134 research outputs found

    Geographical trends in research: a preliminary analysis on authors' affiliations

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    In the last decade, research literature reached an enormous volume with an unprecedented current annual increase of 1.5 million new publications. As research gets ever more global and new countries and institutions, either from academia or corporate environment, start to contribute with their share, it is important to monitor this complex scenario and understand its dynamics. We present a study on a conference proceedings dataset extracted from Springer Nature Scigraph that illustrates insightful geographical trends and highlights the unbalanced growth of competitive research institutions worldwide. Results emerged from our micro and macro analysis show that the distributions among countries of institutions and papers follow a power law, and thus very few countries keep producing most of the papers accepted by high-tier conferences. In addition, we found that the annual and overall turnover rate of the top 5, 10 and 25 countries is extremely low, suggesting a very static landscape in which new entries struggle to emerge. Finally, we highlight the presence of an increasing gap between the number of institutions initiating and overseeing research endeavours (i.e. first and last authors' affiliations) and the total number of institutions participating in research. As a consequence of our analysis, the paper also discusses our experience in working with affiliations: an utterly simple matter at first glance, that is instead revealed to be a complex research and technical challenge yet far from being solved

    Chedoke Arm and Hand Activity Inventory-9 (CAHAI-9): Perceived clinical utility within 14 days of stroke

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    Purpose: The Chedoke Arm and Hand Activity Inventory-9 (CAHAI-9) is an activity-based assessment developed to include relevant functional tasks and to be sensitive to clinically important changes in upper limb function. The aim of this study was to explore both therapists' and clients' views on the clinical utility of CAHAI-9 within 14 days of stroke. Method: Twenty-one occupational therapists actively working in stroke settings were recruited by convenience sampling from 8 hospitals and participated in semistructured focus groups. Five clients within 14 days of stroke were recruited by consecutive sampling from 1 metropolitan hospital and participated in structured individual interviews. The transcripts were analyzed thematically. Results: Six themes emerged from the focus groups and interviews: collecting information, decisions regarding client suitability, administration and scoring, organizational demands, raising awareness, and clients' perceptions of CAHAI-9 utility. All therapists agreed CAHAI-9 was suited for the stroke population and assisted identification of client abilities or difficulties within functional contexts. Opinions varied as to whether CAHAI-9 should be routinely administered with clients who had mild and severe upper limb deficits, but therapists agreed it was appropriate for clients with moderate deficits. Therapists made suggestions regarding refinement of the scoring and training to increase utility. All clients with stroke felt that the assessment provided reassurance regarding their recovery. Conclusion: The findings indicate that CAHAI-9 shows promise as an upper limb ability assessment for clients within 14 days of stroke

    Vitamin D receptor gene polymorphisms are associated with breast cancer risk in a UK Caucasian population

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    There is increasing evidence that vitamin D can protect against breast cancer. The actions of vitamin D are mediated via the vitamin D receptor (VDR). We have investigated whether polymorphisms in the VDR gene are associated with altered breast cancer risk in a UK Caucasian population. We recruited 241 women following a negative screening mammogram and 181 women with known breast cancer. The VDR polymorphism BsmI, an intronic 3′ gene variant, was significantly associated with increased breast cancer risk: odds ratio bb vs BB genotype = 2.32 (95% CI, 1.23–4.39). The BsmI polymorphism was in linkage disequilibrium with a candidate translational control site, the variable length poly (A) sequence in the 3′ untranslated region. Thus, the ‘L’ poly (A) variant was also associated with a similar breast cancer risk. A 5′ VDR gene variant, FokI, was not associated with breast cancer risk. Further investigations into the mechanisms of interactions of the VDR with other environmental and/or genetic influences to alter breast cancer risk may lead to a new understanding of the role of vitamin D in the control of cellular and developmental pathways. © 2001 Cancer Research Campaign http://www.bjcancer.co

    Synchronization of cytoplasmic and transferred mitochondrial ribosomal protein gene expression in land plants is linked to Telo-box motif enrichment

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    <p>Abstract</p> <p>Background</p> <p>Chloroplasts and mitochondria evolved from the endosymbionts of once free-living eubacteria, and they transferred most of their genes to the host nuclear genome during evolution. The mechanisms used by plants to coordinate the expression of such transferred genes, as well as other genes in the host nuclear genome, are still poorly understood.</p> <p>Results</p> <p>In this paper, we use nuclear-encoded chloroplast (cpRPGs), as well as mitochondrial (mtRPGs) and cytoplasmic (euRPGs) ribosomal protein genes to study the coordination of gene expression between organelles and the host. Results show that the mtRPGs, but not the cpRPGs, exhibit strongly synchronized expression with euRPGs in all investigated land plants and that this phenomenon is linked to the presence of a <it>telo</it>-box DNA motif in the promoter regions of mtRPGs and euRPGs. This motif is also enriched in the promoter regions of genes involved in DNA replication. Sequence analysis further indicates that mtRPGs, in contrast to cpRPGs, acquired <it>telo</it>-box from the host nuclear genome.</p> <p>Conclusions</p> <p>Based on our results, we propose a model of plant nuclear genome evolution where coordination of activities in mitochondria and chloroplast and other cellular functions, including cell cycle, might have served as a strong selection pressure for the differential acquisition of <it>telo</it>-box between mtRPGs and cpRPGs. This research also highlights the significance of physiological needs in shaping transcriptional regulatory evolution.</p

    Chlorophyll-deficient mutants of Chlamydomonas reinhardtii that accumulate magnesium protoporphyrin IX

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    Two Chlamydomonas reinhardtii mutants defective in CHLM encoding Mg-protoporphyrin IX methyltransferase (MgPMT) were identified. The mutants, one with a missense mutation (chlM-1) and a second mutant with a splicing defect (chlM-2), do not accumulate chlorophyll, are yellow in the dark and dim light, and their growth is inhibited at higher light intensities. They accumulate Mg-protoporphyrin IX (MgProto), the substrate of MgPMT and this may be the cause for their light sensitivity. In the dark, both mutants showed a drastic reduction in the amounts of core proteins of photosystems I and II and light-harvesting chlorophyll a/b-binding proteins. However, LHC mRNAs accumulated above wild-type levels. The accumulation of the transcripts of the LHC and other genes that were expressed at higher levels in the mutants during dark incubation was attenuated in the initial phase of light exposure. No regulatory effects of the constitutively 7- to 18-fold increased MgProto levels on gene expression were detected, supporting previous results in which MgProto and heme in Chlamydomonas were assigned roles as second messengers only in the transient activation of genes by light

    Ion homeostasis in the Chloroplast

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    peer reviewedThe chloroplast is an organelle of high demand for macro- and micro-nutrient ions, which are required for the maintenance of the photosynthetic process. To avoid deficiency while preventing excess, homeostasis mechanisms must be tightly regulated. Here, we describe the needs for nutrient ions in the chloroplast and briefly highlight their functions in the chloroplastidial metabolism. We further discuss the impact of nutrient deficiency on chloroplasts and the acclimation mechanisms that evolved to preserve the photosynthetic apparatus. We finally present what is known about import and export mechanisms for these ions. Whenever possible, a comparison between cyanobacteria, algae and plants is provided to add an evolutionary perspective to the description of ion homeostasis mechanisms in photosynthesis
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