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PubMed2005

River pollution from non-point sources: a new simplified method of assessment.

Assessment of the pollution of water bodies from non-point sources is a complex data- and time-consuming task. The potential non-point pollution index (PNPI), is a new tool designed to assess the global pressure exerted on rivers and other surface water bodies by different land uses. The main feature of PNPI is the wide availability of its input data. Very detailed input maps, often lacking over many areas, are not needed for PNPI calculation. As a consequence of the input data used, the modelling of physical reality and of processes is heavily simplified. The authors counterbalanced such a simplification using an 'expert system' approach. The system bypasses the accurate representation of the physical reality to assess globally the pollution potential of different land uses according to the judgement of scientists. The scientific community proposes many models for depicting the dynamics of pollutants coming from diffuse sources. Most of them can be grouped into two broad categories: statistical models and physically based models. PNPI belongs to neither of the above-mentioned groups. PNPI is a GIS-based, watershed-scale tool designed to inform decision makers and public opinion about the potential environmental impacts of different land management scenarios. PNPI applies the multicriteria technique to pollutant dynamics and water quality. The pressure exerted on water bodies by diffuse pollution coming from land units is expressed as a function of three indicators: land use, run-off and distance from the river network. They are calculated from land use data, geological maps and a digital elevation model (DEM). The weights given to different land uses and to the three indicators were set according to experts' evaluations and allow calculation of the value of the PNPI for each node of a grid representing the watershed; the higher the PNPI of the cell, the greater the potential impact on the river network. The output of the calculation is presented in the form of maps that highlight areas that are more likely to produce pollution. Last, possibilities, strategies and results of the validation of the PNPI are described. In the authors' view, the explicit link between land use and potential pollution on which PNPI is based, together with its high communication potential, make it particularly interesting for a participatory and integrated approach to land management and environmental protection.

Conservation of Natural Resources↗

PubMed2001

Where value lives in a networked world.

While many management thinkers proclaim an era of radical uncertainty, authors Sawhney and Parikh assert that the seemingly endless upheavals of the digital age are more predictable than that: today's changes have a common root, and that root lies in the nature of intelligence in networks. Understanding the patterns of intelligence migration can help companies decipher and plan for the inevitable disruptions in today's business environment. Two patterns in network intelligence are reshaping industries and organizations. First, intelligence is decoupling--that is, modern high-speed networks are pushing back-end intelligence and front-end intelligence toward opposite ends of the network, making the ends the two major sources of potential profits. Second, intelligence is becoming more fluid and modular. Small units of intelligence now float freely like molecules in the ether, coalescing into temporary bundles whenever and wherever necessary to solve problems. The authors present four strategies that companies can use to profit from these patterns: arbitrage allows companies to move intelligence to new regions or countries where the cost of maintaining intelligence is lower; aggregation combines formerly isolated pieces of infrastructure intelligence into a large pool of shared infrastructure provided over a network; rewiring allows companies to connect islands of intelligence by creating common information backbones; and reassembly allows businesses to reorganize pieces of intelligence into coherent, personalized packages for customers. By being aware of patterns in network intelligence and by acting rather than reacting, companies can turn chaos into opportunity, say the authors.

Commerce↗

PubMed1988

Radiology systems of the nineties: meeting the challenge of change.

Digital imaging technology, particularly reconstructed images such as computed tomography and magnetic resonance imaging, has fueled the increased demand for radiologic services but has intensified storage and communications problems. Today more than 25% of radiologic examinations are digital in origin and, with progressive replacing of film images by digital images likely through the introduction of imaging plate technology, the radiology profession is undertaking the massive effort of evolving a new system where digital images will be transmitted, stored, retrieved and displayed by a multicomponent system connected by a local area network. Through this system, images will be nearly instantly accessible to anyone who needs them. A leading hypothesis is that when the volume of digital examinations reaches 50% of the whole, cost and efficiency considerations will lead to a massive conversion to the digital image management system, which will progress spontaneously. This conversion, unless planned for in today's equipment acquisitions, could lead to great economic stress in hospitals. The 50% point may be reached by the early 1990s.

Database Management Systems↗

PubMed2006

OR/AND neurons and the development of interpretable logic models.

In this paper, we are concerned with the concept of fuzzy logic networks and logic-based data analysis realized within this framework. The networks under discussion are homogeneous architectures comprising of OR/AND neurons originally introduced by Hirota and Pedrycz. Being treated here as generic processing units, OR/AND neurons are neurofuzzy constructs that exhibit well-defined logic characteristics and are endowed with a high level of parametric flexibility and come with significant interpretation abilities. The composite logic nature of the logic neurons becomes instrumental in covering a broad spectrum of logic dependencies whose character spread in-between between those being captured by plain and and or logic descriptors (connectives). From the functional standpoint, the developed network realizes a logic approximation of multidimensional mappings between unit hypercubes, that is transformations from [0, 1]n to [0, 1]m. The way in which the structure of the network has been formed is highly modular and becomes reflective of a general concept of decomposition of logic expressions and Boolean functions (as being commonly encountered in two-valued logic). In essence, given a collection of input variables, selected is their subset and transformed into new composite variable, which in turn is used in the consecutive module of the network. These intermediate synthetic variables are the result of the successive problem (mapping) decomposition. The development of the network is realized through genetic optimization. This helps address important issues of structural optimization (where we are concerned with a selection of a subset of variables and their allocation within the network) and reaching a global minimum when carrying out an extensive parametric optimization (adjustments of the connections of the neurons). The paper offers a comprehensive and user-interactive design procedure including a simple pruning mechanism whose intention is to enhance the interpretability of the network while reducing its size. The experimental studies comprise of three parts. First, we demonstrate the performance of the network on Boolean data (that leads to some useful comparative observations considering a wealth of optimization tools available in two-valued logic and digital systems). Second, we discuss synthetic multivalued data that helps focus on the approximation abilities of the network. Finally, show the generation of logic expressions describing selected data sets coming from the machine learning repository.

Algorithms↗

PubMed2006

[The study and implementation of DICOM conformance in the network printing of PACS].

To implement the network printing in PACS (Picture Archiving and Communication System), each level of DICOM (Digital Imaging and Communication in Medicine) print management service is defined by means of object oriented method, and the corresponding events and properties are implemented with C++ language. It is tested on laser printers of AGFA, KODAK and FUJI to determine whether the network environment supports the print management service and implements the presentation LUT (Look Up Table) correctly. The quality control of printing at the level of data flow is also assessed. The program finally succeeds in realizing the network printing based on DICOM in hospital environment.

Computer Communication Networks↗

PubMed2003

Functional somatotopy of finger representations in human primary motor cortex.

To assess the degree of fine-scale somatotopy within the hand area of the human primary motor cortex (M1), functional mapping of individual movements of all fingers was performed in healthy young subjects (n = 7) using MRI at 0.8 x 0.8 mm2 resolution and 4 mm section thickness. The experimental design comprised both a direct paradigm contrasting single digit movements vs. motor rest and multiple differential paradigms contrasting single digit movements vs. the movement of another digit. Direct mapping resulted in largely overlapping activations. A somatotopic arrangement was only recognizable when considering the mean center-of-mass coordinates of individual digit representations averaged across subjects. In contrast, differential paradigms revealed more segregated and somatotopically ordered activations in single subjects. The use of center-of-mass coordinates yielded inter-digit distances ranging from 2.0 to 16.8 mm, which reached statistical significance for pairs of more distant digits. For the middle fingers, the functional somatotopy obtained by differential mapping was dependent on the choice of the digit used for control. These results confirm previous concepts that finger somatotopy in the human M1 hand area emerges as a functional predominance of individual digit representations sharing common areas in a distributed though ordered network.

Adult↗

PubMed2000

Challenges associated with interfacing computed tomography to a picture archiving and communication system at the Baltimore Veterans Affairs Medical Center--a historical perspective.

The interfacing of digital image acquisition modalities to the picture archiving and communication system (PACS) plays a major part in the conversion from a traditional film-based radiology practice to one that relies almost entirely on soft-copy reading. The Baltimore Veterans Affairs Medical Center (VAMC) is one of the first filmless hospitals in the world. Since 1993, it has used computed tomography (CT) scanners connected to a commercial PACS to provide digitized patient images for filmless reading. Over the years, the evolution of Digital Imaging and Communications in Medicine (DICOM) standards, advances in networking technologies, and enhancements in PACS and hospital information system (HIS) software have greatly improved this system's robustness and patient/study identification accuracy. The result has been a major increase in productivity.

Baltimore↗

PubMed1992

Recognition of chest radiograph orientation for picture archiving and communications systems display using neural networks.

A neural network classification scheme was developed that enables a picture archiving and communications system workstation to determine the correct orientation of posteroanterior or anteroposterior chest images. This technique permits thoracic images to be displayed conventionally when called up on the workstation, and therefore reduces the need for reorientation of the image by the observer. Feature data were extracted from 1,000 digitized chest radiographs and used to train a two-layer neural network designed to classify the image into one of the eight possible orientations for a posteroanterior chest image. Once trained, the neural network identified the correct image orientation in 888 of 1,000 images that had not previously been seen by the neural network. Of the 112 images that were incorrectly classified, 106 were mirror images of the correct orientation, whereas only 6 actually had the caudal-cranial axis aligned incorrectly. The causes for misalignment are discussed.

Humans↗

PubMed1997

A digital imaging and communications in medicine (DICOM) print service for chest imaging.

Large-scale picture archiving and communication systems (PACS) have not been widely implemented in this or other countries. In almost all radiology departments film remains the medium for diagnostic interpretation and image archive. Chest imaging is the dominant screening examination performed within most imaging departments and as such, is an extremely high-volume, low-margin examination. Digital technologies are being applied to chest imaging to overcome limitations of screen-film receptors (limited latitude) and current film management systems (single-image copy). Efficient management of images and information is essential to the success of a chest imaging program. In this article we report on a digital imaging and communications in medicine (DICOM)-based centralized printing network for chest imaging. The system components and their operational characteristics are described. Our experience integrating DICOM-compliant equipment supplied by several vendors is described. We conclude that the print model supported by DICOM is adequate for cross-sectional (eg, computed tomography and magnetic resonance) imaging but is too simplistic to be generally applied to projection radiography.

Humans↗

PubMed2002

Experience with a DICOM-compatible digital pediatric echocardiography laboratory.

A digital pediatric echocardiography laboratory, without videotape redundancy was established at Children's Hospital of Wisconsin in December 1998. To characterize the experience, 1198 consecutive patient studies were reviewed-50% from the first 2 months after establishing the digital protocol and 50% from the last 2 months available. Each study was stored using a protocol that was based on capture of single beat clips of relevant two-dimensional/color Doppler imaging and static frame spectral Doppler tracings. Studies were digitally compressed using a DICOM-compatible JPEG algorithm at 20:1 and edited with deletions of redundant clips to minimize archival storage needs. Study quality was uniformly excellent, and no errors were attributable to the digital protocol or compression-related loss of information. The average study required 21.5 +/- 11.4 MB of storage space with 35.4 +/- 12.3 total clips/study captured. Studies reviewed from the earlier experience were not significantly larger (23.6 +/- 14 vs 19.7 +/- 8.1 MB, 35.6 +/- 12.5 vs 35.2 +/- 12 clips) than those done recently. Studies in patients with isolated ventricular septal defect used comparable storage (23.7 +/- 8.9 MB, 42.8 +/- 11.5 clips) to that of the group as a whole. More complex congenital heart disease studies were slightly larger-tetralogy of Fallot (28.2 +/- 19.5 MB, 43.4 +/- 13.9 clips), transposition of the great arteries (30.6 +/- 17.4 MB, 40.3 +/- 16.7 clips), and single ventricle (29.7 +/- 19.6 MB, 39.9 +/- 12 clips)--although this trend was not significant. This study suggests that digital pediatric echo is feasible using a DICOM-compatible protocol with maintenance of diagnostic integrity despite compression of study size to allow rapid archival storage and retrieval.

Algorithms↗

PubMed1989

Determination of the functionally important heme peripheral vinyl group orientation in paramagnetic hemoprotein by 2D NMR.

2D NMR spectroscopies have been successfully used to characterize the heme peripheral vinyl groups in paramagnetic hemoprotein in spite of the difficulties from the rapid paramagnetic relaxation and the low digital resolution of the 2D NMR map. The scalar coupling network system among the vinyl protons is clearly identified in the COSY spectra from its characteristic cross-peak pattern and the dipolar coupling connectivities of the vinyl proton resonances with other heme side-chain proton resonances not only provide the specific assignment of vinyl beta-proton resonances but also allow the determination of the vinyl group orientation with respect to the heme plane.

Animals↗

PubMed1978

Three-dimensional architecture of blood vessels of tendons demonstrated by corrosion casts.

Three-dimensional observation of the microcirculation of the tendon was readily and clearly demonstrated by preparing methyl methacrylate casts and observing them under the scanning electron microscope. In the muscles blood vessels made a network like a ladder surrounding every muscle fibre. The fibrous digital sheath had blood vessels made in a fine meshed cylinder. By microdissection of the vessels of the sheath the blood vessels of the vinculae and tendons were observed stereoscopically in relation to the peritendinous tissues. The casting method contributes to better understanding of vascular architecture of tendons.

Animals↗

PubMed2002

Optimal green (red-free) digital imaging of conjunctival vasculature.

AIMS/BACKGROUND: Green illumination is commonly used to image vessels of the retina and conjunctiva. The purpose was to derive the best optical set-up for imaging vessels of the conjunctiva. METHODS: The concept of exposure density was used to predict a digital camera response to imaging vessels on a scleral background. Practical verification was performed to verify vessel contrast because of the difficulties in measuring the spectral components of the imaging system, such as the spectral reflectivity of vessels and sclera. Images of the same conjunctiva were repetitively taken through different coloured filters, using the Nikon FS-2 photo slit-lamp and recorded on different coloured channels of the Kodak DCS 100 digital camera. Gaussian blurred tubular models were fitted to densitometric profiles across three vessels from each image, allowing vessel contrast and width to be objectively measured. These measures were compared using different optical set-ups. RESULTS: Optimal exposure density calculations and vessel contrast was obtained with the xenon light source filtered with Wratten 99 (green) and Wratten 96 (neutral density, 0.2 log units) gelatine absorption filters using the green channel of the digital camera. This image set-up was associated with a 46% (99% CI 43-51%) to 64% (99% CI 58-72%) increase in contrast compared with vessels imaged without filtration, using the combined colour channel of the digital camera. Although differences in vessel widths resulted, absolute differences were marginal. CONCLUSION: With the increased use of digital imaging, and the need for image processing of vascular networks, image optimisation is beneficial. This study verified the optimal set-up for non-invasively imaging vessels of the bulbar conjunctiva.

Blood Vessels↗

PubMed2003

The PDA as a portal to knowledge sources in a wireless setting.

Two recent parallel developments, the widespread deployment of wireless networks and increased use of handheld devices like the personal digital assistant (PDA), have contributed to the development of mobile access to the Internet. Recent surveys show that approximately 25% or more of physicians use PDAs. Although used mainly for personal information management and static medical applications, PDAs have capabilities to connect to the Internet. We studied the use of handheld devices to access MEDLINE and other knowledge sources in a wireless setting.

Attitude of Health Personnel↗

PubMed2001

Innervated dorsal adipofascial turnover flap for fingertip amputations.

Traumatic or thermal injury to the fingertip may result in composite tissue loss. Exposed tendon, bone, or joint surface is best treated by flap coverage. The authors present their experience with a new technique that provides coverage for fingertip defects using the innervated dorsal adipofascial turnover flap, which consists of adipofascial tissue only and relies on the arterial anastomotic network of this tissue layer to sustain its vascularization. Eight digital amputations between the distal phalanx proximal to the nail matrix and midportion of the middle phalanx were resurfaced successfully with the innervated dorsal adipofascial turnover flap. The flaps survived completely; the mean follow-up was 9 months. This technique seems to be a relatively simple way of achieving early recovery. It does not require the use of distant flap immobilization of adjacent digits, nor does it require the use of homodigital flaps, which may jeopardize an already injured finger. The main advantages of the innervated dorsal adipofascial turnover flap are its ready availability from the local tissue, its sensation, and the absence of functional and aesthetic disturbance at the donor site.

Adolescent↗

PubMed1993

Future directions in electronic image handling.

After a relatively slow start compared with the United States and Japan, several projects are now being established in Europe that are aimed at the development of prototype systems for medical image processing and management. Frequently, this includes aspects of multimedia communication, as well as legal, ethical, and economic issues. Consideration is also often given to systems security, reliability, and data protection. All these projects are based on the application of modern computer and communication technologies. The following interesting conclusions can be drawn from these preliminary activities: 1. PACS and IMAC systems should not be regarded as products or devices, but as a means to improve the infrastructure in a given medical care environment. Sometimes this activity is also referred to as knowledge business. Individual components of these systems, for example image acquisition devices, networks, storage facilities, and medical workstations, should be provided with standard interfaces allowing a modular build-up and an easy adaptation to the specific conditions of clinical departments. 2. Digital luminescence radiography will further establish itself as a method for image acquisition and increasingly will replace analog radiologic methods. Consequently, digital processing, archiving, and communication will be a necessity for optimal patient care. 3. New network technologies and magnetic-optical storage media offer the possibility of an improved cost-effectiveness for communication and storage. They should therefore be considered an important factor in future economic considerations regarding health care services. 4. The practice of modern medicine is based on team-work; good communication among the parties concerned is a critical factor.(ABSTRACT TRUNCATED AT 250 WORDS)

Computer Communication Networks↗

PubMedDate not supplied

Development of interactive patient-based multimedia computer programs in veterinary orthopedic radiology.

Three computerized multimedia programs on large and small animal veterinary orthopedic radiology were developed and implemented for the radiology curriculum as an alternative to traditional film-based laboratory learning. Programs utilized "hot words" (colored text words that displayed an overlaid image label that highlighted lesions) and interactive quizzes which responded appropriately to selected answers. "Hot words" helped students develop confidence in accurate lesion detection and the interactive quizzes transformed learning from a passive to an active process. Multiple examples were provided for reinforcement and concepts were incorporated from other clinical disciplines for curriculum integration. Programs were written using a presentation software program, Toolbook for DOS based platform, and contained radiographic images made by laser-scanning digitization. Multiple students could simultaneously access the programs through a network server. These pilot programs were implemented successfully and computerized multimedia presentation proved to be well suited to teaching radiology. Development of the programs required attention to a number of hardware, software, time and cost factors.

Computer Communication Networks↗

PubMed2006

Majority logic gate for magnetic quantum-dot cellular automata.

We describe the operation of, and demonstrate logic functionality in, networks of physically coupled, nanometer-scale magnets designed for digital computation in magnetic quantum-dot cellular automata (MQCA) systems. MQCA offer low power dissipation and high integration density of functional elements and operate at room temperature. The basic MQCA logic gate, that is, the three-input majority logic gate, is demonstrated.

Journal Article↗