2,285 research outputs found
A personal experience of performing a systematic literature review
This paper describes the personal experience of two novice reviewers in developing and conducting a systematic literature review (SLR) in the field of medical ultrasound. The review was performed as part of a PhD study by the first author, which required the researcher to critically review all relevant studies in their specific research area. The review was conducted using a formal, scientific process and highlighted 20 relevant papers. Among the lessons learnt, undertaking an SLR was a time-consuming process. The search produced 1,987 papers, and screening the search yield was facilitated by using a pre-defined protocol. Extraction of data from each study was standardised and generated a 1-page summary of the key findings and methodology to facilitate comparisons of the included studies. The Critical Appraisal Skills Programme (CASP) tool was used for quality assessment. In the critical appraisal process, it is essential that reviewers have good baseline knowledge in the research subject, a solid understanding of the fundamentals of a robust research study including potential bias in research. With the great amount of information that a critical appraisal produces, good information management was key throughout the review to ensure the process was explicit and replicable and so that reviewers could justify their decisions. The methods and processes detailed in this report, as well as its lessons, are relevant to an SLR for any research subject
The effect of patient positioning on the duration of venous reflux in Duplex ultrasound for venous insufficiency
Australian Cosmic Ray Modulation Research
Australian research into variations of the cosmic ray flux arriving at the
Earth has played a pivotal role for more than 50 years. The work has been
largely led by the groups from the University of Tasmania and the Australian
Antarctic Division and has involved the operation of neutron monitors and muon
telescopes from many sites. In this paper the achievements of the Australian
researchers are reviewed and future experiments are described. Particular
highlights include: the determination of cosmic ray modulation parameters; the
development of modelling techniques of Ground Level Enhancements; the
confirmation of the Tail-In and Loss-Cone Sidereal anisotropies; the Space Ship
Earth collaboration; and the Solar Cycle latitude survey.Comment: 47 pages, 37 figures, LaTeX, invited review, in press PASA 18(1).
HTML version available at http://www.atnf.csiro.au/pasa/18_1/duldig/paper
Immediate replacement of fishing with dairying by the earliest farmers of the NE Atlantic archipelagos
The appearance of farming, from its inception in the Near East around 12 000 years ago, finally reached the northwestern extremes of Europe by the fourth millennium BC or shortly thereafter. Various models have been invoked to explain the Neolithization of northern Europe; however, resolving these different scenarios has proved problematic due to poor faunal preservation and the lack of specificity achievable for commonly applied proxies. Here, we present new multi-proxy evidence, which qualitatively and quantitatively maps subsistence change in the northeast Atlantic archipelagos from the Late Mesolithic into the Neolithic and beyond. A model involving significant retention of hunter–gatherer–fisher influences was tested against one of the dominant adoptions of farming using a novel suite of lipid biomarkers, including dihydroxy fatty acids, ω-(o-alkylphenyl)alkanoic acids and stable carbon isotope signatures of individual fatty acids preserved in cooking vessels. These new findings, together with archaeozoological and human skeletal collagen bulk stable carbon isotope proxies, unequivocally confirm rejection of marine resources by early farmers coinciding with the adoption of intensive dairy farming. This pattern of Neolithization contrasts markedly to that occurring contemporaneously in the Baltic, suggesting that geographically distinct ecological and cultural influences dictated the evolution of subsistence practices at this critical phase of European prehistory
First light for avian embryos: eggshell thickness and pigmentation mediate variation in development and UV exposure in wild bird eggs
Article first published online: 29 JUL 20141. The avian embryo's development is influenced by both the amount and the wavelength of the light that passes through the eggshell. Commercial poultry breeders use light of specific wavelengths to accelerate embryonic growth, yet the effects of the variably patterned eggshells of wild bird species on light transmission and embryonic development remain largely unexplored. 2. Here, we provide the first comparative phylogenetic analysis of light transmission, through a diverse range of bird eggshells (74 British breeding species), in relation to the eggshell's thickness, permeability, pigment concentration and surface reflectance spectrum (colour). 3. The percentage of light transmitted through the eggshell was measured in the spectral range 250–700 nm. Our quantitative analyses confirm anecdotal reports that eggshells filter the light of the externally coloured shell. Specifically, we detected a positive relationship between surface eggshell reflectance (‘brightness’) and the percentage of light transmitted through the eggshell, and this relationship was strongest at wavelengths in the human-visible blue-green region of the spectra (c. 435 nm). 4. We show that less light passes through thicker eggshells with greater total pigment concentrations. By contrast, permeability (measured as water vapour conductance) did not covary significantly with light transmission. Eggs of closed-nesting species let more light pass through, compared with open nesters. 5. We postulate that greater light transmission is required to assist embryonic development under low light exposure. Importantly, this result provides an ecological explanation for the repeated evolution of immaculate, white- or pale-coloured eggshells in species nesting in enclosed spaces. 6. Finally, we detected correlative support for the solar radiation hypothesis, in that eggshells of bird species with a longer incubation period let significantly less of the potentially harmful, ultraviolet (UV) light pass through the eggshell. In summary, we demonstrate suites of avian eggshell properties, including eggshell structure and pigmentation, which are consistent with an evolutionary pressure to both enhance and protect embryonic development.Golo Maurer, Steven J. Portugal, Mark E. Hauber, Ivan Mikšík, Douglas G. D. Russell and Phillip Casse
Adaptive latitudinal variation in Common Blackbird Turdus merula nest characteristics
Nest construction is taxonomically widespread, yet our understanding of adaptive
intraspecific variation in nest design remains poor. Nest characteristics are
expected to vary adaptively in response to predictable variation in spring temperatures
over large spatial scales, yet such variation in nest design remains largely
overlooked, particularly amongst open-cup-nesting birds. Here, we systematically
examined the effects of latitudinal variation in spring temperatures and precipitation
on the morphology, volume, composition, and insulatory properties of
open-cup-nesting Common Blackbirds’ Turdus merula nests to test the hypothesis
that birds living in cooler environments at more northerly latitudes would build
better insulated nests than conspecifics living in warmer environments at more
southerly latitudes. As spring temperatures increased with decreasing latitude, the
external diameter of nests decreased. However, as nest wall thickness also
decreased, there was no variation in the diameter of the internal nest cups. Only
the mass of dry grasses within nests decreased with warmer temperatures at lower
latitudes. The insulatory properties of nests declined with warmer temperatures at
lower latitudes and nests containing greater amounts of dry grasses had higher insulatory
properties. The insulatory properties of nests decreased with warmer temperatures
at lower latitudes, via changes in morphology (wall thickness) and
composition (dry grasses). Meanwhile, spring precipitation did not vary with latitude,
and none of the nest characteristics varied with spring precipitation. This suggests
that Common Blackbirds nesting at higher latitudes were building nests with
thicker walls in order to counteract the cooler temperatures. We have provided evidence
that the nest construction behavior of open-cup-nesting birds systematically
varies in response to large-scale spatial variation in spring temperatures
Associations of the mechanical, anthropometric and gait contributors to the knee adduction moment during paediatric gait
The knee adduction moment (KAM) during gait has been proposed as an
indirect measure of dynamic knee joint loading and has been reported to be higher in obese
children [1, 2]. The KAM is primarily calculated from the resultant ground reaction force
(GRF) and the lever arm length, both of which can be manipulated through weight-loss or
medical interventions [1]. However, there is little data on the relationships between the
mechanical, anthropometric and gait contributors to the KAM during paediatric gait. The
objectives of the study were to examine the associations with the first (1st) and second (2nd)
peak KAM (pKAM) and: (1) centre of pressure (CoP), KAM lever arm length, vertical and
mediolateral ground reaction forces (GRF) and, (2) fat mass, height, step width, foot rotation,
knee rotation and walking velocity
Reliability of three foot models to examine paediatric gait
Background
A variety of multi-segmental foot models have been produced
to examine patterns of foot segmental movement
during gait cycle to identify biomechanical differences
between normal and pathological foot function[1-3].
The reliability of foot models to accurately describe
motion of the foot joints is dependent on the ability of
the examiner to repeatedly apply markers to specific
landmarks and the relevance of models’ segmental
descriptions to underlying anatomy. The aim of this
study was to test the reliability of segmental angles measured
by three published foot models during paediatric
gait.
Materials and methods
Sixteen children, aged 6 to 12 years old, were recruited
to the study. Marker sets for three foot models 3DFoot
[1], Oxford Foot Model (OFM)[2], and Kinfoot[3] were
applied to their right feet simultaneously which to the
authors knowledge, is the first direct comparison of the
three models during gait. Each foot model was assessed
for repeatability of maximal joint angle and range of
motion during the gait cycle between two testing occasions.
Absolute angular differences and standard error
of measurement (SEM) are reported.
Results
Repeatability of all maximal segmental angles and range
of motions were higher in 3DFoot compared to OFM
and Kinfoot (Table 1)
A NOVEL FUNCTIONAL BIOASSAY PREDICTS 90-DAY SURVIVAL IN PATIENTS WITH SEVERE ALCOHOLIC HEPATITIS
Low intensity strength training for ambulatory stroke patients
PURPOSE: To investigate feasibility and effectiveness of an individually-directed, group strength-training programme on knee muscle strength after stroke. METHOD: Ten volunteers (62 +/- 11 years, mean +/- SD), 6 - 12 months after first-ever unilateral stroke, walking independently with or without aids were recruited. Using an A1-B-A2 design, 3 sets of baseline measures were taken at 2 weekly intervals; volunteers then attended twice weekly sessions of low intensity progressive strengthening exercises and were assessed after each series of 8 sessions to a maximum of 24 sessions; post training, measures were repeated after 4 - 6 weeks. Measures included isometric and concentric knee extensor muscle strength and 10 m walking velocity. RESULTS: Strength of knee extensor muscles was improved after training (ANOVA, p < 0.05). On cessation of training, isometric strength increased by 58 +/- 19% and concentric strength at 30 degrees /s by 51 +/- 14%; walking velocity quickened from 0.47 +/- 0.06 m x s-1 to 0.57 +/- 0.08 m x s-1 (t = -3.31, p < 0.01). These gains were maintained 4 - 6 weeks after completion of training. CONCLUSIONS: These findings support the use of low intensity strength training after stroke and confirm published evidence. It was feasible for one therapist to deliver the training programmes for 4 - 6 participants at a time; an important feature when resources are limited
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