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Results for “built environment”

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At least 235 records · Page 13Linked to original sources

PubMed2004

Effects of experimental parameters on NF(3) decomposition fraction in an oxygen-based RF plasma environment.

Clean procedure is one of the major emitters of perfluorinated compounds (PFCs) in semiconductor manufacturing. Nitrogen trifluoride (NF(3)) is increasingly the process gas of choice for eliminating PFC emissions. However, its toxic to human and similar global warming potential compared to most other PFCs made NF(3) warranted much more investigation. This study demonstrated a radio-frequency plasma system for decomposing NF(3). The effects of experimental parameters: input power, O(2)/NF(3) ratio, operational pressure and NF(3) feeding concentration on NF(3) decomposition fraction (eta(NF3)) and energy efficiency E(NF3) were examined in detail. The analytical results demonstrated that the NF(3) was almost completely decomposed (>99%) at input power=30W, [NF(3)](in)=1.0% and eta(NF3) increased with input power. However, adding O(2) to the system inhibited NF(3) decomposition and decreased E(NF3). Moreover, eta(NF3) and E(NF3), decreased with gradually increasing operational pressure. Notably, increasing the NF(3) feeding concentration increased molecule density, reducing eta(NF3), but increasing E(NF3). Furthermore, the products detected in the NF(3)/O(2)/Ar plasma system were NO(2), NO, N(2)O, SiF(4), N(2) and F(2). Potential reaction pathways in the oxygen-based NF(3) plasma environment were built-up and elucidated.

Environmental Pollution↗

PubMedDate not supplied

Health and social context: social capital's utility as a construct for nursing and health promotion.

Social capital is a health-related construct that is a way for pediatric nurse practitioners (PNPs) to conceptualize the interconnectedness between health and social relations. Applying the concept of "social capital" to child and family health has the capacity to help PNPs reframe persistent questions and explore health issues in new and creative ways. A health-enabling environment must be built using a bottom-up approach, with participatory health promotion programs and internally driven community health projects. PNPs must create opportunities for networking and diffusing knowledge about community-related health issues. PNPs also must build their own social capital and practice "vision therapy" to develop new interventions to enhance child and family health.

Community Networks↗

PubMed2006

Construction of environment states in quantum-chemical density-matrix renormalization group calculations.

The application of the quantum-chemical density-matrix renormalization group (DMRG) algorithm is cumbersome for complex electronic structures with many active orbitals. The high computational cost is mainly due to the poor convergence of standard DMRG calculations. A factor which affects the convergence behavior of the calculations is the choice of the start-up procedure. In this start-up step matrix representations of operators have to be calculated in a guessed many-electron basis of the DMRG environment block. Different possibilities for the construction of these basis states exist, and we first compare four procedures to approximate the environment states using Slater determinants explicitly. These start-up procedures are applied to DMRG calculations on a sophisticated test system: the chromium dimer. It is found that the converged energies and the rate of convergence depend significantly on the choice of the start-up procedure. However, since already the most simple start-up procedure, which uses only the Hartree-Fock determinant, is comparatively good, Slater determinants, in general, appear not to be a good choice as approximate environment basis states for convergence acceleration. Based on extensive test calculations it is demonstrated that the computational cost can be significantly reduced if the number of total states m is successively increased. This is done in such a way that the environment states are built up stepwise from system states of previous truncated DMRG sweeps for slowly increasing m values.

Journal Article↗

PubMed2003

A virtual reality system for neurobehavioral and functional MRI studies.

We are developing a VR system of integrated software and hardware for scientific research and clinical application. The system is sufficiently flexible and broad-based in appeal that neurobehavioral researchers from a variety of disciplines might be interested in using it for basic research and clinical studies. The system runs on a standard Windows-based personal computer with a high-performance graphics card. Options allow a head-mounted display, dataglove, simultaneous physiological monitoring or use within neuroimaging machines such as magnetic resonance imaging (MRI) scanners. Currently, the software consists of a virtual world of nearly a dozen interconnected environments that the subject can freely navigate. Additional environments can be built and easily added to the application. A startup interface provides menus for selecting characters and objects that a researcher might want to put at specific locations within the simulation. Interactivity is provided for many typical objects such as doors, chairs and money. There are more than 50 characters in the world, most of them animated or interactive. All movements and actions of the subject within the world are tracked and recorded to an Excel spreadsheet for data analysis. Overlay maps are available as navigational aids. Concurrent physiological data can be acquired on up to 16 channels. The system provides synchronization of the VR simulation with physiological recordings and functional MR images. A spatial navigation memory task was performed with the integrated VR/fMRI system, and some pilot data is presented that shows robust activation in multiple cortical areas appropriate to the task.

Brain↗

PubMedDate not supplied

Healthy communities must also be sustainable communities.

The author contends that healthy communities must be both environmentally and socially sustainable, given that health depends on the quality of the built and natural environments, and that global change resulting from the industrial economy is affecting the web of life. He argues that suburban sprawl wastes scarce resources and disproportionately places those resources in the hands of suburban dwellers. Urban areas can be made more environmentally sustainable, especially with respect to energy consumption, which will help reduce air pollution and climate change and contribute in other ways to improved health.

City Planning↗

PubMed2007

Getting out of the house: the challenges mothers face when their children have long-term care needs.

In most industrialised countries, the care needs of those who are sick, disabled and frail are increasingly met in peoples' homes. One of the implications of this shift in the site of care is that individuals with long-term care needs and their family care providers experience social and spatial isolation. Many are housebound and most face considerable challenges in getting out of the house. This paper illuminates these challenges as they are experienced by mothers of children with long-term care needs, and the resulting isolation and disconnection that they experience. Eleven semistructured interviews were conducted in two regions of Ontario, Canada. Grounded theory informed the analysis of the mothers' accounts of their experiences of getting out of the house. The present findings are derived from a larger investigation of the meanings and experiences of the home as a place of caring for families with children who have long-term care needs. Secondary analysis of the data found that three main challenges restricted the mothers' abilities to leave their houses. Mothers experienced difficulties getting out of the house when they attempted to leave with the child, and when the child was left with an alternative care provider. Physical challenges were associated with the work and planning required in moving the child's equipment and supplies, meticulous planning of the outing within the daily schedule, and navigating barriers in the built and natural environments. Social challenges reflected the lack of people within the mothers' social network of family and friends who have the knowledge and expertise to care for the child. Service challenges resulted from the gaps between the policies and practices of paid respite, and the conditions that must be satisfied in order for mothers to be able and/or willing to leave the house. The authors also examined the reasons why some of the mothers worked from home, and the strategies that they used to get out of the house for employment. In this paper, the authors discuss each challenge, and how it contributes to the mothers' social and spatial isolation. The mothers' experiences elucidate the differences between living in a community and being part of a community. The consequences of the isolation on mothers' daily lives are not recognised in home and community care policy. The suggestions that are put forward concerning paid respite have relevance for home and community care policy and practice.

Caregivers↗

PubMed2005

Diseases of comfort: primary cause of death in the 22nd century.

CONTEXT: The world has started to feel the impact of a global chronic disease epidemic, which is putting pressure on our health care systems. If uncurbed, a new generation of "diseases of comfort" (such as those chronic diseases caused by obesity and physical inactivity) will become a major public health problem in this and the next century. OBJECTIVE: To describe the concept, causes, and prevention and control strategies of diseases of comfort. METHODS: Brokered by a senior research scientist specialised in knowledge translation, a chair, a president, and a past president of national public health associations contributed their views on the subject. RESULTS: Diseases of comfort have emerged as a price of living in a modern society. It is inevitable that these diseases will become more common and more disabling if human "progress" and civilisation continue toward better (more comfortable) living, without necessarily considering their effects on health. Modern technology must be combined with education, legislation, intersectoral action, and community involvement to create built and social environments that encourage, and make easy, walking, physical activity, and nutritious food choices, to reduce the health damaging effects of modern society for all citizens and not only the few. CONCLUSIONS: Public health needs to be more passionate about the health issues caused by human progress and adopt a health promotion stance, challenging the assumptions behind the notion of social "progress" that is giving rise to the burden of chronic disease and developing the skills to create more health promoting societies in which individual health thrives.

Cause of Death↗

PubMed2006

High throughput modular chambers for rapid evaluation of anesthetic sensitivity.

BACKGROUND: Anesthetic sensitivity is determined by the interaction of multiple genes. Hence, a dissection of genetic contributors would be aided by precise and high throughput behavioral screens. Traditionally, anesthetic phenotyping has addressed only induction of anesthesia, evaluated with dose-response curves, while ignoring potentially important data on emergence from anesthesia. METHODS: We designed and built a controlled environment apparatus to permit rapid phenotyping of twenty-four mice simultaneously. We used the loss of righting reflex to indicate anesthetic-induced unconsciousness. After fitting the data to a sigmoidal dose-response curve with variable slope, we calculated the MAC(LORR) (EC50), the Hill coefficient, and the 95% confidence intervals bracketing these values. Upon termination of the anesthetic, Emergence timeRR was determined and expressed as the mean +/- standard error for each inhaled anesthetic. RESULTS: In agreement with several previously published reports we find that the MAC(LORR) of halothane, isoflurane, and sevoflurane in 8-12 week old C57BL/6J mice is 0.79% (95% confidence interval = 0.78-0.79%), 0.91% (95% confidence interval = 0.90-0.93%), and 1.96% (95% confidence interval = 1.94-1.97%), respectively. Hill coefficients for halothane, isoflurane, and sevoflurane are 24.7 (95% confidence interval = 19.8-29.7%), 19.2 (95% confidence interval = 14.0-24.3%), and 33.1 (95% confidence interval = 27.3-38.8%), respectively. After roughly 2.5 MAC(LORR) x hr exposures, mice take 16.00 +/- 1.07, 6.19 +/- 0.32, and 2.15 +/- 0.12 minutes to emerge from halothane, isoflurane, and sevoflurane, respectively. CONCLUSION: This system enabled assessment of inhaled anesthetic responsiveness with a higher precision than that previously reported. It is broadly adaptable for delivering an inhaled therapeutic (or toxin) to a population while monitoring its vital signs, motor reflexes, and providing precise control over environmental conditions. This system is also amenable to full automation. Data presented in this manuscript prove the utility of the controlled environment chambers and should allow for subsequent phenotyping of mice with targeted mutations that are expected to alter sensitivity to induction or emergence from anesthesia.

Journal Article↗

PubMed1995

Evolving mobile robots in simulated and real environments.

The problem of the validity of simulation is particularly relevant for methodologies that use machine learning techniques to develop control systems for autonomous robots, as, for instance, the artificial life approach known as evolutionary robotics. In fact, although it has been demonstrated that training or evolving robots in real environments is possible, the number of trials needed to test the system discourages the use of physical robots during the training period. By evolving neural controllers for a Khepera robot in computer simulations and then transferring the agents obtained to the real environment we show that (a) an accurate model of a particular robot-environment dynamics can be built by sampling the real world through the sensors and the actuators of the robot; (b) the performance gap between the obtained behaviors in simulated and real environments may be significantly reduced by introducing a "conservative" form of noise; (c) if a decrease in performance is observed when the system is transferred to a real environment, successful and robust results can be obtained by continuing the evolutionary process in the real environment for a few generations.

Algorithms↗

PubMedDate not supplied

A network-based training environment: a medical image processing paradigm.

The capability of interactive multimedia and Internet technologies is investigated with respect to the implementation of a distance learning environment. The system is built according to a client-server architecture, based on the Internet infrastructure, composed of server nodes conceptually modelled as WWW sites. Sites are implemented by customization of available components. The environment integrates network-delivered interactive multimedia courses, network-based tutoring, SIG support, information databases of professional interest, as well as course and tutoring management. This capability has been demonstrated by means of an implemented system, validated with digital image processing content, specifically image enhancement. Image enhancement methods are theoretically described and applied to mammograms. Emphasis is given to the interactive presentation of the effects of algorithm parameters on images. The system end-user access depends on available bandwidth, so high-speed access can be achieved via LAN or local ISDN connections. Network based training offers new means of improved access and sharing of learning resources and expertise, as promising supplements in training.

Computer Communication Networks↗

PubMed1993

Planning and design of children's health care facilities.

Children are not small adults, but children do live in an adult-oriented world. With few exceptions, most of the environment, as designed and built, is intended to meet the needs of adults. Children adapt and have to make do. An increasing body of knowledge is telling us, however, that the sick or injured child heals best in an environment that is unique--one that responds to the child's emotional and physical needs. A health care environment that is responsive to the needs of children and their families, as well as the caregivers, will provide a more tolerable, perhaps even more pleasant experience, for the child and family and thereby enable caregivers to provide services more easily and efficiently. The new result may well be improved outcomes and health status. As planners, designers, or caregivers, we all have a responsibility to create these special environments and help each child achieve his or her highest possible level of health.

Architecture↗

PubMed1993

Navigation in hypertext through virtual environments.

Users of hypertext systems require some form of navigation aid or 'browser'. Typically these have been produced as schematic representations of the hypertext network. The advent of 'virtual reality' technology, and particularly less costly forms of this, offers new possibilities for hypertext navigation whereby information can be presented in the form of a virtual environment. Users can then move around the virtual world in much the same conceptual fashion as they move around the real world. Based upon an extensive review of hypertext navigation problems and the aiding systems proposed to deal with these, four different types of navigation aid have been built; these are schematic and spatial representations in two and three dimensions. Of particular interest is the 3D spatial representation, built as a virtual environment in Virtus Walkthrough; the proposition is that such a virtual world navigation aid will offer substantial usability advantages for hypertext databases.

Journal Article↗

PubMed1998

A development environment for knowledge-based medical applications on the World-Wide Web.

The World-Wide Web (WWW) is increasingly being used as a platform to develop distributed applications, particularly in contexts, such as medical ones, where high usability and availability are required. In this paper we propose a methodology for the development of knowledge-based medical applications on the web, based on the use of an explicit domain ontology to automatically generate parts of the system. We describe a development environment, centred on the LISPWEB Common Lisp HTTP server, that supports this methodology, and we show how it facilitates the creation of complex web-based applications, by overcoming the limitations that normally affect the adequacy of the web for this purpose. Finally, we present an outline of a system for the management of diabetic patients built using the LISPWEB environment.

Artificial Intelligence↗

PubMed1990

On-line acquisition, analysis and presentation of neurophysiological data based on a personal microcomputer system.

A microcomputer based system is described for the acquisition, averaging, displaying, analysis and storage of electrophysiological (EPSP and post-stimulus histogram) data. The system consists of commercially available hardware (IBM-PC AT compatible, 80286 or 80386 based microcomputer, Burr-Brown analog-to-digital (A/D) converter), a custom built interface module, and a combination of commercially available and custom built software packages. The software operates within a Microsoft Windows environment and is comprised of custom built data acquisition and review modules which are linked to Microsoft's Excel program. The system is capable of four channel A/D conversion of EPSP's at a sampling frequency of up to 10 KHz (50 KHz single channel), the averaging of data including the addition and subtraction of various channels, the graphical display of data, the extraction of various data parameters, and the transfer of data to an Excel spreadsheet. The spreadsheet allows for the development of mathematical formulas for statistical analysis of data and presentation of the results in graphical form. Finally, data can easily be output to a laser printer or plotter. A sample experiment, illustrating system operation, is presented.

Electronic Data Processing↗

PubMed2006

Public injecting and the need for 'safer environment interventions' in the reduction of drug-related harm.

BACKGROUND: One key structural dimension in the distribution of drug-related harm associated with injecting drug use is the injecting environment. Epidemiological evidence associates elevated blood-borne viral risk with injecting in 'public' and 'semipublic' environments. Yet the quality of evidence on public injecting and related viral risk is variable, and is lacking in many countries such as the United Kingdom. AIM: This commentary considers the micro-injecting environment as a critical dimension of risk, exploring the need for 'safer injecting environment interventions'. METHODS: We draw upon published research evidence and qualitative case examples. RESULTS: We note the limits in epidemiological evidence on public injecting and emphasize the need for ethnographic research to determine the 'social relations' of how drug users and risk practices interact with injecting environments. We identify three main forms of 'safer environment intervention': purpose-built drug consumption rooms; interventions within existing spatial relations; and spatial programming and urban design. While drug consumption rooms find evidence-based support, they are not a panacea. We emphasize the potential of interventions embedded within existing spatial and social relations. These include low-cost pragmatic interventions enhancing facilities and safety at public and semipublic injecting sites and, primarily, peer-based interventions, including peer-supervised injecting sites. We caution against spatial programming and urban design interventions which can cause the displacement of socially marginalized populations and the redistribution of harm. CONCLUSIONS: Public health interventions in the addictions field have in the past focused upon individual behavioural change at the cost of social interventions and environmental change. We wish to focus greater attention on reducing risks related to public injecting and encourage greater debate on 'safer environment interventions' in harm reduction.

Environment↗

PubMed1989

Knowledge base design for decision support in respirator therapy.

A knowledge base is built for decision support applied to respirator therapy (the KUSIVAR project). The knowledge representation is object-oriented using frames to store multiple forms of knowledge: variable descriptions, transformation tables, rules and mathematical models. The system is data-driven, generating and displaying advice automatically triggered by changes in data from the respirator and the patient. The inferenceing mechanism is forward-chaining i.e. a rule is evaluated as soon as it's condition is satisfied. Temporal aspects of the reasoning are represented by a number of mechanisms, among others limited validity times for data, trend analysis and mathematical models. The knowledge base is organized according to disease groups and decision situation which simplifies knowledge acquisition and improves response times since it enables the system to focus on a limited set of rules in each situation. To test the feasibility of the system design a prototype has been built using Knowledge Engineering Environment (KEE) from Intellicorp on an Explorer workstation from Unisys. The production system, which is interfaced to a Siemens Elema Servo Ventilator 900C, is currently being implemented under the Microsoft Windows multitasking environment on a microcomputer based on an Intel 80386 processor.

Decision Support Techniques↗

PubMed2004

Biomimetic actuators: where technology and cell biology merge.

The structural and functional analysis of biological macromolecules has reached a level of resolution that allows mechanistic interpretations of molecular action, giving rise to the view of enzymes as molecular machines. This machine analogy is not merely metaphorical, as bio-analogous molecular machines actually are being used as motors in the fields of nanotechnology and robotics. As the borderline between molecular cell biology and technology blurs, developments in the engineering and material sciences become increasingly instructive sources of models and concepts for biologists. In this review, we provide a--necessarily selective--summary of recent progress in the usage of biological and biomimetic materials as actuators in artificial environments, focussing on motors built from DNA, classical cellular motor systems (tubulin/kinesin, actin/myosin), the rotary motor F1F0-ATPase and protein-based 'smart' materials.

Actins↗

PubMed2000

Simultaneous measurement of human joint force, surface electromyograms, and functional MRI-measured brain activation.

Functional magnetic resonance imaging (fMRI) has been increasingly used in studying human brain function given its non-invasive feature and good spatial resolution. However, difficulties in acquiring data from peripheral (e.g. information from muscle) during fMRI studies of motor function hinder interpretation of fMRI data and designing more sophisticated investigations. Here we describe a system that was designed to concurrently measure handgrip force, surface electromyograms (EMG) of finger flexor and extensor muscles, and fMRI of human brain. The system included a pressure transducer built in a hydraulic environment, a heavily shielded EMG recording element, and a visual feedback structure for online monitoring of force and/or EMG signal, by the subject positioned in the scanner during an fMRI experiment. System evaluation and subsequent fMRI motor function studies have indicated that by using this system, high quality force and EMG signals can be recorded without sacrificing the quality of the fMRI data.

Brain Mapping↗