946 resultados para critical electrolyte concentration


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of this study was to investigate the expression of GABAB receptors, a subclass of receptors to the inhibitory neurotransmitter gamma-aminobutyric acid (GABAB), in human aortic smooth muscle cells (HASMCs), and to explore if altering receptor activation modified intracellular Ca(2+) concentration ([Ca(2+)]i) of HASMCs. Real-time PCR, western blots and immunofluorescence were used to determine the expression of GABABR1 and GABABR2 in cultured HASMCs. Immunohistochemistry was used to localize the two subunits in human left anterior descending artery (LAD). The effects of the GABAB receptor agonist baclofen on [Ca(2+)]i in cultured HASMCs were demonstrated using fluo-3. Both GABABR1 and GABABR2 mRNA and protein were identified in cultured HASMCs and antibody staining was also localized to smooth muscle cells of human LAD. 100 μM baclofen caused a transient increase of [Ca(2+)]i in cultured HASMCs regardless of whether Ca(2+) was added to the medium, and the effects were inhibited by pre-treatment with CGP46381 (selective GABAB receptor antagonist), pertussis toxin (a Gi/o protein inhibitor), and U73122 (a phospholipase C blocker). GABAB receptors are expressed in HASMCs and regulate the [Ca(2+)]i via a Gi/o-coupled receptor pathway and a phospholipase C activation pathway

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper investigates how Enterprise Architecture (EA) evolves due to emerging trends. It specifically explores how EA integrates the Service-oriented Architecture (SOA). Archer’s Morphogenetic theory is used as an analytical approach to distinguish the architectural conditions under which SOA is introduced, to study the relationships between these conditions and SOA introduction, and to reflect on EA evolution (elaborations) that then take place. The paper focuses on reasons for why EA evolution could take place, or not and what architectural changes could happen due to SOA integration. The research builds on sound theoretical foundations to discuss EA evolution in a field that often lacks a solid theoretical groundwork. Specifically, it proposes that critical realism, using the morphogenetic theory, can provide a useful theoretical foundation to study enterprise architecture (EA) evolution. The initial results of a literature review (a-priori model) were extended using explorative interviews. The findings of this study are threefold. First, there are five different levels of EA-SOA integration outcomes. Second, a mature EA, flexible and well-defined EA framework and comprehensive objectives of EA improve the integration outcomes. Third, the analytical separation using Archer’s theory is helpful in order to understand how these different integration outcomes are generated.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The wave of democratisation across Europe, Africa, Asia and Latin America in the early 1990s triggered an increase in donor funding to media assistance initiatives, primarily within good governance policy frameworks. However, few media assistance projects have managed to effectively evaluate the impacts of their work. This thesis explores how the impacts of Australian media assistance on social change and governance can be most effectively evaluated and understood. The findings of this research suggest the importance of early investment in participatory planning of evaluation designs, which are then periodically revisited. These evaluation designs should be based on a theoretically sound link between models of change, evaluative questions and methods.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Office building retrofit is a sector being highlighted in Australia because of the mature office building market characterised by a large proportion of ageing properties. The increasing number of office building retrofit projects strengthens the need for waste management. Retrofit projects possess unique characteristics in comparison to traditional demolition and new builds such as partial operation of buildings, constrained site spaces and limited access to as-build information. Waste management activities in retrofit projects can be influenced by issues that are different from traditional construction and demolition projects. However, previous research on building retrofit projects has not provided an understanding of the critical issues affecting waste management. This research identifies the critical factors which influence the management of waste in office building retrofit projects through a literature study and a questionnaire survey to industry practitioners. Statistical analysis on a range of potential waste issues reveals the critical factors, as agreed upon by survey respondents in consideration of their different professional responsibilities and work natures. The factors are grouped into five dimensions, comprising industry culture, organisational support and incentive, existing building information, design, and project delivery process. The discussions of the dimensions indicate that the waste management factors of office building retrofit projects are further intensified compared to those for general demolition and construction because retrofit projects involve existing buildings which are partially operating with constrained work space and limited building information. Recommendations for improving waste management in office building retrofit projects are generalised such as waste planning, auditing and assessment in the planning and designing stage, collaboration and coordination of various stakeholders and different specialists, optimised building surveying and BIM technologies for waste analysis, and new design strategies for waste prevention.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study explores how preservice teachers with non-Australian educational backgrounds and prerequisite qualifications make their way into and through a local teacher education program. It is informed by Margaret Archer's sociology of reflexivity to understand the interplay between these people's personal resources and institutional constraints and enablements. Data were collected from seven participants through narrative interviews. A narrative analysis identified big and small stories. Findings show that these preservice teachers purposefully exercise their agency as they invest in a common project for a variety of transnational goals. The outcome of that project emerges from the interaction between structure and agency.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Anthropogenic elemental mercury (Hg0) emission is a serious worldwide environmental problem due to the extreme toxicity of the heavy metal to humans, plants and wildlife. Development of an accurate and cheap microsensor based online monitoring system which can be integrated as part of Hg0 removal and control processes in industry is still a major challenge. Here, we demonstrate that forming Au nanospike structures directly onto the electrodes of a quartz crystal microbalance (QCM) using a novel electrochemical route results in a self-regenerating, highly robust, stable, sensitive and selective Hg0 vapor sensor. The data from a 127 day continuous test performed in the presence of volatile organic compounds and high humidity levels, showed that the sensor with an electrodeposted sensitive layer had 260% higher response magnitude, 3.4 times lower detection limit (,22 mg/m3 or ,2.46 ppbv) and higher accuracy (98% Vs 35%) over a Au control based QCM (unmodified) when exposed to a Hg0 vapor concentration of 10.55 mg/m3 at 1016C. Statistical analysis of the long term data showed that the nano-engineered Hg0 sorption sites on the developed Au nanospikes sensitive layer play a critical role in the enhanced sensitivity and selectivity of the developed sensor towards Hg0 vapor.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Aim The aim was to explore the relationship between nursing casualization and the culture of communication for nurses in a healthcare facility. Background Casualization, or non-standard work, is the use of temporary, contract, part-time and casual labour. An increase in casual labour has been part of a global shift in work organization aimed at creating a more flexible and cheaper workforce. It has been argued that flexibility of labour has enabled nurses to manage both non-work related needs and an increasingly complex work environment. Yet no research has explored casualization and how it impacts on the communication culture for nurses in a healthcare facility. Design Critical ethnography. Methods Methods included observation, field notes, formal interviews and focus groups. Data collection was undertaken over the 2 years 2008–2009. Results The concepts of knowing and belonging were perceived as important to nursing teamwork and yet the traditional time/task work model, designed for a full-time workforce, marginalized non-standard workers. The combination of medical dominance and traditional stereotyping of the nurse and work as full-time shaped the behaviours of nurses and situated casual workers on the periphery. The overall finding was that entrenched systemic structures and processes shaped the physical and cultural dimensions of a contemporary work environment and contributed to an ineffective communication culture. Conclusion Flexible work is an important feature of contemporary nursing. Traditional work models and nurse attitudes and practices have not progressed and are discordant with a contemporary approach to nursing labour management.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Critical reflection is a necessary component of professionalism in early childhood education. Evidence of critical reflection within a service draws attention to the intellectual work of early childhood educators and highlights professional capacities beyond the care of young children.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Leucine is a key amino acid for initiating translation in muscle cells, but the dose-dependent effects of leucine on intracellular signaling are poorly characterized. This study examined the effect that increasing doses of leucine would have on changes in mechanistic target of rapamycin (mTOR)–mediated signaling, rates of protein synthesis, and cell size in C2C12 cells. We hypothesized that a leucine “threshold” exists, which represents the minimum stimulus required to initiate mTOR signaling in muscle cells. Acute exposure to 1.5, 3.2, 5.0, and 16.1 mM leucine increased phosphorylation of mTORSer2448 (~1.4-fold; P < .04), 4E-BP1 Thr37/46 (~1.9-fold; P < .001), and rpS6Ser235/6 (~2.3-fold; P < .001). However, only p70S6kThr389 exhibited a dose-dependent response to leucine with all treatments higher than control (~4-fold; P < .001) and at least 5 mM higher than the 1.5-mM concentration (1.2-fold; P < .02). Rates of protein synthesis were not altered by any treatment. Seven days of exposure to 0.5, 1.5, 5.0, and 16.5 mM leucine resulted in an increase in cell size in at least 5 mM treatments (~1.6-fold, P < .001 vs control). Our findings indicate that even at low leucine concentrations, phosphorylation of proteins regulating translation initiation signaling is enhanced. The phosphorylation of p70S6kThr389 follows a leucine dose-response relationship, although this was not reflected by the acute protein synthetic response. Nevertheless, under the conditions of the present study, it appears that leucine concentrations of at least 5 mM are necessary to enhance cell growth.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Aim: The aim of this survey was to assess registered nurse’s perceptions of alarm setting and management in an Australian Regional Critical Care Unit. Background: The setting and management of alarms within the critical care environment is one of the key responsibilities of the nurse in this area. However, with up to 99% of alarms potentially being false-positives it is easy for the nurse to become desensitised or fatigued by incessant alarms; in some cases up to 400 per patient per day. Inadvertently ignoring, silencing or disabling alarms can have deleterious implications for the patient and nurse. Method: A total population sample of 48 nursing staff from a 13 bedded ICU/HDU/CCU within regional Australia were asked to participate. A 10 item open-ended and multiple choice questionnaire was distributed to determine their perceptions and attitudes of alarm setting and management within this clinical area. Results: Two key themes were identified from the open-ended questions: attitudes towards inappropriate alarm settings and annoyance at delayed responses to alarms. A significant number of respondents (93%) agreed that alarm fatigue can result in alarm desensitisation and the disabling of alarms, whilst 81% suggested the key factors are those associated with false-positive alarms and inappropriately set alarms.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Lewis’s Medical-Surgical Nursing: Assessment and Management of Clinical Problems, 4th Edition is the most comprehensive go-to reference for essential information about all aspects of professional nursing care of patients. Using the nursing process as a framework for practice, the fourth edition has been extensively revised to reflect the rapid changing nature of nursing practice and the increasing focus on key nursing care priorities. Building on the strengths of the third Australian and New Zealand edition and incorporating relevant global nursing research and practice from the prominent US title Medical-Surgical Nursing, 9Th Edition, Lewis’s Medical-Surgical Nursing, 4th Edition is an essential resource for students seeking to understand the role of the professional nurse in the contemporary health environment.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This case study examined four teachers' understandings and teaching of Critical Literacy with senior English as an Additional Language (EAL) learners in two Queensland high schools. Despite continuous, rapid curriculum change in Australia and efforts to diminish Critical Literacy, the four teachers continued to feature it successfully in their teaching with often marginalised learners. They used critical literacy to provide access to and critique dominant language codes, and to draw on learners' diverse experiences. To a lesser extent, the teachers created opportunities for redesigning dominant texts. Implications are important for policy production and interpretation, school planning and teacher professional development.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The estimation of the critical gap has been an issue since the 1970s, when gap acceptance was introduced to evaluate the capacity of unsignalized intersections. The critical gap is the shortest gap that a driver is assumed to accept. A driver’s critical gap cannot be measured directly and a number of techniques have been developed to estimate the mean critical gaps of a sample of drivers. This paper reviews the ability of the Maximum Likelihood technique and the Probability Equilibrium Method to predict the mean and standard deviation of the critical gap with a simulation of 100 drivers, repeated 100 times for each flow condition. The Maximum Likelihood method gave consistent and unbiased estimates of the mean critical gap. Whereas the probability equilibrium method had a significant bias that was dependent on the flow in the priority stream. Both methods were reasonably consistent, although the Maximum Likelihood Method was slightly better. If drivers are inconsistent, then again the Maximum Likelihood method is superior. A criticism levelled at the Maximum Likelihood method is that a distribution of the critical gap has to be assumed. It was shown that this does not significantly affect its ability to predict the mean and standard deviation of the critical gaps. Finally, the Maximum Likelihood method can predict reasonable estimates with observations for 25 to 30 drivers. A spreadsheet procedure for using the Maximum Likelihood method is provided in this paper. The PEM can be improved if the maximum rejected gap is used.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective: To formally evaluate the written discharge advice for people with mild traumatic brain injury (mTBI). Methods: Eleven publications met the inclusion criteria: (1) intended for adults; (2) ≤two A4 pages; (3) published in English; (4) freely accessible; and (5) currently used (or suitable for use) in Australian hospital emergency departments or similar settings. Two independent raters evaluated the content and style of each publication against established standards. The readability of the publication, the diagnostic term(s) contained in it and a modified Patient Literature Usefulness Index (mPLUI) were also evaluated. Results: The mean content score was 19.18 ± 8.53 (maximum = 31) and the mean style score was 6.8 ± 1.34 (maximum = 8). The mean Flesch-Kincaid reading ease score was 66.42 ± 4.3. The mean mPLUI score was 65.86 ± 14.97 (maximum = 100). Higher scores on these metrics indicate more desirable properties. Over 80% of the publications used mixed diagnostic terminology. One publication scored optimally on two of the four metrics and highly on the others. Discussion: The content, style, readability and usefulness of written mTBI discharge advice was highly variable. The provision of written information to patients with mTBI is advised, but this variability in materials highlights the need for evaluation before distribution. Areas are identified to guide the improvement of written mTBI discharge advice.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Protein adsorption at solid-liquid interfaces is critical to many applications, including biomaterials, protein microarrays and lab-on-a-chip devices. Despite this general interest, and a large amount of research in the last half a century, protein adsorption cannot be predicted with an engineering level, design-orientated accuracy. Here we describe a Biomolecular Adsorption Database (BAD), freely available online, which archives the published protein adsorption data. Piecewise linear regression with breakpoint applied to the data in the BAD suggests that the input variables to protein adsorption, i.e., protein concentration in solution; protein descriptors derived from primary structure (number of residues, global protein hydrophobicity and range of amino acid hydrophobicity, isoelectric point); surface descriptors (contact angle); and fluid environment descriptors (pH, ionic strength), correlate well with the output variable-the protein concentration on the surface. Furthermore, neural network analysis revealed that the size of the BAD makes it sufficiently representative, with a neural network-based predictive error of 5% or less. Interestingly, a consistently better fit is obtained if the BAD is divided in two separate sub-sets representing protein adsorption on hydrophilic and hydrophobic surfaces, respectively. Based on these findings, selected entries from the BAD have been used to construct neural network-based estimation routines, which predict the amount of adsorbed protein, the thickness of the adsorbed layer and the surface tension of the protein-covered surface. While the BAD is of general interest, the prediction of the thickness and the surface tension of the protein-covered layers are of particular relevance to the design of microfluidics devices.