the Caribbean coast of Mexico. Predicting the arrival of the sargassum as an aid to addressing these problems is a priority for the government, coastal communities and the society; both mitigating the impacts and providing opportunities for its use. Lack of data concerning precise locations and times of sargassum beachings means that public and private funds are being spent inefficiently and most actions are reactive. The dynamic nature of sargassum beachings/influxes render conventional ground-based monitoring insufficient. Earth observation and cloud-based processing services offer tools to track, quantify and understand sargassum beaching remotely in a frequent, systematic and reliable manner with the temporal and spatial resolutions required for its management. In order to find the right solutions to address this problem, in this paper the needs and requirements of stakeholders are taken into consideration for the development of an Earth observation-based service to monitor sargassum along the Mexican Caribbean coast. Routine monitoring of sargassum over a large area will be cost effective and help mitigate the negative effects of sargassum influxes. The combination of imagery from Planet, specifically their SuperDove systems that provide daily data at 3 m spatial resolutions, with the freely available EU Copernicus data would be useful for many different stakeholders and potential users. A prototype of the service is presented, based on the main user requirements. The system would enable public and private organizations to allocate resources appropriately in affected areas quickly and efficiently, thereby minimizing economic, social and environmental impacts and enhancing the resilience of local communities. It would also assist the sargassum industry in the collection of fresh algae for onward processing. The system could easily be implemented for similar types of environmental monitoring in the Greater Caribbean and beyond

    Fleas as parasites of the family Canidae

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    Historically, flea-borne diseases are among the most important medical diseases of humans. Plague and murine typhus are known for centuries while the last years brought some new flea-transmitted pathogens, like R. felis and Bartonella henselae. Dogs may play an essential or an accidental role in the natural transmission cycle of flea-borne pathogens. They support the growth of some of the pathogens or they serve as transport vehicles for infected fleas between their natural reservoirs and humans. More than 15 different flea species have been described in domestic dogs thus far. Several other species have been found to be associated with wild canids. Fleas found on dogs originate from rodents, birds, insectivores and from other Carnivora. Dogs therefore may serve as ideal bridging hosts for the introduction of flea-borne diseases from nature to home. In addition to their role as ectoparasites they cause nuisance for humans and animals and may be the cause for severe allergic reactions

    X-Ray Structure of the Na<sup>+</sup>-coupled Glycine-Betaine Symporter BetP from Corynebacterium glutamicum

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