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PubMed1999

The challenges of employing performance monitoring in public health community-based efforts: a case study.

The development of community-based coalitions has acquired great popularity as a health promotion strategy. The Institute of Medicine recommends that community-based health coalitions employ a performance monitoring process in their efforts. The results of the current study indicate that in the community setting, implementing a performance monitoring process and sustaining the specialized functions entailed in this strategy are challenging. Many of the challenges result from fundamental differences between the organizational environment of bureaucracies--in which these techniques are developed, supported, and greatly successful--and the realities of the loosely-structured and resource-limited community environment. The performance monitoring process is measurement-driven. One challenge of implementing this process at the community level is that public health problems of local concern are not always documented in current surveillance systems and thus a performance monitoring strategy is not always, or immediately, applicable. When data which document a health problem of local concern are available, a second challenge facing community-based coalitions is acquiring the resources, especially the wide-range of specialized expertise, required to fully implement and sustain the performance monitoring process. These issues are examined in the context of the Massachusetts Department of Public Health's Community Health Network Area (CHNA) Initiative which entails the formation of coalitions of local health service providers. The CHNA initiative is a statewide project in which health service providers in specified geographic regions work collaboratively on health improvement projects.

Adolescent↗
PubMed2003

Explicit neural representations, recursive neural networks and conscious visual perception.

The fundamental question as to whether the neural correlates of any given conscious visual experience are expressed locally within a given cortical area or more globally within some widely distributed network remains unresolved. We inquire as to whether recursive processing-by which we mean the combined flow and integrated outcome of afferent and recurrent activity across a series of cortical areas-is essential for the emergence of conscious visual experience. If so, we further inquire as to whether such recursive processing is essential only for loops between extrastriate cortical areas explicitly representing experiences such as color or motion back to V1 or whether it is processing between still higher levels and the areas computing such explicit representations that is exclusively or additionally essential for visual experience. If recursive processing is not essential for the emergence of conscious visual experience, then it should also be possible to determine whether it is only the intracortical sensory processing within areas computing explicit sensory representations that is required for perceptual experience or whether it is the subsequent processing of the output of such areas within more anterior cortical regions that engenders perception. The present analysis suggests that the questions posed here may ultimately become experimentally resolvable. Whatever the outcome, the results will likely open new approaches to identify the neural correlates of conscious visual perception.

Animals↗
PubMed1997

Dynamical behavior of a neural network with periodical external inputs.

Localized neural populations in different brain areas can undergo periodical external influence. To study this situation we consider the well known model by Wilson and Cowan (1972). It describes the evolution of two interconnected neuronal subpopulations of excitatory and inhibitory neurons correspondingly. Besides, it could be considered as a model of an abstract self-regulatory system. We describe and reveal underlying mechanisms of two regimes of forced oscillations in the model. In the first one the system acts as a phase comparator, demonstrating high sensitivity to a value of a phase shift between inputs to excitatory and inhibitory neurons. In the second regime it acts similar to a low pass filter: amplitudes of forced oscillations of the both components are not small and almost constant for low frequencies of the external input to the excitatory subpopulation. But they decrease significantly when the frequency becomes rather high. For simplified versions of the model analytical estimates for corresponding ranges of parameters are derived. It is shown that they are in good agreement with the results of computer simulations.

Animals↗
PubMed2002

Dynamics of extinction and the selection of nature reserves.

Familiar quantitative reserve-selection techniques are tailored to simple decision problems, where the representation of species is sought at minimum cost. However, conservationists have begun to ask whether representing species in reserve networks is sufficient to avoid local extinctions within selected areas. An attractive, but previously untested idea is to model current species' probabilities of occurrence as an estimate of local persistence in the near future. Using distribution data for passerine birds in Great Britain, we show that (i) species' probabilities of occurrence are negatively related to local probabilities of extinction, at least when a particular 20-year period is considered, and (ii) local extinctions can be reduced if areas are selected to maximize current species' probabilities of occurrence We suggest that more extinctions could be avoided if even a simple treatment of persistence were to be incorporated within reserve selection methods.

Animals↗
PubMed1989

Keratinocytes in lesional skin of atopic eczema bear HLA-DR, CD1a and IgE molecules.

Apparently normal, and lesional skin from patients with atopic eczema were investigated immunohistochemically with anti-HLA-DR, -CD1a and -IgE antisera. A CD1a+ intercellular pattern was observed in uninvolved skin in the majority of the patients whereas an HLA-DR+/CD1a+ network, mostly localized in basal and supra-basal areas, was shown in lesional skin of virtually all of them. Moreover, an HLA-DR+/CD1a+IgE+ intercellular pattern was observed in some of the patients only and was predominantly localized in those areas characterized by lymphocyte exocytosis, spongiosis or vesicle formation. Whether keratinocytes are able to synthesize CD1a antigen and Fc epsilon R or if these molecules are only produced and shed by CD1a+/IgE+ epidermal dendritic cells remains unclear.

Antigens, CD↗
PubMed2003

An artificial neural network for prostate cancer staging when serum prostate specific antigen is 10 ng./ml. or less.

PURPOSE: An artificial neural network was developed to improve the prediction of pathological stage before radical prostatectomy based on variables available at biopsy and clinical parameters. MATERIALS AND METHODS: We used the prospectively accrued European prostate cancer detection data base to train an artificial neural network to predict pathological stage in 200 men with serum prostate specific antigen (PSA) 10 ng./ml. or less who underwent radical prostatectomy. Variables included in the artificial neural network were patient age, serum PSA, free-to-total PSA ratio, PSA velocity, transrectal ultrasound calculated total and transition zone volumes with their associated PSA parameters (transition zone PSA density and PSA density), digital rectal examination and Gleason score on biopsy. Two multilayer perceptron neural networks were trained on the remaining variables. Data on the 200 patients were divided randomly into a training set, a test set and a validation or prospective set. RESULTS: Overall classification accuracy of the artificial neural network was 92.7% and 84.2% for organ confined and advanced prostate cancer staging, respectively. For preoperatively predicting local versus advanced stage the area under the ROC curve for the artificial neural network was significantly larger (0.91) compared with logistic regression analysis (0.83), Gleason score (0.69), PSA density (0.68), prostate transition zone volume (0.63) and serum PSA (0.62) (all p <0.01). CONCLUSIONS: The artificial neural network outperformed logistic regression analysis and correctly predicted pathological stage in more than 90% of the validation patients with serum PSA 10 ng./ml. or less based on clinical, biochemical and biopsy data. In the future artificial neural networks may represent a significant step for improved staging of prostate cancer when counseling patients referred for radical prostatectomy or other curative treatments.

Adult↗
PubMed2003

The neural correlates of conscious vision.

Conflicting accounts of the neurobiology of consciousness have emerged from previous imaging studies. Some studies suggest that visual consciousness relates to a distributed network of frontal and partietal regions while others point to localized activity within individual visual areas. While the two positions seem mutually exclusive, timing issues may help reconcile the two. Networks that appear unified in functional magnetic resonance imaging (fMRI) studies may reflect processes that are widely distributed in time. To help resolve this issue, we have investigated timing across a network correlating with consciousness in parallel fMRI and evoked potential (EP) studies of grating stimuli. At threshold, a stimulus is perceived on some occasions but not on others, dissociating sensory input and perception. We have found correlates of consciousness in the occipital lobe at 100 ms and in parietal, frontal, auditory and motor regions from 260 ms onwards. The broad temporal and spatial distribution of activity argues against a unified, distributed fronto-parietal correlate of consciousness. Instead, it suggests that correlates of consciousness are divided into primary and secondary network nodes, with early activity in the occipital lobe correlating with perception and later activity in downstream areas with secondary processes contingent on the outcome of earlier perceptual processing.

Adult↗
PubMed2006

Analyzing and shaping human attentional networks.

In this paper we outline a conception of attentional networks arising from imaging studies as connections between activated brain areas carrying out localized mental operations. We consider both the areas of functional activation (nodes) and the structural (DTI) and functional connections (DCM) between them in real time (EEG, frequency analysis) as important tools in analyzing the network. The efficiency of network function involves the time course of activation of nodes and their connectivity to other areas of the network. We outline landmarks in the development of brain networks underlying executive attention from infancy and childhood. We use individual differences in network efficiency to examine genetic alleles that are related to performance. We consider how animal studies might be used to determine the genes that influence network development. Finally we indicate how training may aid in enhancing attentional networks. Our goal is to show the wide range of methods that can be used to suggest and analyze models of network function in the study of attention.

Attention↗
PubMed2002

A network system of medical and welfare information service for the patients, their families, hospitals, local governments, and commercial companies in a medical service area.

A service information system using the Internet, which connected the various people who are related to medical treatment and nursing welfare, was constructed. An intractable neurological disease patient who lives in the Onga district, Fukuoka, Japan, and the people who are related to the service were chosen as test users in an experimental model. The communicated service information was divided into open-use data (electronic bulletin board, welfare service, medical care service, and link to private company service home page) and closed-use data (the individual patient's hysterics). The open data server was installed in an Internet service provider The open data could be accessed not only by the patient, but also by the family, information center, companies, hospitals, and nursing commodity store related to patient's nursing and medical treatment. Closed data server was installed in an information center (public health center). Only patient and information center staff can access the closed data. Patients should search and collect the service information of various medical and welfare services by themselves. Therefore, services prepared for the patient are difficult to know, and they cannot be sufficiently utilized. With the use of this information system, all usable service information became accessible, and patients could easily use it. The electronic bulletin board system (BBS) was used by patients for knowing each other or each others' family, and was used as a device for exchange of wisdom. Also, the questions for the specialist, such as doctor, dentist, teacher, physical therapist, care manager, welfare office staff member, and public health nurse, and the answers were shown on the BBS. By arranging data file, a reference of various patients in question and answer, which appeared in this BBS, was made as "advisory hints" and was added to the open data. The advisory hints became the new service information for the patients and their family. This BBS discovered the possibility of becoming an important information source for companies, hospital and, administration to know the requirements of patients and their families and the kind of services to be served. Although suppliers provide medical and welfare services for the patient, there is a tendency that the service information is sent by the suppliers at their own convenience. The information system in which various people participated was constructed in order to collect information for the patient, taking a patient-oriented approach. The result of the model test showed that this information system using Internet technology is a good system for both the service supplier and its receiver.

Access to Information↗
PubMed2006

Neural representation of language: activation versus long-range connectivity.

Cognitive functions are thought to build on connectivity within large-scale neuronal networks, rather than on strictly localized processes. Yet, present understanding of neural mechanisms of language function, as derived from neuroimaging, is based on mapping brain areas that are more active during specific linguistic tasks than in control conditions. Connectivity can then be evaluated among those areas. However, network nodes should ideally be determined based on their correlated time series of activity. Recent developments in analysis methods now facilitate localization and characterization of functionally connected neural networks directly from real-time magnetoencephalography data. Analysis of long-range connectivity might clarify and expand the view provided by traditional neurophysiological and hemodynamic activation studies. Here, we use silent reading as the example process.

Brain↗
PubMed1994

Classification of the enteric nerve cells of the porcine small intestine into two subpopulations using enzyme histochemical techniques.

Using acetylcholinesterase (AChE), nicotinamide adenine dinucleotide diaphorase (NADHd), and nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) enzyme histochemical techniques, the ganglionated plexuses of the porcine enteric nervous system were investigated in small intestine whole-mount preparations. Both AchE and NADHd techniques revealed a majority of the neurons in the ganglia of all three major plexuses. The AchE technique also demonstrated clearly the axodendritic networks of the plexus myentericus. Intraganglionic blank areas revealed the localization of negative cell groups. A very high correlation was found between the activity of both enzymes in one neuron, although this correlation was certainly not linear. Many neurons exhibited a stronger signal for one enzyme. A very small part of the positive nerve cells showed intense staining for both AchE and NADHd. The NADPHd technique demonstrated that the NADPHd-positive neurons fill the negative intraganglionic spaces in the ganglia. Double staining with the two other enzymes showed virtually no colocalization of NADPHd with either NADHd or AchE in the porcine jejunal enteric ganglia. Little negative intraganglionic spaces were seldom found, leaving room for perhaps still more negative enteric neurons. Based upon these results we suggest that the enteric neurons of the porcine small intestine can be subdivided into AchE-NADHd and NADPHd subpopulations. Since the latter colocalizes with the neuronal NO synthase enzyme, we further suggest a subdivision of the enteric nerve cells into AchE-NADHd and NOS-NADHd neurons.

Acetylcholinesterase↗
PubMed2006

Thrombin receptor expression is upregulated in prostate cancer.

BACKGROUND: Aberrant expression of protease-activated receptors (PARs) has been associated with increased angiogenesis, tumor growth, and metastasis of various cancers. We assessed the status of PAR1 expression in prostate cancer. METHODS: The study compared the abundance levels of PAR1 RNA and protein using real-time reverse-transcriptase polymerase chain reaction and immunoblotting in freshly resected prostate tissues from early localized-stage disease (n=9) to those from patients with advanced metastatic disease (n=7). PAR1 expression and localization was evaluated using immunohistochemical staining of prostate specimens with benign prostatic hyperplasia (n=27), early- (n=32) and advanced-stage (n=22) prostate cancer. Association analyses of PAR1 expression with expression of VEGF-family of growth factors, their receptors, and clinicopathological characteristics of the patients were also performed. RESULTS: PAR1 RNA expression in advanced-stage prostate was 2.39-fold higher (P=0.024) and its protein expression was 2.75-fold higher (P=5.89x10(-5)) when compared with early-stage prostate cancer. PAR1 expression was localized to endothelial cells in vascular network of prostate tumor areas. The expression of PAR1 correlated statistically significantly with advanced disease stage (P=0.0006) and pre-operative PSA levels (P=0.005) in these samples. CONCLUSIONS: These findings demonstrate that PAR1 expression is increased in prostate cancer. Its predominant expression in vascular network suggests that it may play a direct and crucial role in angiogenesis and could be a relevant target for therapeutic interventions to control or to prevent disease progression.

Adult↗
PubMed2002

Functional consequences of nutrient translocation in mycelial fungi.

Fungi are of fundamental importance for plant and microbial nutrition with primary roles in decomposition and nutrient recycling. They also have great potential for use in areas of biotechnology such as bioremediation of organic and inorganic pollutants and biocontrol of plant pathogens. In all these contexts, environmental heterogeneity has a strong influence on growth and function. A large class of fungi overcome the difficulties encountered in such environments by the mechanism of translocation which results in the internal redistribution of nutrients within the fungal mycelium. In this paper, we use a combination of experimental techniques and mathematical modelling to examine fungal growth in general, and in particular, translocation in the common soil saprophytic fungus Rhizoctonia solani. A detailed mathematical model is presented where translocation is considered to have both diffusive and metabolically-driven components. A calibration experiment provided the necessary parameter values. Growth experiments were compared with model solutions and thus we provide strong evidence that diffusion is the dominant mechanism for translocation in homogeneous environments. In heterogeneous environments, we conclude that diffusion is still vital for exploration, i.e. the expansion of the fungal network into the surrounding area. However, we also conclude that localized resources may be utilized faster if energy is invested, i.e. when exploitation of the fungal microenvironment is enhanced by metabolically driven translocation.

Food Chain↗
PubMed1998

Cortical control of saccades.

Saccadic eye movements are controlled by a cortical network composed of several oculomotor areas that are now accurately localized. Clinical and experimental studies have enabled us to understand their specific roles better. These areas are: (1) the parietal eye field (PEF) located in the intraparietal sulcus involved in visuospatial integration and in reflexive saccade triggering; (2) the frontal eye field (FEF), located in the precentral gyrus, involved in the preparation and the triggering of purposive saccades; and (3) the supplementary eye field (SEF) on the medial wall of the frontal lobe, probably involved in the temporal control of sequences of visually guided saccades and in eye-hand coordination. A putative cingulate eye field (CEF), located in the anterior cingulate cortex, would be involved in motivational modulation of voluntary saccades. Besides these motor areas, the dorsolateral prefrontal cortex (dlPFC) in the midfrontal gyrus is involved in reflexive saccade inhibition and visual short-term memory.

Cerebral Cortex↗
PubMedDate not supplied

Working with your local Medicare contractor to shape patient care.

When hospitals pursue appropriate Medicare coverage by interacting effectively with their local Medicare contractor, they have an opportunity to provide their patients with greater access to care and help their hospital meet important revenue objectives. This is especially true when ensuring Medicare coverage of appropriate cardiovascular services. Local contractors are private entities that administer national Medicare policies regionally and interpret the "gray areas" of coverage. This article will examine the local Medicare network; the way local contractors make Medicare policy; and how hospitals like yours can influence Medicare policy, with the ultimate goal of appropriately improving beneficiaries' access to care.

Cardiology↗
PubMed2004

[Disorders of executive consciousness].

UNLABELLED: Executive function is a higher order cognitive capacity that involves memory, perception and performance of complex tasks. Disorders of the executive functions are sign of lesions in the prefrontal cortex, involving the prefrontal-striatal-thalamic networks and the parietal association areas. According to signs and localization, five basic prefrontal syndromes are recognised. 1. Damage in posterior dorsolateral prefrontal cortex and subcortical nuclei causes the dorsolateral syndrome with impaired decision making, working memory and planning. 2. The ventromedial-orbitofrontal syndrome: if lesion spares the basal forebrain, memory can be preserved, but poor social decision making develops. 3. The dorsomedial syndrome consists of attention disorder, akinesia, mutism and apathy. 4. The bilateral ventrolateral prefrontal regions serve perception of self and environment. 5. The ventral lateral (verbalizer) area of the dominant hemisphere coordinates language. Executive impairments can be found in cerebrovascular, Parkinson's and other diseases of basal ganglia, and in frontotemporal lobar degeneration. The dorsolateral syndrome can be examined by the use of Wisconsin card sorting test, self ordered pointing task and the delayed response task. Prefrontal-basal function can be assessed by Gambling-, Faux Pas-, and Emotion identification tasks. CONCLUSIONS: 1. A dysexecutive syndrome does not fulfil the criteria of dementia. 2. A "frontal syndrome" is an indefinite eponym. Focal lesions in prefrontal systems lead to localization-specific symptoms, which can be defined by psychometric tests. 3. In neurological diseases associated with multifocal damage of the brain neuropsychologic tests may help to determine strategic lesions, which are responsible for the actual syndromes.

Akinetic Mutism↗
PubMed2005

Functional localization and double dissociations: the relationship between internal structure and behavior.

Lesioning studies are often used in cognitive neuroscience to make inferences about the architecture of cognition. Recently, computational models have been used to address some of the underlying assumptions-such as modularity and locality-often implicitly used when interpreting lesion data. In this article, we explore the "functional localization" assumption and its role in interpreting lesioning data, especially from double dissociations. The functional localization assumption states that units or subunits within an information processing system become functionally specialized for dealing with specific aspects of the input environment. Networks were trained on one of two problems-an abstract "rules and sub-rules" problem, and a more concrete "logic classification" problem-and then systematically lesioned. Networks were analyzed in terms of their overt behavior, and more importantly, in terms of their internal structure. Performance deficits in both form and magnitude could be directly related to the ablated internal structure of the networks. That is, if an ablated area had little or no functional localization, then little or no behavioral dissociations were observed. If, however, the ablated area had very specific internal structure, then very specific behavioral dissociations were observed. It is important to note, however, that there was not a one-to-one correspondence between internal structure and behavioral dissociations, implying that cognitive neuroscientists must be careful when using lesioning data to theorize about the functional architecture of cognition.

Brain↗
PubMed2005

Developmental refinement of inhibitory sound-localization circuits.

The ability to localize sound rapidly and accurately depends on the precise organization of inhibitory neuronal circuits in the auditory brainstem. However, the rules and mechanisms by which this precision is established during development are still poorly understood. Although activity-dependent reorganization has been known for over a decade to have a central role in this process, more recent studies have revealed an unanticipated degree of reorganization that occurs on levels ranging from cellular phenotype to network connectivity. These results suggest novel mechanisms by which immature inhibitory sound-localization circuits become optimized. Lessons from auditory brainstem circuits thus could provide insight into inhibitory development in other brain areas, where inhibitory networks are less experimentally accessible.

Age Factors↗