1,240 research outputs found

    A granular cell tumor: an unusual colon polyp

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    We read with interest the article by Sevilla Ribota et al1 that described an unexpected finding of a granular cell tumour (GCT) of the rectum, which was removed by band ligation-assisted mucosectomy. We present a similar case of a GCT of the cecum, which was resected using a different endoscopic procedure.info:eu-repo/semantics/publishedVersio

    Grazing improves habitat suitability for many ground foraging birds in Mediterranean wooded grasslands

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    Wooded grasslands, usually grazed, cover vast areas in Southern Europe and Northern Africa. They host rich resident bird communities and, in winter, receive large numbers of migrants from Central and Northern European woodlands. Many species are partly or entirely dependent on ground foraging, and since in winter food is often the most limiting factor for birds, maintaining suitable ground habitat is crucial. To study how grazing influences suitability of winter ground habitat for birds, we carried out an experiment in a wooded grassland in Southern Iberia, whereby grazing was controlled in 12 purposely fenced two-hectare plots (4 x 15 sheep/ha, 4 x 3 sheep/ha and 4 x no grazing). We quantified ground habitat features, food abundance and intensity of use by ground-foraging birds in each of these 12 plots. In addition, we made focal observations of birds feeding on the ground and compared the habitat of 1m2 foraging patches with those of nearby control patches. We found that virtually all birds prefer to forage in patches with short ground vegetation and high food abundance. Measurements of these parameters in the experimental plots showed that while grazing shortens vegetation it decreases food availability, and thus has opposing effects on important determinants of habitat suitability. Nevertheless, the numbers of birds foraging in the plots indicate that, overall, grazing benefits the assemblage of ground-feeding birds, presumably because for most species the advantages of foraging in less cluttered habitats more than compensate the lower abundance of prey. However, arboreal bird species that make short foraging forays to the ground had lower numbers in grazed plots. Most bird species that forage on the ground benefited from grazing, and although they can forage under a broad range of grazing levels, some showed clear preferences along the gradient of grazing intensity. Such preferences should be taken into consideration by managers. In general, grazing should be maintained at a level sufficient to open up ground vegetation, increasing the area occupied by patches of short vegetation, in which almost all bird species prefer to forage. At moderate levels, grazing is thus a valuable management tool to promote winter bird habitat quality in Mediterranean wooded grasslands, while increasing the economic value of these threatened landscapes

    Mapping the global flow of tungsten to identify key material efficiency and supply security opportunities

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    Tungsten is an economically important metal with diverse applications ranging from wear resistant cutting tools to its use in specialized steels and alloys. Concerns about its supply security have been raised by various studies in literature, mostly due to trade disputes arising from supply concentration and exports restrictions in China and its lack of viable substitutes. Although tungsten material flows have been analysed for specific regions, a global mass flow analysis of tungsten is still missing in literature and its global supply chain remains opaque for industry outsiders. The objective of this paper is to create a map of global tungsten flows to highlight and discuss key material efficiency (i.e. using less of a material to make a product or supply a service, or reducing the material entering production but ending up in waste) and supply security opportunities along tungsten‘s supply chain that could be incorporated into the planning and prioritization of future supply security strategies. The results indicate the existence of various intervention alternatives that could help to broaden the supply base and improve the overall material efficiency of the system. In particular, future policy and research and development (R&D) efforts to improve tungsten‘s material efficiency should focus on minimizing tungsten losses as fine particles during beneficiation and extraction (current global losses estimated at 10–40%), as well as on evaluating alternatives to improve recycling collection systems and technologies, which could lead to 17–45% more tungsten discards being recycled into new products.E. Petavratzi, T.J. Brown and A.G. Gunn publish with the permission of the Executive Director of the British Geological Survey. David R. Leal-Ayala and Julian M. Allwood were supported by the UK Engineering and Physical Sciences Research Council (EPSRC) through a Leadership fellowship (reference EP/G007217/1) and a research grant awarded to the UK Indemand Centre (reference EP/K011774/1). We thank Michael Dornhofer, Felix Gaul and Markus Ettl from Wolfram Bergbau und HĂŒtten AG for their generous contributions to the paper.This is the accepted manuscript. The final version is available at http://www.sciencedirect.com/science/article/pii/S0921344915300367

    Superpulsed low-level laser therapy protects skeletal muscle of mdx mice against damage, inflammation and morphological changes delaying dystrophy progression.

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    Aim: To evaluate the effects of preventive treatment with low-level laser therapy (LLLT) on progression of dystrophy in mdx mice. Methods: Ten animals were randomly divided into 2 experimental groups treated with superpulsed LLLT (904 nm, 15 mW, 700 Hz, 1 J) or placebo-LLLT at one point overlying the tibialis anterior muscle (bilaterally) 5 times per week for 14 weeks (from 6th to 20th week of age). Morphological changes, creatine kinase (CK) activity and mRNA gene expression were assessed in animals at 20th week of age. Results: Animals treated with LLLT showed very few morphological changes in skeletal muscle, with less atrophy and fibrosis than animals treated with placebo-LLLT. CK was significantly lower (p = 0.0203) in animals treated with LLLT (864.70 U.l−1, SEM 226.10) than placebo (1708.00 U.l−1, SEM 184.60). mRNA gene expression of inflammatory markers was significantly decreased by treatment with LLLT (p<0.05): TNF-α (placebo-control = 0.51 ”g/”l [SEM 0.12], - LLLT = 0.048 ”g/”l [SEM 0.01]), IL-1ÎČ (placebo-control = 2.292 ”g/”l [SEM 0.74], - LLLT = 0.12 ”g/”l [SEM 0.03]), IL-6 (placebo-control = 3.946 ”g/”l [SEM 0.98], - LLLT = 0.854 ”g/”l [SEM 0.33]), IL-10 (placebo-control = 1.116 ”g/”l [SEM 0.22], - LLLT = 0.352 ”g/”l [SEM 0.15]), and COX-2 (placebo-control = 4.984 ”g/”l [SEM 1.18], LLLT = 1.470 ”g/”l [SEM 0.73]). Conclusion: Irradiation of superpulsed LLLT on successive days five times per week for 14 weeks decreased morphological changes, skeletal muscle damage and inflammation in mdx mice. This indicates that LLLT has potential to decrease progression of Duchenne muscular dystrophy

    Climate change adaptation as a development challenge to small Island states: A case study from the Solomon Islands

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    © 2020 Elsevier Ltd Small Island Developing States (SIDS) are known to be particularly vulnerable to climate change, which poses a challenge to their economic and social development. This vulnerability is expressed in several ways, from exposure to sea level rises, to salt intrusion, and extensive droughts in some areas. Despite this rather negative trend, there are examples of initiatives where the vulnerability of SIDS can be reduced, and their resilience may be increased. Based on the paucity of the literature on concrete examples of successful climate change adaptation initiatives on SIDS, this paper presents an overview of pertinent challenges faced, and introduces two case studies from the Solomon Islands, which illustrate how much can be achieved by systematically pursuing adaptation strategies. The lessons learned from these case studies are outlined and some useful insights are provided, which may help SIDS to better foster the development opportunities with climate change adaptation offers to them

    Geometric Mixing, Peristalsis, and the Geometric Phase of the Stomach

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    Mixing fluid in a container at low Reynolds number - in an inertialess environment - is not a trivial task. Reciprocating motions merely lead to cycles of mixing and unmixing, so continuous rotation, as used in many technological applications, would appear to be necessary. However, there is another solution: movement of the walls in a cyclical fashion to introduce a geometric phase. We show using journal-bearing flow as a model that such geometric mixing is a general tool for using deformable boundaries that return to the same position to mix fluid at low Reynolds number. We then simulate a biological example: we show that mixing in the stomach functions because of the "belly phase": peristaltic movement of the walls in a cyclical fashion introduces a geometric phase that avoids unmixing.Comment: Revised, published versio
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