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PubMed2005

Social capital in settings with a high concentration of road traffic injuries. The case of Cuernavaca, Mexico.

There exists a differential ability within local communities to maintain effective social controls to prevent road traffic injuries (RTIs) in high risks areas. In 2002 we conducted a cross-sectional study in Cuernavaca, Mexico which incorporated 339 adults living in three areas which were characterized by high RTI concentrations. Multivariate analyses demonstrated that even when participants perceived RTIs as a local problem, they expressed no expectations that community members would exert social control through their involvement in local issues and law adherence. The study revealed four key conclusions regarding the association between the low levels of social capital and RTIs: (a) public roads are used solely for transportation, are not viewed as a communal space, and consequently reciprocity is not viewed as a relevant way of controlling behaviors in public places; (b) "strong immediate personal networks" bring about a lack of reciprocity between those sharing the public space which generates uncooperative behavior; (c) high levels of residential instability hinders the identification of common problems; (d) when there exists a low level of civic commitment and a scarcity of social resources directed towards the problem, the possibilities of social control over RTIs are low.

Accidents, Traffic↗
PubMed1994

Intracellular distribution of beta-actin mRNA is polarized in embryonic corneal epithelia.

The intracellular distribution of filamentous actin (F-actin), all actin isoforms and beta-actin mRNA were analyzed in whole-mount preparations of freshly isolated corneal epithelia. Filamentous actin distribution was analyzed with fluorescently tagged phalloidin. An antibody that recognizes an epitope on both globular (G-actin) and F-actin was used in an immunohistochemical analysis of actin protein distribution. Whole-mount epithelial tissues were examined with a confocal laser scanning microscope (CLSM). Biotinylated oligonucleotide probes specific for the beta-actin mRNA were used, and visualized with avidin-FITC. The intracellular localization of the beta-actin mRNA was similar to the F-actin protein distribution. In the most apical optical sections of embryonic cornea, actin staining delineated the cell borders and microvilli of the periderm cells. The actin is also detected as an organized network at the interface between the basal and periderm cells. At the level of the basal cell nucleus, F-actin is sparse, associating only with the lateral cell membranes. However, at the optical plane below the nuclei, the actin forms an elaborate actin cortical mat. Actin mRNA staining was visualized as discrete punctate areas. The beta-actin mRNA was positive at the optical plane just below the periderm cell apical membrane surface, similar to actin in microvilli. These cells also contained punctate staining near the cell membranes and in the periderm-basal cell junction area. At the level of the basal cell nucleus the actin mRNA was present in a punctate pattern along the cell membranes. Below the basal cell nuclei the actin mRNA staining increased at the level of the actin cortical mat. These experiments are the first demonstration that actin mRNA is polarized in embryonic corneal epithelia and co-localized with actin protein in an intact tissue.

Actins↗
PubMed1979

Electrophysiological studies on the neural networks among estrogen and progesterone effective brain areas on lordosis behavior of the rat.

The present study was performed in an attempt to elucidate the possible neural networks and their functional modification by progesterone among estrogen and progesterone effective brain areas for lordosis behavior of the rat. Single and multiple unit activities were recorded in the medial preoptic area (MPO), dorsomedial thalamic nucleus (MD), interpeduncular nucleus (IP) and ventral part of midbrain reticular formation (MRF), and single or train pulse stimulation was applied to the MPI, MD, IP, MRF, caudate-putamen (CP), habenular nucleus (HB), dorsal hippocampus (HPC), medial and lateral septum (m- and 1-SEPT) and lateral amygdala (1-AMYG). Unit activity was recorded under urethane anesthesia in ovariectomized rats pretreated with estrogen or with estrogen and progesterone. MPO units showed facilitatory responses to stimulation in the MRF, HB and 1-SEPT, and inhibitory responses to stimulation in the MD, HPC, m-SEPT and 1-AMYG in ovariectomized estrogen-primed rats. CP stimulation inhibited the MD unit activity. Stimulation in the IP had no effect on the MPO or MD units, while the IP units were affected by stimulation in the MPO, MD, CP and HB. MRF unit was accelerated by the MD and CP and inhibited by the MPO stimulation. In the ovariectomized, estrogen and progesterone-treated rat, the MPO unit responses to the MRF and MD stimulation, and the MD unit responses to the MRF and CP stimulation were different from those in the rat with only estrogen treatment. In addition, in the ovariectomized estrogen-primed rat, local application of progesterone to the MD prevented the inhibitory effect of the MD on the MPO unit. Progesterone, when given to the stimulated brain area, accelerated the MPO unit which was activated by the MRF stimulation, and inhibited the MD neuron which was inhibited by the CP stimulation. Multiple unit recordings showed similar results. Moreover, multi-unit activity in the HB and IP was elevated following a systemic progesterone application. On the basis of these results, the possible neural networks in the brain which participate in the lordosis control mechanisms are discussed.

Animals↗
PubMed1988

Progressive supranuclear palsy: extensive neuropil threads in addition to neurofibrillary tangles. Very similar antigenicity of subcortical neuronal pathology in progressive supranuclear palsy and Alzheimer's disease.

Light microscopic immunohistochemical investigations were performed on neurofibrillary tangles (NFT) in four histologically confirmed cases of Alzheimer's disease (AD) and in five patients with a progressive supranuclear palsy (PSP). The antibody panel included antisera to the neuronal microtubule-associated protein, tau, and to isolated paired helical filaments (PHF), as well as mouse monoclonal antibodies (MAbs) to phosphorylated epitopes on high and medium molecular weight neurofilament subunits (RT97 and BF10, respectively). Paraffin sections were also impregnated with the Gallyas silver method, which specifically stains tangles and cortical neuropil threads in AD, but does not stain normal neurofilaments. All tangles in PSP and AD showed consistent immunostaining with antibodies to tau protein and isolated PHF, regardless of their localization. MAbs RT97 and BF10, however, did not stain or only weakly stained, subcortical tangles in PSP and AD, whereas most cortical NFT in AD were intensely immunostained. All tangles in PSP were as heavily impregnated with Gallyas as they were in AD. Furthermore there were extensive networks of Gallyas-positive, tau- and PHF-immunoreactive neurites in subcortical gray areas containing NFT, and bundles of positive axons in white matter tracts interconnecting subcortical nuclei of PSP. Our studies indicate a much more extensive disruption of fibrillar proteins in PSP subcortical neurons than previously reported. They furthermore indicate a very similar antigenic profile of NFT in PSP and AD, as far as subcortical neurons are concerned.

Aged↗
PubMed1997

A network of tufted layer 5 pyramidal neurons.

Tufted layer 5 (TL5) pyramidal neurons are important projection neurons from the cerebral cortex to subcortical areas. Recent and ongoing experiments aimed at understanding the computational analysis performed by a network of synaptically connected TL5 neurons are reviewed here. The experiments employed dual and triple whole-cell patch clamp recordings from visually identified and preselected neurons in brain slices of somatosensory cortex of young (14- to 16-day-old) rats. These studies suggest that a local network of TL5 neurons within a cortical module of diameter 300 microns consists of a few hundred neurons that are extensively inter-connected with reciprocal feedback from at least first-, second- and third-order target neurons. A statistical analysis of synaptic innervation suggests that this recurrent network is not randomly arranged and hence each neuron could be functionally unique. Synaptic transmission between these neurons is characterized by use-dependent synaptic depression which confers novel properties to this recurrent network of neurons. First, a range of rates of depression for different synaptic connections enable each TL5 neuron to receive a unique mixture of information about the average firing rates and the temporally correlated action potential (AP) activity in the population of presynaptic TL5 neurons. Second, each AP generated by any neuron in the network induces a change (defined as an iteration step) in the functional coupling of the neurons in the network (defined as network configuration). It is proposed that the network configuration is iterated during a stimulus to achieve an optimally orchestrated network response. Hebbian, anti-Hebbian and neuromodulatory-induced modifications of neurotransmitter release probability change the rates of synaptic depression and thereby alter the iteration step size. These data may be important to understand the dynamics of electrical activity within the network.

Animals↗
PubMed2003

Use-dependent shift from inhibitory to excitatory GABAA receptor action in SP-O interneurons in the rat hippocampal CA3 area.

Cortical inhibitory interneurons set the pace of synchronous neuronal oscillations implicated in synaptic plasticity and various cognitive functions. The hyperpolarizing nature of inhibitory postsynaptic potentials (IPSPs) in interneurons has been considered crucial for the generation of oscillations at beta (15-30 Hz) and gamma (30-100 Hz) frequency. Hippocampal basket cells and axo-axonic cells in stratum pyramidale-oriens (S-PO) play a central role in the synchronization of the local interneuronal network as well as in pacing of glutamatergic principal cell firing. A lack of conventional forms of plasticity in excitatory synapses onto interneurons facilitates their function as stable neuronal oscillators. We have used gramicidin-perforated and whole cell clamp recordings to study properties of GABAAR-mediated transmission in CA3 SP-O interneurons and in CA3 pyramidal cells in rat hippocampal slices during electrical 5- to 100-Hz stimulation and during spontaneous activity. We show that GABAergic synapses onto SP-O interneurons can easily switch their mode from inhibitory to excitatory during heightened activity. This is based on a depolarizing shift in the GABAA reversal potential (EGABA-A), which is much faster and more pronounced in interneurons than in pyramidal cells. We also found that the shift in interneuronal function was frequency dependent, being most prominent at 20- to 40-Hz activation of the GABAergic synapses. After 40-Hz tetanic stimulation (100 pulses), GABAA responses remained depolarizing for approximately 45 s in the interneurons, promoting bursting in the GABAergic network. Hyperpolarizing EGABA-A was restored >60 s after the stimulus train. Similar but spontaneous GABAergic bursting was induced by application of 4-aminopyridine (100 microM) to slices. A shift to depolarizing IPSPs by the GABAAR permeant weak acid anion formate provoked interneuronal population bursting, supporting the role of GABAergic excitation in burst generation. Furthermore, depolarizing GABAergic potentials and synchronous interneuronal bursting were enhanced by pentobarbital (100 microM), a positive allosteric modulator of GABAARs, and were blocked by picrotoxin (100 microM). Intriguingly, GABAergic bursts displayed short (<1 s) oscillations at 15-40 Hz, even though only depolarizing GABAA responses were seen in the SP-O interneurons. This beta-gamma rhythmicity in the interneuron network was dependent on electrotonic coupling, and was abolished by blockade of gap junctions with carbenoxolone (200 microM). Results here implicate the rapid activity-dependent degradation of hyperpolarizing IPSPs in SP-O interneurons in setting the temporal limits for a given interneuron to participate in beta-gamma oscillations synchronized by GABAergic synapses. Furthermore, they imply that mutual GABAergic excitation provided by interneurons may be an integral part in the function of neuronal networks. We suggest that the use-dependent change in EGABA-A could represent a form of short-term plasticity in interneurons promoting coherent and sustained activation of local GABAergic networks.

Animals↗
PubMed2006

Contribution to the knowledge of the veterinary science and of the ethnobotany in Calabria region (Southern Italy).

BACKGROUND: A series of preliminary research projects on plants used in Calabria (Southern Italy) in veterinary science and in other ethno-botanical fields (minor nourishment, domestic and handicraft sector) was carried out in the last twenty years. From the ethno-botanical point of view, Calabria is one of the most interesting region, since in the ancient times it was subject to the dominant cultures of several people (Greeks, Romans, Byzantines, Arabs, Normans etc.). Until some decades ago the road network was poorly developed and villages were isolated, so that the culture of the "subsistence" and some archaic customs were kept. METHODS: Data were collected by means of "open" interviews to farmers, shepherds and housewives in the last twenty years. More than 100 informants were interviewed, mostly over 50 years old. Plants were identified by local informants through gathering in the area or through examination of the fresh plants collected by the researchers. The collected data were compared with pharmacobotanical papers mainly of southern Italy and with other studies, in order to highlight novelties or concordances of uses. RESULTS: The use of 62 taxa distributed into 34 families are described. Among these, 8 are or were employed in veterinary science, 8 as anti-parasitic agents, 19 in minor nourishment, 5 as seasoning, 38 for other uses. Some toxic species for cattle are also mentioned. CONCLUSION: Among the major findings: the use of Helleborus bocconei for bronchitis of bovines and of Scrophularia canina for lameness in veterinary science; Nerium oleander and Urginea maritima as anti-parasitic agents; Epilobium angustifolium, Centaurea napifolia L. and C. sphaerocephala L. in minor nourishment.

Aged↗
PubMedDate not supplied

Teleradiology: opportunities, problems, implementation.

With the introduction of computerized tomography and magnetic resonance imaging in the early 1970s, computers became integral to the imaging process. Shortly thereafter, scanners that create digitized images from film were introduced and teleradiology--images transmitted in real time--became possible. In the early 1980s, the idea of a picture archiving and communications system (PACS) began to develop. It promised to retrieve, connect and store every kind of image, from x-ray to CT, and render film obsolete. However, inflated expectations and inadequate technology hindered PACS implementation. Digital imaging offers the following benefits over film-based systems: - Less space is needed to store imaging studies. - Digital imaging files can be faster and easier for referring physicians to retrieve than film and are not susceptible to loss and damage. - Digital images can be enhanced, contrasted, colored and otherwise manipulated to maximize available information. - There are no chemicals to dispose of. While telemedicine promises to increase the efficiency and effectiveness of medical professionals, wide-scale implementation faces the following obstacles: - It has been difficult to establish a uniform standard that allows file transfer among systems made by different vendors. - There are unresolved legal questions about "interstate" medical practice as it occurs in teleradiology and about standards of care and image quality. - Any system available on a network is vulnerable to unauthorized users who may invade the database or operation of the system, and it is very difficult to detect fraud--data that has been tampered with--in digital records. - Connections to remote locations depend on local telephone lines, which may be slow. Other options are available, but they may be too expensive for facilities in the rural areas that need them the most. - Digital imaging equipment is still very costly to acquire and install. The future of telemedicine rests now with those who implement it. Once instituted, it will surpass traditional medicine by reducing the expense of storage and misplaced information and allowing faster and more accurate diagnoses.

Computer Security↗
PubMed2002

Policy requirements and performance indicators for good practice in workplace health: public health perspectives.

The author lists the main objectives, work areas and benefits of good practice in health, environment and social management in enterprises (GP HESME). History of this cross-sectoral and multidisciplinary approach to management of occupational, lifestyle, environmental and social health determinants is outlined. Health policy requirements and performance indicators are provided to facilitate GP HESME implementation at the enterprise and local levels. The role of local authorities and networking of enterprises, representing various sectors is highlighted.

Health Policy↗
PubMed1982

[Morphological studies of the regulatory mechanisms of intracerebral blood circulation].

The intracerebral branches of the posterior and medial cerebral arteries in the area of the grey and white substances of the parietal, occipital and temporal cerebral lobes, of the nuclei in the superior and inferior colliculi in the tectum mesencephali. as well as in the pons have been studied in 36 male corpses at the age of 5--49 years by means of Cajal, Koelle, Furness and Costa methods. Presence of sensitive neural terminals, cholinergic plexuses has been stated in the intracerebral artery walls with the diameter up to 100 mcm and more, as well as adrenergic neural network on the arteries with the diameter up to 100 mcm and more, as well as adrenergic neural network on the arteries with the diameter up to 40 mcm and more. Besides, near the cerebral substance vessels monoaminocytes situating both in the area of the sphincter torus and in the arterial walls have been revealed. A suggestion is made that the proper neural and other apparatuses of the intracerebral circulatory bed play a certain role in regulation of the local cerebral circulation.

Acetylcholinesterase↗
PubMed2001

Neural networks for improved target differentiation and localization with sonar.

This study investigates the processing of sonar signals using neural networks for robust differentiation of commonly encountered features in indoor robot environments. Differentiation of such features is of interest for intelligent systems in a variety of applications. Different representations of amplitude and time-of-flight measurement patterns acquired from a real sonar system are processed. In most cases, best results are obtained with the low-frequency component of the discrete wavelet transform of these patterns. Modular and non-modular neural network structures trained with the back-propagation and generating-shrinking algorithms are used to incorporate learning in the identification of parameter relations for target primitives. Networks trained with the generating-shrinking algorithm demonstrate better generalization and interpolation capability and faster convergence rate. Neural networks can differentiate more targets employing only a single sensor node, with a higher correct differentiation percentage (99%) than achieved with previously reported methods (61-90%) employing multiple sensor nodes. A sensor node is a pair of transducers with fixed separation, that can rotate and scan the target to collect data. Had the number of sensing nodes been reduced in the other methods, their performance would have been even worse. The success of the neural network approach shows that the sonar signals do contain sufficient information to differentiate all target types, but the previously reported methods are unable to resolve this identifying information. This work can find application in areas where recognition of patterns hidden in sonar signals is required. Some examples are system control based on acoustic signal detection and identification, map building, navigation, obstacle avoidance, and target-tracking applications for mobile robots and other intelligent systems.

Algorithms↗
PubMed1998

Localization of carbonic anhydrase in the goat mammary gland during involution and lactogenesis.

The aim of this study was to determine whether carbonic anhydrase (CA) activity in goat mammary capillaries is regulated mainly by local or systemic mechanisms. One gland was dried before the contralateral gland, and after parturition only one gland was milked. Biopsies were taken from the mammary glands of three goats at 14 d intervals during involution and the start of the following lactation. A histochemical method was used to visualize sites of CA activity. To follow the involution process, milk (liquid) samples were taken from both teats each week and analysed for pH and composition. The time course of CA activity disappearance and reappearance in the capillaries was related to changes in milk composition and alveolar area. A dense network of capillaries showing membrane-bound staining for CA was found surrounding the alveoli in the lactating gland. CA activity gradually decreased in the drying gland, although the other gland was being milked. After 8 weeks involution the dried gland had a significantly lower number of stained capillaries than the milked gland. Almost no stained capillaries were found during late pregnancy, when both glands were dried and the tissue growth maximal. During lactation milk pH was 6.6 +/- 0.3 and this increased to 7.0 +/- 0.1 in the course of involution. In the last trimester of pregnancy the pH returned to its lower value, while the mammary gland was devoid of stained capillaries. Therefore, the capillary CA could not have been directly involved in the pH regulation of milk. The CA activity reappeared in the capillaries directly after delivery, but only in the milked gland. Clearly the regulation of CA activity is influenced more by local than by systemic factors and is associated with the metabolic activity of milk secretion.

Animals↗
PubMed2005

Evidence for developmental changes in the visual word processing network beyond adolescence.

Late development of specialization in the visual word processing system was examined using event-related potentials (ERP) and functional magnetic resonance imaging (fMRI) of word and symbol string processing in groups of adolescents (15.2-17.3 years) and adults (19.8-30.8 years). We focused our ERP analyses on fast visual activity: the occipital P1 (82-131 ms) modulated by physical stimulus characteristics and the occipito-temporal N1 (132-256 ms) reflecting visual tuning for print. Our fMRI analyses concentrated on basal occipito-temporal activations in the visual word form area VWFA. For words, the correlation of fMRI activation in the VWFA and N1 amplitude confirmed the close relationship of the electrophysiological N1 with metabolic activity in the VWFA. Further support for this relationship came from low resolution electromagnetic tomography localizing the word-specific N1 near the VWFA. Both imaging techniques revealed age-independent differences between words and symbol strings. Late development, however, was preferentially detected with ERPs. Decreases of P1 and N1 amplitudes with age were not limited to words and suggested further maturation of the underlying brain microstructure and function. Following adolescence, decreasing N1 latencies specific to words point to continued specialization of the visual word processing system. Both N1 and fMRI measures correlated with reading performance. In summary, the similarity of global fMRI activation patterns between groups suggests a fully established distribution of the reading network in adolescence, while the decreasing N1 latencies for words indicate protracted fine tuning after adolescence.

Adolescent↗
PubMed1998

Specific localization of gap junction protein, connexin45, in the deep muscular plexus of dog and rat small intestine.

Cellular networks of pacemaker activity in intestinal movements are still a matter of debate. Because gap-junctional intercellular communication in the intestinal wall may provide important clues for understanding regulatory mechanisms of intestinal movements, we have attempted to clarify the distribution patterns of three types of gap junction proteins. Using antibodies for connexin40, connexin43, connexin45, smooth muscle actin, and vimentin, immunocytochemical observations were made with the confocal laser scanning microscope on cryosections of fresh-frozen small intestine and colon of the dog and rat. Connexin 45 was localized along the deep muscular plexus of the small intestine in both dog and rat. Double labeling studies revealed that connexin45 overlapped with vimentin -, but not actin-positive areas, indicating the fibroblast-like nature of the cells, rather than their being smooth muscle-like. Connexin43 immunoreactivity appeared along the smooth muscle cell surface in the outer circular layer of the small intestine of both animals. Connexin 40 immunoreactivity was not observed in the muscle layer other than in the wall of large blood vessels. It is suggested that connexin45-expressing cells along the deep muscular plexus of dog and rat small intestine are likely to act as a constituent of a pacemaker system, which may include a conductive system, by forming a cellular network operating via specific types of gap junctions.

Animals↗
PubMed1989

Immunohistochemical distribution of delta sleep inducing peptide in the rabbit brain and hypophysis.

The distribution of delta sleep inducing peptide (DSIP) in the rabbit brain has been studied with immunohistochemical techniques. DSIP-like immunoreactivity was predominantly detected in the basal forebrain, hypothalamus and hypophysis. Even in colchicine-pretreated animals, immunolabeled cell bodies were relatively few. They were mostly scattered through the ventrolateral septum, the diagonal band of Broca and preoptic areas. Clusters of positive cell bodies were also found in the arcuate nucleus and adjacent lateral hypothalamic areas. Large populations of varicose fibers and terminal-like structures were observed in the juxtaventricular zone of the ventrolateral septum, in the preoptic areas and lamina terminalis especially around the preoptic recess of the third ventricle and more caudally, in the ventromedial nucleus of the hypothalamus. Dense networks of immunolabeled fibers were visualized in the median eminence and pituitary stalk where many fibers could be seen in close apposition to the capillaries. Many DSIP-immunoreactive fibers were observed in the subfornical organ. Other extra-hypothalamic regions displaying a low-to-moderate density of immunoreactive fibers were the indusium griseum, the hippocampus, the fimbria of the fornix, the subcommissural organ, the medial habenula and, occasionally, the medial periaqueductal gray. Most cells of the pars intermedia and a few cells of the pars distalis of the anterior pituitary were DSIP-immunoreactive. Taken together these results in the rabbit brain emphasize the predominant localization of DSIP-like immunoreactivity in areas related to the hypothalamic neurosecretory systems.

Animals↗
PubMed2004

Architectural analysis of oral cancer, dysplastic, and normal epithelia.

BACKGROUND: We present a novel, automated, and quantitative approach to evaluate local epithelial tissue architecture based on mathematical graph theory. METHODS: Four hundred forty-one images of three diagnostic classes of oral epithelium (normal, dysplastic, and neoplastic) were analysed. The epithelial compartment was partitioned into exclusive areas associated with each nucleus to approach the theoretical cell extents. The spatial arrangement of cells in neighbourhoods of two sizes was characterised by constructing graph networks based on the cell centroids and recording 29 statistical properties. We analysed 104,627 and 67,590 neighbourhoods of diameters 37.5 and 75 microm, respectively. RESULTS: The discrimination power of the architectural descriptors was evaluated by using discriminant analysis. The best neighbourhood discrimination rate was 75% for normal versus carcinoma. For the pooled data, discrimination into three classes based on largest number of neighbourhoods associated with each class was 100% correct. Case-wise, discrimination rates were 67%, 100%, and 80% correct for normal, premalignant, and malignant. When considering two classes, discrimination rates was 89% (normal) and 100% (malignant) correct, with 71% of premalignant cases assigned to the malignant class. CONCLUSIONS: The results indicate that unbiased and reproducible quantification of tissue architectural features is possible and may provide valuable morphological information for diagnostic purposes.

Cytodiagnosis↗
PubMed1998

Relations between cortical and thalamic cellular activities during absence seizures in rats.

In a rat model of generalized absence epilepsies (Genetic Absence Epilepsy Rats from Strasbourg, GAERS), multiunit activity was recorded simultaneously at different sites of the thalamocortical system under neurolept anaesthesia (fentanyl-droperidol). Under these conditions, bilaterally synchronized spike-and-wave-discharges (SWDs) occurred spontaneously on the electroencephalogram (EEG) that were in principle identical to those reported earlier from unanaesthetized preparations. The generation of SWDs on the EEG was associated with spike-concurrent, rhythmic burst-like activity in (mono-)synaptically connected regions of specific (somatosensory) thalamic regions and layers IVN of the somatosensory cortex, and the reticular thalamic nucleus. Precursor activity was typically recorded in cortical units, concomitant with 'embryonic' SW seizures on the EEG, before the paroxysm was evident on the gross EEG and in the thalamus. On average, SWD-correlated activity in layers IVN of the somatosensory cortex started significantly earlier than correlated burst-like firing in reticular and in ventrobasal thalamic neurons. Cellular peak firing in thalamus and cortex during bilaterally synchronized SWDs was related to the spike component on the gross EEG with the temporal rank order ventroposteromedial > ventrolateral > or = ventroposterolateral thalamic > > rostral reticular thalamic nuclei > or = cortex (layers IVN) = caudal reticular thalamic nucleus. A spike-related depression and wave-related increase in firing was recorded in anteroventral ventrolateral thalamic areas, presumably reflecting their peculiar anatomical arrangement within the thalamus. These results from an in vivo preparation with intact synaptic connections that spontaneously produces SWDs indicate that SWDs spread within the thalamocortical network, involving short and long delays. The order of concurrent rhythmic firing observed in thalamocortical circuits during SW seizures are supportive of the hypothesis that the processes of rhythmogenesis recruit local thalamic networks, while cortical mechanisms appear to synchronize rhythmic activities on a larger spatiotemporal scale, thereby providing an important contribution to the generalization of epileptiform activity and expression of SWDs on the EEG.

Animals↗
PubMed2001

A conceptual model for leadership development.

Collaboration among schools of public health and national, state, and local health agencies has resulted in creation of comprehensive public health workforce education and training initiatives that offer integrated, sequential, and accessible professional development programs, including a nation-wide network of public health leadership institutes. A conceptual model for leadership development is presented. It contains seven elements considered critical for design of leadership programs in public health: capacity/competence needs; program target; area served; program content; training level; learning approach; and implementation methods. This model can be used to design leadership as well as public health workforce education and training programs.

Cooperative Behavior↗