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At least 973 records · Page 54Linked to original sources
PubMed2005

A longitudinal assessment of inter-sectoral participation in a community-based diabetes prevention programme.

To understand the development of inter-sectoral participation in the three intervention municipalities of Stockholm Diabetes Prevention Programme (SDPP) case studies with a longitudinal assessment were conducted using the spidergram method, document analysis and group discussions. At three time points, the members of the local steering committees assessed the extent of participation from narrow to wide inter-sectoral participation in five key areas: planning, resources, leadership, network and implementation. Wide participation of various interest groups was recognised in planning and implementing activities whereas local resources, the representation of the leadership and the extent of the network were perceived as more restricted. Expert involvement varied during the programme period but was not regarded as exerting control over the local programmes. Participation within the local steering committees decreased, with a stronger focus on the project co-ordinator and other local partners in latter years. The extent of partner engagement increased due to focusing on activities approaching multi-sector collaboration and institutionalisation. Overall, communication and shared responsibility appeared critical in influencing both the development and perception of participation. In conclusion, to understand the dynamic process of participation at different times, areas and levels, the development and use of evaluation designs combining different methods and information sources throughout the lifespan of a project are recommended.

Communication↗
PubMed1994

Contractile proteins and nonerythroid spectrin in oogenesis of Xenopus laevis.

The distribution of contractile proteins, actin and myosin, and an actin-binding protein, spectrin, was studied in oogenesis of Xenopus laevis. These proteins are present in oocytes already at the previtellogenic stages, which are characterized by their diffuse distribution. The localization of proteins changed with the beginning of vitellogenesis. At all vitellogenic stages, including the fully grown oocyte, animal-vegetal differences were noted in localization of actin and myosin: in the animal hemisphere they appear as fibrillar-like structures, while in the vegetal one they are localized around the yolk platelets. By the end of the oocyte's growth, a cortical gradient appeared: predominant localization of actin and myosin in the cortical area. As the oocyte maturation proceeded, the distribution of actin and myosin again became diffuse and nonuniform, so that a cortical gradient appears. At the beginning of vitellogenesis spectrin is distributed as a network all over the ooplasm, while in the fully grown oocyte it is localized mostly in the subcortical area of the animal hemisphere and, as individual inclusions, in other regions of the oocyte. No spectrin is found by the end of maturation. Actin, myosin, and spectrin are also present in the oocyte's nuclei. Changes in the distribution of contractile proteins and spectrin during oocyte maturation are discussed with respect to the development of cortical contractility, as well as to the changes in spatial distribution of yolk platelets and regional sensitivity of the maturing oocyte to cytochalasin B.

Actins↗
PubMed2006

Functional local connections with differential activity-dependence and critical periods surrounding the primary auditory cortex in rat cerebral slices.

Sensory information is processed in neural networks connecting the primary sensory cortices with surrounding higher areas. Here, we investigated the properties of local connections between the primary auditory cortex (area 41) and surrounding areas (areas 20, 36, 18a and 39) in rat cerebral slices. Neural activities elicited by repetitive electrical stimulation were visualized using the activity-dependent changes in endogenous fluorescence derived from mitochondrial flavoproteins, which mostly reflect activities produced by polysynaptic glutamatergic transmission. Polysynaptic feedforward propagation was dominant compared with the corresponding polysynaptic feedback propagation between the primary (area 41) and secondary (areas 20 and 36) auditory cortices, while such a tendency was less clear in other pathways. Long inter-areal (>1 mm) propagation with the same dominancy was observed after layer V stimulation between areas 41 and 20, and was not affected by cutting the underlying white matter. Activity-dependent changes in neural activities induced by low-frequency stimulation in the presence of 1 microM bicuculline were investigated using Ca2+ imaging. Significant potentiation of the polysynaptic Ca2+ activities was only observed in polysynaptic feedforward pathways from the primary to secondary auditory cortices. Experience-dependence of the connections between areas 41 and 20 was investigated using flavoprotein fluorescence imaging. The activities from areas 41 to 20 were reduced by cochlear lesions produced at P12 but not at P28, while the activities from areas 20 to 41 were reduced by the lesions at P28, suggesting the critical period for the polysynaptic feedforward connection was before P28, while for the polysynaptic feedback connection was after P28.

Animals↗
PubMed2001

Spatially structured metapopulation models: global and local assessment of metapopulation capacity.

We model metapopulation dynamics in finite networks of discrete habitat patches with given areas and spatial locations. We define and analyze two simple and ecologically intuitive measures of the capacity of the habitat patch network to support a viable metapopulation. Metapopulation persistence capacity lambda(M) defines the threshold condition for long-term metapopulation persistence as lambda(M)>delta, where delta is defined by the extinction and colonization rate parameters of the focal species. Metapopulation invasion capacity lambda(I) sets the condition for successful invasion of an empty network from one small local population as lambda(I)>delta. The metapopulation capacities lambda(M) and lambda(I) are defined as the leading eigenvalue or a comparable quantity of an appropriate "landscape" matrix. Based on these definitions, we present a classification of a very general class of deterministic, continuous-time and discrete-time metapopulation models. Two specific models are analyzed in greater detail: a spatially realistic version of the continuous-time Levins model and the discrete-time incidence function model with propagule size-dependent colonization rate and a rescue effect. In both models we assume that the extinction rate increases with decreasing patch area and that the colonization rate increases with patch connectivity. In the spatially realistic Levins model, the two types of metapopulation capacities coincide, whereas the incidence function model possesses a strong Allee effect characterized by lambda(I)=0. For these two models, we show that the metapopulation capacities can be considered as simple sums of contributions from individual habitat patches, given by the elements of the leading eigenvector or comparable quantities. We may therefore assess the significance of particular habitat patches, including new patches that might be added to the network, for the metapopulation capacities of the network as a whole. We derive useful approximations for both the threshold conditions and the equilibrium states in the two models. The metapopulation capacities and the measures of the dynamic significance of particular patches can be calculated for real patch networks for applications in metapopulation ecology, landscape ecology, and conservation biology.

Animals↗
PubMed1996

The geography of availability and driving after drinking.

This paper reports on an analysis of geographically based data from four communities conducted to evaluate relationships between measures of the physical availability of alcohol and rates of driving after drinking. From a review of the literature, it was expected that rates of driving after drinking would be directly related to the availability of alcohol at on-premise establishments. Based on theoretical arguments regarding the life activities which underlie drinking and driving it was expected that the effects of availability upon these outcomes would extend significantly beyond the local areas of outlets. Taking into account the geographic variations in environmental characteristics (road network density, traffic flow, population density), and socioeconomic (age, gender, race, marital status, income, employment) and drinking characteristics (rates of abstention, frequency and quantity of use) of resident populations, a spatial analysis of drinking driving and alcohol-related crashes was conducted. The results of the analysis showed that physical availability was unrelated to self-reports of driving after drinking and driving while intoxicated and significantly related to rates of single vehicle night-time crashes. In the latter case, physical availability affected both local and adjacent area rates of crashing.

Accidents, Traffic↗
PubMed2000

Cortical dynamics of memory.

Memory networks are formed in the cerebral cortex by associative processes, following Hebbian principles of synaptic modulation. Sensory and motor memory networks are made of elementary representations in cell assemblies of primary sensory and motor cortex (phyletic memory). Higher-order individual memories, e.g. episodic, semantic, conceptual - are represented in hierarchically organized neuronal networks of the cortex of association. Perceptual memories are organized in posterior (post-rolandic) cortex, motor (executive) memories in cortex of the frontal lobe. Memory networks overlap and interact profusely with one another, such that a cellular assembly can be part of many memories or networks. Working memory essentially consists in the temporary activation of a memory network, as needed for the execution of successive acts in a temporal structure of behavior. That activation of the network is maintained by recurrent excitation through reentrant circuits. The recurrent reentry may occur within local circuits as well as between separate cortical areas. In either case. recurrence binds together the associated components of the network and thus of the memory it represents.

Animals↗
PubMed1987

[Characteristics of the structural organization of the epicardial lymphatic network of the heart in young children].

In infancy formation of the epicardial lymphatic network is not completed, its spatial organization is polymorphic and depends on localization in the heart. Already in newborns at the apex cordis small areas of regularly formed double-layered lymphatic network are noted. In all other parts the network is monolayered. Near the apex cordis its loops are finer, there are more closed loops. In the middle and superior third of the ventricles the lymphatic network density is less, a great number of open loops and lateral blind protrusions are recorded. Presence of the areas with double-layered network in the apex cordis is connected with a thicker myocardium in this part, and certain increase of its area during infancy demonstrates that there is a tendency of gradual formation of the epicardial lymphatic network from the apex towards the base of the organ.

Child, Preschool↗
PubMed2005

Function of local networks in palliative care: a Dutch view.

BACKGROUND: Although network formation is considered an effective method of stimulating the integrated delivery of palliative care, scientific evidence on the usefulness of network formation is scarce. In 1998 the Ministry of Health of The Netherlands started a 5-year stimulation program on palliative care by founding and funding six regional Centres for the Development of Palliative Care. These centers were structured around pivotal organizations such as university hospitals and comprehensive cancer centers. As part of the stimulation program a locoregional network model was introduced within each center for the Development of Palliative Care to integrate palliative care services in the Dutch health care system. OBJECTIVE: We performed a study on network formation in the southwestern area of The Netherlands with 2.4 million inhabitants. The study aimed to answer the following questions: (1) how do networks in palliative care develop, which care providers participate and how do they function? (2) which are the achievements of the palliative care networks as perceived by their participants? (3) which are the success factors of the palliative care networks according to their participants and which factors predict the achievements? DESIGN: Between September 2000 and January 2004 eight local palliative care networks in the region of the Center for Development of Palliative Care-Rotterdam (southwestern area of The Netherlands) were closely followed to gain information on their characteristics and developmental course. MEASUREMENTS: At the start of the study semistructured interviews were held with the coordinators of the eight networks. The information from these interviews and from the network documents were used to constitute a questionnaire to assess the opinions and experiences of the network participants. RESULTS: According to the vast majority of responders, the most important reason to install the networks was the lack of integration between the existing local health care services. The networks were initiated to stimulate mutual collaboration, improve accessibility to health care services and increase the quality of these services. The most important achievements obtained by the palliative care networks were: increase in personal contacts between colleagues in a region, improved engagement and collaboration between participating organizations, enhanced insight in the health care provisions, joined initiatives for the development of new care products, and organization of patient-tailored care. Important success factors for the networks were deemed: fruitful mutual contacts, regular funding and the collective development of care products. By logistic regression analyses, the collective development of new care products and the organization of case discussions between caregivers from different health care services turned out to be the most important predictors for success of the palliative care networks. CONCLUSIONS: Projects that stimulate the communication between professionals appear to improve the mutual collaboration between individual participants and between the participating organizations, which consequently enhances the quality of palliative care.

Community Networks↗
PubMed2004

New approaches for exploring anatomical and functional connectivity in the human brain.

Information processing in the primate brain is based on the complementary principles of modular and distributed information processing. The former emphasizes the specialization of functions within different brain areas. The latter emphasizes the massively parallel nature of brain networks and the fact that function also emerges from the flow of information between brain areas. The localization of function to specific brain areas ("functional segregation") is the commonest approach to investigating function; however, an emerging, complementary approach ("functional integration") describes function in terms of the information flow across networks of areas. Here, we highlight recent advances in neuroimaging methodology that have made it possible to investigate the anatomical architecture of networks in the living human brain with diffusion tensor imaging (DTI). We also highlight recent thinking on the ways in which functional imaging can be used to characterize information transmission across networks in the human brain (functional and effective connectivity).

Animals↗
PubMed1996

Kainic acid versus carbachol induced emotional-defensive response in the cat.

The emotional-defensive response (EDR) and accompanied neurotoxic and electroencephalographic (EEG) effects induced by injection of kainic acid (KA, 0.1; 0.2 microgram) into the midbrain periaqueductal grey region (PAG) and antero-medial hypothalamus (AMH) in the cat were examined and compared with EDR and accompanied neurotoxic and EEG effects induced by injection of cholinergic agent, carbachol (CCH), into the same sites. The injections of KA (0.2 microgram) into the PAG induced EDR which closely resembled the defense behavior typically observed after administration of CCH. However, in contrast to CCH-induced EDR, the defensive response induced by KA was found to be accompanied by EEG symptoms of epileptiform activity in the limbic cortex and a massive cell loss in the site of injection. It is proposed that KA-induced EDR and seizure activity may have resulted from the activation of different cell populations localized either in the vicinity of the injection (i.e., PAG region) and in the area remote from the injection loci, the limbic cortex. KA induced activation of PAG neuronal network would trigger the 'local response' (emotional-defensive response) and produce a remote effect-epileptiform activity.

Agonistic Behavior↗
PubMed1995

A simple competitive account of some response properties of visual neurons in area MSTd.

A simple and biologically plausible model is proposed to simulate the optic flow computation taking place in the dorsal part of medial superior temporal (MSTd) area of the visual cortex in the primates' brain. The model is a neural network composed of competitive learning layers. The input layer of the network simulates the neurons in the middle temporal (MT) area that selectively respond to the visual stimuli of the input motion patterns with different local velocities. The output layer of the network simulates the MSTd neurons that selectively respond to different types of optic flow motion patterns including planar, circular, radial, and spiral motions. Simulation results obtained from this model show that the behaviors of the output nodes of the network resemble very closely the known responsive properties of the MSTd neurons found neurophysiologically, such as the existence of three types of MSTd neurons that respond, respectively, to one, two, or three types of the input motion patterns with different position dependences, and the continuum of response selectivity formed by the three types of neurons.

Animals↗
PubMed1985

The structure and effectiveness of the U.S. organ procurement system.

Despite the overall success of the U.S. organ procurement network, local success rates vary widely, from three kidneys procured for transplantation per million population in some areas to 40 per million in others. Of the two kinds of organ procurement agencies (OPAs) that operate within the network--independently organized and hospital based--the former are more successful. In this study, I analyze the organizational characteristics of the two kinds of OPAs in an attempt to account for their differing success rates. I found that organ procurement appears to require an effective program of "medical marketing," that is, a commitment to convincing medical professionals in intensive care units to refer potential donors to an OPA.

Allied Health Personnel↗
PubMed1999

Corticotropin-releasing factor--immunolabeled fibers in brain regions with localized kainate neurotoxicity.

Rats treated with the neuroepileptic drug, kainic acid, exhibit a specific regional pattern of neurodegeneration 24 h following onset of acute limbic status epilepticus. At 24 h post-seizure, the areas undergoing neurodegeneration also exhibit substantial amounts of the neuropeptide corticotropin-releasing factor (CRF) which is not present under normal conditions. In experimental brains, CRF is localized immunocytochemically to cells and densely labeled fibers in areas with neurodegeneration. Networks of CRF fibers closely surround moribund neurons staining intensely for acid fuchsin. Acid fuchsin, an acidophilic dye, is used routinely as a marker for irreversible neuronal injury, and acid fuchsin-positive neurons are identified in specific areas affected by kainic neurotoxicity. Evidence exists in the literature that CRF functions in brain as a excitatory neurotransmitter/neuromodulator. Under certain pathological conditions (i.e., seizures, brain trauma, ischemia), it has been postulated that CRF could act as an neurotoxic agent. This study provides anatomical evidence that CRF may function following seizures as an neurotoxin because of the close proximity of CRF-labeled fibers to degenerating neurons.

Animals↗
PubMed2002

Characterization of Cep135, a novel coiled-coil centrosomal protein involved in microtubule organization in mammalian cells.

By using monoclonal antibodies raised against isolated clam centrosomes, we have identified a novel 135-kD centrosomal protein (Cep135), present in a wide range of organisms. Cep135 is located at the centrosome throughout the cell cycle, and localization is independent of the microtubule network. It distributes throughout the centrosomal area in association with the electron-dense material surrounding centrioles. Sequence analysis of cDNA isolated from CHO cells predicted a protein of 1,145-amino acid residues with extensive alpha-helical domains. Expression of a series of deletion constructs revealed the presence of three independent centrosome-targeting domains. Overexpression of Cep135 resulted in the accumulation of unique whorl-like particles in both the centrosome and the cytoplasm. Although their size, shape, and number varied according to the level of protein expression, these whorls were composed of parallel dense lines arranged in a 6-nm space. Altered levels of Cep135 by protein overexpression and/or suppression of endogenous Cep135 by RNA interference caused disorganization of interphase and mitotic spindle microtubules. Thus, Cep135 may play an important role in the centrosomal function of organizing microtubules in mammalian cells.

Animals↗
PubMed2004

The social capital:health relationship in two disadvantaged neighbourhoods.

OBJECTIVES: Research into the social determinants of health inequalities is increasingly focusing on macro-level forces affecting individuals and communities. The concept of social capital has been at the centre of this research as a potential explanatory framework for understanding these inequalities. The aim of this study was to identify the components that define social capital and its relationship to self-reported health in two neighbourhoods known to be disadvantaged in south-western Sydney. METHODS: This study uses data from cross-sectional household (door-knock) surveys originally developed as evaluation tools for neighbourhood based interventions. Secondary analyses including factor analysis and multiple regression analysis were used to provide empirical evidence of the components defining social capital and how these, as a concept, were associated with self-reported health. RESULTS: The study revealed six common social capital components in each sample and an additional component in one neighbourhood. These included neighbourhood attachment, support networks, feelings of trust and reciprocity, local engagement, personal attachment to the area, feelings about safety and proactivity in the social context. The social capital model incorporating demographic and socio-economic characteristics explained 23.4% of health variance in one neighbourhood, and 19.3% in the other. Examining the social capital:health relationship revealed that with the exception of feelings of trust and reciprocity, no other social capital component made significant contributions to explaining health variance and that macro-level factors such as housing conditions and employment opportunities emerged as key explanatory factors. CONCLUSION: If interventions are to use social capital as a way of addressing health inequalities, these need to look closely at the role of trust for improving health outcomes of deprived populations as well as ensuring access to resources and infrastructure.

Adolescent↗
PubMed2006

Scoping supermarket availability and accessibility by socio-economic status in Adelaide.

METHODS: We use a geographic information system to measure availability and accessibility of supermarkets in four case study local government areas (LGAs). The location of supermarkets is analysed in relation to residential dwellings, car ownership and in terms of travel distance along the road network. RESULTS: This methodology identifies differences in both availability and accessibility between and within LGAs. It shows that a local-level approach to the issue of food deserts is warranted and suggests that generalisations based on large geographic areas are unlikely to be meaningful. CONCLUSIONS: A significant number of households live in 'food deserts' in Adelaide and these can only be identified using a local-level approach.

Geographic Information Systems↗
PubMedDate not supplied

Digital echocardiography and telemedicine applications in pediatric cardiology.

Digital echocardiography offers several advantages over videotape, including easy review, comparison, storage, postprocessing, and sharing of studies, quantitative analysis, and superior resolution. Newer echocardiography systems can write digital data to computer hardware, whereas older systems require digitization of analog data. Clinical and digital data compression is required to reduce study size. Clinical compression has been validated in several adult studies and one pediatric study. JPEG and MPEG digital compression ratios of 26:1 and 200:1, respectively, approximate S-videotape quality. JPEG is the DICOM 3.0 standard and is ideal for short loops, serial comparisons, and quantitative analysis. MPEG (the motion picture standard) lends itself to digitization of video streams and may be more attractive to pediatric cardiologists. Options for data storage and transfer range from limited local review to multiple offline review stations linked by a wide-area network. Telemedicine expands the capabilities of digital echocardiography in a "store and forward" or "real-time" format. Real-time neonatal telecardiology is accurate, impacts patient care, is cost-effective, and does not increase utilization. Cost, increased reliance on sonographers' skills, lack of accepted standards, and legal, licensure, and billing issues are obstacles to widespread acceptance of digital echocardiography and telemedicine.

Echocardiography↗
PubMed2005

In vitro expression of natriuretic peptides in cardiomyocytes differentiated from monkey embryonic stem cells.

Functional characterization of ES cell-derived cardiomyocytes is important for differentiation control and application to the cell therapy. One of the crucial functions of cardiomyocytes is a production of atrial and brain natriuretic peptides (ANP and BNP, respectively), which have important endocrine, autocrine, and paracrine functions. In this study, we focused on the functional aspect of the cardiomyocytes differentiated from monkey ES cells in vitro and investigated the expression of ANP and BNP. Spontaneously contracting cells showed nodal-like action potentials, and expression of ANP and BNP by RT-PCR and immunocytochemistry. Interestingly, ANP and BNP expressions were detected as immunoreactive granules in the perinuclear area and these signals appeared to co-localize with trans-Golgi network. These findings suggest that monkey ES cells were able to differentiate into cardiomyocytes with functional characteristics in vitro and therefore can be used as a useful model to study mechanisms and functions in early cardiogenesis.

Action Potentials↗