385 research outputs found

    Land in Landscapes circum Landnám: an Integrated Study of Settlements in Reykholtsdalur, Iceland

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    The initial settlement of Iceland in the ninth and tenth centuries AD was based on animal husbandry, with an emphasis on dairy cattle and sheep. For this activity, land resources that offered a range of grazing and fodder production opportunities were required to sustain farmsteads. In this paper the nature of land within the boundaries of settlements in an area of Western Iceland centred on Reykholt, which became the estate of the writer and chieftain Snorri Sturluson in the thirteenth century, is analysed with a Geographical Information Systems (GIS) approach. The results, combining historical, archaeological and environmental data with the GIS-based topographic analysis suggests that although inherent land qualities seem to have played a part in shaping the initial hierarchy of settlement in the area, it was the acquisition of additional property and of access to resources outside the valley that ultimately pushed Reykholt to the forefront in the hierarchal order

    Sustainable rangeland grazing in Norse Faroe

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    The introduction of domestic livestock - particularly sheep - and rangeland grazing by Norse settlers to Faroe during the 9th century has generally been described as a major pressure on a sensitive landscape, leading to rapid and widespread vegetation change and contributing to land degradation. This view has, however, been developed without consideration of Norse grazing management practices which may have served to minimise grazing impacts on landscapes as well as sustaining and enhancing vegetation and livestock productivity. These alternative scenarios are considered using a historical grazing management simulation model with Faroese climate and vegetation inputs and given archaeological, historical and palaeo-environmental parameters. Three contrasting rangeland areas are investigated and, based on the maximum number of ewe / lamb pairs the rangeland could sustain, modeling suggests that utilisable biomass declined with the onset of grazing activity, but not to a level that would cause major changes in vegetation cover or contribute to soil erosion even under climatically determined poor growth conditions. When rangeland areas partitioned into what are termed hagi and partir are modeled, grazing levels are still within rangeland carrying capacities, but productivities are variable. Some rangeland areas increase biomass and livestock productivity's and biomass utilisation rates while other rangeland areas that were too finely partitioned were likely to suffer substantial decline in livestock productivities. Partitioning of rangeland is a likely contributor to long-term differentiation of landscapes and the relative success of settlements across Faroe beyond the Norse period

    Quantifying gross vs. net agricultural land use change in Great Britain using the Integrated Administration and Control System

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    Land use change has impacts upon many natural processes, and is one of the key measures of anthropogenic disturbance on ecosystems. Agricultural land covers 70% of Great Britain's (GB) land surface and annually undergoes disturbance and change through farming practices such as crop rotation, ploughing and the planting and subsequent logging of forestry. It is important to quantify how much of GB's agricultural land undergoes such changes and what those changes are at an annual temporal resolution. Integrated Administration and Control System (IACS) data give annual snapshots of agricultural land use at the field level, allowing for high resolution spatiotemporal land use change studies at the national scale. Crucially, not only do the data allow for simple net change studies (total area change of a land use, in a specific areal unit) but also for gross change calculations (summation of all changes to and from a land use), meaning that both gains and losses to and from each land use category can be defined. In this study we analysed IACS data for GB from 2005 to 2013, and quantified gross change for over 90% of the agricultural area in GB for the first time. It was found that gross change totalled 63,500 km2 in GB compared to 20,600 km2 of net change, i.e. the real year-on-year change is, on average, three times larger than net change. This detailed information on nature of land use change allows for increased accuracy in modelling the impact of land use change on ecosystem processes and is directly applicable across EU member states, where collection of such survey data is a requirement. The modelled carbon flux associated with gross land use change was at times >100 Gg C y−1 larger than that based on net land use change for some land use transitions

    Shorter Lines Facilitate Reading in Those Who Struggle

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    People with dyslexia, who ordinarily struggle to read, sometimes remark that reading is easier when e-readers are used. Here, we used eye tracking to observe high school students with dyslexia as they read using these devices. Among the factors investigated, we found that reading using a small device resulted in substantial benefits, improving reading speeds by 27%, reducing the number of fixations by 11%, and importantly, reducing the number of regressive saccades by more than a factor of 2, with no cost to comprehension. Given that an expected trade-off between horizontal and vertical regression was not observed when line lengths were altered, we speculate that these effects occur because sluggish attention spreads perception to the left as the gaze shifts during reading. Short lines eliminate crowded text to the left, reducing regression. The effects of attention modulation by the hand, and of increased letter spacing to reduce crowding, were also found to modulate the oculomotor dynamics in reading, but whether these factors resulted in benefits or costs depended on characteristics, such as visual attention span, that varied within our sample

    Land: Its Organisation and Management at Norse Hofstaðir

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    Land, its organisation and management as well as its intrinsic quality are little understood aspects of the settlement process in Iceland. Yet an understanding of the concept and significance of land is vital if we are to recognise the way in which environmental resources were used to create and maintain social structures, the role of management decisions in setting new directions of environmental change, and the adoption and adaptation of land management strategies to sustain food production. Organisation of land was needed to ensure the requirements of grazing domestic livestock (dominantly sheep, cattle and cows) and access to fuel resources were met in order to provide foundations for subsistence and local economies

    Social media for the dissemination of Cochrane child health evidence: evaluation study

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    © Michele P Dyson, Amanda S Newton, Kassi Shave, Robin M Featherstone, Denise Thomson, Aireen Wingert, Ricardo M Fernandes, Lisa Hartling. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 01.09.2017. This is an open-access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in the Journal of Medical Internet Research, is properly cited. The complete bibliographic information, a link to the original publication on http://www.jmir.org/, as well as this copyright and license information must be included.Background: Health care providers value ready access to reliable synthesized information to support point-of-care decision making. Web-based communities, facilitated by the adoption of social media tools such as Facebook, Twitter, and YouTube, are increasingly being used for knowledge dissemination, bridging the gap between knowledge generation and synthesis and knowledge implementation. Objective: Our objective was to implement and evaluate a structured social media strategy, using multiple platforms, to disseminate Cochrane Child Health evidence to health care providers caring for children. Methods: Our social media strategy had three components: daily "tweets" using the Cochrane Child Health Twitter account, weekly WordPress blog posts, and a monthly journal club on Twitter ("tweet chat"). Each tweet, blog, and journal club shared Cochrane evidence on a child health topic. We evaluated the strategy through (1) Twitter and blog site analytics, (2) traceable link (Bitly) statistics, (3) Altmetric.com scores for promoted evidence, and (4) participant feedback. We also tracked the resources required to write the blog, tweet content, and manage the strategy. Results: The 22-week social media strategy ran between November 2014 and April 2015. We created 25 blog posts, sent 585 tweets, and hosted 3 tweet chats. Monthly blog visits and views and Twitter account followers increased over time. During the study period, the blog received 2555 visitors and 3967 page views from a geographically diverse audience of health care providers, academics, and health care organizations. In total, 183 traceable Bitly links received 3463 clicks, and the Twitter account gained 469 new followers. The most visited and viewed blog posts included gastrointestinal topics (lactose avoidance), research on respiratory conditions (honey for cough and treatments for asthma), and maternal newborn care (skin-to-skin contact). On Twitter, popular topics were related to public health (vaccination) and pain management. We collected Altmetric.com scores for 61 studies promoted during the study period and recorded an average increase of 11 points. Research staff (n=3) contributed approximately 433 hours to promotion activities and planning (6.5 hours each per week) to implement the social media strategy, and study investigators reviewed all content (blog posts and tweets). Conclusions: This study provides empirical evidence on the use of a coordinated social media strategy for the dissemination of evidence to professionals providing health services to children and youth. The results and lessons learned from our study provide guidance for future knowledge dissemination activities using social media tools.This work was supported by Alberta Innovates—Health Solutions, grant number 201300653. LH and ASN are supported, in part, by Canadian Institutes of Health Research New Investigator Awards.info:eu-repo/semantics/publishedVersio

    Investigation into the role of the germline epigenome in the transmission of glucocorticoid-programmed effects across generations.

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    BACKGROUND: Early life exposure to adverse environments affects cardiovascular and metabolic systems in the offspring. These programmed effects are transmissible to a second generation through both male and female lines, suggesting germline transmission. We have previously shown that prenatal overexposure to the synthetic glucocorticoid dexamethasone (Dex) in rats reduces birth weight in the first generation (F1), a phenotype which is transmitted to a second generation (F2), particularly through the male line. We hypothesize that Dex exposure affects developing germ cells, resulting in transmissible alterations in DNA methylation, histone marks and/or small RNA in the male germline. RESULTS: We profile epigenetic marks in sperm from F1 Sprague Dawley rats expressing a germ cell-specific GFP transgene following Dex or vehicle treatment of the mothers, using methylated DNA immunoprecipitation sequencing, small RNA sequencing and chromatin immunoprecipitation sequencing for H3K4me3, H3K4me1, H3K27me3 and H3K9me3. Although effects on birth weight are transmitted to the F2 generation through the male line, no differences in DNA methylation, histone modifications or small RNA were detected between germ cells and sperm from Dex-exposed animals and controls. CONCLUSIONS: Although the phenotype is transmitted to a second generation, we are unable to detect specific changes in DNA methylation, common histone modifications or small RNA profiles in sperm. Dex exposure is associated with more variable 5mC levels, particularly at non-promoter loci. Although this could be one mechanism contributing to the observed phenotype, other germline epigenetic modifications or non-epigenetic mechanisms may be responsible for the transmission of programmed effects across generations in this model

    Testing a brief web-based intervention to increase recognition of tobacco constituents

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    Objective: We examined website formats to increase smokers\u27 recognition of harmful and potentially harmful constituents (HPHCs) in cigarettes. Methods: Adult, daily smokers (N = 279) were randomized to view a brief, single-page study website showing HPHC names and uses. The intervention site was tailored + interactive, labeled by cigarette brand/subbrand showing color imagery and pop-up boxes; the generic + static website (control) was unbranded in greyscale. Eye tracking equipment measured attention (dwell time) to precise website features. Linear regression analyses compared attention to HPHC descriptions and the correct recognition of 15 HPHC chemicals. A randomly selected sub-sample (N = 30) of participants qualitatively rated website usability. Results: Despite spending less dwell time on the HPHC text and entire website, adult smokers who viewed the generic + static website had greater improvement in HPHC recognition compared to the tailored + interactive website (4.6 vs 3.6; p = .02); this finding contrasts with current literature on tailoring and interactivity. Both websites were rated highly on ease-of-use and readability. Conclusions: Basic formats and narrative HPHC Web-based content attracted less visual attention, yet increased recognition of these chemicals in cigarettes, compared to brand-tailored, interactive web-based content

    Investigation of fatigue by Australian General Practice Registrars: a cross-sectional study

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    INTRODUCTION: Fatigue is the most common undifferentiated problem presenting in general practice. Previous studies have shown that this presentation leads to multiple investigations. There is no published literature describing the management of patients with fatigue by general practice (GP) registrars. AIM: To document the investigation-ordering behaviour of GP registrars in managing patients with a new diagnosis of unexplained fatigue. METHODS: This was a cross-sectional analysis of data from Registrar Clinical Encounters in Training (ReCEnT), an ongoing cohort study of GP registrars’ consultations. We established the prevalence of new diagnoses of unexplained fatigue and associations with that diagnosis, the rate of test ordering and the number and types of investigations ordered. RESULTS: 644 registrars contributed data from 68 986 encounters. In 0.78% of patient encounters, a new diagnosis of unexplained fatigue was made. Pathology was ordered in 78.4% of these problems (versus 18.1% in non-fatigue problems), at a rate of 488 tests per 100 new fatigue problems. DISCUSSION: Our study suggests that unexplained fatigue elicits a non-rational approach to test ordering by registrars. These findings contribute to the understanding of GP registrar management of fatigue, and undifferentiated presentations more broadly, and suggest educational approaches to improve practice, including dealing with uncertainty
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