90 research outputs found

    Identification of two chickpea multidrug and toxic compound extrusion transporter genes transcriptionally upregulated upon aluminum treatment in root tips

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    Aluminum (Al) toxicity poses a significant challenge for the yield improvement of chickpea, which is an economically important legume crop with high nutritional value in human diets. The genetic basis of Al-tolerance in chickpea remains unclear. Here, we assessed the Al-tolerance of 8 wild Cicer and one cultivated chickpea (PBA Pistol) accessions by measuring the root elongation in solution culture under control (0 μM Al3+) and Al treatments (15, 30 μM Al3+). Compared to PBA Pistol, the wild Cicer accessions displayed both tolerant and sensitive phenotypes, supporting wild Cicer as a potential genetic pool for Al-tolerance improvement. To identify potential genes related to Al-tolerance in chickpea, genome-wide screening of multidrug and toxic compound extrusion (MATE) encoding genes was performed. Fifty-six MATE genes were identified in total, which can be divided into 4 major phylogenetic groups. Four chickpea MATE genes (CaMATE1-4) were clustered with the previously characterized citrate transporters MtMATE66 and MtMATE69 in Medicago truncatula. Transcriptome data showed that CaMATE1-4 have diverse expression profiles, with CaMATE2 being root-specific. qRT-PCR analyses confirmed that CaMATE2 and CaMATE4 were highly expressed in root tips and were up-regulated upon Al treatment in all chickpea lines. Further measurement of carboxylic acids showed that malonic acid, instead of malate or citrate, is the major extruded acid by Cicer spp. root. Protein structural modeling analyses revealed that CaMATE2 has a divergent substrate-binding cavity from Arabidopsis AtFRD3, which may explain the different acid-secretion profile for chickpea. Pangenome survey showed that CaMATE1-4 have much higher genetic diversity in wild Cicer than that in cultivated chickpea. This first identification of CaMATE2 and CaMATE4 responsive to Al3+ treatment in Cicer paves the way for future functional characterization of MATE genes in Cicer spp., and to facilitate future design of gene-specific markers for Al-tolerant line selection in chickpea breeding programs

    Urbanization and mortality in Britain, c. 1800-50.

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    In the long-running debate over standards of living during the industrial revolution, pessimists have identified deteriorating health conditions in towns as undermining the positive effects of rising real incomes on the 'biological standard of living'. This article reviews long-run historical relationships between urbanization and epidemiological trends in England, and then addresses the specific question: did mortality rise especially in rapidly growing industrial and manufacturing towns in the period c. 1830-50? Using comparative data for British, European, and American cities and selected rural populations, this study finds good evidence for widespread increases in mortality in the second quarter of the nineteenth century. However, this phenomenon was not confined to 'new' or industrial towns. Instead, mortality rose in the 1830s especially among young children (aged one to four years) in a wide range of populations and environments. This pattern of heightened mortality extended between c. 1830 and c. 1870, and coincided with a well-established rise and decline in scarlet fever virulence and mortality. The evidence presented here therefore supports claims that mortality worsened for young children in the middle decades of the nineteenth century, but also indicates that this phenomenon was more geographically ubiquitous, less severe, and less chronologically concentrated than previously argued.Leverhulme Trust (award RPG-2012-803) Wellcome Trust (award no. 103322

    Establishing test form and individual task comparability: a case study of a semi-direct speaking test

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    Examination boards are often criticized for their failure to provide evidence of comparability across forms, and few such studies are publicly available. This study aims to investigate the extent to which three forms of the General English Proficiency Test Intermediate Speaking Test (GEPTS-I) are parallel in terms of two types of validity evidence: parallel-forms reliability and content validity. The three trial test forms, each containing three different task types (read-aloud, answering questions and picture description), were administered to 120 intermediate-level EFL learners in Taiwan. The performance data from the different test forms were analysed using classical procedures and Multi-Faceted Rasch Measurement (MFRM). Various checklists were also employed to compare the tasks in different forms qualitatively in terms of content. The results showed that all three test forms were statistically parallel overall and Forms 2 and 3 could also be considered parallel at the individual task level. Moreover, sources of variation to account for the variable difficulty of tasks in Form 1 were identified by the checklists. Results of the study provide insights for further improvement in parallel-form reliability of the GEPTS-I at the task level and offer a set of methodological procedures for other exam boards to consider. © 2006 Edward Arnold (Publishers) Ltd

    SHOULDER DISARTICULATION FITTING WITH 6 INDEPENDENTLY CONTROLLED MOTORS AFTER TARGETED HYPER-REINNERVATION NERVE TRANSFER SURGERY

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    In 2002, targeted hyper-reinnervation nerve transfer surgery was performed unilaterally on a bilateral shoulder disarticulation amputee. The goal of this surgery was to create additional sites using the remaining unused brachial plexus nerves to allow simultaneous control of multiple movements using more natural control schemes [1,2,3]. As a result of the nerve transfer procedure, 4 new myoelectric control sites were created on the left pectoralis muscle. Subsequent prosthetic fitting found that the user was able to operate the elbow and hand in a coordinated fashion using three electrodes. Various outcome measurements showed an improvement in prosthetic function. However, with the increase in the number of input signals, a goal was set to build a prosthesis with the maximum number of controlled motors available. Six motorized components were identified: three were commercially available in the USA, one was commercially available in other countries and two were a research prototype

    Applying Data Mining Techniques to the Mapping of Complex Disease Genes

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    The simulated sequence data for the Genetic Analysis Workshop 12 were analyzed using data mining techniques provided by SAS ENTERPRISE MINERTM Release 4.0 in addition to traditional statistical tests for linkage and association of genetic markers with disease status. We examined two ways of combining these approaches to make use of the covariate data along with the genotypic data. The result of incorporating data mining techniques with more classical methods is an improvement in the analysis, both by correctly classifying the affection status of more individuals and by locating more single nucleotide polymorphisms related to the disease, relative to analyses that use classical methods alone. © 2001 Wiley‐Liss, Inc
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