731 research outputs found

    An empirical model approach for assessing soil organic carbon stock changes following biomass crop establishment in Britain

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    Land-use change (LUC) is a major influence on soil organic carbon (SOC) stocks and the global carbon cycle. LUC from conventional agricultural to biomass crops has increased in Britain but there is limited understanding of the effects on SOC stocks. Results from paired plot studies investigating site-specific effects document both increasing and decreasing SOC stocks over time. Such variation demonstrates the sensitivity of SOC to many factors including environmental conditions. Using a chronosequence of 93 biomass crop sites in England and Wales, mainly of 1–14 y age, empirical models were developed of SOC trajectory following LUC from arable and grassland to short rotation coppice (SRC) willow and Miscanthus production. SOC stocks were calculated for each site using a fixed sampling depth of 30 cm and changes were estimated by comparing with typical pre-conversion SOC stocks. Most LUCs had no demonstrable net effect on SOC stocks. An estimated net SOC loss of 45.2 ± 24.1 tonnes per hectare (±95% confidence intervals) occurred after 14 y following LUC from grassland to SRC willow. Soil texture and climate data for each site were included in multivariable models to assess the influence of different environmental conditions on SOC trajectory. In most cases the addition of explanatory variables improved the model fit. These models may provide some preliminary estimates of more region-specific changes in SOC following LUC. However, the model fit did not improve sufficiently as to provide a basis for adopting a more targeted LUC strategy for lignocellulosic biomass crop production

    Witnessing eigenstates for quantum simulation of Hamiltonian spectra

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    The efficient calculation of Hamiltonian spectra, a problem often intractable on classical machines, can find application in many fields, from physics to chemistry. Here, we introduce the concept of an "eigenstate witness" and through it provide a new quantum approach which combines variational methods and phase estimation to approximate eigenvalues for both ground and excited states. This protocol is experimentally verified on a programmable silicon quantum photonic chip, a mass-manufacturable platform, which embeds entangled state generation, arbitrary controlled-unitary operations, and projective measurements. Both ground and excited states are experimentally found with fidelities >99%, and their eigenvalues are estimated with 32-bits of precision. We also investigate and discuss the scalability of the approach and study its performance through numerical simulations of more complex Hamiltonians. This result shows promising progress towards quantum chemistry on quantum computers.Comment: 9 pages, 4 figures, plus Supplementary Material [New version with minor typos corrected.

    A global risk assessment of primates under climate and land use/cover scenarios

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    Primates are facing an impending extinction crisis, driven by extensive habitat loss, land use change, and hunting. Climate change is an additional threat, which alone or in combination with other drivers, may severely impact those taxa unable to track suitable environmental conditions. Here, we investigate the extent of climate and land use/cover (LUC) change‐related risks for primates. We employed an analytical approach to objectively select a subset of climate scenarios, for which we then calculated changes in climatic and LUC conditions for 2050 across primate ranges (N=426 species) under a best‐ and a worst‐case scenario. Generalised linear models were used to examine whether these changes varied according to region, conservation status, range extent, and dominant habitat. Finally, we reclassified primate ranges based on different magnitudes of maximum temperature change, and quantified the proportion of ranges overall and of primate hotspots in particular that are likely to be exposed to extreme temperature increases. We found that, under the worst‐case scenario, 74% of Neotropical forest‐dwelling primates are likely to be exposed to maximum temperature increases up to 7°C. In contrast, 38% of Malagasy savanna primates will experience less pronounced warming of up to 3.5°C. About one quarter of Asian and African primates will face up to 50% crop expansion within their range. Primary land (undisturbed habitat) is expected to disappear across species’ ranges, whereas secondary land (disturbed habitat) will increase by up to 98%. With 86% of primate ranges likely to be exposed to maximum temperature increases >3°C, primate hotspots in the Neotropics are expected to be particularly vulnerable. Our study highlights the fundamental exposure risk of a large percentage of primate ranges to predicted climate and LUC changes. Importantly, our findings underscore the urgency with which climate change mitigation measures need to be implemented to avert primate extinctions on an unprecedented scale

    Using mobile phone technology to support young liver transplant recipients moving to adult services: a systematic rapid review

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    Background: The process and preparation of moving from child to adult services (transition) is a challenging period of time for young people and represents significant changes in care and support systems. The proliferation of mobile phone applications for health purposes suggests that it is an area for further investigation. Objective: The review explores the potential to use mobile phone technology to help support young liver transplant recipients moving to adult services. It represents the first review conducted in this specialism and considers a new model of support for young liver patients. Methods: A systematic rapid review of the published peer-reviewed literature. Results: Two searches were conducted: Search 1: the use of technology to support transition to adult services (6 studies) and Search 2: how best to support liver transplant recipients during transition (6 studies). Discussion: Research shows that to achieve positive transition young people need information about their condition and transition. The process needs to be guided by transition readiness, rather than the young persons’ age. Although parents and support networks should be in place and are valued, transition should build upon self-management and independence. Results suggest that there appears to be scope to use mobile phone technology to support transition. This is the first time a review has explored the types of issues or concerns facing liver transplant patients and how these can be addressed through mobile phone technology

    The experiences of young liver patients transferring from children's to adult services and their support needs for a successful transition

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    Background: The period of transition from pediatric to adult services represents a time when young people need support, information, and appropriate care in order to successfully move. It is a period that is associated with nonadherence and disengagement with care. Objective: To explore the experiences of young liver transplant recipients transitioning to adult services and determine what they require in order to achieve a successful move. The research also explored the possibility of using a mobile phone application (app) as a tool to support transition. Design: Qualitative approach using novel arts-based focus groups and one-to-one interviews. Participants: Twenty-one young people aged 16 to 25 years, 16 health-care professionals involved in their care, and 7 young people as follow-up. Participants used services provided by the 3 liver centers in England (Leeds, Birmingham, and London). Results: Data highlighted the variability of transition pathways in England for young people moving from child to adult health services. The results showed that they required clear information regarding transition processes including specific medical information and that there was a shortfall in such information. Support was required in the form of a designated transition coordinator or similar specialist who could act as a point of reference and guidance throughout the process. Transitions needed to be individualized and based upon transition readiness rather than age, although the research showed that age cut-offs were still used. Conclusion: Young people welcomed apps to provide information, reminders, contacts, and connections. Future research should explore the efficacy of such apps

    The experiences of young liver patients transferring from children's to adult services and their support needs for a successful transition

    Get PDF
    Background: The period of transition from pediatric to adult services represents a time when young people need support, information, and appropriate care in order to successfully move. It is a period that is associated with nonadherence and disengagement with care. Objective: To explore the experiences of young liver transplant recipients transitioning to adult services and determine what they require in order to achieve a successful move. The research also explored the possibility of using a mobile phone application (app) as a tool to support transition. Design: Qualitative approach using novel arts-based focus groups and one-to-one interviews. Participants: Twenty-one young people aged 16 to 25 years, 16 health-care professionals involved in their care, and 7 young people as follow-up. Participants used services provided by the 3 liver centers in England (Leeds, Birmingham, and London). Results: Data highlighted the variability of transition pathways in England for young people moving from child to adult health services. The results showed that they required clear information regarding transition processes including specific medical information and that there was a shortfall in such information. Support was required in the form of a designated transition coordinator or similar specialist who could act as a point of reference and guidance throughout the process. Transitions needed to be individualized and based upon transition readiness rather than age, although the research showed that age cut-offs were still used. Conclusion: Young people welcomed apps to provide information, reminders, contacts, and connections. Future research should explore the efficacy of such apps

    Evaluation of diversity among common beans (Phaseolus vulgaris L.) from two centers of domestication using 'omics' technologies

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    <p>Abstract</p> <p>Background</p> <p>Genetic diversity among wild accessions and cultivars of common bean (<it>Phaseolus vulgaris </it>L.) has been characterized using plant morphology, seed protein allozymes, random amplified polymorphic DNA, restriction fragment length polymorphisms, DNA sequence analysis, chloroplast DNA, and microsatellite markers. Yet, little is known about whether these traits, which distinguish among genetically distinct types of common bean, can be evaluated using omics technologies.</p> <p>Results</p> <p>Three 'omics' approaches: transcriptomics, proteomics, and metabolomics were used to qualitatively evaluate the diversity of common bean from two Centers of Domestication (COD). All three approaches were able to classify common bean according to their COD using unsupervised analyses; these findings are consistent with the hypothesis that differences exist in gene transcription, protein expression, and synthesis and metabolism of small molecules among common bean cultivars representative of different COD. Metabolomic analyses of multiple cultivars within two common bean gene pools revealed cultivar differences in small molecules that were of sufficient magnitude to allow identification of unique cultivar fingerprints.</p> <p>Conclusions</p> <p>Given the high-throughput and low cost of each of these 'omics' platforms, significant opportunities exist for their use in the rapid identification of traits of agronomic and nutritional importance as well as to characterize genetic diversity.</p

    Testing the paradox of enrichment along a land use gradient in a multitrophic aboveground and belowground community

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    In the light of ongoing land use changes, it is important to understand how multitrophic communities perform at different land use intensities. The paradox of enrichment predicts that fertilization leads to destabilization and extinction of predator-prey systems. We tested this prediction for a land use intensity gradient from natural to highly fertilized agricultural ecosystems. We included multiple aboveground and belowground trophic levels and land use-dependent searching efficiencies of insects. To overcome logistic constraints of field experiments, we used a successfully validated simulation model to investigate plant responses to removal of herbivores and their enemies. Consistent with our predictions, instability measured by herbivore-induced plant mortality increased with increasing land use intensity. Simultaneously, the balance between herbivores and natural enemies turned increasingly towards herbivore dominance and natural enemy failure. Under natural conditions, there were more frequently significant effects of belowground herbivores and their natural enemies on plant performance, whereas there were more aboveground effects in agroecosystems. This result was partly due to the “boom-bust” behavior of the shoot herbivore population. Plant responses to herbivore or natural enemy removal were much more abrupt than the imposed smooth land use intensity gradient. This may be due to the presence of multiple trophic levels aboveground and belowground. Our model suggests that destabilization and extinction are more likely to occur in agroecosystems than in natural communities, but the shape of the relationship is nonlinear under the influence of multiple trophic interactions.
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