291 research outputs found

    Imprint of past and present environmental conditions on microbiology and biogeochemistry of coastal Quaternary sediments

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    To date, North Sea tidal-flat sediments have been intensively studied down to a depth of 5 m below seafloor (mbsf). However, little is known about the biogeochemistry, microbial abundance, and activity of sulfate reducers as well as methanogens in deeper layers. In this study, two 20 m-long cores were retrieved from the tidal-flat area of Spiekeroog Island, NW Germany. The drill sites were selected with a close distance of 900 m allowing to compare two depositional settings: first, a paleo-channel filled with Holocene sediments and second, a mainly Pleistocene sedimentary succession. Analyzing these cores, we wanted to test to which degree the paleo-environmental imprint is superimposed by present processes. <br><br> In general, the numbers of bacterial 16S rRNA genes are one to two orders of magnitude higher than those of <i>Archaea</i>. The abundances of key genes for sulfate reduction and methanogenesis (<i>dsr</i>A and <i>mcr</i>A) correspond to the sulfate and methane profiles. A co-variance of these key genes at sulfate-methane interfaces and enhanced ex situ AOM rates suggest that anaerobic oxidation of methane may occur in these layers. Microbial and biogeochemical profiles are vertically stretched relative to 5 m-deep cores from shallower sediments in the same study area, but still appear compressed compared to deep sea sediments. Our interdisciplinary analysis shows that the microbial abundances and metabolic rates are elevated in the Holocene compared to Pleistocene sediments. However, this is mainly due to present environmental conditions such as pore water flow and organic matter availability. The paleo-environmental imprint is still visible but superimposed by these processes

    Optical coherence tomography characteristics of group 2A idiopathic parafoveal telangiectasis

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    PURPOSE: To describe the optical coherence tomography (OCT) characteristics of patients with group 2A idiopathic parafoveal telangiectasis (IPFT) and to correlate them with biomicroscopic and fluorescein angiographic (FA) findings based on Gass and Blodi staging classification for group 2A IPFT. METHODS: Fifty-two eyes of 26 consecutive patients with IPFT underwent biomicroscopic fundus examination, color fundus photography, FA, and OCT. Main outcome measures were OCT characteristics and their correlation with biomicroscopy and FA. RESULTS: The most common OCT findings that help differentiate between stages in group 2A IPFT are 1) highly reflective dots in the inner retina that correspond with microvessels seen by FA in Stage 1 (5 eyes [62.5%]); 2) the presence of hyporeflective intraretinal spaces in the absence of retinal thickening and highly reflective dots in the retina in Stage 2 (9 [81.8%] and 10 eyes [90.9%], respectively); 3) in Stage 3, both outer and inner retina exhibit areas of similar high reflectivity. In addition, the retinal pigment epithelium (RPE)/choriocapillaris complex is thickened or disrupted as evidenced by an area of high reflectivity (13 eyes [81.2%]); 4) a highly reflective area nasal or temporal to the fovea in the inner or outer retinal layers in Stage 4 suggesting RPE proliferation and migration (13 eyes [100%]); and 5) a fusiform thickening and duplication of the highly reflective RPE/choriocapillaris complex corresponding to choroidal neovascularization in Stage 5 (4 eyes [100%]). Our OCT characteristics correlated well with biomicroscopic and FA findings for Stages 4 and 5. However, the hyporeflective spaces that are evident on OCT could not be seen clinically at the slit lamp or on FA. In addition, our OCT findings on eyes with group 2A IPFT Stage 3 have not, to our knowledge, been previously described. CONCLUSIONS: Optical coherence tomography findings in group 2A IPFT were characteristic for each stage and may be helpful in making the diagnosis as well as defining the anatomical staging proposed by Gass and Blodi. Optical coherence tomography complements biomicroscopic and FA findings in the evaluation of group 2A IPFT. © The Ophthalmic Communications Society, Inc

    History of Foot Ulcer Increases Mortality Among Individuals With Diabetes: Ten-year follow-up of the Nord-TrĂžndelag Health Study, Norway

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    OBJECTIVE To compare mortality rates for individuals with diabetes with and without a history of foot ulcer (HFU) and with that for the nondiabetic population. RESEARCH DESIGN AND METHODS This population-based study included 155 diabetic individuals with an HFU, 1,339 diabetic individuals without an HFU, and 63,632 nondiabetic individuals who were all followed for 10 years with mortality as the end point. RESULTS During the follow-up period, a total of 49.0% of diabetic individuals with an HFU died, compared with 35.2% of diabetic individuals without an HFU and 10.5% of those without diabetes. In Cox regression analyses adjusted for age, sex, education, current smoking, and waist circumference, having an HFU was associated with more than a twofold (2.29 [95% CI 1.82–2.88]) hazard risk for mortality compared with that of the nondiabetic group. In corresponding analyses comparing diabetic individuals with and without an HFU, an HFU was associated with 47% increased mortality (1.47 [1.14–1.89]). Significant covariates were older age, male sex, and current smoking. After inclusion of A1C, insulin use, microalbuminuria, cardiovascular disease, and depression scores in the model, each was significantly related to life expectancy. CONCLUSIONS AN HFU increased mortality risk among community-dwelling adults and elderly individuals with diabetes. The excess risk persisted after adjustment for comorbidity and depression scores, indicating that close clinical monitoring might be warranted among individuals with an HFU, who may be particularly vulnerable to adverse outcomes. Hospital-based studies have shown that mortality rates in individuals with diabetic foot ulcers are about twice those observed in individuals with diabetes without foot ulcers (1,2). A diabetic foot ulcer reflects the presence of underlying pathological conditions, and the risk of recurrent ulcers is high (3,4). It has been suggested that the elevated mortality rate among individuals with diabetic foot ulcers is related to comorbid disease such as cardiovascular disease and nephropathy (5) or to psychological factors including depression (6). Although the mortality rate in individuals with diabetes is high, no large population-based studies have examined the impact on mortality of a history of foot ulcers (HFU) among individuals with diabetes. The purpose of this study was to compare mortality rates for individuals with diabetes reporting an HFU with those for individuals without an HFU and the nondiabetic population. These issues were investigated in the Nord-Trþndelag Health Study (HUNT 2), which includes a very large population-based sample of men and women from a well-defined geographic area. Participants with self-reported diabetes were well characterized with regard to their diabetes, and information on demographics, lifestyle, and prevalent disease including depression was available

    Young children's research: children aged 4-8 years finding solutions at home and at school

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    Children's research capacities have become increasingly recognised by adults, yet children remain excluded from the academy, with reports of their research participation generally located in adults' agenda. Such practice restricts children's freedom to make choices in matters affecting them, underestimates children’s capabilities and denies children particular rights. The present paper reports on one aspect of a small-scale critical ethnographic study adopting a constructivist grounded approach to conceptualise ways in which children's naturalistic behaviours may be perceived as research. The study builds on multi-disciplinary theoretical perspectives, embracing 'new' sociology, psychology, economics, philosophy and early childhood education and care (ECEC). Research questions include: 'What is the nature of ECEC research?' and 'Do children’s enquiries count as research?' Initially, data were collected from the academy: professional researchers (n=14) confirmed 'finding solutions' as a research behaviour and indicated children aged 4-8 years, their practitioners and primary carers as 'theoretical sampling'. Consequently, multi-modal case studies were constructed with children (n=138) and their practitioners (n=17) in three ‘good’ schools, with selected children and their primary carers also participating at home. This paper reports on data emerging from children aged 4-8 years at school (n=17) and at home (n=5). Outcomes indicate that participating children found diverse solutions to diverse problems, some of which they set themselves. Some solutions engaged children in high order thinking, whilst others did not; selecting resources and trialing activities engaged children in 'finding solutions'. Conversely, when children's time, provocations and activities were directed by adults, the quality of their solutions was limited, they focused on pleasing adults and their motivation to propose solutions decreased. In this study, professional researchers recognised 'finding solutions' as research behaviour and children aged 4-8 years naturalistically presented with capacities for finding solutions; however, the children's encounters with adults affected the solutions they found

    Value/s in early childhood education

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    Twenty years ago, as an early childhood teacher, I was fortunate to attend a professional development day conference led by the inimitable Professor Tina Bruce. At the conference, Tina asked we early childhood teachers: ‘What one thing would you put your back to the wall for in your job?’ In other words, Tina wanted us to share with one another the values that guide our daily work with young children and their families. An avowed Froebelian, Tina herself subscribes to a very particular set of values (Bruce 2015) and she is not alone. Many early childhood educators over two centuries have been influenced by the principles and philosophy developed by Froebel, the original kindergarten practitioner (Froebel Trust 2018). Indeed, as for so many others, my own initial teacher education was strongly influenced by Froebelian principles which have continued to guide my work in the field for thirty-five years. We live in an era of unprecedented global focus on early childhood development (UNESCO 2017; WHO 2018), in this editorial I revisit Froebel’s principles and I argue that we would be wise to continue to regard them as relevant and valuable touchstones for early childhood education in the twenty-first century

    Intravitreal bevacizumab in diabetic retinopathy. Recommendations from the Pan-American Collaborative Retina Study Group (PACORES): The 2016 knobloch lecture

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    The advent of intravitreal anti-vascular endothelial growth factor (anti-VEGF) medications has revolutionized the treatment of diabetic eye diseases. Herein, we report the outcomes of clinical studies carried out by the Pan-American Collaborative Retina Study Group (PACORES), with a specific focus on the efficacy of intravitreal bevacizumab in the management of diabetic macular edema and proliferative diabetic retinopathy. We will also discuss the use of intravitreal bevaci-zumab as a preoperative, adjuvant therapy before vitrectomy for prolif-erative diabetic retinopathy. Copyright © 2017 by Asia Pacific Academy of Ophthalmology
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