UK PubMed Central (United Kingdom)

T-type calcium channels are responsible for generating low-threshold spikes that facilitate burst firing and neurotransmitter release in neurons. GnRH neurons exhibit burst firing, but the underlying...Full Text Available

UK PubMed Central (United Kingdom)

Spike-timing-dependent plasticity (STDP), a form of Hebbian plasticity, is inherently stabilizing. Whether and how GABAergic inhibition influences STDP is not well understood. Using a model neuron driven...Full Text Available

Science.gov (United States)

Spike-timing-dependent plasticity (STDP), a form of Hebbian plasticity, is inherently stabilizing. Whether and how GABAergic inhibition influences STDP is not well understood. Using a model neuron driven by converging inputs modifiable by STDP, we determined that a sufficient level of inhibition was critical to ensure that temporal coherence (correlation among presynaptic spike times) of synaptic inputs, rather than initial strength or number of inputs within a pathway, controlled postsynaptic spike timing. Inhibition exerted this effect by preferentially reducing synaptic efficacy, the ability of inputs to evoke postsynaptic action potentials, of the less coherent inputs. In visual cortical slices, inhibition potently reduced synaptic efficacy at ages during but not before the critical period of ocular dominance (OD) plasticity. Whole-cell recordings revealed that the amplitude of unitary IPSCs from ...

UK PubMed Central (United Kingdom)

Purpose.There is a paucity of neuron replacement studies for retinal ganglion cells. Given the complex phenotype of these neurons, replacement of ganglion cells may be impossible....Full Text Available

UK PubMed Central (United Kingdom)

Neurons are born throughout adulthood in the hippocampus and show enhanced plasticity compared to mature neurons. However, there are conflicting reports on whether or not young neurons contribute...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundVisual neurons respond essentially to luminance variations occurring within their receptive fields. In primary visual cortex, each neuron is a filter for stimulus features...Full Text Available

UK PubMed Central (United Kingdom)

Several different neuronal populations are involved in regulating energy homeostasis. Among these, agouti-related protein (AgRP) neurons are thought to promote feeding and weight gain; however, the...Full Text Available

UK PubMed Central (United Kingdom)

Sensory experience plays a crucial role in regulating neuronal shape and in developing synaptic contacts during brain formation. These features are required for a neuron to receive, integrate, and transmit...Full Text Available

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Udgivelsesdato: 1991-null

KoreaScience (Korea)

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International Nuclear Information System (INIS)

This paper shows that a stochastic regime-switching model can represent the volatile behavior of wholesale electricity prices associated with price spikes effectively. The structure of the model is very flexible because the mean prices in the two regimes and the two transition probabilities are functions of the load and/or the implicit reserve margin. Using price data from the single settlement market in PJM (May 1999 to May 2000), the results show that the estimated switching probability from the low to the high regime predicts price spikes well if the reserve margin is measured accurately.

International Nuclear Information System (INIS)

One of the most profound features of electricity spot prices are the price spikes. Markov regime-switching (MRS) models seem to be a natural candidate for modeling this spiky behavior. However, in the studies published so far, the goodness-of-fit of the proposed models has not been a major focus. While most of the models were elegant, their fit to empirical data has either been not examined thoroughly or the signs of a bad fit ignored. With this paper we want to fill the gap. We calibrate and test a range of MRS models in an attempt to find parsimonious specifications that not only address the main characteristics of electricity prices but are statistically sound as well. We find that the best structure is that of an independent spike 3-regime model with time-varying transition probabilities, heteroscedastic diffusion-type base regime dynamics and shifted spike regime distributions. Not only does it allow for a seasonal ...

UK PubMed Central (United Kingdom)

In utero electroporation is widely used to study neuronal development and function by introducing plasmid DNA into neural progenitors during embryogenesis. This is an effective and...Full Text Available

UK PubMed Central (United Kingdom)

In anaesthetized rats, extracellular and intracellular recordings were taken from 106 respiratory neurones in the intermediate region of the nucleus ambiguus. We observed unprovoked shortening of expiratory...Full Text Available

UK PubMed Central (United Kingdom)

Sensory neurons in aging mammals undergo changes in anatomy, physiology and gene expression that correlate with reduced sensory perception. In this study we compared young and aged mice to identify...Full Text Available

UK PubMed Central (United Kingdom)

Some pathological conditions with feeding pattern alterations, including obesity and Huntington disease (HD) are associated with hypothalamic dysfunction and neuronal cell death. Additionally, the hypothalamus...Full Text Available

International Nuclear Information System (INIS)

The paper gives a generic idea of the solutions that the neuronal nets contribute to the robotics. The advantages and the inconveniences are exposed that have regarding the conventional techniques. It also describe the more excellent applications as the pursuit of trajectories, the positioning based on images, the force control or of the mobile robots management, among others

UK PubMed Central (United Kingdom)

We have developed a method for dissecting single neurons from the nematode Ascaris suum, in order to determine their peptide content by mass spectrometry (MS). In this paper,...Full Text Available

UK PubMed Central (United Kingdom)

In order to maintain stable functionality in the face of continually changing input, neurones in the CNS must dynamically modulate their electrical characteristics. It has been hypothesized that in...Full Text Available

UK PubMed Central (United Kingdom)

To successfully grow, neurons need to overcome the effects of hostile environments, such as the inhibitory action of myelin. We have evaluated the potential of exercise to overcome the intrinsic...Full Text Available

UK PubMed Central (United Kingdom)

Neurons containing the neuropeptide hypocretin (orexin) are localized only in the lateral hypothalamus from where they innervate multiple regions implicated in arousal, including the basal forebrain....Full Text Available

UK PubMed Central (United Kingdom)

The neurotransmitter glutamate is released by excitatory projection neurons throughout the brain. However, non-glutamatergic cells, including cholinergic and monoaminergic neurons, express markers that...Full Text Available

UK PubMed Central (United Kingdom)

Calcium ions represent universal second messengers within neuronal cells integrating multiple cellular functions, such as release of neurotransmitters, gene expression, proliferation, excitability,...Full Text Available

UK PubMed Central (United Kingdom)

This report investigates acute changes in the sensitivity of 5-HT_1A receptors in dorsal raphe (dr) neurons in response to elevated serotonin. DR neurons were isolated from adult rats...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

This paper describes the structure of dynamic neuronal ensembles (DNEs). DNEs represent a new paradigm for learning, based on biological neural networks that use variable structures. We present a computational neural element that demonstrates biological neuron functionality such as neurotransmitter feedback absolute refractory period and multiple output potentials. More specifically, we will develop a network of neural elements that have the ability to dynamically strengthen, weaken, add and remove interconnections. We demonstrate that the DNE is capable of performing dynamic modifications to neuron connections and exhibiting biological neuron functionality. In addition to its applications for learning, DNEs provide an excellent environment for testing and analysis of biological neural systems. An example of habituation and hyper-sensitization in biological systems, using a neural circuit from a snail ...

International Nuclear Information System (INIS)

As part of the general QC/QA management of the k_0-standardization, three types of 'SMELS' (synthetic multi-element standards) are being developed to check the performance of k_0-NAA when implemented in a laboratory. Phenol-formaldehyde resin is proposed in this paper as the matrix of choice. Based on previous work, this material could be prepared with sufficient purity so as to make interferences with the spiking elements negligible. The matrix was found to be adequately resistant towards high neutron flux irradiation. A selection was made of compounds, soluble in ethyl alcohol, for spiking the prepolymer ethanolic solution with the elements of interest. Finally, some prototypes were prepared and a satisfactory homogeneity of the spiked elements was found for 50 mg sample intake.

UK PubMed Central (United Kingdom)

During antibiotic drug development, media are frequently spiked with either serum/plasma or protein supplements to evaluate the effect of protein binding. Usually, previously reported serum or plasma...Full Text Available

International Nuclear Information System (INIS)

Neuron differentiation is a complex process involving various cell-cell interactions, and multiple signaling pathways. We showed previously that CD40 is expressed and functional on mouse and human neurons. In neurons, ligation of CD40 protects against serum withdrawal-induced injury and plays a role in survival and differentiation. CD40 deficient mice display neuron dysfunction, aberrant neuron morphologic changes, and associated gross brain abnormalities. Previous studies by Tone and colleagues suggested that five isoforms of CD40 exist with two predominant isoforms expressed in humans: signal-transducible CD40 type I and a C-terminal truncated, non-signal-transducible CD40 type II. We hypothesized that differential expression of CD40 isoform type I and type II in neurons may modulate neuron differentiation. Results show that adult ...

UK PubMed Central (United Kingdom)

SUMMARYHomeostatic synaptic plasticity is a negative feedback mechanism neurons use to offset excessive excitation or inhibition by adjusting their synaptic strengths. Recent...Full Text Available

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SummaryPrimary visual cortex recombines inputs from magnocellular (M) and parvocellular (P) streams to create functionally specialized outputs. Understanding these input-output relationships is complicated by the fact that layer 4B, which provides outputs to dorsal visual areas, contains multiple cell types. Using a modified rabies virus that expresses green fluorescent protein, we show that layer 4B neurons projecting to MT are a majority spiny stellate, whereas those projecting to V2 are overwhelmingly pyramidal. Regardless of cell type, MT-projecting neurons have larger cell bodies, more dendritic length, and are deeper within layer 4B. Furthermore, MT-projecting pyramidal neurons are located preferentially underneath cytochrome oxidase blobs, indicating that MT-projecting neurons of bo...

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The processes of neuronal outgrowth and guidance have typically been studied in classic 2D cell culture systems that do not recapitulate topographical cues present in the in vivo extracellular matrix...Full Text Available

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Nitric oxide (NO) is a gas produced through the action of nitric oxide synthase that acts as a neurotransmitter in the central nervous system (CNS) of adult gastropod mollusks. There are no known reports of the presence of NOS-containing neurons and glial cells in young and adult Megalobulimus abbreviatus. Therefore, NADPH-d histochemistry was employed to map the nitrergic distribution in the CNS of young and adult snails in an attempt to identify any transient enzymatic activity in the developing CNS. Reaction was observed in neurons and fibers in all CNS ganglia of both age groups, but in the pedal and cerebral ganglia, positive neurons were more intense than in other ganglia, forming clusters symmetrically located in both paired ganglia. However, neuronal NADPH-d activity in the mesocer...

International Nuclear Information System (INIS)

Two candidate small interfering RNAs (siRNAs) corresponding to severe acute respiratory syndrome-associated coronavirus (SARS-CoV) spike gene were designed and in vitro transcribed to explore the possibility of silencing SARS-CoV S gene. The plasmid pEGFP-optS, which contains the codon-optimized SARS-CoV S gene and expresses spike-EGFP fusion protein (S-EGFP) as silencing target and expressing reporter, was transfected with siRNAs into HEK 293T cells. At various time points of posttransfection, the levels of S-EGFP expression and amounts of spike mRNA transcript were detected by fluorescence microscopy, flow cytometry, Western blot, and real-time quantitative PCR, respectively. The results showed that the cells transfected with pEGFP-optS expressed S-EGFP fusion protein at a higher level compared with those transfected with pEGFP-S, which contains wildtype SARS-CoV spike gene sequence. The green ...

UK PubMed Central (United Kingdom)

SUMMARYWe recorded Ca²⁺ current and intracellular Ca²⁺ ([Ca²⁺]_i) in isolated adult rat dorsal root ganglion (DRG) neurons at 20 and...Full Text Available

International Nuclear Information System (INIS)

We examined the effect of the trophic protein, nerve growth factor (NGF), on cultures of fetal rat neostriatum and basal forebrain-medial septal area (BF-MS) to define its role in brain development. Treatment of cultures with NGF resulted in an increase in the specific activity of the cholinergic enzyme choline acetyltransferase (CAT) in both brain areas. CAT was immunocytochemically localized to neurons. In the BF-MS, NGF treatment elicited a marked increase in staining intensity and an apparent increase in the number of CAT-positive neurons. Moreover, treatment of BF-MS cultures with NGF increased the activity of acetylcholinesterase, suggesting that the cholinergic neuron as a whole was affected. To begin defining mechanisms of action of NGF in the BF-MS, we detected NGF receptors by two independent methods. Receptors were localized to two different cellular populations: neuron-like cells, and ...

Science.gov (United States)

This study investigated whether estradiol influenced the survival of new granule neurons, independent of altering cell proliferation, in the adult rodent dentate gyrus and whether estradiol-induced changes in new neuron number relate to any observed changes in hippocampus-dependent behavior. To test whether estradiol specifically promotes the survival of new neurons we injected castrated adult male meadow voles with the cell synthesis marker bromodeoxyuridine (BrdU; 50 mg/kg) twice on day 0 and then injected either estradiol (10 microg) or vehicle for 5 consecutive days either over days 1-5, days 6-10 or days 11-15 and perfused them on day 16. Estradiol doubled the number of hippocampal BrdU-labeled neurons but only when administered during a discrete period (days 6-10; P< or =0.01) when most new neurons extend their axons [J Comp Neurol 413 (1999) 146]. To test whether the ...

Science.gov (United States)

Neuronal transcription factors play vital roles in the specification and development of neurons, including dopaminergic (DA) neurons. Mutations in the gene encoding the purine biosynthetic enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT) cause the resulting intractable and largely untreatable neurological impairment of Lesch-Nyhan disease (LND). The disorder is associated with a defect in basal ganglia DA pathways. The mechanisms connecting the purine metabolic defect and the central nervous system (CNS) phenotype are poorly understood but have been presumed to reflect a developmental defect of DA neurons. We have examined the effect of HPRT deficiency on the differentiation of neurons in the well-established human (NT2) embryonic carcinoma neurogenesis model. We have used a retrovirus expressing a small hairpin RNA (shRNA) to knock down HPRT gene expression and have ...

International Nuclear Information System (INIS)

Black pepper, white pepper, red pepper, ginger and turmeric were irradiated with 10 MeV electrons from a linear accelerator to a dose of 100 kGy and radioactivity was measured in order to estimate induced radioactivity in the irradiated foods. Induced radioactivity could not be detected significantly by #gamma#-ray spectrometry in the irradiated samples except for spiked samples which contain some photonuclear target nuclides in the list of photonuclear reactions which could produce radioactivity below 10 MeV. From the amount of observed radioactivities of short-lived photonuclear products in the spiked samples and calculation of H_5_0 according to ICRP Publication 30, it was concluded that the induced radioactivity and its biological effects in the 10 MeV electron-irradiated natural samples were negligible in comparison with natural radioactivity from "4"0K contained in the samples. (author).

British Library Electronic Table of Contents (United Kingdom)

Reduced systems such as brain slices offer a powerful approach to study the physiology of auditory neurons in great detail. However, when studying auditory nuclei in reduced systems such as brain slices, especially highly active auditory brain stem nuclei, one has to be aware that the unphysiological lack of activity in the reduced system compared to the in-vivo situation has a number of important effects on the neurons under investigation, and thus on the data that are measured. Most importantly, the lack of chronic activity in the slice preparation has important effects on the properties of short-term plasticity of the synapses. The main purpose of this article is to discuss how spontaneous activity in auditory neurons, or the lack thereof, can affect the data measured.

British Library Electronic Table of Contents (United Kingdom)

Mutations or multiplications in a-synuclein gene cause familial forms of Parkinson disease or dementia with Lewy bodies (LB), and the deposition of wild-type a-synuclein as LB occurs as a hallmark lesion of these disorders, collectively referred to as synucleinopathies, implicating a-synuclein in the pathogenesis of synucleinopathy. To identify modifier genes of a-synuclein-induced neurotoxicity, we conducted an RNAi screen in transgenic C. elegans (Tg worms) that overexpress human a-synuclein in a pan-neuronal manner. To enhance the RNAi effect in neurons, we crossed a-synuclein Tg worms with an RNAi-enhanced mutant eri-1 strain. We tested RNAi of 1673 genes related to nervous system or synaptic functions, and identified 10 genes that, upon knockdown, caused severe growth/motor abnormalit...

International Nuclear Information System (INIS)

Nineteen lesion mimic mutants (xsl1-19) of japonica rice Xiushui11 were obtained by ?-rays irradiation treatment. All mutants belonged to whole life lesion mimic. Lesion mimic of mutants didn't largen after tillering stage, leaves didn't wither, and no effect on the plants exsert spikes and seed. When the highest temperature in day exceeded 32 degree C in seedling stage, lesion mimic of all mutant expect xsl19 disappeared. Under 32 degree C, lesion mimic would appear gradually, and symptoms weren't inhibited by high temperature after 5 leaf stage. The plant heights of all lesion mimic mutants were 47.56-63.54 cm in the tillering stage, and that of CK was 83.75 cm; but the dwarf phenomenon of mutants only appeared before tillering stage, and didn't affect plant heights finally; the heading dates of mutants were the same to the CK, the ear length of all mutants were 9.43-15.19 cm, and that of CK was 16.41 cm; the total grain quantity per spike of ...

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Increased use of wetlands for habitat and water quality improvement emphasize the need for further study of abiotic-biotic interactions in these systems. This research examined contaminant assimilation within the water column of two newly created Colorado prairie wetlands (RMA3 and RMA4). To examine the influence of abiotic factors (e.g., alkalinity, suspended solids), ten chronic toxicity tests were performed from December 1991 through November 1993. In the first set of tests, Ceriodaphnia dubia were exposed to water from the two wetlands which was spiked with various concentrations of zinc. These tests suggested that water from RMA4 had higher contaminant assimilative capacity than water from RMA3. Preliminary analysis suggested suspended solids, pH, conductivity, and temperature were important factors affecting neonate production by C. dubia when exposed to zinc-spiked wetland water. To test the importance of suspended solids in contaminant ...

UK PubMed Central (United Kingdom)

Auditory neurons in the superior colliculus (SC) respond preferentially to sounds from restricted directions to form a map of auditory space. The development of this representation is shaped...Full Text Available

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The effects of lead on the development of the nervous system are of immediate concern to human health. While it is clear that lead can affect neuronal development at levels of exposure within the range found in the environment, the particular mechanism of the disruption is not readily ascertained. The goal of the authors research is to develop a model system in which the effects of lead on central nervous system development can be demonstrated. To study neuronal development in a system that minimizes such difficulties, the authors have grafted discrete brain regions derived from rat fetuses into the anterior chamber of the eye of adult hosts. The brain pieces continue organotypic development in the eye, but are isolated from possible secondary changes due to alterations in the development of the endocrine and other somatic systems because the adult host has these systems already fully developed. Using this system, they have discovered that lead ...

UK PubMed Central (United Kingdom)

The functional outcome after stroke is unpredictable; it is not accurately predicted by clinical pictures upon hospital admission. The presence of apoptotic neurons in the ischemic penumbra and perihematoma...Full Text Available

UK PubMed Central (United Kingdom)

Understanding the mechanisms whereby information encoded within patterns of action potentials is deciphered by neurons is central to cognitive psychology. The multiprotein complexes formed by...Full Text Available

UK PubMed Central (United Kingdom)

Deep brain stimulation of the subthalamic nucleus (STN-DBS) is efficacious in treating the motor symptoms of Parkinson’s disease (PD). However, the impact of STN-DBS on the progression...Full Text Available

UK PubMed Central (United Kingdom)

Since Src kinase inhibitors decrease brain injury produced by intracerebral hemorrhage (ICH) and thrombin is activated following ICH, this study determined whether Src kinase inhibitors decrease...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundCalcitonin gene related peptide (CGRP) is a neuropeptide that is abundant in the sensory neurons which innervate bone. The effects of CGRP on isolated bone cells have been...Full Text Available

UK PubMed Central (United Kingdom)

The Pde6b^rd10 (rd10) mouse has a moderate rate of photoreceptor degeneration and serves as a valuable model for human autosomal recessive retinitis pigmentosa...Full Text Available

UK PubMed Central (United Kingdom)

Previous studies in several different trigeminal nerve injury/inflammation models indicated that the hyperexcitability of primary afferent neurons contributes to the pain pathway underlying mechanical...Full Text Available

UK PubMed Central (United Kingdom)

Ionotropic P2X and metabotropic P2Y purinergic receptors are expressed in the central nervous system and participate in the synaptic process particularly associated with acetylcholine, GABA, and glutamate...Full Text Available

UK PubMed Central (United Kingdom)

Neonatal bacterial infection in rats alters the responses to a variety of subsequent challenges later in life. Here we explored the effects of neonatal bacterial infection on a subsequent drug...Full Text Available

UK PubMed Central (United Kingdom)

An optical flow gradient algorithm was applied to spontaneously forming networks of neurons and glia in culture imaged by fluorescence optical microscopy in order to map functional calcium signaling...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundThe various tasks of visual systems, including course control, collision avoidance and the detection of small objects, require at the neuronal level the dendritic integration...Full Text Available

UK PubMed Central (United Kingdom)

AMP-activated-protein-kinase (AMPK) is a key sensor and regulator of cellular and whole-body energy metabolism and plays a key role in regulation of lipid metabolism. Since lipid metabolism...Full Text Available

UK PubMed Central (United Kingdom)

Place fields of hippocampal pyramidal cells expand asymmetrically when adult rats repeatedly follow the same route. This behaviorally-induced expression of neuronal plasticity utilizes an NMDA_R-dependent,...Full Text Available

UK PubMed Central (United Kingdom)

The neuronal nitric oxide synthase gene (NOS1) is located at 12q24, a susceptibility region for schizophrenia, and produces nitric oxide (NO). NO has been reported to play important...Full Text Available

UK PubMed Central (United Kingdom)

1. One hundred and thirty-two antidromically identified paraventricular (PV) and supraoptic (SO) neurones were studied during milk ejection evoked by the suckling of the young, in thirty-four lactating...Full Text Available

UK PubMed Central (United Kingdom)

We introduce in this paper a new method for reducing neurodynamical data to an effective diffusion equation, either experimentally or using simulations of biophysically detailed models. The dimensionality...Full Text Available

UK PubMed Central (United Kingdom)

Several theories have proposed a functional role for synchronous neuronal firing in generating the neural code of a sensory perception. Synchronous neural activity develops during a critical...Full Text Available

UK PubMed Central (United Kingdom)

Short-hairpin RNA (shRNA)–mediated gene knockdown is a powerful tool for targeted gene silencing and an emerging novel therapeutic strategy. Recent publications, however, reported unexpected...Full Text Available

UK PubMed Central (United Kingdom)

Despite their wide use, the physiological relevance of organotypic slices remains controversial. Such cultures are prepared at 5 days postnatal. Although some local circuitry remains intact, they develop...Full Text Available

UK PubMed Central (United Kingdom)

Proprioceptive sensory signals inform the CNS of the consequences of motor acts, but effective motor planning involves internal neural systems capable of anticipating actual sensory feedback....Full Text Available

UK PubMed Central (United Kingdom)

1. The effect of capsaicin pre-treatment on adrenal catecholamine (CA) secretion in response to stress is controversial. In earlier experiments performed under pentobarbitone anaesthesia, the release...Full Text Available

UK PubMed Central (United Kingdom)

Decreased cognitive performance reduces independence and quality of life for aging individuals. Healthy brain aging does not involve significant neuronal loss, but little is known about the...Full Text Available

UK PubMed Central (United Kingdom)

Corticostriatal synapse plasticity of medium spiny neurons is regulated by glutamate input from the cortex and dopamine input from the substantia nigra. While cortical stimulation alone results in long-term...Full Text Available

UK PubMed Central (United Kingdom)

The vanilloid receptor-1 (VR1, or transient receptor potential vanilloid-1 receptor, TRPV1) is activated by capsaicin, the key ingredient of hot peppers. TRPV1 was originally described on sensory neurons...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

An overview of current concepts on neuroinflammation and on the dialogue between neurons and non-neuronal cells in three important infections of the central nervous systems (rabies, cerebral malaria, and human African trypanosomiasis or sleeping sickness) is here presented. Large numbers of cases affected by these diseases are currently reported. In the context of an issue dedicated to Camillo Golgi, historical notes on seminal discoveries on these diseases are also presented. Neuroinflammation is currently closely associated with pathogenetic mechanisms of chronic neurodegenerative diseases. Neuroinflammatory signaling in brain infections is instead relatively neglected in the neuroscience community, despite the fact that the above infections provide paradigmatic examples of alterations o...

International Nuclear Information System (INIS)

The main challenges for PMOS ultra shallow junction formation remain the transient enhanced diffusion (TED) and the solid solubility limit of boron in silicon. It has been demonstrated that low energy boron implantation and spike annealing are key in meeting the 90nm technology node ITRS requirements. To meet the 65nm technology requirements many studies have used fluorine co-implantation with boron and Si"+ or Ge"+ pre-amorphization (PAI) and spike annealing. Although using BF_2"+ can be attractive for its high throughput, self-amorphization and the presence of fluorine, many studies have shown that the fluorine successfully reduce TED, its energy needs to be well optimized with respect to the boron's, therefore BF_2"+ does not present the right fluorine/boron energy ratio for the optimum junction formation. In this work we optimize the fluorine energy for boron energies down to 200eV. We show the dependence of optimized junction on Ge"+ ...

Science.gov (United States)

Nucleic acid extraction and human immunodeficiency virus type 1 (HIV-1) genotyping using the NucliSens miniMAG platform and the TruGene HIV-1 genotyping kit gave HIV-1 sequence data from HIV-1-negative plasma spiked with 100 copies/ml reference HIV-1 RNA and from low-viremia clinical samples (<500 copies/ml) without the need for ultracentrifugation or nested second-round PCR. PMID:17122019

International Nuclear Information System (INIS)

Neuron-restrictive silencer factor (NRSF) binds its consensus element to repress the transcription of various genes. The dominant-negative form (dnNRSF) has a hypertrophic effect on cardiogenesis through an unidentified mechanism. We examined the involvement of transient receptor potential (TRP) channel proteins, using transgenic mice overexpressing dnNRSF (dnNRSF mice). Electrophoretic mobility-shift assays revealed an interaction between NRSF and a neuron-restrictive silencer element-like sequence in intron 4 of TRPC1 genomic DNA. According to RT-PCR and Western analyses, TRPC1 was up-regulated in dnNRSF mouse heart. Transient overexpression of TRPC1 in HEK 293T cells increased the activity of the nuclear factor in activated T cells (NFAT) promoter and stimulated store-operated Ca"2"+ channel (SOCC)-mediated Ca"2"+ entry. Transfection of TRPC1 into primary cardiomyocytes increased NFAT activity, indicating a major role for TRPC1 in NFAT ...

British Library Electronic Table of Contents (United Kingdom)

Integrative and firing properties are important characteristics of neuronal circuits and these responses are determined in large part by the repertoire of ion channels they express, which can vary considerably between cell types. Recently, a new mode of operation of voltage dependent sodium channels has been described that generates a so-called resurgent Na^+ current. Accumulating evidence suggests resurgent Na current participates in the generation of sub-threshold inward Na^+ current causing membrane depolarization which provides the necessary drive to fire high-frequency action potentials. Recent studies indicate that resurgent Na^+ current could be a more widespread feature than previously thought.

British Library Electronic Table of Contents (United Kingdom)

Precocious puberty is a significant child health problem, especially in girls, because 95% of cases are idiopathic. Our earlier studies demonstrated that low-dose levels of manganese (Mn) caused precocious puberty via stimulating the secretion of luteinizing hormone-releasing hormone (LHRH). Because glial-neuronal communications are important for the activation of LHRH secretion at puberty, we investigated the effects of prepubertal Mn exposure on specific glial-derived puberty-related genes known to affect neuronal LHRH release. Animals were supplemented with MnCl2 (10 mg/kg) or saline by gastric gavage from day 12 until day 22 or day 29, then decapitated, and brains removed. The site of LHRH release is the medial basal hypothalamus (MBH), and tissues from this area were analyzed by real-...

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The anticonvulsant drugs carbamazepine, phenobarbital, trimethadione, valproic acid and ethosuximide at pharmacologically relevant concentrations inhibit (/sup 3/H)diazepam binding to astrocytes in primary cultures but have much less effect on a corresponding preparation of neurons. Phenytoin as well as pentobarbital (which is not used chronically as an anticonvulsant) are equipotent in the two cell types. The convulsants picrotoxinin and pentylenetetrazol, the convulsant benzodiazepine RO 5-3663 and the two convulsant barbiturates DMBB and CHEB similarly inhibit diazepam binding to astrocytes but have little effect on neurons. On the basis of these findings it is suggested that these convulsants and anticonvulsants owe at least part of their effect to an interaction with the astrocytic benzodiazepine receptor, perhaps by interference with a calcium channel.

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Amphiphysin is a protein concentrated in neuronal synapses and peripherally associated with neurotransmitter vesicles. It is expressed in many neurons of the central and peripheral nervous systems, in the adrenal medulla, in the anterior and posterior pituitary, in cell lines of the endocrine pancreas, and in spermatocytes. Its subcellular localization and tissue distribution indicate a potential involvement in mechanisms of regulated exocytosis. A role in the dynamic organization of the membrane-associated cytoskeleton is suggested by structural homology to the products of two yeast genes, RVS161 and RVS167, whose mutation results in an abnormal actin distribution, disturbs budding morphology, and impairs cell entry into stationary phase. Limited stretches of sequence similarity, including an SH3 domain, are also shared with other actin-binding proteins. Amphiphysin is the dominant autoantigen in paraneoplastic Stiff-Man syndrome, a ...

UK PubMed Central (United Kingdom)

mRNP granules at adult central synapses are postulated to regulate local mRNA translation and synapse plasticity. However, they are very poorly characterized in vivo. Here, in Drosophila...Full Text Available

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This paper deals with the control of an electromechanical valves engine. The control uses neural networks in order to build a non-linear model of engine filing which depends on the driven inlets. The aim is to build this real-time model and to integrate this model to a control system which performs an iterative inversion. (J.S.)

Scientific Electronic Library Online (English)

Abstract in english BACKGROUND: Severe pathogenic infection triggers excessive release of cytokines as part of the massive inflammatory response associated with septic shock. OBJECTIVES: To investigate the protective effect of caffeic acid phenethye ester (CAPE) against lipopolysaccharide (LPS) induced endotoxemia, hepatic and neuronal damage and the associated systemic inflammatory response (SIR). METHODS: Fifty male Wister rats were divided into: control, LPS, and CAPE+LPS groups. Plasma c (more) oncentrations of various cytokines, including TNF-?, IL-1?, IL-1?, IL-6, IL-4, IL-10, and sICAM-1 were evaluated. In addition, the histopathological changes in the hepatic and neural cells were assessed. RESULTS: The LPS group showed high inflammatory cytokines and sICAM-1 levels reflecting the presence of SIR. Hepatocyte necrosis, apoptosis, extensive hemorrhage and inflammatory cellular infiltration together with brain astrocytes swelling, early ...

UK PubMed Central (United Kingdom)

We have identified another Drosophila GTP-binding protein (G protein) alpha subunit, dGq alpha-3. Transcripts encoding dGq alpha-3 are derived from alternative splicing of the dGq alpha locus previously...Full Text Available

International Nuclear Information System (INIS)

Computed tomographic findings in developmental brain anomalies are more easily classified when the system used is based on embryogenesis related to morphology. Analysis of computed tomographic findings in a series of 154 patients with brain anomalies (Chiari malformation not included) revealed that specific examples of abnormalities occurring in major stages of brain development may be recognized by computed tomography. This paper deals with a group of patients with abnormalities that reflect a disturbance in neuronal migration. (orig.).

UK PubMed Central (United Kingdom)

A collection of neurons in the upper lumbar spinal cord of male rats projects to the lower lumbar spinal cord, releasing gastrin-releasing peptide (GRP) onto somatic and autonomic centers known to regulate...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Abstract The past and future dynamical evolution of all 64 long-period comets having 1/aori 3.0-au and discovered after 1970 is studied. For this sample of Oort-spike comets we have obtained a new, homogeneous set of osculating orbits, including 15 orbits with detected non-gravitational parameters. The non-gravitational effects for 11 comets have been determined for the first time. This means that more than 50 per cent of all comets with perihelion distances between 3 and 4-au and discovered after 1970 show detectable deviations from purely gravitational motion. Each comet was then replaced with a swarm of 5001 virtual comets representing the observations well. These swarms were propagated numerically back and forth up to a heliocentric distance of 250-au, constitutin...

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This Report includes copies of transparencies and notes from the presentations made at the Center for Accelerator Physics at Brookhaven National Laboratory Editing and changes to the authors` contributions in this Report were made only to fulfill the publication requirements. This volume includes notes and transparencies on nine presentations: ``The Energy Exchange and Efficiency Consideration in Klystrons``, ``Some Properties of Microwave RF Sources for Future Colliders + Overview of Microwave Generation Activity at the University of Maryland``, ``Field Quality Improvements in Superconducting Magnets for RHIC``, ``Hadronic B-Physics``, ``Spiking Pulses from Free Electron Lasers: Observations and Computational Models``, ``Crystalline Beams in Circular Accelerators``, ``Accumulator Ring for AGS & Recent AGS Performance``, ``RHIC Project Machine Status``, and ``Gamma-Gamma Colliders.``

International Nuclear Information System (INIS)

It has been demonstrated that, by incorporating a thin #approx#20 nm Si_1_-_yC_y (with y as low as 0.1%) layer at the deep indium implant end-of-range (EOR) region, the EOR defects and enhanced diffusion behavior associated with indium implant can be eliminated. The Si_1_-_yC_y layer was grown epitaxially followed by a silicon epitaxy cap of 60 nm. Indium implantations were performed at 1x10"1"4 cm"-"2 at 115 keV followed by spike annealing at 1050 deg. C. The experimentally observed EOR defect and enhanced diffusion elimination are explained based on the undersaturation of implantation-induced silicon interstitials with the presence of substitutional carbon at the Si_1_-_yC_y layer.

International Nuclear Information System (INIS)

Cell surface glycosaminoglycans play important roles in cell adhesion and viral entry. Laboratory strains of two alphaviruses, Sindbis and Semliki Forest virus, have been shown to utilize heparan sulfate as an attachment receptor, whereas Ross River virus (RRV) does not significantly interact with it. However, a single amino acid substitution at residue 218 in the RRV E2 glycoprotein adapts the virus to heparan sulfate binding and expands the host range of the virus into chicken embryo fibroblasts. Structures of the RRV mutant, E2 N218R, and its complex with heparin were determined through the use of electron cryo-microscopy and image reconstruction methods. Heparin was found to bind at the distal end of the RRV spikes, in a region of the E2 glycoprotein that has been previously implicated in cell-receptor recognition and antibody binding.

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Abstract Dynamic testing of a phosphoric acid-based high temperature PEM fuel cell shows a peculiar phenomenon. A certain current loss is observed after temperature cycling at constant voltage. This loss is incidentally recovered by applying a cell voltage spike to open circuit voltage. Experimental investigations into temperature, cell voltage, and ageing effects show that this phenomenon might occur due to the orientation of the adsorbed phosphate species on the platinum catalyst surface. Along with some supporting literature and experimental results, a hypothesis is presented in order to explain this occurrence. Phosphoric acid adsorption hysteresis on platinum catalyst due to temperature cycling could cause the temporary cell current loss. Electrode potential-dependent molecule symmetr...

Science.gov (United States)

Herpes simplex virus type-1 (HSV-1) entry into target cell is initiated by the ionic interactions between positively charged viral envelop glycoproteins and a negatively charged cell surface heparan sulfate (HS). This first step involves the induction of HS-rich filopodia-like structures on the cell surface that facilitate viral transport during cell entry. Targeting this initial first step in HSV-1 pathogenesis, we generated different zinc oxide (ZnO) micro-nano structures (MNSs) that were capped with multiple nanoscopic spikes mimicking cell induced filopodia. These MNSs were predicted to target the virus to compete for its binding to cellular HS through their partially negatively charged oxygen vacancies on their nanoscopic spikes, to affect viral entry and subsequent spread. Our results demonstrate that the partially negatively charged ZnO-MNSs efficiently trap the virions via a novel virostatic mechanism rendering them unable to enter into ...

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PAH biomineralization measurements of yardwaste compost samples indicated heterogeneous distribution of active microorganisms and substantial sequestration of the non-polar substrate in the compost matrix. - The purpose of the study was to evaluate the potential of phenanthrene and fluoranthene biodegradation in yardwaste compost materials. These polynuclear aromatic hydrocarbons were chosen for this work because they are relatively readily biodegradable and ubiquitous in the environment. Compost samples were incubated in biometers with "1"4C-labeled phenanthrene and the evolution of "1"4CO_2 was assessed as a measure of mineralization. The "1"4CO_2 evolution varied widely among replicate biometers, possibly as the result of (1) uneven and patchy colonization of phenanthrene-degrading microorganisms on compost particles, and (2) non-uniform dispersion of the labeled substrate spike into the yardwaste microenvironment. Mineralization of phenanthrene reached about ...

Science.gov (United States)

The mixture of 1,3-dichloropropene (1,3-D) and chloropicrin (CP) is used as a preplant soil fumigant. In comparison with individual fumigants, application of a mixture may affect the environmental dissipation and fate of each chemical, such as emission and degradation. We investigated the degradation of CP, 1,3-D, and their mixture in fresh soils and sterile soils, and evaluated the competitive characteristic of fumigants in the mixture. The degradation of low concentrations of CP in fresh soil was accelerated at early times in the presence of 1,3-D, whereas the addition of CP reduced the degradation rate of trans-1,3-D, possibly by inhibiting the activity of trans-1,3-D degrading microorganisms. The potential of applying amendments to the soil to increase the rate of CP and 1,3-D degradation was also illustrated. The degradation of both fumigants was significantly enhanced in soils amended with ammonium thiosulfate (ATS) and sodium diethyldithiocarbamate (Na-DEDTC) compared with ...

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High energy physics facilities must monitor the radiation doses received by their personnel. This monitoring can only be effective if the radiation detection devices can be calibrated with a good degree of accuracy. Radiation fields are usually composed of several types of radiation, including gamma rays, beta radiation, neutrons, etc. The neutron detection instruments respond not only to the neutrons coming directly from the source but also those scattered from the floor, walls, and ceiling. The amount of neutron scattering varies from site to site depending on the construction materials and layout of the building. The purpose of this study was to determine the scattered neutron fraction in the central volume of the calibration mezzanine of the Radiation Physics Calibration Facility (RPCF) at the Fermi National Accelerator Laboratory (Fermilab). At Fermilab, radiation workers dosimeters use CR39 for neutron detection, which are sent to an outside vendor for reading. As part of the ...

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Locomotion is a complex behavior affected by many different brain- and spinal cord systems, as well as by variations in the peripheral nervous system. Recently, we found increased gene expression for EphA4, a gene intricately involved in motor neuron development, between high-active parental strain C57BL/6J and the low-active chromosome substitution strain 1 (CSS1). CSS1 mice carry chromosome 1 from A/J mice in a C57BL/6J genetic background, allowing localization of quantitative trait loci (QTL) on chromosome 1. To find out whether differences in motor neuron anatomy, possibly related to the changes in EphA4 expression, are involved in the motor activity differences observed in these strains, motor performance in various behavioral paradigms and anatomical differences in the ventral roots ...

International Nuclear Information System (INIS)

The purpose of the present study was to examine the in vitro effects of low-dose cadmium (Cd) on developing cortical cells. The cortical cells removed from fetuses (embryonic day 15) were treated with 10 nM of Cd for 24 h. The effects of Cd on dendritic and synaptic development were immunocytochemically observed with anti-microtubule associated protein-2 (MAP2) and anti-synapsin I antibodies, respectively. Administration of Cd suppressed dendritic as well as synaptic development at 10 nM. By two-dimensional gel electrophoresis and liquid chromatography-tandem mass spectrometric (LC/MS/MS) analysis, we identified three proteins with different expression after Cd-treatment; dihydropyrimidinase-related protein 2 (DRP-2/CRMP-2), 14-3-3-epsillon and calmodulin (CaM). Though the number of identified proteins was small, these proteins are known to be involved in neuronal development. The present study demonstrated the morphological effects as well as affected proteins in ...

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We report the isolation of cDNA clones for the mouse {alpha}7 neuronal nicotinic acetylcholine receptor subunit (gene symbol Acra7), the only nicotinic receptor subunit known to bind a-bungarotoxin in mammalian brain. This gene may have relevance to nicotine sensitivity and to some electrophysiologic findings in schizophrenia. The mouse {alpha}7 subunit gene encodes a protein of 502 amino acids with substantial identity to the rat (99.6%), human (92.8%), and chicken (87.5%) amino acid sequences. The {alpha}7 gene was mapped to mouse chromosome 7 near the p locus with the following gene order from proximal to distal: Myod1-3.5 {+-}1.7 cM-Gas2-0.9 cM {+-} 0.9 cM-D7Mit70-1.8 {+-} 1.2 cM- Acra7-4.4 {+-}1.0 cM-Hras1-ps11/Igf1r/Snrp2a. The human gene was confirmed to map to the homologous region of human chromosome 15q13-q14. 26 refs., 3 figs.

DEFF Research Database (Denmark)

Efflux of dopamine through the dopamine transporter (DAT) is critical for the psychostimulatory properties of amphetamines, but the underlying mechanism is unclear. Here we show that Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) plays a key role in this efflux. CaMKIIalpha bound to the distal C terminus of DAT and colocalized with DAT in dopaminergic neurons. CaMKIIalpha stimulated dopamine efflux via DAT in response to amphetamine in heterologous cells and in dopaminergic neurons. CaMKIIalpha phosphorylated serines in the distal N terminus of DAT in vitro, and mutation of these serines eliminated the stimulatory effects of CaMKIIalpha. A mutation of the DAT C terminus impairing CaMKIIalpha binding also impaired amphetamine-induced dopamine efflux. An in vivo role for CaMKII was supported by chronoamperometry measurements showing reduced amphetamine-induced dopamine efflux in response to the CaMKII inhibitor KN93. Our data suggest that ...

International Nuclear Information System (INIS)

Two aspects of the chromatin repeat length (r_l) are discussed: (i) Why is r_l longer for slowly dividing cells than in rapidly dividing cells?, and (ii) Why is the temporal evolution of r_l a decreasing function of time (t) in mammalian cortical neurons whereas it is an increasing function of t for granule cells around the time of birth? These questions are discussed in terms of a hypothesis which assumes a correlation between deoxyribonucleic acid (DNA) packaging, transcription, and replication. (author). 27 refs.

British Library Electronic Table of Contents (United Kingdom)

Sex steroids and thyroid hormones play a key role in the development of the central nervous system. The critical role of these hormonal systems may explain the sensitivity of the hypothalamus, the cerebral cortex, and the hippocampus to endocrine-disrupting chemicals (EDC). This review examines the evidence for endocrine disruption of glial-neuronal functions in the hypothalamus, hippocampus, and cerebral cortex. Focus was placed on two well-studied EDC, the insecticide dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenyls (PCB). DDT is involved in neuroendocrine disruption of the reproductive axis, whereas polychlorinated biphenyls (PCB) interact with both the thyroid hormone- and sex steroid-dependent systems and disturb the neuroendocrine control of reproduction and develo...

Science.gov (United States)

The epileptogenic and neurodegenerative effects of gamma-dendrotoxin, from Dendroaspis angusticeps, a specific blocker of a non-inactivating, voltage-sensitive K+ channel, were studied after focal injection into one dorsal hippocampus in rats pretreated with CGP040116, a N-methyl-D-aspartate (NMDA) receptor antagonist, and in rats bearing a monolateral surgical lesion of the Schaffer collaterals whose terminals originate from CA3 pyramids and release glutamate in the CA1 hippocampal area. Administration of 35 pmol gamma-dendrotoxin elicited in all of the treated animals (n=8) bilateral EEG discharges and damage to the hippocampal formation. Quantitation of the damage revealed significant bilateral neuronal cell loss in the CA1, CA3 and CA4 pyramidal cell layers. The lowest dose (0.35 pmol; n=4) of the toxin used did not affect EEG activity and failed to cause significant hippocampal cell loss whereas the 3.5 pmol (n=6) dose caused EEG seizures and hippocampal cell ...

International Nuclear Information System (INIS)

Cadmium is a non-essential heavy metal found abundantly in the environment. Children of women exposed to cadmium during pregnancy display lower motor and perceptual abilities. High cadmium body burden in children is also related to impaired intelligence and lowered school achievement. However, little is known about the molecular and cellular basis of developmental neurotoxicity in the sensitive early life stages of animals. In this study, we explore neurological deficits caused by cadmium during early embryonic stages in zebrafish by examining regionalization of the neural tube, pattern formation and cell fate determination, commitment of proneural genes and induction of neurogenesis. We show that cadmium-treated embryos developed a smaller head with unclear boundaries between the brain subdivisions, particularly in the mid-hindbrain region. Embryos display normal anterior to posterior regionalization; however, the commitment of neural progenitor cells was affected by cadmium. We ...

International Nuclear Information System (INIS)

Three simulated low-level reactor wastes were dried using a spray dryer-baghouse system. The three aqueous feedstocks were sodium sulfate waste characteristic of a BWR, boric acid waste characteristic of a PWR, and a waste mixture of ion exchange resins and filter aid. These slurries were spiked with nonradioactive iron, cobalt, and manganese (representing corrosion products) and nonradioactive cesium and iodine (representing fission products). The throughput for the 2.1-m-diameter spray dryer and baghouse system was 160-180 kg/h, which is comparable to the requirements for a full-scale commercial installation. A free-flowing, dry product was produced in all of the tests. The volume reduction factor ranged from 2.5 to 5.8; the baghouse decontamination factor was typically in the range of 10"3 to 10"4. Using an overall system decontamination factor of 10"6, the activity of the off-gas was calculated to be one to two orders of magnitude less than the nuclide release ...

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Transient enhanced diffusion (TED) of boron in silica after low energy boron implantation and annealing was investigated using boron-doping superlattices (DSLs) grown by low temperature molecular beam epitaxy. Boron ions were implanted at 5, 10, 20, and 40 keV at a constant dose of 2{times}10{sup 14}/cm{sup 2}. Subsequent annealing was performed at 750{degree}C for times of 3 min, 15 min, and 2 h in a nitrogen ambient. The broadening of the boron spikes was measured by secondary ion mass spectroscopy and simulated. Boron diffusivity enhancement was quantified as a function of implant energy. Transmission electron microscopy results show that {l_angle}311{r_angle} defects are only seen for implant energies {ge}10 keV at this dose and that the density increases with energy. DSL studies indicate the point defect concentration in the background decays much slower when {l_angle}311{r_angle} defects are present. These results imply there are at least two sources of TED ...

International Nuclear Information System (INIS)

Fluorine is known to have a beneficial role for the B diffusion reduction in preamorphized Si, and is promising for the realization of ultra-shallow junctions. Thus, we studied the F incorporation in Si during the solid phase epitaxy (SPE) process, pointing out the effects of the implanted F energy and fluence and the role played by the possible presence of dopants. The incorporation of fluorine proceeds by F segregation at the amorphous-crystalline interface, with a kinetics driven by the SPE rate. In fact, the quicker the SPE rate, the higher is the F fluence retained. Moreover, we demonstrated that F incorporated in Si layers does not appreciably affect the Is emission from spatially separated end-of-range (EOR) defects. The modification, induced by the presence of F, of the point defect density (Is and Vs) was also studied by means of B and Sb spike layers, used as local markers for Is and Vs, respectively. We showed that F is not only able to completely ...

International Nuclear Information System (INIS)

The diffusion of ion beam injected self-interstitials (I) and their interaction with impurities in crystalline Si has been investigated and modeled. In particular, the I-substitutional carbon (C) interactions have been studied, using a molecular-beam-epitaxy grown Si_1_-_yC_y layer interposed between the shallow I-source and a deeper B-spike (marker for I-concentration). Substitutional C atoms are shown to trap I's, to be removed from their substitutional sites, and to form stable precipitates into the C-rich region. The I-trapping mechanism was quantitatively studied by a simulation code. The reactions causing trapping and deactivation are described. In addition, the boron markers approach was extended to the two dimensional (2D) diffusion. High resolution scanning capacitance microscopy was used for quantitative measurements of the 2D boron transient enhanced diffusion induced on a boron delta array by the I's ion beam injected through a sub-micron dimension ...

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A rapid extraction procedure has been developed for speciation of arsenic in chicken tissue. Water, methanol-water (1:1), and methanol-chloroform (1:1) were tested as extraction media. Individual use of an ultrasonic bath, a microwave oven, or an ultrasonic probe was not sufficient for quantitative recovery of As(III), dimethylarsinate, monomethylarsonate, As(V), and arsenobetaine in spiked samples of chicken tissue. A new extraction procedure using a methanol-water mixture and a microwave oven then an ultrasonic probe enabled extraction of the arsenic species in 7 min with efficiencies ranging from 80 to 100%. HPLC-UV-HG-AFS was used for the determinations. The extraction procedure was 100% efficient when applied to real samples of chicken tissue. AsB (48{+-}5 {mu}g As kg {sup -1}) and one containing-arsenic feed additive, Nitarsone (227{+-}5 {mu}g As kg {sup -1}) were detected. (orig.)

Science.gov (United States)

In this paper we consider the adsorption of argon on the surface of graphitized thermal carbon black and in slit pores at temperatures ranging from subcritical to supercritical conditions by the method of grand canonical Monte Carlo simulation. Attention is paid to the variation of the adsorbed density when the temperature crosses the critical point. The behavior of the adsorbed density versus pressure (bulk density) shows interesting behavior at temperatures in the vicinity of and those above the critical point and also at extremely high pressures. Isotherms at temperatures greater than the critical temperature exhibit a clear maximum, and near the critical temperature this maximum is a very sharp spike. Under the supercritical conditions and very high pressure the excess of adsorbed density decreases towards zero value for a graphite surface, while for slit pores negative excess density is possible at extremely high pressures. For imperfect pores (defined as ...

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The main driver in ultra-shallow formation for the 65 nm technology node and beyond is to find solutions that both reduce boron transient enhanced diffusion and can be integrated in the CMOS process flow. To this end, many studies have recently focused on using co-doping techniques with fluorine and most recently with carbon. In most cases, one or both of these is co-implanted with a dopant specie in pre-amorphized silicon. In this work, we show a comparative study of fluorine or carbon co-implanted with low-energy boron to form source and drain extension junctions for PMOS devices. We will show that by a systematic optimization of germanium, boron, fluorine or carbon energies and doses, spike annealing technology can be extended to the 65 nm node. These results will be used to discuss how the different formed junctions offer potential solutions for either low-power or high-performance PMOS device fabrication.

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The regional concentrations of nine radiochemicals were measured in rat brain after induction of cerebral ischemia to identify tracers concentrated by brain undergoing selective neuronal necrosis. Transient (30 minute) forebrain ischemia was produced in the rat; 24 hours after cerebral recirculation the radiochemicals were injected intravenously and allowed to circulate for 5 hours. The brain concentrations of the radiochemicals in dissected regions were determined by scintillation counting. Forebrain ischemia of this nature will produce extensive injury to striatal neurons but will spare the great majority of neocortical neurons at 24 hours. The regional concentrations of these radiochemicals varied considerably in both control and ischemic animals. In postischemic animals, 4 radionuclides (/sup 63/Ni, /sup 99/TcO/sub 4/, /sup 22/Na, and (/sup 3/H)tetracycline) were concentrated in the irreversibly damaged striatum in ...

British Library Electronic Table of Contents (United Kingdom)

In previous studies we have demonstrated that prion protein (PrP) interacts with tubulin and disrupts microtubular cytoskeleton by inducing tubulin oligomerization. These observations may explain the molecular mechanism of toxicity of cytoplasmic PrP in transmissible spongiform encephalopathies (TSEs). Here, we check whether microtubule associated proteins (MAPs) that regulate microtubule stability, influence the PrP-induced oligomerization of tubulin. We show that tubulin preparations depleted of MAPs are more prone to oligomerization by PrP than those containing traces of MAPs. Tau protein, a major neuronal member of the MAPs family, reduces the effect of PrP. Importantly, phosphorylation of Tau abolishes its ability to affect the PrP-induced oligomerization of tubulin. We propose that t...

British Library Electronic Table of Contents (United Kingdom)

Alzheimer's disease (AD) is a progressive neurodegenerative disorder of the elderly accounting for the vast majority of dementia. Recently, many studies have implicated the role of inflammatory response, especially neuroinflammatory response in the development and progression of AD. However, the underlying mechanism of how inflammatory response induces AD is unknown. Kynurenine pathway is a major route of the amino acid tryptophan catabolism, resulting in the production of nicotine adenine dinucleotide and other neuroactive intermediates: quinolinic acid (QA) and kynurenic acid (KA). QA exerts different toxic effects, including over-activation of N-methyl-d-aspartate (NMDA) receptor and excitotoxicity, synaptic dysfunction and neuronal death. On the other hand, KA is identified as the only...

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There is a thermal range for the operation of neural circuits beyond which nervous system function is compromised. Locusta migratoria is native to the semiarid regions of the world and provides an excellent model for studying neural phenomena. In this organism previous exposure to sublethal high temperatures (heat shock, HS) can protect neuronal function against future hyperthermia but, unlike many organisms, the profound physiological adaptations are not accompanied by a robust increase of Hsp70 transcript or protein in the nervous system. We compared Hsp70 increase following HS in the tissues of isolated and gregarious locusts to investigate the effect of population density. We also localized Hsp70 in the metathoracic ganglion (MTG) of gregarious locusts to determine if HS affects Hsp70 ...

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This study has been carried out in the framework of a collaboration between the laboratory of processes automation (LAP, Caen (France)), and Air Com, a monitoring network for the prevention of atmospheric pollution in Basse-Normandie. It aims at obtaining a medium and long term forecast of the ozone level above the Caen city. The expected goal is to foresee the pollution peaks exceeding the warning thresholds, but the rareness of such events make them more difficult to predict. In order to solve this kind of problem, a neural modeling method combined with a noise injection technique has been implemented in order to obtain a sufficiently performing model over the whole domain of operation. (J.S.)

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Entorhinal grid cells in mammals fire as a function of animal location, with spatially periodic response patterns. This nonlocal periodic representation of location, a local variable, is unlike other neural codes. There is no theoretical explanation for why such a code should exist. We examined how accurately the grid code with noisy neurons allows an ideal observer to estimate location and found this code to be a previously unknown type of population code with unprecedented robustness to noise. In particular, the representational accuracy attained by grid cells over the coding range was in a qualitatively different class from what is possible with observed sensory and motor population codes. We found that a simple neural network can effectively correct the grid code. To the best of our kn...

CERN Document Server

We consider the effect of distributed delays in neural feedback systems. The avian optic tectum is reciprocally connected with the nucleus isthmi. Extracellular stimulation combined with intracellular recordings reveal a range of signal delays from 4 to 9 ms between isthmotectal elements. This observation together with prior mathematical analysis concerning the influence of a delay distribution on system dynamics raises the question whether a broad delay distribution can impact the dynamics of neural feedback loops. For a system of reciprocally connected model neurons, we found that distributed delays enhance system stability in the following sense. With increased distribution of delays, the system converges faster to a fixed point and converges slower toward a limit cycle. Further, the introduction of distributed delays leads to an increased range of the average delay value for which the system's equilibrium point is stable. The enhancement of stability with ...

British Library Electronic Table of Contents (United Kingdom)

Bilateral breast carcinoma accounts for approximately 5% of all patients with breast cancer, while neuroendocrine breast carcinomas comprise less than 5% of invasive breast carcinomas. In addition, most patients with breast neuroendocrine carcinomas are older. Therefore, bilateral primary breast neuroendocrine carcinoma at a young age is extremely rare. We herein report bilateral neuroendocrine carcinoma of the breast in a 29-year-old woman who underwent bilateral lumpectomy with the initial symptom of bilateral nipple discharge. Grossly, the lesions in both breasts were masses with infinite margins. Histologically, this case was consistent with primary neuroendocrine carcinoma arising in bilateral breasts. Cells from both breast tumors were positive for chromogranin A, neuron-specific eno...

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The neuronal nicotinic acetylcholine receptor {alpha}7 subunit is a member of a family of ligand-gated ion channels, and is the only subunit know to bind {alpha}-bungarotoxin in mammalian brain. {alpha}-Bungarotoxin binding sites are known to be more abundant in the hippocampus of mouse strains that are particularly sensitive to nicotine-induced seizures. The {alpha}7 receptor is highly permeable to calcium, which could suggest a role in synaptic plasticity in the nervous system. Auditory gating deficiency, an abnormal response to a second auditory stimulus, is characteristic of schizophrenia. Mouse strains that exhibit a similar gating deficit have reduced hippocampal expression of the {alpha}7 subunit. We have cloned and sequenced the full length cDNA for the mouse {alpha}7 gene (Acra-7) and characterized its gene structure. The murine {alpha}7 shares amino acid identity of 99% and 93% with the rat and human {alpha}7 subunits, respectively. Using an interspecies ...

Science.gov (United States)

The precedence effect (PE) is thought to be beneficial for proper localization and perception of sounds. The majority of recent physiological studies focus on the neural discharges correlated with PE in the inferior colliculus (IC). Pentobarbital anesthesia is widely used in physiological studies. However, little is known of the effect of pentobarbital on the discharge of neurons in PE. Neuronal responses in the IC from 23 male SD rats were recorded by standard extracellular recording techniques following presentation of 4 ms white noise bursts, presented from either or both of two loud speakers, at different interstimulus delays (ISDs). The neural responses were recorded for off-line analysis before or after intraperitoneal administration of pentobarbital at a loading or maintenance dose. Data were assessed by one-way repeated measures analysis of variance and pairwise comparisons. When the ipsilateral stimuli were leading, pentobarbital at a ...

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A study was made of the actions of the excitant neurotoxin, kainic acid, on the uptake and the release of D-(2,3-3H)aspartate (D-ASP) in slices of guinea pig cerebral neocortex and striatum. The slices took up D-ASP, reaching concentrations of the amino acid in the tissue which were 14-23 times that in the medium. Subsequently, electrical stimulation of the slices evoked a Ca2+-dependent release of a portion of the D-ASP. Kainic acid (10(-5)-10(-3) M) produced a dose-dependent inhibition of D-ASP uptake. The electrically evoked release of D-ASP was increased 1.6-2.0 fold by 10(-5) and 10(-4)M kainic acid. The kainate-enlarged release was Ca2+-dependent. Dihydrokainic acid, an analogue of kainic acid with little excitatory or toxic action, did not increase D-ASP release but depressed D-ASP uptake. Attempts were made to block the action of kainic acid with baclofen and pentobarbital, compounds which depress the electrically evoked release of L-glutamate (L-GLU) and L-aspartate (L-ASP). ...

Science.gov (United States)

Excitotoxicity plays a major role in various neurological disorders. In this study, we explored the behavioral and neurotoxic effects of intraventricular NMDA administration in mice. After NMDA injection, acute seizures were followed by impairments in locomotor activity, motor performance on a rotarod, and climbing ability. Mice killed 1 day after NMDA administration showed increased synaptosomal reactive oxygen species ROS production and calcium concentration and decreased mitochondrial membrane potential, mitochondrial reductase activities, and neuronal membrane Na+, K+ -ATPase and mg2+ -ATPase activities. One and 3 days after excitotoxic injury, Golgi stains showed that dendritic length and spine density were significantly decreased in neurons of the hippocampal dentate gyrus. Some mice received honokiol, tea polyphenol plus memantine, and honokiol plus memantine prior to NMDA treatment; the occurrence of generalized seizures was attenuated, ...

Science.gov (United States)

The technology for flue gas desulfurization (FGD) with seawater is widely adopted by coal-fired power plants in coastal areas. SO2 in the flue gas is absorbed by alkaline seawater and transfered in aqueous phase as sulfite (SO3(2-)), and most SO3(2-) is transformed to sulfate (SO4(2-)) after an aeration process. The remaining SO3(2-) in the seawater discharged to sea area may be harmful to marine organism because of its biological toxicity, thus it is necessary to determine the concentration of SO3(2-) in the seawater for desulfurization. In this study, the method of determination of SO3(2-) in the seawater by ion chromatography was investigated. The separation was achieved on an IonPac AS14A column with 14 mmol/L NaOH-12 mmol/L Na2 CO3 solution as the mobile phase at a flow rate of 1.2 mL/min, and the detection was performed by a pulsed amperometric detector. Formaldehyde was added as a protective agent when sampling because the SO3(2-) is easy to be oxidized. To avoid the formation ...

International Nuclear Information System (INIS)

Three CRMs of plant origin (SRM 1515 Apple Leaves, SRM 1570a Trace Elements in Spinach Leaves, and SRM 1575 Pine Needles) were used for analytical quality assurance of Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Mo, Cd, and Pb determination by ICP-MS. The samples were decomposed using microwave assisted pressurized digestion by HNO_3 and HNO_3 + H_2O_2 mixture and temperature programmed dry ashing. Concentrations of elements in samples were evaluated by external calibration. All samples, blanks, and standards were spiked to 100 #mu#g/L concentration of In and Bi as internal standards. During the measurement, signals of "5"2Cr, "5"3Cr, "5"4Fe, "5"5Mn, "5"9Co, "6"0Ni, "6"2Ni, "6"3Cu, "6"5Cu, "6"6Zn, "9"5Mo, "1"1"1Cd, "1"1"2Cd, "1"1"5In, "2"0"6Pb, "2"0"7Pb, "2"0"8Pb and "2"0"9Bi were monitored. Results of Pb, Cd, Cu, Zn, Mo and Co determination were in good agreement with certified values. In order to obtain accurate results for As at low levels, it was necessary to ...

International Nuclear Information System (INIS)

In the present paper the contamination levels of trace and toxic metals in drinking water collected from Tarapur industrial area, Thane were investigated. The concentrations of trace and toxic metals (Pb, Cd, Cu, Cr, Ni, Se, V, Zn, Mn, Mo, Co, As and Ba) were determined simultaneously using Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The results were compared with international water quality guidelines (WHO, 2008) and were found within the permissible limits. The quality assurance was checked by standard addition method and spike recovery. The concentration of Pb, Cd, Cu, Cr, Ni, Se, V, Zn, Mn, Mo, Co, As and Ba varies from 4.25-19.62 #mu#g/L, 0.13-1.49 #mu#g/L, 0.60-65.55 #mu#g/L, 0.46-4.15 #mu#g/L, <0.1 #mu#g/L, 0.5- 9.35 #mu#g/L, <0.5 #mu#g/L, 3.41-99.64 #mu#g/L, 0.80-9.62 #mu#g/L, 0.30-1.48 #mu#g/L, <0.1-0.90 #mu#g/L, <0.63 #mu#g/L and 0.71-9.0 #mu#g/L respectively. Similarly Na, K, Ca and Mg varies from 8.83-61.54 mg/L, ...

International Nuclear Information System (INIS)

In this work the diffusion of ion-beam-injected self-interstitials (Is) and their interaction with impurities in crystalline Si are presented. In particular, the I penetration into a molecular beam epitaxy grown Si structure was studied by means of diffusion effects induced on B spikes, analyzed by a developed simulation code. Trapping effects at sample-surface and bulk are evidenced and modeled. The B marker approach was extended to the two-dimensional (2D) I-diffusion occurring as a consequence of ion implantation through a sub-micron dimension patterned oxide mask. I-source size effects on the I penetration have been found and modeled, quantitatively describing the 2D I-diffusion. The I-substitutional carbon interactions have been also studied, showing the C ability to effectively retain Is. The I-trapping mechanism was quantitatively studied by the simulation code, showing that one I is able to deactivate about two C traps by means of I-trapping and ...

Energy Technology Data Exchange (ETDEWEB)

Microbial dechlorination of polychlorinated biphenyls (PCBs) often stops although a significant number of removable chlorines remain. To determine the reason for the cessation, we investigated the limitation of organic carbon, PCB bioavailability, and inhibition by metabolic products. Enrichment with carbon sources did not induce additional chlorination, indicating the plateau was not due to depletion of organic carbon. The bioavailability was not limiting, since a subcritical micelle concentration of the surfactant, which enhanced desorption without inhibiting dechlorinating microorganisms, failed to lower the plateau. Neither was it due to accumulation of metabolites, since no additional dechlorination was detected when plateau sediments were incubated with fresh medium. Similarly, dechlorination was not inhibited in freshly spiked sediment slurries. Dechlorination ended up at the same level with nearly identical congener profiles, regardless of treatment. These ...

Energy Technology Data Exchange (ETDEWEB)

To prove that two-layer, TBP-nitric acid mixtures can be safely stored in the canyon evaporators, it must be demonstrated that a runaway reaction between TBP and nitric acid will not occur. Previous bench-scale experiments showed that, at typical evaporator temperatures, this reaction is endothermic and therefore cannot run away, due to the loss of heat from evaporation of water in the organic layer. However, the reaction would be exothermic and could run away if the small amount of water in the organic layer evaporates before the nitric acid in this layer is consumed by the reaction. Provided that there is enough water in the aqueous layer, this would occur if the organic layer is sufficiently thick so that the rate of loss of water by evaporation exceeds the rate of replenishment due to mixing with the aqueous layer. This report presents measurements of mass transfer rates for the mixing of water and butanol in two-layer, TBP-aqueous mixtures, where the top layer is primarily TBP and ...

Energy Technology Data Exchange (ETDEWEB)

The objective of this project is to develop a pellet formulation which is capable of achieving low sulfur partial pressures and a high capacity for sulfur, loaded from a hot fuel gas and which is readily regenerable. Furthermore the pellet must be strong for potential use in a fluidized bed and regenerable over many cycles of loading and regeneration. Regeneration should be in air or oxygen-depleted air to produce a high-concentration sulfur dioxide. Fixed-bed tests were conducted with several formulations of manganese sesquioxide and titania, and alumina They were subject to a simplified fuel gas of the oxygen-blown Shell type spiked with a 30,000ppmv concentration of H{sub 2}S. Pellet crush strengths for 4 and 2mm diameter pellets was typically 12 lbs per pellet and 4 lbs per pellet, respectively. For the most favorable of the formulations tested and under the criteria of break-through at less than 100ppmv H2S and loading temperatures of 500{degrees}C and an ...

Science.gov (United States)

Metam sodium (metam) is a widely used soil fumigant. Combined application of metam and other available fumigants is intended to produce synergic pesticidal effects for a broad spectrum of pest control in soil fumigation. This study aimed to test the compatibility of metam with the halogenated fumigants 1,3-dichloropropene (1,3-D), chloropicrin, methyl bromide, methyl iodide and propargyl bromide. Halogenated fumigants and metam were spiked simultaneously into organic solvents, water and moist soils, and metam-induced degradation of these halogenated chemicals was evaluated. In all three media, the halogenated fumigants were incompatible with metam and degraded via rapid chemical reactions. The degradation rate varied with halogenated fumigant species and increased as the amount of metam present was increased. In moist soil, 15-95% of the halogenated fumigants were decomposed within 72 h by metam at a 1:1 molar ratio. Combined application of Telone C-35 (62.5% 1,3-D ...

Energy Technology Data Exchange (ETDEWEB)

The electrochemical behavior of the anti-thalassemia and anti-HIV replication drug, deferiprone, was investigated on a carbon nanotube-modified glassy carbon (GC-CNT) electrode in phosphate buffer solution, pH 7.40 (PBS). During oxidation of deferiprone, two irreversible anodic peaks, with E{sub 1}{sup 0}=452 and E{sub 2}{sup 0}=906mV, appeared, using GC-CNT. Cyclic voltammetric study indicated that the oxidation process is irreversible and diffusion controlled. The number of exchanged electrons in the electro-oxidation process was obtained, and the data indicated that deferiprone is oxidized via two two-electron steps. The results revealed that carbon nanotube (CNT) promotes the rate of oxidation by increasing the peak current, so that deferiprone is oxidized at lower potentials, which thermodynamically is more favorable. This result was confirmed by impedance measurements. The diffusion coefficient, electron-transfer coefficient and heterogeneous electron-transfer rate constant of ...

International Nuclear Information System (INIS)

Chinese brake fern (Pteris vittata L.), an arsenic (As) hyperaccumulator, has shown the potential to remediate As-contaminated soils. This study investigated the effects of soil amendments on the leachability of As from soils and As uptake by Chinese brake fern. The ferns were grown for 12 weeks in a chromated-copper-arsenate (CCA) contaminated soil or in As spiked contaminated (ASC) soil. Soils were treated with phosphate rock, municipal solid waste, or biosolid compost. Phosphate amendments significantly enhanced plant As uptake from the two tested soils with frond As concentrations increasing up to 265% relative to the control. After 12 weeks, plants grown in phosphate-amended soil removed >8% of soil As. Replacement of As by P from the soil binding sites was responsible for the enhanced mobility of As and subsequent increased plant uptake. Compost additions facilitated As uptake from the CCA soil, but decreased As uptake from the ASC soil. Elevated As uptake ...

Science.gov (United States)

The commercial solid phase microextraction (SPME) fibers are not stable enough in organic solvent and tend to swell and strip off from the silica fiber in the high performance liquid chromatography (HPLC) mobile phase, and therefore the application of SPME coupled online with HPLC is limited. In this study, an SPME fiber coated with single walled carbon nanotubes (SWCNTs), prepared by means of electrophoretic deposition, was coupled on line to HPLC for the determination of four endocrine-disrupting compounds, i.e. bisphenol A (BPA), estrone (E(1)), 17?-ethynylestradiol (EE(2)) and octylphenol (OP), in aqueous samples. The results showed that the SWCNTs coating on the prepared fiber did not swell and strip off from the platinum fiber throughout the experiment, thus indicating a high resistance to the HPLC mobile phase, the mixture of water and acetonitrile. The SWCNTs fiber had similar (for OP) or higher (for BPA, EE(2) and E(1)) extraction efficiencies than the commonly used ...

International Nuclear Information System (INIS)

Arsenic was predominantly present as inorganic arsenite in the fronds of the hyperaccumulator Chinese brake. - Arsenic speciation is important not only for understanding the mechanisms of arsenic accumulation and detoxification by hyperaccumulators, but also for designing disposal options of arsenic-rich biomass. The primary objective of this research was to understand the speciation and leachability of arsenic in the fronds of Chinese brake (Pteris vittata L.), an arsenic hyperaccumulator, with an emphasis on the implications for arsenic-rich biomass disposal. Chinese brake was grown for 18 weeks in a soil spiked with 50 mg As kg"-"1 as arsenate (AsO_4"3"-), arsenite (AsO_3"3"-), dimethylarsinic acid (DMA), or methylarsonic acid (MMA). Plant samples were extracted with methanol/water (1:1) and arsenic speciation was performed using high performance liquid chromatography coupled with atomic fluorescence spectrometry. The impacts of air-drying on arsenic species and ...

Energy Technology Data Exchange (ETDEWEB)

Previous work showed that the segl mutant of barley (Hordeum vulgare o Betzes) did not differ from normal Betzes in plant growth, photosynthesis, or fertility, but it produced only shrunken seeds regardless of pollen source. To determine whether defects in sucrose uptake or starch synthesis resulted in the shrunken condition, developing grains of Betzes and segl were cultured in (/sup 14/C)sucrose solutions after slicing transversely to expose the endosperm cavity and free space. In both young grains (before genotypes differed in dry weight) and older grains (17 days after anthesis, when segl grains were smaller than Betzes), sucrose uptake and starch synthesis were similar in both genotypes on a dry weight basis. To determine if sucrose was hydrolyzed during uptake, spikes of Betzes and segl were allowed to take up (fructose-U-/sup 14/C)sucrose 14 days after anthesis and the radioactivity of endosperm sugars was examined during 3 hours of incubation. Whereas less ...

British Library Electronic Table of Contents (United Kingdom)

Nerve growth factor (NGF), a survival factor for neurons enforces pain by sensitizing nociceptors. Also in the pancreas, NGF was associated with pain and it can stimulate the proliferation of pancreatic cancer cells. Hepatic stellate cells (HSC) respond to NGF with apoptosis. Transforming growth factor (TGF)-b, one of the strongest pro-fibrogenic activators of pancreatic stellate cells (PSC) induced NGF and its two receptors in an immortalized human cell line (ihPSC) and primary rat PSC (prPSC) as determined by RT-PCR, western blot, and immunofluorescence. In contrast to HSC, PSC expressed both NGF receptors, although p75NTR expression was weak in prPSC. In contrast to ihPSC TGF-b activated both Smad signaling cascades in prPSC. NGF secretion was diminished by the activin-like kinase (ALK)...

Science.gov (United States)

Prairie (Microtus ochrogaster) and meadow voles (M. pennsylvanicus) are closely related species that differ in life strategy and social behaviors, and thus provide an excellent comparative model for the study of neuronal and hormonal mechanisms underlying behavior. In the present study using the elevated plus maze (EPM) test, we found that male prairie voles entered the open arms of the EPM more and remained there longer, and showed a higher level of overall locomotor activity than did male meadow voles. In addition, two weeks of social isolation induced an increase in open arm entries in prairie, but not meadow, voles. Prairie voles also had a higher level of circulating corticosterone compared to meadow voles, and the EPM test increased circulating corticosterone in prairie voles. Finally, social isolation coupled with the EPM test influenced Fos-immunoreactive expression in several brain areas, including the medial preoptic area, ventromedial hypothalamus, ...

Science.gov (United States)

Therapeutic hypothermia is a promising method for controlling intracranial pressure (ICP) in severely brain-injured patients. However, clinical data regarding the effect of brain hypothermia on overall outcome of these patients is limited. This may be because there are specific pitfalls associated with the clinical management of induced hypothermia in patients with severe traumatic brain injury (TBI). These pitfalls may be avoided by preventing specific risk factors when cooling is induced and with rewarming. However, these risk factors have not been well systematically discussed in the literature. In this paper, three categories of clinical issues regarding the management of brain hypothermia are discussed: (1) stress-induced secondary brain injury mechanisms; (2) technical aspects of intensive care unit (ICU) cooling management; and (3) rewarming rates and methods. For patients with a Glasgow Coma Scale (GCS) score of less than 8, management of stress-induced insulin-resistant ...

Energy Technology Data Exchange (ETDEWEB)

Patients with acquired immunodeficiency syndrome (AIDS) are subject to a spectrum of central nervous system (CNS) disorders. Recent evidence implicates the human T-cell lymphotropic virus type III (HTLV-III) in the pathogenesis of some of these illnesses, although the cells infected by the virus have yet to be identified. Using in situ hybridization, the authors examined brain tissue from two patients with AIDS encephalopathy for the presence of HTLV-III RNA. In both cases, viral RNA was detected and concentrated in, though not limited to, the white matter. The CNS cells most frequently infected included macrophages, pleomorphic microglia, and multinucleated giant cells. Less frequently, cells morphologically consistent with astrocytes, oligodendroglia, and rarely neurons were also infected. The findings strengthen the association of HTLV-III with the pathogenesis of AIDS encephalopathy. In situ hybridization can be applied to routinely prepared biopsy tissue in ...

Science.gov (United States)

The objective of the study was to investigate neuronal processing during the encoding, retention and retrieval phases of a serial visual working memory task. Particularly, we were interested in how these phases are affected by working memory load and how processing is modulated by methylphenidate. Healthy adults were asked to memorize the order of four, five or six pictures under methylphenidate (20mg) and under placebo while brain electrical activity was recorded. On the performance level, the number of correct responses decreased with increasing working memory load. Concerning brain electrical activity, in the encoding phase P3 amplitudes increased at midline electrodes with increasing memory load while load had no effect in the retention and retrieval phase. Medication neither influenced performance nor the different processing stages significantly. Our data provide evidence that during the encoding phase more attentional resources are allocated in trials with ...

Science.gov (United States)

Snake envenomation employs three well integrated strategies: prey immobilization via hypotension, prey immobilization via paralysis, and prey digestion. Purines (adenosine, guanosine and inosine) evidently play a central role in the envenomation strategies of most advanced snakes. Purines constitute the perfect multifunctional toxins, participating simultaneously in all three envenomation strategies. Because they are endogenous regulatory compounds in all vertebrates, it is impossible for any prey organism to develop resistance to them. Purine generation from endogenous precursors in the prey explains the presence of many hitherto unexplained enzyme activities in snake venoms: 5'-nucleotidase, endonucleases (including ribonuclease), phosphodiesterase, ATPase, ADPase, phosphomonoesterase, and NADase. Phospholipases A(2), cytotoxins, myotoxins, and heparinase also participate in purine liberation, in addition to their better known functions. Adenosine contributes to prey immobilization ...

International Nuclear Information System (INIS)

Understanding prostate stem cells may provide insight into the origin of prostate cancer. Primary cells have been cultured from human prostate tissue but they usually survive only 15-20 population doublings before undergoing senescence. We report here that RC-170N/h/clone 7 cells, a clonal cell line from hTERT-immortalized primary non-malignant tissue-derived human prostate epithelial cell line (RC170N/h), retain multipotent stem cell properties. The RC-170N/h/clone 7 cells expressed a human embryonic stem cell marker, Oct-4, and potential prostate epithelial stem cell markers, CD133, integrin #alpha#2#beta#1"h"i and CD44. The RC-170N/h/clone 7 cells proliferated in KGM and Dulbecco's Modified Eagle Medium with 10% fetal bovine serum and 5 #mu#g/ml insulin (DMEM + 10% FBS + Ins.) medium, and differentiated into epithelial stem cells that expressed epithelial cell markers, including CK5/14, CD44, p63 and cytokeratin 18 (CK18); as well as the mesenchymal cell markers, vimentin, desmin; ...

International Nuclear Information System (INIS)

The stunning, intricate interaction between the visual, vestibular and optomotor systems--each a miracle on its own--ensures maintenance of orientation in space as well as visual recognition and target selection despite a host of sensory conflicts and adversary disturbances. Their main goals are to keep a target of interest on the fovea by either maintaining or shifting the direction of gaze in order to produce an accurate internal representation of the visual surroundings, in particular the selected target, and to continuously mirror the spatial relationship between these various visual elements and the self. Not surprising, the implementation of this host of elaborate neural networks encompasses almost every part of the brain, including the brainstem, cerebellum, extrapyramidal system and many areas of the cerebral cortex. Thus far, these systems are among the best investigated in brain research; and enormous knowledge was amassed over the last century employing a variety of ...

International Nuclear Information System (INIS)

The sixth AER benchmark is the second AER benchmark for couplings of the thermal hydraulic codes and three dimensional neutron kinetic core models. It concerns a double end break of one main steam line in a WWER-440 plant. The core is at the end of its first cycle in full power conditions. In VTT HEXTRAN2.9 is used for the core kinetics and dynamics and SMABRE4.8 as a thermal hydraulic model for the primary and secondary loop. The plant model for SMABRE consists mainly of two input models, Loviisa model and a standard WWER-440/213 plant model. The primary loop includes six separate loops, the pressure vessel is divided into six parallel channels in SMABRE and the whole core calculation is performed in the core with HEXTRAN. The horizontal steam generators are modelled with heat transfer tubes in five levels and vertically with two parts, riser and downcomer. With this kind of detailed modelling of steam generators there occurs strong flashing after break opening. As a sequence of the ...

International Nuclear Information System (INIS)

The gender-specific expression pattern of aromatase and 5alpha-reductases (5alpha-R) during brain development provides neurons the right amount of estradiol and DHT to induce a dimorphic organization of the structure. Polychlorinated biphenyls (PCBs) are endocrine disruptive pollutants; exposure to PCBs through placental transfer and breast-feeding may adversely affect the organizational action of sex steroid, resulting in long-term alteration of reproductive neuroendocrinology. The study was aimed at: a) evaluating the hypothalamic expression of aromatase, 5alpha-R1 and 5alpha-R2 in fetuses (GD20), infant (PN12), weaning (PN21) and young adult (PN60) male and female rats exposed to PCBs during development; b) correlating these parameters with the time of testicular descent, puberty onset, estrous cyclicity and copulatory behavior; c) evaluating possible alterations of some non reproductive behaviors (locomotion, learning and memory, depression/anxiety behavior). A ...

Science.gov (United States)

Testing was performed to determine the feasibility and processing characteristics of evaporation of actual Defense Waste Processing Facility (DWPF) recycle material. Samples of the Off Gas Condensate Tank (OGCT) and Slurry Mix Evaporator Condensate Tank (SMECT) were transferred from DWPF to the Savannah River National Lab (SRNL) Shielded Cells and blended with De-Ionized (DI) water and a small amount of Slurry Mix Evaporator (SME) product. A total of 3000 mL of this feed was concentrated to approximately 90 mL during a semi-batch evaporation test of approximately 17 hours. One interruption occurred during the run when the feed tube developed a split and was replaced. Samples of the resulting condensate and concentrate were collected and analyzed. The resulting analysis of the condensate was compared to the Waste Acceptance Criteria (WAC) limits for the F/H Effluent Treatment Plant (ETP). Results from the test were compared to previous testing using simulants and OLI modeling. ...