1,721,174 research outputs found
‘We shall defend our island' - investigating a forgotten militarised landscape
No full textThe outmanoeuvring of Allied forces in May 1940 led to the eventual evacuation of the BEF from the continent in June 1940. Fearing an invasion, GHQ Home Forces set about the rapid re-militarisation of the UK to oppose, arguably, the first very real threat to this country’s sovereignty since the Norman conquest of 1066 AD. Constructing a series of anti-invasion defences throughout the countryside, a network of defensive fieldworks and concrete gun emplacements were erected, with linear stop lines forming part of the overall stratagem for a countrywide defence in depth. Examining one particular linear stop line, GHQ Line Green, despite previous research into its archaeological route through the landscape several questions still remain unanswered - Did the proposed wartime route for the stop line match the documented archaeology? Did the defensive fieldworks conform to 1940 WO specifications, or were they similar in design to the linear fieldworks of the First World War? Did GHQ Line Green dismiss the defensive ‘folly’ notion of the Maginot Line by being strategically sited in the Bristol hinterland? A prepared battlefield that never faced the unpredictable test of conflict, evidence offered by original cartographic, archaeological and GIS ‘Fields-of- Fire’ analysis concluded that the GHQ Line Green was strategically placed in the landscape. In ideal conditions GHQ Line Green could have had limited success in slowing down an invasion force. This dismisses the notion that the stop line was a defensive ‘folly’. With its origins found to lay in First World War fortifications, the research undertaken for this thesis will further our understanding of an often forgotten Second World War landscape
An investigation of the association between grip strength and hip and knee joint moments in older adults
No full textGrip strength is a predictor of health outcomes but with differing rates of age-related decline in muscle strength, it is unclear whether handgrip is a reliable indicator of lower limb moments. This study investigated the relationship between grip strength and lower extremity moments in community- dwelling older adults. Eighty-two healthy volunteers aged 60–82 years (mean age 73.2 years) performed maximal voluntary contractions of knee and hip extensors and flexors at three positions and at neutral position for hip abductors and adductors using a custom-built dynamometer. Grip strength was measured using an electronic Jamar dynamometer. The relative reduction in muscle strength of 80s age category compared to 60-year-olds ranged from 14% for grip strength to 27% for hip abductors. Peak torque of flexors and extensors of the knee and hip joints were significantly correlated with grip strength and Pearson’s correlation coefficients ranged from 0.56 to 0.78 with the highest correlations observed between knee moments and grip strength. ‘‘Good’’ correlation was found but only 31–60% of the variation in grip strength could be related to changes in joint torques. Hence the assumption that grip strength is an indicator of strength in the lower limb would seem unjustified in the healthy older adul
The biomechanical functional demand placed on knee and hip muscles of older adults during stair ascent and descent
No full textAge-related decline in physical capabilities may lead to older adults experiencing difficulty in performing everyday activities due to high demands placed on the muscles of their lower extremity. This study aimed to determine the biomechanical functional demand in terms of joint moments and maximal muscle capabilities at the knee and hip joints while older adults performed stair ascent (SA) and stair descent (SD). Eighty-four healthy older adults aged 60–88 years were tested. A torque dynamometer attached to a purpose-built plinth was utilized to measure muscle moments at the knee and hip joints. Participants also underwent full body 3-D biomechanical assessment of stair ascent and descent using an 8-camera VICON system (120 Hz) with 3 Kistler force plates. Stair negotiation required knee extensor moments in excess of the maximum isometric muscle strength available (SA 103%, SD 120%). For the hip, the levels of demand were high, but were slightly lower than those of the knee joint. Stair negotiation placed a high level of demand on the knee extensors with demand in SA reaching maximal isometric capacity and demand in SD exceeding maximal isometric capacity. The levels of demand leave little reserve capacity for the older adult to draw on in unexpected situations or circumstances
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Sequential MRI of growing scoliotic spines reveals individual level deformities that are clinically masked by the cobb angle
No full textINTRODUCTION. Clinically, the Cobb angle method measures the overall scoliotic curve in the coronal plane but does not measure individual vertebra and disc wedging. The contributions of the vertebrae and discs in the growing scoliotic spine were measured to investigate coronal plane deformity progression with growth. \ud
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METHODS. A 0.49mm isotropic 3D MRI technique was developed to investigate the level-by-level changes that occur in the growing spine of a group of Adolescent Idiopathic Scoliosis (AIS) patients, who received two to four sequential scans (spaced 3-12 months apart). The coronal plane wedge angles of each vertebra and disc in the major curve were measured to capture any changes that occurred during their adolescent growth phase. \ud
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RESULTS. Seventeen patients had at least two scans. Mean patient age was 12.9 years (SD 1.5 years). Sixteen were classified as right-sided major thoracic Lenke Type 1 (one left sided). Mean standing Cobb angle at initial presentation was 31° (SD 12°). Six received two scans, nine three scans and two four scans, with 65% showing a Cobb angle progression of 5° or more between scans. Overall, there was no clear pattern of deformity progression of individual vertebrae and discs, nor between patients who progressed and those who didn’t. There were measurable changes in the wedging of the vertebrae and discs in all patients. In sequential scans, change in direction of wedging was also seen. In several patients there was reverse wedging in the discs that counteracted increased wedging of the vertebrae such that no change in overall Cobb angle was seen. \ud
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CONCLUSION. Sequential MRI data showed complex patterns of deformity progression. Changes to the wedging of individual vertebrae and discs may occur in patients who have no increase in Cobb angle measure; the Cobb method alone may be insufficient to capture the complex mechanisms of deformity progression
Using low dose computerized tomography to morphometrically analyse the thoracic intervertebral foramen osseous anatomy in adolescent idiopathic scoliosis
No full textINTRODUCTION\ud
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The dimensions of the thoracic intervertebral foramen in adolescent idiopathic scoliosis (AIS) have not previously been quantified. During posterior approach scoliosis correction surgery pedicle screws may occasionally breach into the foramen. Better understanding of the dimensions of the foramen may be useful in surgical planning. This study describes a reproducible method for measurement of the thoracic foramen in AIS using computerized tomography (CT).\ud
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METHODS\ud
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In 23 pre-operative female patients with Lenke 1 type AIS with right side convexity major curves confined to the thoracic spine the foraminal height (FH), foraminal width (FW), pedicle to superior articular process distance (P-SAP) and cross sectional foraminal area (FA) were measured using multiplanar reconstructed CT. Measurements were made at entrance, midpoint and exit of the thoracic foramina from T1/T2 to T11/T12. Results were correlated with potential dependent variables of major curve Cobb Angle measured on X-ray and CT, Age, Weight, Lenke classification subtype, Risser Grade and number of spinal levels in the major curve.\ud
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RESULTS\ud
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The FH, FW, P-SAP and FA dimensions and ratios are all significantly larger on the convexity of the major curve and maximal at or close to the apex. Mean thoracic foraminal dimensions change in a predictable manner relative to position on the major thoracic curve. There was no significant correlation with the measured foraminal dimensions or ratios and the potential dependent variables. The average ratio of convexity to concavity dimensions at the apex foramina for entrance, midpoint and exit respectively are FH (1.50, 1.38, 1.25), FW (1.28, 1.30, 0.98), FA (2.06, 1.84, 1.32), P-SAP (1.61, 1.47, 1.30).\ud
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CONCLUSION\ud
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Foraminal dimensions of the thoracic spine are significantly affected by AIS. Foraminal dimensions have a predictable convexity to concavity ratio relative to the proximity to the major curve apex. Surgeons should be aware of these anatomical differences during scoliosis correction surgery
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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