390 resultados para minimal occlusive volume technique


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3D registration of brain MRI data is vital for many medical imaging applications. However, purely intensitybased approaches for inter-subject matching of brain structure are generally inaccurate in cortical regions, due to the highly complex network of sulci and gyri, which vary widely across subjects. Here we combine a surfacebased cortical registration with a 3D fluid one for the first time, enabling precise matching of cortical folds, but allowing large deformations in the enclosed brain volume, which guarantee diffeomorphisms. This greatly improves the matching of anatomy in cortical areas. The cortices are segmented and registered with the software Freesurfer. The deformation field is initially extended to the full 3D brain volume using a 3D harmonic mapping that preserves the matching between cortical surfaces. Finally, these deformation fields are used to initialize a 3D Riemannian fluid registration algorithm, that improves the alignment of subcortical brain regions. We validate this method on an MRI dataset from 92 healthy adult twins. Results are compared to those based on volumetric registration without surface constraints; the resulting mean templates resolve consistent anatomical features both subcortically and at the cortex, suggesting that the approach is well-suited for cross-subject integration of functional and anatomic data.

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The caudate is a subcortical brain structure implicated in many common neurological and psychiatric disorders. To identify specific genes associated with variations in caudate volume, structural magnetic resonance imaging and genome-wide genotypes were acquired from two large cohorts, the Alzheimer's Disease NeuroImaging Initiative (ADNI; N=734) and the Brisbane Adolescent/Young Adult Longitudinal Twin Study (BLTS; N=464). In a preliminary analysis of heritability, around 90% of the variation in caudate volume was due to genetic factors. We then conducted genome-wide association to find common variants that contribute to this relatively high heritability. Replicated genetic association was found for the right caudate volume at single-nucleotide polymorphism rs163030 in the ADNI discovery sample (P=2.36 × 10 -6) and in the BLTS replication sample (P=0.012). This genetic variation accounted for 2.79 and 1.61% of the trait variance, respectively. The peak of association was found in and around two genes, WDR41 and PDE8B, involved in dopamine signaling and development. In addition, a previously identified mutation in PDE8B causes a rare autosomal-dominant type of striatal degeneration. Searching across both samples offers a rigorous way to screen for genes consistently influencing brain structure at different stages of life. Variants identified here may be relevant to common disorders affecting the caudate.

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As conservatoire-style dance teaching has traditionally utilised a hierarchical approach through which the student must conform to the ideal requirements of the conventional technique, current discourse is beginning to question how dance training can develop technical acuity without stifling students' ability to engage creatively. In recent years, there has been growing interest in the field of somatics and its relationship to tertiary dance training due to the understanding that this approach supports creative autonomy by radically repositioning the student's relationship to embodied learning, skill acquisition, enquiry and performance. This research addresses an observable disjuncture between the skills of dancers graduating from tertiary training and Australian dance industry needs, which increasingly demand the co-creative input of the dancer in choreographic practice. Drawing from Action Research, this paper will discuss a project which introduces somatic learning approaches, primarily from Feldenkrais Method and Hanna Somatics, to first-year dance students in their transition into tertiary education. This paper acknowledges previous research undertaken, most specifically the Somdance Manual by the University of Western Sydney, while directing focus to the first-year student transition from private dance studio training into the pre-professional arena.

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Skin temperature is an important physiological measure that can reflect the presence of illness and injury as well as provide insight into the localised interactions between the body and the environment. The aim of this systematic review was to analyse the agreement between conductive and infrared means of assessing skin temperature which are commonly employed in in clinical, occupational, sports medicine, public health and research settings. Full-text eligibility was determined independently by two reviewers. Studies meeting the following criteria were included in the review: 1) the literature was written in English, 2) participants were human (in vivo), 3) skin surface temperature was assessed at the same site, 4) with at least two commercially available devices employed—one conductive and one infrared—and 5) had skin temperature data reported in the study. A computerised search of four electronic databases, using a combination of 21 keywords, and citation tracking was performed in January 2015. A total of 8,602 were returned. Methodology quality was assessed by 2 authors independently, using the Cochrane risk of bias tool. A total of 16 articles (n = 245) met the inclusion criteria. Devices are classified to be in agreement if they met the clinically meaningful recommendations of mean differences within ±0.5 °C and limits of agreement of ±1.0 °C. Twelve of the included studies found mean differences greater than ±0.5 °C between conductive and infrared devices. In the presence of external stimulus (e.g. exercise and/or heat) five studies foundexacerbated measurement differences between conductive and infrared devices. This is the first review that has attempted to investigate presence of any systemic bias between infrared and conductive measures by collectively evaluating the current evidence base. There was also a consistently high risk of bias across the studies, in terms of sample size, random sequence generation, allocation concealment, blinding and incomplete outcome data. This systematic review questions the suitability of using infrared cameras in stable, resting, laboratory conditions. Furthermore, both infrared cameras and thermometers in the presence of sweat and environmental heat demonstrate poor agreement when compared to conductive devices. These findings have implications for clinical, occupational, public health, sports science and research fields.

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This volume continues the story of football in Marvellous Melbourne during the 1880s. At this time the VFA continued to expand as Melbourne’s boom continued apace. In 1886 Port Melbourne, Prahran, St Kilda, Footscray and South Williamstown joined the competition, and the Ballarat clubs Ballarat, Ballarat Imperial and South Ballarat were also contending for the VFA premiership. In 1886 matches were divided into four quarters, goal umpires waved two flags to announce a goal, and time clocks and bells were employed to mark the end of quarters. Victoria also played inter-colonial matches against New South Wales, Tasmania and South Australia. VFA secretary T.S. Marshall was at the forefront of fighting the game’s turn towards professionalism, but although it was illegal to pay players, the practice continued. The period 1886 to 1890 also set the stage for the eventual formation of the Victorian Football League, for by the end of the 1880s the Victorian Football Association had become in effect a two-tier competition. The most popular clubs in the VFA, South Melbourne, Geelong, Carlton and Essendon collected the lion’s share of the gate money, which they used to build their wealth and entrench their position as the dominant Victorian teams. The lower tier clubs had to make do with paltry gate money and season fixtures that advantaged the strong clubs. In these fixtures the strong clubs elected to play each other first to increase their gate money, and only deemed to play the poorer clubs at the start of the season. This led to an increasing divide between the VFA’s rich and poor, and by 1890 South Williamstown and Prahran merged with Williamstown and St Kilda respectively, University dropped out of senior ranks, and the Ballarat clubs were excluded from competing for the VFA premiership, which left 12 senior clubs until Collingwood’s emergence in 1892. At this time, no team was as powerful as South Melbourne, which experienced the greatest success in the club’s VFA and VFL history when it collected triple premiership crowns in 1888, 1889, and 1890. South Melbourne was a most ambitious club and spearheaded the move towards professionalism, although this could not be made public. The fine teams it produced at this time contained some of the greatest players of the era, such as Peter Burns, “Sonny” Elms and “Dinny” McKay, and it looked after players with health insurance, jobs, inter-colonial trips, and other incentives. Geelong’s premiership in 1886 was perhaps its greatest triumph, but this success was followed by a premiership drought that would last for 39 years. Carlton remained one of Victorian football’s power clubs, and after securing the premiership in 1887 continued to compete for top honours. As always, the game became ever more popular and world record crowds of over 30,000 attended matches between South Melbourne, Carlton, Geelong and Essendon.

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It is well known that the neutralisation of Bayer liquor with seawater causes the precipitation of stable alkaline products and a reduction in pH and dissolved metal concentrations in the effluent. However, there is limited information available on solution chemistry effects on the stability and reaction kinetics of these precipitates. This investigation shows the influence of reactive species (magnesium and calcium) in seawater on precipitate stabilities and volumetric efficiencies during the neutralisation of bauxite refinery residues. Correlations between synthetic seawater solutions and real samples of seawater (filtered seawater, nanofiltered seawater and reverse osmosis brine) have been made. These investigations have been used to confirm that alternative seawater sources can be used to increase the productivity potential of the neutralisation process with minimal implications on the composition and stability of precipitates formed. The volume efficiency of the neutralisation process using synthetic analogues has been shown to be almost directly proportional with the concentration of magnesium. This was further confirmed in the nanofiltered seawater and reverse osmosis brine that showed increases in the efficiency of neutralisation by factors of 3 and 2 compared to seawater, which corresponds with relatively the same increase in the concentration of magnesium in these alternative seawater sources. An assessment of the chemical stability of the precipitates, volumetric efficiency, and discharge water quality have been determined using numerous techniques that include pH, conductivity, inductively coupled plasma optical emission spectroscopy, infrared spectroscopy, thermogravimetric analysis coupled to mass spectrometry and X-ray diffraction. Correlations between synthetic solution compositions and alternative seawater sources have been used to determine if alternative seawater sources are potential substitutes for seawater based on improvements in productivity, implementation costs, savings to operations and environmental benefits.

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Law is narration: it is narrative, narrator and the narrated. As a narrative, the law is constituted by a constellation of texts – from official sources such as statutes, treaties and cases, to private arrangements such as commercial contracts, deeds and parenting plans. All are a collection of stories: cases are narrative contests of facts and rights; statutes are recitations of the substantive and procedural bases for social, economic and political interactions; private agreements are plots for future relationships, whether personal or professional. As a narrator, law speaks in the language of modern liberalism. It describes its world in abstractions rather than in concrete experience, universal principles rather than individual subjectivity. It casts people into ‘parties’ to legal relationships; structures human interactions into ‘issues’ or ‘problems’; and tells individual stories within larger narrative arcs such as ‘the rule of law’ and ‘the interests of justice’. As the narrated, the law is a character in its own story. The scholarship of law, for example, is a type of story-telling with law as its central character. For positivists, still the dominant group in the legal genre, law is a closed system of formal rules with an “immanent rationality” and its own “structure, substantive content, procedure and tradition,” dedicated to finality of judgment. For scholars inspired by the interpretative tradition in the humanities, law is a more ambivalent character, susceptible to influences from outside its realm and masking a hidden ideological agenda under its cloak of universality and neutrality. For social scientists, law is a protagonist on a wider social stage, impacting on society, the economy and the polity is often surprising ways.

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A novel, highly selective resonance light scattering (RLS) method was researched and developed for the analysis of phenol in different types of industrial water. An important aspect of the method involved the use of graphene quantum dots (GQDs), which were initially obtained from the pyrolysis of citric acid dissolved in aqueous solutions. The GQDs in the presence of horseradish peroxidase (HRP) and H2O2 were found to react quantitatively with phenol such that the RLS spectral band (310 nm) was quantitatively enhanced as a consequence of the interaction between the GQDs and the quinone formed in the above reaction. It was demonstrated that the novel analytical method had better selectivity and sensitivity for the determination of phenol in water as compared to other analytical methods found in the literature. Thus, trace amounts of phenol were detected over the linear ranges of 6.00×10−8–2.16×10−6 M and 2.40×10−6–2.88×10−5 M with a detection limit of 2.20×10−8 M. In addition, three different spiked waste water samples and two untreated lake water samples were analysed for phenol. Satisfactory results were obtained with the use of the novel, sensitive and rapid RLS method.

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Poisoned protein baits comprise a recognized method for controlling tephritid fruit flies in the form of a ‘lure-and-kill’ technique. However, little is known about how a fly's internal protein and carbohydrate levels (i.e. nutritional status) might influence the efficacy of this control. In the present study, the relationships between the internal levels of protein (as measured by total body nitrogen) and carbohydrate (as measured by total body carbon) of the fruit fly Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) are investigated, as well as its foraging behaviours in response to protein, fruit and cue-lure (a male-specific attractant) baits. Small cage behavioural experiments are conducted using flies from cultures of different nutritional status and wild flies sampled from the field during the fruiting cycle of a guava crop. For female flies, increasing total body nitrogen is correlated with decreased protein foraging and increased oviposition activity; increasing total body carbon levels generate the same behavioural changes except that the oviposition response is not significant. For males, there are no significant correlations between changes in total body nitrogen and total body carbon and protein or cue-lure foraging. For wild flies from the guava orchard, almost all of them are sexually mature when entering the crop and, over the entire season, total body nitrogen and total body carbon levels are such that protein hunger is unlikely for most flies. The results infer strongly that the requirements of wild, sexually mature flies for protein are minimal and that flies can readily gain sufficient nutrients from wild sources for their physiological needs. The results offer a mechanistic explanation for the poor response of male and mature female fruit flies to protein bait spray.

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Pattern recognition is a promising approach for the identification of structural damage using measured dynamic data. Much of the research on pattern recognition has employed artificial neural networks (ANNs) and genetic algorithms as systematic ways of matching pattern features. The selection of a damage-sensitive and noise-insensitive pattern feature is important for all structural damage identification methods. Accordingly, a neural networks-based damage detection method using frequency response function (FRF) data is presented in this paper. This method can effectively consider uncertainties of measured data from which training patterns are generated. The proposed method reduces the dimension of the initial FRF data and transforms it into new damage indices and employs an ANN method for the actual damage localization and quantification using recognized damage patterns from the algorithm. In civil engineering applications, the measurement of dynamic response under field conditions always contains noise components from environmental factors. In order to evaluate the performance of the proposed strategy with noise polluted data, noise contaminated measurements are also introduced to the proposed algorithm. ANNs with optimal architecture give minimum training and testing errors and provide precise damage detection results. In order to maximize damage detection results, the optimal architecture of ANN is identified by defining the number of hidden layers and the number of neurons per hidden layer by a trial and error method. In real testing, the number of measurement points and the measurement locations to obtain the structure response are critical for damage detection. Therefore, optimal sensor placement to improve damage identification is also investigated herein. A finite element model of a two storey framed structure is used to train the neural network. It shows accurate performance and gives low error with simulated and noise-contaminated data for single and multiple damage cases. As a result, the proposed method can be used for structural health monitoring and damage detection, particularly for cases where the measurement data is very large. Furthermore, it is suggested that an optimal ANN architecture can detect damage occurrence with good accuracy and can provide damage quantification with reasonable accuracy under varying levels of damage.

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Aging is associated with reductions in hippocampal volume that are accelerated by Alzheimer's disease and vascular risk factors. Our genome-wide association study (GWAS) of dementia-free persons (n = 9,232) identified 46 SNPs at four loci with P values of <4.0 × 10 -7. In two additional samples (n = 2,318), associations were replicated at 12q14 within MSRB3-WIF1 (discovery and replication; rs17178006; P = 5.3 × 10 -11) and at 12q24 near HRK-FBXW8 (rs7294919; P = 2.9 × 10 -11). Remaining associations included one SNP at 2q24 within DPP4 (rs6741949; P = 2.9 × 10 -7) and nine SNPs at 9p33 within ASTN2 (rs7852872; P = 1.0 × 10 -7); along with the chromosome 12 associations, these loci were also associated with hippocampal volume (P < 0.05) in a third younger, more heterogeneous sample (n = 7,794). The SNP in ASTN2 also showed suggestive association with decline in cognition in a largely independent sample (n = 1,563). These associations implicate genes related to apoptosis (HRK), development (WIF1), oxidative stress (MSR3B), ubiquitination (FBXW8) and neuronal migration (ASTN2), as well as enzymes targeted by new diabetes medications (DPP4), indicating new genetic influences on hippocampal size and possibly the risk of cognitive decline and dementia.

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Aims: To establish a model to measure bidirectional flow of water from a glucose oral rehydration solution (G-ORS) and a newly developed rice-based oral rehydration solution (R-ORS) using a dual isotope tracer technique in a rat perfusion model. To measure net water, sodium and potassium absorption from the ORS. Methods: In viva steady-state perfusion studies were carried out in normal and secreting (induced by cholera toxin) rat small intestine (n = 11 in each group). To determine bidirectional flow of water from the ORS the animals were initially labelled with tritium, and deuterium was added to the perfusion solution. Sequential perfusate and blood samples were collected after attainment of steady-state conditions and analysed for water and electrolyte content. Results: There was a significant increase in net water absorption from the R-ORS compared to the G-ORS in both the normal (P < 0.02) and secreting intestine (P < 0.05). Water efflux was significantly reduced in the R-ORS group compared to the G-ORS group in both the normal (P < 0.01) and the secreting intestine (P < 0.01). There was an increase in sodium absorption in the R-ORS group compared to the G-ORS. The G-ORS produced a significantly greater blood glucose level at 75 min compared to the R-ORS (P < 0.03) in the secreting intestine. Conclusions: This study demonstrates the improved water absorption from a rice-based ORS in both the normal and secreting intestine. Evidence that the absorption of water may be influenced by the osmolality of the ORS was also demonstrated.

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Background: The use of large-volume electrolyte balanced solutions as preparation for colonoscopy often results in poor patient compliance and acceptance. The tolerance, safety, and efficacy of high-versus low volume colon-cleansing methods as preparation for colonoscopy in children were compared by randomized operator-blinded trial. Methods: Twenty-nine children ages 3.6-14.6 years had either high-volume nasogastric balanced polyethylene glycol electrolyte lavage (20 ml/kg/h) until the effluent was clear (n = 15), or two oral doses of sodium phosphate solution (22.5-45 ml) separated by oral fluid intake (n = 14). Results: Both preparations were equally effective. The low-volume preparation was better tolerated and caused less discomfort that the high-volume preparation, judging by serial nurse observations. The incidence of abdominal symptoms, diarrhea, sleep disturbance, and vomiting was not significantly different between the two groups. Both groups had a small reduction in mean hematocrit and serum calcium levels. The sodium phosphate preparation caused increases in mean serum sodium concentrations from 140 to 145 mmol/L and serum phosphate concentrations from 1.41 to 2.53 mmol/L. Ten hours after the commencement of the preanesthetic fast, these concentrations had returned to normal. Conclusions: There are advantages in terms of tolerance, discomfort, and case of administration with acceptable colonic cleansing with the use of the less-invasive oral sodium phosphate low-volume colon-cleansing preparation in children. Safe use requires ensuring an adequate oral fluid intake during the preparation time and avoidance of use in patients with renal insufficiency.

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The acceptance of broadband ultrasound attenuation (BUA) for the assessment of osteoporosis suffers from a limited understanding of both ultrasound wave propagation through cancellous bone and its exact dependence upon the material and structural properties. It has recently been proposed that ultrasound wave propagation in cancellous bone may be described by a concept of parallel sonic rays; the transit time of each ray defined by the proportion of bone and marrow propagated. A Transit Time Spectrum (TTS) describes the proportion of sonic rays having a particular transit time, effectively describing the lateral inhomogeneity of transit times over the surface aperture of the receive ultrasound transducer. The aim of this study was to test the hypothesis that the solid volume fraction (SVF) of simplified bone:marrow replica models may be reliably estimated from the corresponding ultrasound transit time spectrum. Transit time spectra were derived via digital deconvolution of the experimentally measured input and output ultrasonic signals, and compared to predicted TTS based on the parallel sonic ray concept, demonstrating agreement in both position and amplitude of spectral peaks. Solid volume fraction was calculated from the TTS; agreement between true (geometric calculation) with predicted (computer simulation) and experimentally-derived values were R2=99.9% and R2=97.3% respectively. It is therefore envisaged that ultrasound transit time spectroscopy (UTTS) offers the potential to reliably estimate bone mineral density and hence the established T-score parameter for clinical osteoporosis assessment.

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A new technique called the reef resource inventory (RRI) was developed to map the distribution and abundance of benthos and substratum on reefs. The rapid field sampling technique uses divers to visually estimate the percentage cover of categories of benthos and substratum along 2x20 in plotless strip-transects positioned randomly over the tops, and systematically along the edge of reefs. The purpose of this study was to compare the relative sampling accuracy of the RRI against the line intercept transect technique (LIT), an international standard for sampling reef benthos and substratum. Analysis of paired sampling with LIT and RRI at 51 sites indicated sampling accuracy was not different (P > 0.05) for 8 of the 12 benthos and substratum categories used in the study. Significant differences were attributed to small-scale patchiness and cryptic coloration of some benthos; effects associated with sampling a sparsely distributed animal along a line versus an area; difficulties in discriminating some of the benthos and substratum categories; and differences due to visual acuity since LIT measurements were taken by divers close to the seabed whereas RRI measurements were taken by divers higher in the water column. The relative cost efficiency of the RRI technique was at least three times that of LIT for all benthos and substratum categories and as much as 10 times higher for two categories. These results suggest that the RRI can be used to obtain reliable and accurate estimates of relative abundance of broad categories of reef benthos and substratum.