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At least 811 records · Page 45Linked to original sources

PubMed2005

Visual learning by coevolutionary feature synthesis.

In this paper, a novel genetically inspired visual learning method is proposed. Given the training raster images, this general approach induces a sophisticated feature-based recognition system. It employs the paradigm of cooperative coevolution to handle the computational difficulty of this task. To represent the feature extraction agents, the linear genetic programming is used. The paper describes the learning algorithm and provides a firm rationale for its design. Different architectures of recognition systems are considered that employ the proposed feature synthesis method. An extensive experimental evaluation on the demanding real-world task of object recognition in synthetic aperture radar (SAR) imagery shows the ability of the proposed approach to attain high recognition performance in different operating conditions.

Algorithms↗

PubMed2006

Association of different prediction methods for determination of the efficiency and selectivity on neuron-based sensors.

A technique has been developed to determine the efficiency and the selectivity of a single neuron-based sensor in identifying the nature of the chemical agents in an unknown sample. This has been achieved by exploiting the unique electrical identifiers, also known as "signature patterns", generated by the neuronal cell membrane. These were generated based on the variations to the extracellular electrical activity, due to the effect of a broad range of chemical agents. We demonstrate the prediction capability of the sensor in identifying the nature of an unknown test sample from a combination of three chemical agents, namely, ethanol, pyrethroid, and hydrogen peroxide. This was achieved through a two-step process. The first step was experimentally achieved by in situ recording of the changes to the extracellular electrical activity from the sensing sites or the array of microelectrodes that form the platform for patterning neurons. Simultaneous optical characterization of the cell array during the sensing process was performed to identify the associated physiological changes. The second step was mathematical and was based on developing a library of signature patterns for a set of concentrations of the various combinations of the three chemical agents. Two variants of the nearest neighbor algorithm scheme - (a) partial distance search method, and (b) search tree method, were implemented for the accurate detection of all the components with varying concentrations in the test samples of unknown nature. This technique exhibits reliability in identification up to parts-per-billion (ppb) sensitivity. The capability of standardization of this technique for potential commercial applications is also discussed.

Action Potentials↗

PubMedDate not supplied

The epitheliome: agent-based modelling of the social behaviour of cells.

We have developed a new computational modelling paradigm for predicting the emergent behaviour resulting from the interaction of cells in epithelial tissue. As proof-of-concept, an agent-based model, in which there is a one-to-one correspondence between biological cells and software agents, has been coupled to a simple physical model. Behaviour of the computational model is compared with the growth characteristics of epithelial cells in monolayer culture, using growth media with low and physiological calcium concentrations. Results show a qualitative fit between the growth characteristics produced by the simulation and the in vitro cell models.

Algorithms↗

PubMed2006

User modeling and adaptation in health promotion dialogs with an animated character.

In this paper, we describe our experience with the design and implementation of an embodied conversational agent (ECA) that converses with users to change their dietary behavior. Our intent is to develop a system that dynamically models the agent and the user and adapts the agent's counseling dialog accordingly. Towards this end, we discuss our efforts to automatically determine the user's dietary behavior stage of change and attitude towards the agent on the basis of unconstrained typed text dialog, first with another person and then with an ECA controlled by an experimenter in a wizard of Oz study. We describe how the results of these studies have been incorporated into an algorithm that combines the results from simple parsing rules together with contextual features using a Bayesian network to determine user stage and attitude automatically.

Artificial Intelligence↗

PubMed1980

Osteoarthritis: perspectives on treatment.

Osteoarthritis is an almost universal complication of aging, analogous to arteriosclerosis. Most important in management is education of the patient, which fosters intelligent cooperation. Reduction of stress on affected joints is essential. Relief of symptoms can be achieved locally by steroid injection or systemically by administration of nonsteroidal antiinflammatory drugs, but complete obliteration of symptoms may cause harm by encouraging continued abuse of the damaged joint. When all else fails and the osteoarthritic joint is persistently painful even on limited use and/or its function has been greatly restricted, then replacement surgery should be considered.

Anti-Inflammatory Agents↗

PubMedDate not supplied

Bioresponsive phosphoester hydrogels for bone tissue engineering.

Bioresponsive and intelligent biomaterials are a vehicle for manipulating cell function to promote tissue development and/or tissue engineering. A photopolymerized hydrogel based on a phosphoester- poly(ethylene glycol) polymer (PhosPEG) was synthesized for application to marrow-derived mesenchymal stem cell (MSC) encapsulation and tissue engineering of bone. The phosphor-containing hydrogels were hydrolytically degradable and the rate of degradation increased in the presence of a bone-derived enzyme, alkaline phosphatase. Gene expression and protein analysis of encapsulated MSCs demonstrated that PhosPEG-PEG cogels containing an intermediate concentration of phosphorus promoted the gene expression of bone-specific markers including type I collagen, alkaline phosphatase, and osteonectin, without the addition of growth factors or other biological agents, compared with pure poly(ethylene glycol)-based gels. Secretion of alkaline phosphatase, osteocalcin, and osteonectin protein was also increased in the PhosPEG cogels. Mineralization of gels increased in the presence of phosphorus in both cellular and acellular constructs compared with PEG gels. In summary, phosphate-PEG-derived hydrogels increase gene expression of bone-specific markers, secretion of bone-related matrix, and mineralization and may have a potential impact on bone-engineering therapies.

Alkaline Phosphatase↗

PubMed2000

Edward P. Abraham, cell-free systems and the fungal biosynthesis of beta-lactams.

Today much is known about the biology of penicillin and cephalosporin production by fungi including the pathways, the biosynthetic enzymes including some crystal structures, the genes and their cloning, expression, sequencing and chromosomal locations, the regulation of the genes and enzymes and even some intelligent guesses about their evolutionary relationships. The key breakthrough that led to rapid progress in these areas was the subcellular work done by EDWARD P. ABRAHAM and his Oxford colleagues in the early 1970s. With his advice and encouragement, my laboratory was able to prepare reliably active soluble cell-free preparations which were instrumental in elucidation of the biosynthetic pathways in fungi (and also in bacteria) by laboratories throughout the world.

Anti-Bacterial Agents↗

PubMed2000

[Pharmacopuncture in combined treatment of children with neurosensory hypoacusis].

Pharmacopuncture treatment (cerebrolysin, cavinton, prozerin) was given to 120 children with neurosensory hypoacusis aged 4-15 years. The treatment consisted of 3 courses 10 days each with 7-10-day interval. The drugs were injected in the dose 0.1 ml in biologically active points according to the original technique. The treatment lowered tonal thresholds more than by 15 dB in 36% children. Speech intelligibility increased, head ache and nose in the ears relieved in 85% cases. Adaptation to the hearing aid was positive. Clinical evidence was confirmed by REG picture indicating normalization of hemodynamics. Pharmacopuncture is a promising method in the treatment of children with neurosensory hypoacusis.

Acupuncture Therapy↗

PubMed2003

EURISWEB--Web-based epidemiological surveillance of antibiotic-resistant pneumococci in day care centers.

BACKGROUND: EURIS (European Resistance Intervention Study) was launched as a multinational study in September of 2000 to identify the multitude of complex risk factors that contribute to the high carriage rate of drug resistant Streptococcus pneumoniae strains in children attending Day Care Centers in several European countries. Access to the very large number of data required the development of a web-based infrastructure - EURISWEB - that includes a relational online database, coupled with a query system for data retrieval, and allows integrative storage of demographic, clinical and molecular biology data generated in EURIS. METHODS: All components of the system were developed using open source programming tools: data storage management was supported by PostgreSQL, and the hypertext preprocessor to generate the web pages was implemented using PHP. The query system is based on a software agent running in the background specifically developed for EURIS. RESULTS: The website currently contains data related to 13,500 nasopharyngeal samples and over one million measures taken from 5,250 individual children, as well as over one thousand pre-made and user-made queries aggregated into several reports, approximately. It is presently in use by participating researchers from three countries (Iceland, Portugal and Sweden). CONCLUSION: An operational model centered on a PHP engine builds the interface between the user and the database automatically, allowing an easy maintenance of the system. The query system is also sufficiently adaptable to allow the integration of several advanced data analysis procedures far more demanding than simple queries, eventually including artificial intelligence predictive models.

Child↗

PubMedDate not supplied

Psychological study in children addicted to inhalation of volatile substances.

Deliberate inhalation of volatile substances is a common and harmful practice among young persons around the world. Psychological studies were performed in 40 children habituated to inhalation of volatile agents, with the aim to define the psychological profile of inhalers, particularly their reactions against frustration. A significant difference in the extrapunitive attitude (p less than 0.001) and in the reaction of ego-defense (p less than 0.02) was found in sniffers as compared with controls. Addicted children also showed inadequate handling of frustration, aggressive and defensive behaviours, and passive and irresponsible attitude when confronted with problems.

Administration, Inhalation↗

PubMed2002

Biological warfare in a historical perspective.

There are some early examples of biological warfare (BW), but in modern times it was used first for sabotage by Germany during WWI. Development of biological weapons on a military significant scale was initiated in several countries in the period between the world wars. During WWII, several countries had active programs such as the USA, UK, Canada, Germany, Japan and the Soviet Union. It was only Japan that on a fairly large scale used BW. The US program continued until 1969, when President Nixon took a decision to end it in connection with signing the BTWC. The Soviet Union had also continued its program after the war, and this was enhanced after signing the BTWC: in the 1980s the program consisted of around fifty facilities and involved around 60,000 people. The Soviet Union produced and maintained a large stockpile of BW-agents. After the collapse of the Soviet Union, and due to pressure from USA and UK, President Yeltsin issued a decree in 1992 banning continued offensive BW activity. However, there are still concerns of residual activity in Russia. Another program of concern is the Iraqi BW-program. After 10 years of UN inspections that were stopped in 1998, there are still many unanswered questions concerning the BW program. There was also a covert BW-program in South Africa that was terminated around 1993. There have also been a number of allegations of alleged use or possession. In addition, there are indications that 10-12 states are now trying to acquire BW, and this assessment is based on intelligence information, mainly from the USA. For example Iraq, North Korea, Iran, Syria, Sudan and Libya. Another aspect is the strong driving force of technology developments to promote this type of program, opening new risks for future potential military misuse.

Animals↗

PubMed2005

Exploring fungal biodiversity for the production of water-soluble pigments as potential natural food colorants.

The production of many currently authorized natural food colorants has a number of disadvantages, including a dependence on the supply of raw materials and variations in pigment extraction. Fungi provide a readily available alternative source of naturally derived food colorants that could easily be produced in high yields. The recent authorization of a fungal food colorant has fuelled research to explore the extraordinary chemical diversity and biodiversity of fungi for the biotechnological production of pigments as natural food colorants. These studies require an appropriate use of chemotaxonomic tools and a priori knowledge of fungal metabolites to carry out intelligent screening for known or novel colorants as lead compounds. Such screening would result in the preselection of some potential pigment producers and the deselection of pathogenic strains and toxin producers. With advances in gene technology, in the future it should be possible to employ metabolic engineering to create microbial cell factories for the production of food colorants.

Biodiversity↗

PubMed1995

MONI: an intelligent database and monitoring system for surveillance of nosocomial infections.

Recording, recognition, and prevention of nosocomial infections are the primary responsibilities of the hospital infection control unit. To perform these tasks, this unit needs information from diverse sources--the patient's symptoms and signs, microbiological and virological test results, and information regarding antibiotics and treatment come from different levels of healthcare delivery. Because of the large amount of data (e.g., about 300 microbiological requests daily) a computer system is required to store this information and to provide a means for subsequent evaluation. MONI (Monitoring of nosocomial infections) is an intelligent database and monitoring system for surveillance and detection of nosocomial infections. Data can be entered into the system manually as well as transferred automatically from external information systems. The central feature of the system is the automatic detection of and calling attention to conditions that may be a detriment to patient recovery, such as possible hospital-acquired infections, risk factors, diseases to be reported, etc. By using this system, we seek to reduce the frequency of infection and the frequency of nosocomial deaths by improving the quality of patient treatment, shortening the length of stay in a hospital, and the use of fewer and/or cheaper antibiotics. MONI provides a means to access relevant medical data (names of infectious agents, antibiotics, department names, monitoring rules, etc.) from a library. This library can be updated or otherwise modified, even during use. An infection control team using this system can customize it to suit the demands of that particular unit. Automatic data transfer from external information systems is made possible by tables that translate between different code systems. The system also offers flexibility; the program can be configured to adapt it for use in other hospitals and institutions. The core element of MONI is the monitoring module, which is implemented as a layer between data input and the database. Upon data acquisition, the system checks the input against several monitoring tools and alerts the user to matches, which may indicate an infection risk. Processing of a rule may be deferred, depending on complexity of the rule and the actual and estimated workload of the system. Examples of the monitoring guidelines are: (1) suspicion of nosocomial infection; (2) infection at a normally sterile site; (3) infection due to bacteria with unusual antibiotic sensitivity patterns; (4) lab report indicates that patient is treated with ineffective antibiotic; (5) possible choice for less expensive antibiotic; (6) infection which is required to be reported to state and/or health authorities; (7) patients receiving prophylactic antibiotics longer than medically indicated; and (8) infections of two or more patients in different wards with the same bacteria (cf. Evans 85). The MONI system was developed at one of the largest hospitals in Europe, the Vienna General Hospital (2,200 beds). This facility serves as the teaching hospital of the University of Vienna Medical School. The size of the hospital and the large amount of data made it necessary to introduce such a system into clinical routine. MONI was programmed in C and C++ with a state-of-the-art graphical user interface (Presentation Manager, Workplace Shell) for OS/2. IBM Database 2 for OS/2 (dB 2/2) was used in constructing the database. The layer between the database and the monitoring application is driven by the multitasking and interprocess communication abilities of OS/2. A pen-based support system that assists in mobile data acquisition is currently under development.

Anti-Bacterial Agents↗

PubMed2006

Colloidal microgels in drug delivery applications.

Colloidal microgels have recently received attention as environmentally responsive systems and now are increasingly used in applications as carriers for therapeutic drugs and diagnostic agents. Synthetic microgels consist of a crosslinked polymer network that provides a depot for loaded drugs, protection against environmental hazards and template for post-synthetic modification or vectorization of the drug carriers. The aim of this manuscript is to review recent attempts to develop new microgel formulations for oral drug delivery, to design metal-containing microgels for diagnostic and therapeutic applications, and to advance approaches including the systemic administration of microgels. Novel nanogel drug delivery systems developed in the authors' laboratory are discussed in details including aspects of their synthesis, vectorization and recent applications for encapsulation of low molecular weight drugs or formulation of biological macromolecules. The findings reviewed here are encouraging for further development of the nanogels as intelligent drug carriers with such features as targeted delivery and triggered drug release.

Administration, Oral↗

PubMed2002

Formulation and biopharmaceutical issues in the development of drug delivery systems for antiparasitic drugs.

The development of really new antiparasitic drugs to market level is a very rare event. A large number of lead structures have already been screened and discarded, the market is large but poor, and the administrative barriers are increasingly high and costly. Novel antiparasitics must not only be better, they must also be substantially safer than the existing repertoire. There are two major aspects to drug development. One is the strategy of pathogen-specific biochemical intervention, the other the strategy of optimal formulation and application. This review focuses on the latter. In finding and adapting innovative and "intelligent", i.e. parasite- and disease-specific formulations and delivery systems, established but deficient drugs might be optimised, enhancing their efficiency and reducing negative side effects at relatively low cost. Further, many promising new ideas are severely hampered by the low water solubility of the antiparasitic drug. Here as well, some of the innovative drug formulation and delivery systems discussed below might offer highly efficient, while technologically simple, solutions.

Animals↗

PubMed1991

Interictal cognitive changes in epilepsy.

There is little evidence for significant intellectual deterioration in well-controlled seizure disorders. With recurrent convulsive seizures, the picture is less clear and depends on severity, type, age of onset, and frequency of toxic levels of antiepileptic drugs (see Table 1). In the interictal state, deficits in verbal language and memory have been observed, especially in patients with complex partial seizure foci in the left (dominant) hemisphere. The memory deficits appear to affect new learning and retention of material; the verbal deficits are more subtle, affecting word-finding, verbal fluency, and comprehension abilities. Both of these changes may either go unnoticed by the patient in day to day activities or be attributed to the effects of antiepileptic medication. Antiepileptic drugs can also affect interictal cognitive functioning. The worst of these appears to be phenobarbital; phenytoin has an intermediate effect; valproic acid and carbamazepine as single agents seem to produce fewer adverse effects. However, individual patients may be particularly sensitive to cognitive side effects of certain drugs. Finally, attention deficits and slowing of cognitive processes, either chronically or intermittently, appear to affect all seizure patients to some extent. The syndrome is more prominent in frontal or generalized seizure patterns. The intermittent nature of these disturbances has been emphasized in recent research on subclinical interictal spike-wave electrical phenomena.

Anticonvulsants↗

PubMed2004

Relationships between cognitive and neurological performance in neuroleptic-naïve psychosis.

The authors explored relationships between neuropsychological performance and neurological exam abnormalities in 86 never-medicated patients with nonorganic psychosis (59 with schizophrenia or schizoaffective disorder) and 51 healthy subjects. Assessments include a reliable subset of the Neurological Evaluation Scale (rNES) and several neuropsychological tests of attention, executive function, memory, and current and premorbid intelligence. Principal components analysis of the rNES yielded two main factors. Of these, CogPer (consisting of more cognitively demanding perceptual tasks) showed stronger relationships than RepMot (consisting of repetitive manual motor tasks) to neuropsychological measures. Customarily, frontal neuropsychological tasks also relate more strongly to CogPer than to RepMot. Approximately one-half of the variability in these cognitive and neurological assessments is shared.

Adult↗

PubMed2004

Basic problems of serological laboratory diagnosis.

Serological laboratory diagnosis of infectious diseases is inflicted with several kinds of basic problems. One difficulty relates to the fact that the serological diagnosis of infectious diseases is double indirect: The first indirect aim in diagnosing an infectious disease is to identify the microbial agent that caused the disease. The second indirect aim is to identify this infectious agent by measuring the patient's immune response to the potential agent. Thus, the serological test is neither measuring directly disease nor the cause of the disease, but the patient's immune system. The latter poses another type of problem, because each person's immune system is unique. The immune response to an infectious agent is usually of polyclonal nature, and the exact physicochemical properties of antibodies are unique for each clone of antibody. The clonal makeup and composition and, therefore, the way an individual's immune system sees an infectious agent, depends not only on the genetic background of the person but also on the individual experience from former encounters with various infectious agents. In consequence, the reaction of a patient's serum in an analytical system is not precisely predictable. Also, the antigenic makeup of an infectious agent is not always foreseeable. Antigenic variations leading to different serotypes is a quite common phenomenon. Altogether, these biological problems lead to complexities in selecting the appropriate tests and strategies for testing, in interpreting the results, and in standardizing serological test systems. For that reason, a close collaboration of the laboratory with the clinic is mandatory to avoid erroneous conclusions from serological test results, which might lead to wrong decisions in patient care.

Antibody Affinity↗