569 resultados para dominant
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Study Design Cross-sectional study. Objective To explore aspects of cervical musculoskeletal function in female office workers with neck pain. Summary of Background Data Evidence of physical characteristics that differentiate computer workers with and without neck pain is sparse. Patients with chronic neck pain demonstrate reduced motion and altered patterns of muscle control in the cervical flexor and upper trapezius (UT) muscles during specific tasks. Understanding cervical musculoskeletal function in office workers will better direct intervention and prevention strategies. Methods Measures included neck range of motion; superficial neck flexor muscle activity during a clinical test, the craniocerivcal flexion test; and a motor task, a unilateral muscle coordination task, to assess the activity of both the anterior and posterior neck muscles. Office workers with and without neck pain were formed into 3 groups based on their scores on the Neck Disability Index. Nonworking women without neck pain formed the control group. Surface electromyographic activity was recorded bilaterally from the sternocleidomastoid, anterior scalene (AS), cervical extensor (CE) and UT muscles. Results Workers with neck pain had reduced rotation range and increased activity of the superficial cervical flexors during the craniocervical flexion test. During the coordination task, workers with pain demonstrated greater activity in the CE muscles bilaterally. On completion of the task, the UT and dominant CE and AS muscles demonstrated an inability to relax in workers with pain. In general, there was a linear relationship between the workers’ self-reported levels of pain and disability and the movement and muscle changes. Conclusion These results are consistent with those found in other cervical musculoskeletal disorders and may represent an altered muscle recruitment strategy to stabilize the head and neck. An exercise program including motor reeducation may assist in the management of neck pain in office workers.
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Entomological surveillance and control are essential to the management of dengue fever (DF). Hence, understanding the spatial and temporal patterns of DF vectors, Aedes (Stegomyia) aegypti (L.) and Ae. (Stegomyia) albopictus (Skuse), is paramount. In the Philippines, resources are limited and entomological surveillance and control are generally commenced during epidemics, when transmission is difficult to control. Recent improvements in spatial epidemiological tools and methods offer opportunities to explore more efficient DF surveillance and control solutions: however, there are few examples in the literature from resource-poor settings. The objectives of this study were to: (i) explore spatial patterns of Aedes populations and (ii) predict areas of high and low vector density to inform DF control in San Jose village, Muntinlupa city, Philippines. Fortnightly, adult female Aedes mosquitoes were collected from 50 double-sticky ovitraps (SOs) located in San Jose village for the period June-November 2011. Spatial clustering analysis was performed to identify high and low density clusters of Ae. aegypti and Ae. albopictus mosquitoes. Spatial autocorrelation was assessed by examination of semivariograms, and ordinary kriging was undertaken to create a smoothed surface of predicted vector density in the study area. Our results show that both Ae. aegypti and Ae. albopictus were present in San Jose village during the study period. However, one Aedes species was dominant in a given geographic area at a time, suggesting differing habitat preferences and interspecies competition between vectors. Density maps provide information to direct entomological control activities and advocate the development of geographically enhanced surveillance and control systems to improve DF management in the Philippines.
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Tumor cells in ascites are a major source of disease recurrence in ovarian cancer patients. In an attempt to identify and profile the population of ascites cells obtained from ovarian cancer patients, a novel method was developed to separate adherent (AD) and non-adherent (NAD) cells in culture. Twenty-five patients were recruited to this study; 11 chemonaive (CN) and 14 chemoresistant (CR). AD cells from both CN and CR patients exhibited mesenchymal morphology with an antigen profile of mesenchymal stem cells and fibroblasts. Conversely, NAD cells had an epithelial morphology with enhanced expression of cancer antigen 125 (CA125), epithelial cell adhesion molecule (EpCAM) and cytokeratin 7. NAD cells developed infiltrating tumors and ascites within 12-14 weeks after intraperitoneal (i.p.) injections into nude mice, whereas AD cells remained non-tumorigenic for up to 20 weeks. Subsequent comparison of selective epithelial, mesenchymal and cancer stem cell (CSC) markers between AD and NAD populations of CN and CR patients demonstrated an enhanced trend in mRNA expression of E-cadherin, EpCAM, STAT3 and Oct4 in the NAD population of CR patients. A similar trend of enhanced mRNA expression of CD44, MMP9 and Oct4 was observed in the AD population of CR patients. Hence, using a novel purification method we demonstrate for the first time a distinct separation of ascites cells into epithelial tumorigenic and mesenchymal non-tumorigenic populations. We also demonstrate that cells from the ascites of CR patients are predominantly epithelial and show a trend towards increased mRNA expression of genes associated with CSCs, compared to cells isolated from the ascites of CN patients. As the tumor cells in the ascites of ovarian cancer patients play a dominant role in disease recurrence, a thorough understanding of the biology of the ascites microenvironment from CR and CN patients is essential for effective therapeutic interventions.
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Fibroblast growth factors (FGFs) are potent mitogens, morphogens, and inducers of angiogenesis, and FGF signaling governs the genesis of diverse tissues and organs from the earliest stages. With such fundamental embryonic and homeostatic roles, it follows that aberrant FGF signaling underlies a variety of diseases. Pathological modifications to FGF expression are known to cause salivary gland aplasia and autosomal dominant hypophosphatemic rickets, while mutations in FGF receptors (FGFRs) result in a range of skeletal dysplasias. Anomalous FGF signaling is also associated with cancer development and progression. Examples include the overexpression of FGF2 and FGF6 in prostate cancer, and FGF8 overexpression in breast and prostate cancers. Alterations in FGF signaling regulators also impact tumorigenesis, which is exemplified by the down-regulation of Sprouty 1, a negative regulator of FGF signaling, in prostate cancer. In addition, several FGFRs are mutated in human cancers (including FGFR2 in gastric cancer and FGFR3 in bladder cancer). We recently identified intriguing alterations in the FGF pathway in a novel model of bladder carcinoma that consists of a parental cell line (TSU-Pr1/T24) and two sublines with increasing metastatic potential (TSU-Pr1-B1 and TSU-Pr1-B2), which were derived successively through in vivo cycling. It was found that the increasingly metastatic sublines (TSU-Pr1-B1 and TSU-Pr1-B2) had undergone a mesenchymal to epithelial transition. FGFR2IIIc expression, which is normally expressed in mesenchymal cells, was increased in the epithelial-like TSU-Pr1-B1 and TSU-Pr1-B2 sublines and FGFR2 knock-down was associated with the reversion of cells from an epithelial to a mesenchymal phenotype. These observations suggest that modified FGF pathway signaling should be considered when studying other cancer types.
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WA’s experience, as portrayed in this volume, not only highlights the changeable nature of the mining industry, the volatility of global commodity markets and the impact of global capital on people and place, it also draws into question the promise of lasting value derived from resource development as currently practiced. It is in this context that Chapter 18 revisits WA's resource boom and assesses the sustainability of resource-led development in the state, to arrive at an answer to the question of ‘curse or cure?’. Opening up the discourse beyond the dominant developmentalist narrative invites discussion on new perspectives of economic sustainability that include well-being, equity and the protection of people, culture and place.
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The paradigm that mangroves are critical for sustaining production in coastal fisheries is widely accepted, but empirical evidence has been tenuous. This study showed that links between mangrove extent and coastal fisheries production could be detected for some species at a broad regional scale (1000s of kilometres) on the east coast of Queensland, Australia. The relationships between catch-per-unit-effort for different commercially caught species in four fisheries (trawl, line, net and pot fisheries) and mangrove characteristics, estimated from Landsat images were examined using multiple regression analyses. The species were categorised into three groups based on information on their life history characteristics, namely mangrove-related species (banana prawns Penaeus merguiensis, mud crabs Scylla serrata and barramundi Lates calcarifer), estuarine species (tiger prawns Penaeus esculentus and Penaeus semisulcatus, blue swimmer crabs Portunus pelagicus and blue threadfin Eleutheronema tetradactylum) and offshore species (coral trout Plectropomus spp.). For the mangrove-related species, mangrove characteristics such as area and perimeter accounted for most of the variation in the model; for the non-mangrove estuarine species, latitude was the dominant parameter but some mangrove characteristics (e.g. mangrove perimeter) also made significant contributions to the models. In contrast, for the offshore species, latitude was the dominant variable, with no contribution from mangrove characteristics. This study also identified that finer scale spatial data for the fisheries, to enable catch information to be attributed to a particular catchment, would help to improve our understanding of relationships between mangroves and fisheries production.
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Even when no baseline data are available, the impacts of 150 years of livestock grazing on natural grasslands can be assessed using a combined approach of grazing manipulation and regional-scale assessment of the flora. Here, we demonstrate the efficacy of this method across 18 sites in the semidesert Mitchell grasslands of northeastern Australia. Fifteen-year-old exclosures (ungrazed and macropod grazed) revealed that the dominant perennial grasses in the genus Astrebla do not respond negatively to grazing disturbance typical of commercial pastoralism. Neutral, positive, intermediate, and negative responses to grazing disturbance were recorded amongst plant species with no single life-form group associated with any response type. Only one exotic species, Cenchrus ciliaris, was recorded at low frequency. The strongest negative response was from a native annual grass, Chionachne hubbardiana, an example of a species that is highly sensitive to grazing disturbance. Herbarium records revealed only scant evidence that species with a negative response to grazing have declined through the period of commercial pastoralism. A regional analysis identified 14 from a total of 433 plant species in the regional flora that may be rare and potentially threatened by grazing disturbance. However, a targeted survey precluded grazing as a cause of decline for seven of these based on low palatability and positive responses to grazing and other disturbance. Our findings suggest that livestock grazing of semidesert grasslands with a short evolutionary history of ungulate grazing has altered plant composition, but has not caused declines in the dominant perennial grasses or in species richness as predicted by the preceding literature. The biggest impact of commercial pastoralism is the spread of woody leguminous trees that can transform grassland to thorny shrubland. The conservation of plant biodiversity is largely compatible with commercial pastoralism provided these woody weeds are controlled, but reserves strategically positioned within water remote areas are necessary to protect grazing-sensitive species. This study demonstrates that a combination of experimental studies and regional surveys can be used to understand anthropogenic impacts on natural ecosystems where reference habitat is not available.
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Intense resistance exercise causes mechanical loading of skeletal muscle, followed by muscle adaptation. Chemotactic factors likely play an important role in these processes. Purpose We investigated the time course of changes in the expression and tissue localization of several key chemotactic factors in skeletal muscle during the early phase of recovery following resistance exercise. Methods Muscle biopsy samples were obtained from vastus lateralis of eight untrained men (22+-0.5 yrs) before and 2, 4 and 24 h after three sets of leg press, squat and leg extension at 80% 1 RM. Results Monocyte chemotactic protein-1 (95×), interleukin-8 (2,300×), IL-6 (317×), urokinase-type plasminogen activator (15×), vascular endothelial growth factor (2×) and fractalkine (2.5×) mRNA was significantly elevated 2 h post-exercise. Interleukin-8 (38×) and interleukin-6 (58×) protein was also significantly elevated 2 h post-exercise, while monocyte chemotactic protein-1 protein was significantly elevated at 2 h (22×) and 4 h (21×) post-exercise. Monocyte chemotactic protein-1 and interleukin-8 were expressed by cells residing in the interstitial space between muscle fibers and, in some cases, were co-localized with CD68+ macrophages, PAX7+ satellite cells and blood vessels. However, the patterns of staining were inconclusive and not consistent. Conclusion In conclusion, resistance exercise stimulated a marked increase in the mRNA and protein expression of various chemotactic factors in skeletal muscle. Myofibers were not the dominant source of these factors. These findings suggest that chemotactic factors regulate remodeling/adaptation of skeletal muscle during the early phase of recovery following resistance exercise.
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The wind loading on most structural elements is made up of both an external and internal pressure. Internal pressures are also important for the design of naturally ventilated buildings. The internal pressure is the interaction between the external pressure propagating through the building envelope and any internal plant causing building pressurization. Although the external pressure field can be well defined through a series of wind tunnel tests, modeling complexities makes accurate prediction of the internal pressure difficult. For commercial testing for the determination of design cladding pressures, an internal pressure coefficient is generally assumed from wind loading standards. Several theories regarding the propagation of internal pressures through single and multiple dominant openings have been proposed for small and large flexible buildings (Harris (1990), Holmes, (1979), Liu & Saathoff (1981 ), Vickery (1986, 1994), Vickery & Bloxham (1992), Vickery & Georgiou (1991))...
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The possibility of effective control of morphology and electrical properties of self-organized graphene structures on plasma-exposed Si surfaces is demonstrated. The structures are vertically standing nanosheets and can be grown without any catalyst and any external heating upon direct contact with high-density inductively coupled plasmas at surface temperatures not exceeding 673–723 K. Study of nucleation and growth dynamics revealed the possibility to switch-over between the two most common (turnstile- and maze-like) morphologies on the same substrates by a simple change of the plasma parameters. This change leads to the continuous or discontinuous native oxide layer that supports self-organized patterns of small carbon nanoparticles on which the structures nucleate. It is shown that by tailoring the nanoparticle arrangement one can create various three-dimensional architectures and networks of graphene nanosheet structures. We also demonstrate effective control of the degree of graphitization of the graphene nanosheet structures from the initial through the final growth stages. This makes it possible to tune the electrical resistivity properties of the produced three-dimensional patterns/networks from strongly dielectric to semiconducting. Our results contribute to enabling direct integration of graphene structures into presently dominant Si-based nanofabrication platform for next-generation nanoelectronic, sensor, biomedical, and optoelectronic components and nanodevices.
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The charge and chemical composition of ambient particles in an urban environment were determined using a Neutral Particle and Air Ion Spectrometer and an Aerodyne compact Time-Of-Flight Aerosol Mass Spectrometer. Particle formation and growth events were observed on 20 of the 36 days of sampling, with eight of these events classified as strong. During these events, peaks in the concentration of intermediate and large ions were followed by peaks in the concentration of ammonium and sulphate, which were not observed in the organic fraction. Comparison of days with and without particle formation events revealed that ammonium and sulphate were the dominant species on particle formation days while high concentrations of biomass burning OA inhibited particle growth. Analyses of the degree of particle neutralisation lead us to conclude that an excess of ammonium enabled particle formation and growth. In addition, the large ion concentration increased sharply during particle growth, suggesting that during nucleation the neutral gaseous species ammonia and sulphuric acid react to form ammonium and sulphate ions. Overall, we conclude that the mechanism of particle formation and growth involved ammonia and sulphuric acid, with limited input from organics.
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Experimentally observed optical and photoelectrical spectra of nitrogen-contaminated (unintentionally doped) nano-crystalline CVD diamond films are simulated using semi-empirical adiabatic General Skettrup Model (GSM), which presumes dominant contributions of defect states from sp 3-coordinated intra-granular carbon atoms to intra-band single electron spectrum N(E) of the material. This picture disagrees with a common viewpoint that the N(E) spectrum of the gap states in diamond powders and polycrystalline CVD films mainly originates from π and π* bonds of sp2-coordinated carbon atoms, which are distributed nearly uniformly over outer surfaces and/or interfaces of the diamond grains. The GSM predicts as well strong effect of granular morphology on the density of intra-band defect states in polycrystalline diamonds.
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The plasma-assisted RF sputtering deposition of a biocompatible, functionally graded calcium phosphate bioceramic on a Ti6A14 V orthopedic alloy is reported. The chemical composition and presence of hydroxyapatite (HA), CaTiO3, and CaO mineral phases can be effectively controlled by the process parameters. At higher DC biases, the ratio [Ca]/[P] and the amount of CaO increase, whereas the HA content decreases. Optical emission spectroscopy suggests that CaO+ is the dominant species that responds to negative DC bias and controls calcium content. Biocompatibility tests in simulated body fluid confirm a positive biomimetic response evidenced by in-growth of an apatite layer after 24 h of immersion.
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Experimental investigation of functionally graded calcium phosphate-based bio-active films on Ti-6A1-4V orthopaedic alloy prepared in an RF magnetron sputtering plasma reactor is reported. The technique involves concurrent sputtering of Hydroxyapatite (HA) and Ti targets, which results in remarkably enhanced adhesion of the film to the substrate and stability of the interface. The films have been characterized using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The XPS data show that the films are composed of O, Ca, P and Ti, and reveal the formation of O=P groups and hybridization of O-Ca-P. The XRD pattern shows that the Ca-P thin films are of crystalline calcium oxide phosphate (4CaO·P2O5) with preferred orientation varying with processing parameters. High-resolution optical emission spectra show that the emission of CaO is dominant. The CaO, PO and CaPO species are strongly influenced by deposition conditions. The introduction of Ti element during deposition provides a stable interface between bio-inert substrates Ti-6A1-4V and bioactive HA coating. In-vitro cell culturing tests suggest excellent biocompatibility of the Ca-P-Ti films.
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Informed broadly by the theory of planned behaviour, this study used qualitative methodology to understand Australian adults' sun-protective decisions. Forty-two adults participated in focus groups where they discussed behavioural (advantages and disadvantages), normative (important referents), and control (barriers and facilitators) beliefs, as well as potential social influences and images of tanned and non-tanned people. Responses were analysed using the consensual qualitative research approach to determine the dominant themes. Themes of fashion and comfort were prominent, the important role of friends and family in sun safe decision-making was highlighted, as was the availability of sun-protective measures (e.g., in an accessible place or in the environment). Additional themes included the need to model sound sun-protective behaviours to (current and future) children, the emphasis on personal choice and personal responsibility to be sun safe, and the influence of Australian identity and culture on tanning and socially acceptable forms of sun protection. These beliefs can be used to inform interventions and public health campaigns targeting sun safety among Australians, a population with the highest skin cancer incidence in the world.