Fragile X Mental Retardation Protein Regulates Activity-Dependent Membrane Trafficking and Trans-Synaptic Signaling Mediating Synaptic Remodeling

Science.gov (United States)

Sears, James C.; Broadie, Kendal

2018-01-01

Fragile X syndrome (FXS) is the leading monogenic cause of autism and intellectual disability. The disease arises through loss of fragile X mental retardation protein (FMRP), which normally exhibits peak expression levels in early-use critical periods, and is required for activity-dependent synaptic remodeling during this transient developmental window. FMRP canonically binds mRNA to repress protein translation, with targets that regulate cytoskeleton dynamics, membrane trafficking, and trans-synaptic signaling. We focus here on recent advances emerging in these three areas from the Drosophila disease model. In the well-characterized central brain mushroom body (MB) olfactory learning/memory circuit, FMRP is required for activity-dependent synaptic remodeling of projection neurons innervating the MB calyx, with function tightly restricted to an early-use critical period. FMRP loss is phenocopied by conditional removal of FMRP only during this critical period, and rescued by FMRP conditional expression only during this critical period. Consistent with FXS hyperexcitation, FMRP loss defects are phenocopied by heightened sensory experience and targeted optogenetic hyperexcitation during this critical period. FMRP binds mRNA encoding Drosophila ESCRTIII core component Shrub (human CHMP4 homolog) to restrict Shrub translation in an activity-dependent mechanism only during this same critical period. Shrub mediates endosomal membrane trafficking, and perturbing Shrub expression is known to interfere with neuronal process pruning. Consistently, FMRP loss and Shrub overexpression targeted to projection neurons similarly causes endosomal membrane trafficking defects within synaptic boutons, and genetic reduction of Shrub strikingly rescues Drosophila FXS model defects. In parallel work on the well-characterized giant fiber (GF) circuit, FMRP limits iontophoretic dye loading into central interneurons, demonstrating an FMRP role controlling core neuronal properties through the

A review of pruning fruit trees

Science.gov (United States)

Zhang, L.; Koc, A. B.; Wang, X. N.; Jiang, Y. X.

2018-05-01

The focus of this review is to present the results of studies and articles about ways to prune fruit trees. Pruning should be done in late winter or early spring so that the infection risk can be significantly decreased. This review will also offer an overview of methods to prevent infections and speed up recovery on the trees. The following is an interpretation of why high-power ultrasonic assisted pruning in the fruits trees is needed and will elaborate on the efficiency, labor costs, and safety, as well as space, location, and some environmental issues.

DANNP: an efficient artificial neural network pruning tool

KAUST Repository

Alshahrani, Mona

2017-11-06

Background Artificial neural networks (ANNs) are a robust class of machine learning models and are a frequent choice for solving classification problems. However, determining the structure of the ANNs is not trivial as a large number of weights (connection links) may lead to overfitting the training data. Although several ANN pruning algorithms have been proposed for the simplification of ANNs, these algorithms are not able to efficiently cope with intricate ANN structures required for complex classification problems. Methods We developed DANNP, a web-based tool, that implements parallelized versions of several ANN pruning algorithms. The DANNP tool uses a modified version of the Fast Compressed Neural Network software implemented in C++ to considerably enhance the running time of the ANN pruning algorithms we implemented. In addition to the performance evaluation of the pruned ANNs, we systematically compared the set of features that remained in the pruned ANN with those obtained by different state-of-the-art feature selection (FS) methods. Results Although the ANN pruning algorithms are not entirely parallelizable, DANNP was able to speed up the ANN pruning up to eight times on a 32-core machine, compared to the serial implementations. To assess the impact of the ANN pruning by DANNP tool, we used 16 datasets from different domains. In eight out of the 16 datasets, DANNP significantly reduced the number of weights by 70%–99%, while maintaining a competitive or better model performance compared to the unpruned ANN. Finally, we used a naïve Bayes classifier derived with the features selected as a byproduct of the ANN pruning and demonstrated that its accuracy is comparable to those obtained by the classifiers trained with the features selected by several state-of-the-art FS methods. The FS ranking methodology proposed in this study allows the users to identify the most discriminant features of the problem at hand. To the best of our knowledge, DANNP (publicly

7 CFR 993.149 - Receiving of prunes by handlers.

Science.gov (United States)

2010-01-01

... SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE DRIED... certifies that the dehydration process of the prunes being certified resulted in prunes eligible to be... conditioning by further drying or dehydration: Provided, That such prunes shall be identified and kept separate...

Prune Belly Syndrome in Adolescence: A Case Report

Directory of Open Access Journals (Sweden)

Prasad Mylarappa

2015-01-01

Full Text Available The Prune Belly syndrome also known as Eagle Barret syndrome is a rare disorder. We report a rare case of Prune Belly syndrome in 17 year old boy. Patient presented with complains of absence of both testis in scrotum since birth. On examination patient was found to have lax abdominal wall. Patient was further evaluated and found to have shrunken small right kidney and left hydroureteronephrosis and the diagnosis of Prune Belly Syndrome was made. Prune Belly Syndrome represents a wide spectrum of disease. Each patient must be dealt with on an individual basis. A course of watchful waiting with selective surgical intervention has also been successful.

Prune belly syndrome

Science.gov (United States)

Eagle-Barrett syndrome; Triad syndrome ... The exact causes of prune belly syndrome are unknown. The condition affects mostly boys. While in the womb, the developing baby's abdomen swells with fluid. Often, the cause is ...

Respiratory function in the prune-belly syndrome.

OpenAIRE

Crompton, C H; MacLusky, I B; Geary, D F

1993-01-01

Respiratory function was evaluated in 11 patients with prune-belly syndrome. Nine had evidence of gas trapping and six of restrictive lung disease. These abnormalities of lung function appear to be secondary to the musculoskeletal disorder associated with prune-belly syndrome rather than parenchymal lung disease.

Respiratory function in the prune-belly syndrome.

Science.gov (United States)

Crompton, C H; MacLusky, I B; Geary, D F

1993-01-01

Respiratory function was evaluated in 11 patients with prune-belly syndrome. Nine had evidence of gas trapping and six of restrictive lung disease. These abnormalities of lung function appear to be secondary to the musculoskeletal disorder associated with prune-belly syndrome rather than parenchymal lung disease. PMID:8503677

Composability-Centered Convolutional Neural Network Pruning

Energy Technology Data Exchange (ETDEWEB)

Shen, Xipeng [North Carolina State University; Guan, Hui [North Carolina State University; Lim, Seung-Hwan [ORNL; Patton, Robert M. [ORNL

2018-02-01

This work studies the composability of the building blocks ofstructural CNN models (e.g., GoogleLeNet and Residual Networks) in thecontext of network pruning. We empirically validate that a networkcomposed of pre-trained building blocks (e.g. residual blocks andInception modules) not only gives a better initial setting fortraining, but also allows the training process to converge at asignificantly higher accuracy in much less time. Based on thatinsight, we propose a {\\em composability-centered} design for CNNnetwork pruning. Experiments show that this new scheme shortens theconfiguration process in CNN network pruning by up to 186.8X forResNet-50 and up to 30.2X for Inception-V3, and meanwhile, the modelsit finds that meet the accuracy requirement are significantly morecompact than those found by default schemes.

Prune belly syndrome associated with incomplete VACTERL

Directory of Open Access Journals (Sweden)

Ghritlaharey R

2007-01-01

Full Text Available A Prune Belly syndrome with VATER/VACTERL association is an extremely rare. They are either stillborn or die within few days of life, only few such cases have been reported in literature. We are presenting here a male neonate of Prune Belly syndrome associated with incomplete VACTERL with brief review of literature.

Prune belly syndrome in an adult Nigerian: case report.

Science.gov (United States)

Salako, A A; Takure, A O; Olajide, A O; Aarowolo, O A; Egberongbe, A A

2009-12-01

Prune Belly Syndrome is a rare congenital anomaly characterized by deficient anterior abdominal wall musculature, bilateral cryptorchidism, bilateral megaureters and often unilateral or bilateral vesico-ureteric junction obstruction. The report of prune belly syndrome in the adult is scanty. We report a case of prune belly syndrome in a 24 year old Nigerian who presented with 3 year history of recurrent right loin pain. Examination showed wrinkled abdominal skin, bilateral undescended testes and an hypoplastic rectus abdominis, below the umbilicus. Further evaluation revealed enlarged bladder, bilateral megaureters and right intra-abdominal testis. A diagnosis of Prune Belly Syndrome was made. The challenges in the diagnosis and management of this rare condition are highlighted in this presentation.

Efficient Pruning Method for Ensemble Self-Generating Neural Networks

Directory of Open Access Journals (Sweden)

Hirotaka Inoue

2003-12-01

Full Text Available Recently, multiple classifier systems (MCS have been used for practical applications to improve classification accuracy. Self-generating neural networks (SGNN are one of the suitable base-classifiers for MCS because of their simple setting and fast learning. However, the computation cost of the MCS increases in proportion to the number of SGNN. In this paper, we propose an efficient pruning method for the structure of the SGNN in the MCS. We compare the pruned MCS with two sampling methods. Experiments have been conducted to compare the pruned MCS with an unpruned MCS, the MCS based on C4.5, and k-nearest neighbor method. The results show that the pruned MCS can improve its classification accuracy as well as reducing the computation cost.

Prune Belly Syndrome | Hammond | South African Medical Journal

African Journals Online (AJOL)

Two cases of prune belly syndrome in Black infants are presented. The prune belly syndrome, or congenital absence of abdominal muscles, is accompanied by hydro-ureter, hydronephrosis, megalocystis and usually undescended testes. Other associated congenital defects occur, of which orthopaedic defects appear to be ...

Iterative Mixture Component Pruning Algorithm for Gaussian Mixture PHD Filter

Directory of Open Access Journals (Sweden)

Xiaoxi Yan

2014-01-01

Full Text Available As far as the increasing number of mixture components in the Gaussian mixture PHD filter is concerned, an iterative mixture component pruning algorithm is proposed. The pruning algorithm is based on maximizing the posterior probability density of the mixture weights. The entropy distribution of the mixture weights is adopted as the prior distribution of mixture component parameters. The iterative update formulations of the mixture weights are derived by Lagrange multiplier and Lambert W function. Mixture components, whose weights become negative during iterative procedure, are pruned by setting corresponding mixture weights to zeros. In addition, multiple mixture components with similar parameters describing the same PHD peak can be merged into one mixture component in the algorithm. Simulation results show that the proposed iterative mixture component pruning algorithm is superior to the typical pruning algorithm based on thresholds.

DANNP: an efficient artificial neural network pruning tool

KAUST Repository

AlShahrani, Mona; Soufan, Othman; Magana-Mora, Arturo; Bajic, Vladimir B.

2017-01-01

Although the ANN pruning algorithms are not entirely parallelizable, DANNP was able to speed up the ANN pruning up to eight times on a 32-core machine, compared to the serial implementations. To assess the impact of the ANN pruning by DANNP tool, we used 16 datasets from different domains. In eight out of the 16 datasets, DANNP significantly reduced the number of weights by 70%–99%, while maintaining a competitive or better model performance compared to the unpruned ANN. Finally, we used a naïve Bayes classifier derived with the features selected as a byproduct of the ANN pruning and demonstrated that its accuracy is comparable to those obtained by the classifiers trained with the features selected by several state-of-the-art FS methods. The FS ranking methodology proposed in this study allows the users to identify the most discriminant features of the problem at hand. To the best of our knowledge, DANNP (publicly available at www.cbrc.kaust.edu.sa/dannp) is the only available and on-line accessible tool that provides multiple parallelized ANN pruning options. Datasets and DANNP code can be obtained at www.cbrc.kaust.edu.sa/dannp/data.php and https://doi.org/10.5281/zenodo.1001086.

Alteration of synaptic connectivity of oligodendrocyte precursor cells following demyelination

Science.gov (United States)

Sahel, Aurélia; Ortiz, Fernando C.; Kerninon, Christophe; Maldonado, Paloma P.; Angulo, María Cecilia; Nait-Oumesmar, Brahim

2015-01-01

Oligodendrocyte precursor cells (OPCs) are a major source of remyelinating oligodendrocytes in demyelinating diseases such as Multiple Sclerosis (MS). While OPCs are innervated by unmyelinated axons in the normal brain, the fate of such synaptic contacts after demyelination is still unclear. By combining electrophysiology and immunostainings in different transgenic mice expressing fluorescent reporters, we studied the synaptic innervation of OPCs in the model of lysolecithin (LPC)-induced demyelination of corpus callosum. Synaptic innervation of reactivated OPCs in the lesion was revealed by the presence of AMPA receptor-mediated synaptic currents, VGluT1+ axon-OPC contacts in 3D confocal reconstructions and synaptic junctions observed by electron microscopy. Moreover, 3D confocal reconstructions of VGluT1 and NG2 immunolabeling showed the existence of glutamatergic axon-OPC contacts in post-mortem MS lesions. Interestingly, patch-clamp recordings in LPC-induced lesions demonstrated a drastic decrease in spontaneous synaptic activity of OPCs early after demyelination that was not caused by an impaired conduction of compound action potentials. A reduction in synaptic connectivity was confirmed by the lack of VGluT1+ axon-OPC contacts in virtually all rapidly proliferating OPCs stained with EdU (50-ethynyl-20-deoxyuridine). At the end of the massive proliferation phase in lesions, the proportion of innervated OPCs rapidly recovers, although the frequency of spontaneous synaptic currents did not reach control levels. In conclusion, our results demonstrate that newly-generated OPCs do not receive synaptic inputs during their active proliferation after demyelination, but gain synapses during the remyelination process. Hence, glutamatergic synaptic inputs may contribute to inhibit OPC proliferation and might have a physiopathological relevance in demyelinating disorders. PMID:25852473

Genetic basis of prune belly syndrome: screening for HNF1β gene.

Science.gov (United States)

Granberg, Candace F; Harrison, Steven M; Dajusta, Daniel; Zhang, Shaohua; Hajarnis, Sachin; Igarashi, Peter; Baker, Linda A

2012-01-01

Although the cause of prune belly syndrome is unknown, familial evidence suggests a genetic component. Recently 2 nonfamilial cases of prune belly syndrome with chromosome 17q12 deletions encompassing the HNF1β gene have made this a candidate gene for prune belly syndrome. To date, there has been no large-scale screening of patients with prune belly syndrome for HNF1β mutations. We assessed the role of HNF1β in prune belly syndrome by screening for genomic mutations with functional characterization of any detected mutations. We studied patients with prune belly syndrome who were prospectively enrolled in our Pediatric Genitourinary DNA Repository since 2001. DNA from patient samples was amplified by polymerase chain reaction, sequenced for coding and splice regions of the HNF1β gene, and compared to control databases. We performed functional assay testing of the ability of mutant HNF1β to activate a luciferase construct with an HNF1β DNA binding site. From 32 prune belly syndrome probands (30 males, 2 females) HNF1β sequencing detected a missense mutation (V61G) in 1 child with prune belly syndrome. Absent in control databases, V61G was previously reported in 2 patients without prune belly syndrome who had congenital genitourinary anomalies. Functional testing showed similar luciferase activity compared to wild-type HNF1β, suggesting the V61G substitution does not disturb HNF1β function. One genomic HNF1β mutation was detected in 3% of patients with prune belly syndrome but found to be functionally normal. Thus, functionally significant HNF1β mutations are uncommon in prune belly syndrome, despite case reports of HNF1β deletions. Further genetic study is necessary, as identification of the genetic basis of prune belly syndrome may ultimately lead to prevention and improved treatments for this rare but severe syndrome. Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Prune belly syndrome with pouch colon with scaphoid megalourethra

African Journals Online (AJOL)

We here report a rare association of megalourethra with pouch colon with prune belly syndrome. We also provide a newer embryological and prognostic perspective to this association. Keywords: megalourethra, prune belly syndrome pouch colon, scaphoid ...

Prune Belly Syndrome

Directory of Open Access Journals (Sweden)

Koyye Ravindranath Tagore

2011-01-01

Full Text Available Prune belly syndrome is a rare congenital disorder of the urinary system, characterized by a triad of abnormalities. The aetiology is not known. Many infants are either stillborn or die within the first few weeks of life from severe lung or kidney problems, or a combination of congenital anomalies.

A Case of Prune Belly Syndrome

Directory of Open Access Journals (Sweden)

Wei Xu

2015-06-01

Full Text Available Prune belly syndrome (PBS is a rare congenital disorder characterized by deficient abdominal wall muscles, urinary tract malformation, and, in males, cryptorchidism. We present a case of PBS in China. The patient was a newborn baby boy who had wrinkled, “prune-like” abdominal skin, bilateral cryptorchidism, and urinary system malformation, complicated with hypoplasia of the lung and branch of the coronary artery–right ventricular fistula. His kidney function was inadequate. The patient subsequently died at age 28 days due to septicemia from a severe urinary tract infection.

A case of prune belly syndrome.

Science.gov (United States)

Xu, Wei; Wu, Hui; Wang, Dong-Xuan; Mu, Zhi-Hong

2015-06-01

Prune belly syndrome (PBS) is a rare congenital disorder characterized by deficient abdominal wall muscles, urinary tract malformation, and, in males, cryptorchidism. We present a case of PBS in China. The patient was a newborn baby boy who had wrinkled, "prune-like" abdominal skin, bilateral cryptorchidism, and urinary system malformation, complicated with hypoplasia of the lung and branch of the coronary artery-right ventricular fistula. His kidney function was inadequate. The patient subsequently died at age 28 days due to septicemia from a severe urinary tract infection. Copyright © 2013. Published by Elsevier B.V.

TREE CANOPY PRUNING DOES NOT REGULATE BIENNIAL BEARING IN ”ELSTAR” APPLE (Malus domestica Borkh.

Directory of Open Access Journals (Sweden)

Nikola Pavičić

2004-12-01

Full Text Available Four alternative pruning strategies (A– 25 generative buds, B– 50 generative buds, C– 75 generative buds and D–100 generative buds per tree for Elstar apple cultivar and their possible impact on improvement in productivity were examined in 1999 and 2000. Year was significant factor for all traits, except yield. The pruning strategy is significant for number of fruits per flower cluster and fruit mass. Interaction year and pruning strategy is significant only for number of fruits per flower cluster. Fruit mass was larger for pruning strategy A compared to the pruning strategies C and D. Yield efficiency and biennial bearing index were not affected by pruning strategies. The biennial bearing index variance was the lowest for the pruning strategy B. Trunk cross sectional area (TCSA had negative impact on fruit mass in pruning strategy C. Correlation between the flower and crop density was positive in pruning strategy A. Flower density was in positive correlation with yield in pruning strategy C. The research shows that tree pruning alone will not result in adequate yield regulation in ‘Elstar’ apple.

Opposing Effects of Intrinsic Conductance and Correlated Synaptic Input on V-Fluctuations during Network Activity

DEFF Research Database (Denmark)

Kolind, Jens; Hounsgaard, Jørn Dybkjær; Berg, Rune W

2012-01-01

Neurons often receive massive concurrent bombardment of synaptic inhibition and excitation during functional network activity. This increases membrane conductance and causes fluctuations in membrane potential (V(m)) and spike timing. The conductance increase is commonly attributed to synaptic....... If the spikes arrive at random times the changes in synaptic conductance are therefore stochastic and rapid during intense network activity. In comparison, sub-threshold intrinsic conductances vary smoothly in time. In the present study this discrepancy is investigated using two conductance-based models: a (1...... conductance, but also includes the intrinsic conductances recruited during network activity. These two sources of conductance have contrasting dynamic properties at sub-threshold membrane potentials. Synaptic transmitter gated conductance changes abruptly and briefly with each presynaptic action potential...

Spinal motor neuron involvement in a patient with homozygous PRUNE mutation.

Science.gov (United States)

Iacomino, Michele; Fiorillo, Chiara; Torella, Annalaura; Severino, Mariasavina; Broda, Paolo; Romano, Catia; Falsaperla, Raffaele; Pozzolini, Giulia; Minetti, Carlo; Striano, Pasquale; Nigro, Vincenzo; Zara, Federico

2018-05-01

In the last few years, whole exome sequencing (WES) allowed the identification of PRUNE mutations in patients featuring a complex neurological phenotype characterized by severe neurodevelopmental delay, microcephaly, epilepsy, optic atrophy, and brain or cerebellar atrophy. We describe an additional patient with homozygous PRUNE mutation who presented with spinal muscular atrophy phenotype, in addition to the already known brain developmental disorder. This novel feature expands the clinical consequences of PRUNE mutations and allow to converge PRUNE syndrome with previous descriptions of neurodevelopmental/neurodegenerative disorders linked to altered microtubule dynamics. Copyright © 2017 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

Unified commutation-pruning technique for efficient computation of composite DFTs

Science.gov (United States)

Castro-Palazuelos, David E.; Medina-Melendrez, Modesto Gpe.; Torres-Roman, Deni L.; Shkvarko, Yuriy V.

2015-12-01

An efficient computation of a composite length discrete Fourier transform (DFT), as well as a fast Fourier transform (FFT) of both time and space data sequences in uncertain (non-sparse or sparse) computational scenarios, requires specific processing algorithms. Traditional algorithms typically employ some pruning methods without any commutations, which prevents them from attaining the potential computational efficiency. In this paper, we propose an alternative unified approach with automatic commutations between three computational modalities aimed at efficient computations of the pruned DFTs adapted for variable composite lengths of the non-sparse input-output data. The first modality is an implementation of the direct computation of a composite length DFT, the second one employs the second-order recursive filtering method, and the third one performs the new pruned decomposed transform. The pruned decomposed transform algorithm performs the decimation in time or space (DIT) data acquisition domain and, then, decimation in frequency (DIF). The unified combination of these three algorithms is addressed as the DFTCOMM technique. Based on the treatment of the combinational-type hypotheses testing optimization problem of preferable allocations between all feasible commuting-pruning modalities, we have found the global optimal solution to the pruning problem that always requires a fewer or, at most, the same number of arithmetic operations than other feasible modalities. The DFTCOMM method outperforms the existing competing pruning techniques in the sense of attainable savings in the number of required arithmetic operations. It requires fewer or at most the same number of arithmetic operations for its execution than any other of the competing pruning methods reported in the literature. Finally, we provide the comparison of the DFTCOMM with the recently developed sparse fast Fourier transform (SFFT) algorithmic family. We feature that, in the sensing scenarios with

Structural study of gubernaculum testis in fetuses with prune belly syndrome.

Science.gov (United States)

Costa, Suelen F; Costa, Waldemar S; Sampaio, Francisco J B; Favorito, Luciano A

2015-05-01

We compared and contrasted the structure of the gubernaculum testis in fetuses with prune belly syndrome and normal controls. We studied a total of 6 gubernacula from 3 male fetuses with prune belly syndrome and a total of 14 from 7 male fetuses without an anomaly. Gubernacular specimens were cut into 5 μm sections and stained with Masson trichrome to quantify connective tissue and smooth muscle cells, with Weigert stain to observe elastic fibers and with picrosirius red with polarization to observe collagen. Immunohistochemical analysis was done with tubulin to observe the nerves. Images were captured with a BX51 microscope and DP70 camera (Olympus®). Stereological analysis was done with Image-Pro and ImageJ (MediaCybernetics®) using a grid to determine volumetric density. Means were statistically compared with the Mann-Whitney test. All tests were 2-sided with p Prune belly syndrome fetuses were at 17 to 31 weeks of gestation and control fetuses were at 12 to 35 weeks of gestation. Quantitative analysis showed no difference in the volumetric density of smooth muscle cells in prune belly syndrome vs control gubernacula (mean 15.70% vs 19%, p = 0.2321). Collagen fiber analysis revealed a predominance of green areas in prune belly syndrome gubernacula, suggesting collagen type III, and a predominance of red areas in control gubernacula, suggesting collagen type I. Elastic fibers were significantly smaller in prune belly syndrome gubernacula than in control gubernacula (mean 14.06% vs 24.6%, p = 0.0190). Quantitative analysis demonstrated no difference in the volumetric density of nerves in prune belly syndrome or control gubernacula (mean 5.200% vs 3.158%, p = 0.2302). The gubernaculum in fetuses with prune belly syndrome had altered concentrations of collagen and elastic fibers. These structural alterations could be one of the factors involved in cryptorchidism in prune belly syndrome. Copyright © 2015. Published by Elsevier Inc.

RECONSTRUCTION OF THE URINARY TRACT IN PRUNE BELLY SYNDROME

OpenAIRE

竹内, 秀雄; 小松, 洋輔; 友吉, 唯夫; 吉田, 修

1981-01-01

Three of five patients with prune belly syndrome which we experienced had constructive surgery of the urinary tract and had good results. In the Japanese literatures, 23 of 56 cases which had been reported up to date died. More proper treatment should be done in prune belly syndrome.

Effects of pruning in Monterey pine plantations affected by Fusarium circinatum

Energy Technology Data Exchange (ETDEWEB)

Bezos, D.; Lomba, J. M.; Martinez-Alvarez, P.; Fernandez, M.; Diez, J. J.

2012-07-01

Fusarium circinatum Nirenberg and O'Donnell (1998) is the causal agent of Pitch Canker Disease (PCD) in Pinus species, producing damage to the main trunk and lateral branches as well as causing branch dieback. The disease has been detected recently in northern Spain in Pinus spp. seedlings at nurseries and in Pinus radiata D. Don adult trees in plantations. Fusarium circinatum seems to require a wound to enter the tree, not only that as caused by insects but also that resulting from damage by humans, i.e. mechanical wounds. However, the effects of pruning on the infection process have yet to be studied. The aim of the present study was to know how the presence of mechanical damage caused by pruning affects PCD occurrence and severity in P. radiata plantations. Fifty P. radiata plots (pruned and unpruned) distributed throughout 16 sites affected by F. circinatum in the Cantabria region (northern Spain) were studied. Symptoms of PCD presence, such as dieback, oozing cankers and trunk deformation were evaluated in 25 trees per plot and related to pruning effect. A significant relationship between pruning and the number of cankers per tree was observed, concluding that wounds caused by pruning increase the chance of pathogen infection. Other trunk symptoms, such as the presence of resin outside the cankers, were also higher in pruned plots. These results should be taken into account for future management of Monterey Pine plantations. (Author) 36 refs.

Synaptic vesicle proteins under conditions of rest and activation: analysis by 2-D difference gel electrophoresis.

Science.gov (United States)

Burré, Jacqueline; Beckhaus, Tobias; Corvey, Carsten; Karas, Michael; Zimmermann, Herbert; Volknandt, Walter

2006-09-01

Synaptic vesicles are organelles of the nerve terminal that secrete neurotransmitters by fusion with the presynaptic plasma membrane. Vesicle fusion is tightly controlled by depolarization of the plasma membrane and a set of proteins that may undergo post-translational modifications such as phosphorylation. In order to identify proteins that undergo modifications as a result of synaptic activation, we induced massive exocytosis and analysed the synaptic vesicle compartment by benzyldimethyl-n-hexadecylammonium chloride (BAC)/SDS-PAGE and difference gel electrophoresis (DIGE) followed by MALDI-TOF-MS. We identified eight proteins that revealed significant changes in abundance following nerve terminal depolarization. Of these, six were increased and two were decreased in abundance. Three of these proteins were phosphorylated as detected by Western blot analysis. In addition, we identified an unknown synaptic vesicle protein whose abundance increased on synaptic activation. Our results demonstrate that depolarization of the presynaptic compartment induces changes in the abundance of synaptic vesicle proteins and post-translational protein modification.

Rare association of prune belly syndrome with pouch colon

Directory of Open Access Journals (Sweden)

M Ragavan

2011-01-01

Full Text Available M Ragavan1, U Haripriya1, PV Pradeep1, J Sarvavinothini21Department of Endocrine Surgery, 2Department of Anaesthesia, Narayana Medical College and Superspeciality Hospital, Nellore, Andhra Pradesh, IndiaAbstract: Prune belly syndrome is a triad characterized by abdominal wall musculature deficiency, cryptorchidism and urinary tract abnormalities, and is often associated with other anomalies. Although associated anorectal anomalies have been reported with this syndrome, only two cases of pouch colon, a rare type of anorectal malformation, have been reported. We report a case of prune belly syndrome with pouch colon presenting with retention of urine.Keywords: prune belly, triad syndrome, pouch colon, anorectal malformation

Effect of Root Pruning and Irrigation Regimes on Yield and Physiology of Pear Trees

DEFF Research Database (Denmark)

Wang, Yufei

Clara Frijs’ is the dominant pear (Pyrus communis L.) cultivar in Denmark. It is vigorous with long annual shoots, and therefore can be difficult to prune. Root pruning has been widely used to control the canopy size of fruit trees including pears. However, root pruned trees are more likely......, it was concluded that root pruning not only decreases water uptake but also nutrient uptake, and both have contributed to the reduced canopy growth. Supplemental irrigation partially improved the tree water status and nitrogen uptake without stimulating additional shoot growth in the root pruned trees....... A combination of root pruning and irrigation could be a promising practice to control tree size and secure a stable fruit yield in pear orchard....

Energy potential of fruit tree pruned biomass in Croatia

Energy Technology Data Exchange (ETDEWEB)

Bilandzija, N.; Voca, N.; Kricka, T.; Martin, A.; Jurisic, V.

2012-11-01

The world's most developed countries and the European Union (EU) deem that the renewable energy sources should partly substitute fossil fuels and become a bridge to the utilization of other energy sources of the future. This paper will present the possibility of using pruned biomass from fruit cultivars. It will also present the calculation of potential energy from the mentioned raw materials in order to determine the extent of replacement of non-renewable sources with these types of renewable energy. One of the results of the intensive fruit-growing process, in post pruning stage, is large amount of pruned biomass waste. Based on the calculated biomass (kg ha{sup 1}) from intensively grown woody fruit crops that are most grown in Croatia (apple, pear, apricots, peach and nectarine, sweet cherry, sour cherry, prune, walnut, hazelnut, almond, fig, grapevine, and olive) and the analysis of combustible (carbon 45.55-49.28%, hydrogen 5.91-6.83%, and sulphur 0.18-0.21%) and non-combustible matters (oxygen 43.34-46.6%, nitrogen 0.54-1.05%, moisture 3.65-8.83%, ashes 1.52-5.39%) with impact of lowering the biomass heating value (15.602-17.727 MJ kg{sup 1}), the energy potential of the pruned fruit biomass is calculated at 4.21 PJ. (Author) 31 refs.

7 CFR 52.3182 - Varietal types of dried prunes.

Science.gov (United States)

2010-01-01

... PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Dried Prunes Product Description, Varietal Types, Sizes, Grades § 52.3182 Varietal types of dried prunes. (a) Type I. French; or Robe; or a mixture of French and Robe. (b) Type II. Italian. (c) Type III. Imperial; or Sugar; or a mixture of Imperial...

Stereotyped Synaptic Connectivity Is Restored during Circuit Repair in the Adult Mammalian Retina.

Science.gov (United States)

Beier, Corinne; Palanker, Daniel; Sher, Alexander

2018-06-04

Proper function of the central nervous system (CNS) depends on the specificity of synaptic connections between cells of various types. Cellular and molecular mechanisms responsible for the establishment and refinement of these connections during development are the subject of an active area of research [1-6]. However, it is unknown if the adult mammalian CNS can form new type-selective synapses following neural injury or disease. Here, we assess whether selective synaptic connections can be reestablished after circuit disruption in the adult mammalian retina. The stereotyped circuitry at the first synapse in the retina, as well as the relatively short distances new neurites must travel compared to other areas of the CNS, make the retina well suited to probing for synaptic specificity during circuit reassembly. Selective connections between short-wavelength sensitive cone photoreceptors (S-cones) and S-cone bipolar cells provides the foundation of the primordial blue-yellow vision, common to all mammals [7-18]. We take advantage of the ground squirrel retina, which has a one-to-one S-cone-to-S-cone-bipolar-cell connection, to test if this connectivity can be reestablished following local photoreceptor loss [8, 19]. We find that after in vivo selective photoreceptor ablation, deafferented S-cone bipolar cells expand their dendritic trees. The new dendrites randomly explore the proper synaptic layer, bypass medium-wavelength sensitive cone photoreceptors (M-cones), and selectively synapse with S-cones. However, non-connected dendrites are not pruned back to resemble unperturbed S-cone bipolar cells. We show, for the first time, that circuit repair in the adult mammalian retina can recreate stereotypic selective wiring. Copyright © 2018 Elsevier Ltd. All rights reserved.

PHENOLOGICAL CHARACTERISTICS OF GENOTYPES FROM CATTLEY GUAVA AND GUAVA TREES SUBMITTED TO FRUCTIFICATION PRUNING

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CINTIA APARECIDA BREMENKAMP

Full Text Available ABSTRACT Psidium cattleianum Sabine is a species from the Myrtaceae family that serves as an option for the native fruits cultivation, besides being considered a source of resistance to the Meloidogyne enterolobii nematode. Although cattley guava trees from this species produce flower buds in young branches, there are no reports of response to fructification pruning or phenological synchronism with the guava tree. The objective of this paper was the comparative evaluation of the genotype response of strawberry guava trees and guava cultivars to fructification pruning, thus, describing the phenology of both species under the same cultivation conditions. The experiment was conducted under an entirely randomized outline, in 7x2 factorial scheme, being evaluated seven genotypes (three from strawberry guava and four from guava trees, and with pruning performed in two seasons (May 2012 and March 2013, with three repetitions. Fructification pruning was executed by a lopping on all mature branches, from the last growth flow in the woody branch region. Were evaluated budding characteristics and fruit harvesting, as well as number of days from pruning to the observation of the phenological event. Cattley guava tree pruning stimulated fructification of all three genotypes after pruning done on May and two genotypes after the March’s pruning. There has been a sync between the guava cultivars’ flowering and both strawberry guava trees genotypes, when those were pruned on May.

Pruning Boltzmann networks and hidden Markov models

DEFF Research Database (Denmark)

Pedersen, Morten With; Stork, D.

1996-01-01

We present sensitivity-based pruning algorithms for general Boltzmann networks. Central to our methods is the efficient calculation of a second-order approximation to the true weight saliencies in a cross-entropy error. Building upon previous work which shows a formal correspondence between linear...... Boltzmann chains and hidden Markov models (HMMs), we argue that our method can be applied to HMMs as well. We illustrate pruning on Boltzmann zippers, which are equivalent to two HMMs with cross-connection links. We verify that our second-order approximation preserves the rank ordering of weight saliencies...

Síndrome de Prune Belly: Presentación de un caso y revisión de la literatura Prune Belly Syndrome: Case report and review

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Albert Franz Guerrero

2010-04-01

Full Text Available Introducción: El síndrome de Prune Belly (SPB, también conocido como el síndrome de Eagle Barrett, se caracteriza por una triada de anomalías que incluye grados variables de hipoplasia de la musculatura abdominal, anomalías del tracto urinario y criptorquidia bilateral. Objetivo: Se describe el caso de un paciente masculino con Síndrome de Prune Belly y se realiza una revisión de la literatura sobre esta rara enfermedad. Conclusión: La característica arrugada del abdomen similar a una ciruela pasa, le da el nombre al síndrome. Además, puede estar asociado a alteraciones cardiovasculares, respiratorias, ortopédicas y gastrointestinales. Salud UIS 2010; 42: 78-85Introduction: Prune-belly syndrome, also known as Eagle-Barrett syndrome is characterized by a triad of anomalies that include varying degrees of abdominal musculature hypoplasia, urinary tract anomalies, and bilateral cryptorchidism. Objective: We describe the case of a male patient with Prune Belly Syndrome and we review the literature on this rare disease. Conclusions: The characteristic wrinkled, prune-like abdomen, gives the name to the syndrome. Can also be associated with cardiovascular, respiratory, orthopedic and gastrointestinal anomalies. Salud UIS 2010; 42: 78-85.

Pruning high-value Douglas-fir can reduce dwarf mistletoe severity and increase longevity in central Oregon

Science.gov (United States)

Maffei, Helen M; Filip, Gregory M; Gruelke, Nancy E; Oblinger, Brent W; Margolis, Ellis; Chadwick, Kristen L

2016-01-01

Mid- to very large-sized Douglas-fir (Pseudotsuga menzieseii var. menziesii) that were lightly- to moderately-infected by dwarf mistletoe (Arceuthobium douglasii) were analyzed over a 14-year period to evaluate whether mechanical pruning could eradicate mistletoe (or at least delay the onset of severe infection) without significantly affecting tree vitality and by inference, longevity. Immediate and longterm pruning effects on mistletoe infection severity were assessed by comparing pruned trees (n = 173) to unpruned trees (n = 55) with respect to: (1) percentage of trees with no visible infections 14 years post-pruning, (2) Broom Volume Rating (BVR), and (3) rate of BVR increase 14 years postpruning. Vitality/longevity (compared with unpruned trees) was assessed using six indicators: (1) tree survival, (2) the development of severe infections, (3) the development of dead tops, (4) tree-ring width indices, (5) Normalized Difference Vegetation Index (NDVI) from high-resolution multi-spectral imagery, and (6) live-crown ratio (LCR) and increment. Twenty-four percent of the pruned trees remained free of mistletoe 14 years post-pruning. Pruning is most likely to successfully eradicate mistletoe in lightly infected trees (BVR 1 or 2) without infected neighbors. Pruning significantly decreased mean BVR in the pruned versus the unpruned trees. However, the subsequent average rate of intensification (1.3–1.5 BVR per decade) was not affected, implying that a single pruning provides ~14 years respite in the progression of infection levels. Post-pruning infection intensification was slower on dominant and co-dominants than on intermediate or suppressed trees. The success of mistletoe eradication via pruning and need for follow-up pruning should be evaluated no sooner than 14 years after pruning to allow for the development of detectable brooms. Based on six indicators, foliage from witches brooms contribute little to long-term tree vitality since removal appears to have

Optogenetic Examination of Prefrontal-Amygdala Synaptic Development.

Science.gov (United States)

Arruda-Carvalho, Maithe; Wu, Wan-Chen; Cummings, Kirstie A; Clem, Roger L

2017-03-15

A brain network comprising the medial prefrontal cortex (mPFC) and amygdala plays important roles in developmentally regulated cognitive and emotional processes. However, very little is known about the maturation of mPFC-amygdala circuitry. We conducted anatomical tracing of mPFC projections and optogenetic interrogation of their synaptic connections with neurons in the basolateral amygdala (BLA) at neonatal to adult developmental stages in mice. Results indicate that mPFC-BLA projections exhibit delayed emergence relative to other mPFC pathways and establish synaptic transmission with BLA excitatory and inhibitory neurons in late infancy, events that coincide with a massive increase in overall synaptic drive. During subsequent adolescence, mPFC-BLA circuits are further modified by excitatory synaptic strengthening as well as a transient surge in feedforward inhibition. The latter was correlated with increased spontaneous inhibitory currents in excitatory neurons, suggesting that mPFC-BLA circuit maturation culminates in a period of exuberant GABAergic transmission. These findings establish a time course for the onset and refinement of mPFC-BLA transmission and point to potential sensitive periods in the development of this critical network. SIGNIFICANCE STATEMENT Human mPFC-amygdala functional connectivity is developmentally regulated and figures prominently in numerous psychiatric disorders with a high incidence of adolescent onset. However, it remains unclear when synaptic connections between these structures emerge or how their properties change with age. Our work establishes developmental windows and cellular substrates for synapse maturation in this pathway involving both excitatory and inhibitory circuits. The engagement of these substrates by early life experience may support the ontogeny of fundamental behaviors but could also lead to inappropriate circuit refinement and psychopathology in adverse situations. Copyright © 2017 the authors 0270-6474/17/372976-10$15.00/0.

Effect of Time and Level of Pruning on Vegetative Growth, Flowering, Yield, and Quality of Guava

DEFF Research Database (Denmark)

Adhikari, Shiva; Kandel, Tanka Prasad

2015-01-01

Poor quality fruit production in the rainy season and failure to manipulate production periods are common problems for guava production in India and Nepal. As a possible management to overcome these problems, a field experiment was conducted to understand the effect of time and level of pruning...... (%) of fruits increased with the increased level of pruning in both seasons irrespective of timing of pruning, but fruit acidity was not affected by both treatments. In conclusion, pruning plants at a 20 cm pruning level in early May was the most effective management to reduce yield in the rainy season...... on growth, flowering, yield, and quality of guava. An experiment was laid out with split-pot design allocating three pruning times (mid-April, early May, and mid-May) and four pruning levels (0-, 10-, 20-, and 30-cm tip removal) with three replications in each treatment. Increased level of pruning in early...

Regulating mineralization rates of Tithonia diversifolia and Lantana camara prunings to improve phosphorus availability in calcareous soils

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Y. Nuraini

2014-01-01

Full Text Available The effect of mixing of Tithonia diversifolia and Lantana camara prunings to improve synchronization between P released from the prunings with crop demand for P was studied in a laboratory and in a glasshouse. Tithonia diversifolia prunings (Td, Lantana camara prunings (Lc, and farmyard manure (Pk were thoroughly mixed with the proportion (% of dry weight of; 25Td +75 Lc ; 50Td +50 Lc ; 75Td +25 Lc ; 90Lc +10 Pk ; 45Td +45 +10 Lc Pk ; 100Td and 100Lc, and then mixed with 100 g of air-dried soil with a rate equivalent to 100 kg P / ha. Results of the study showed that the pruning mixtures decomposed and mineralized faster than that of Lantana camara pruning only, but slower than that of Tithonia diversifolia pruning only. The amount of P released from the pruning mixtures increased with increasing proportion of Tithonia diversifolia pruning in the mixtures. Increasing proportion of Tithonia diversifolia pruning in the mixture applied to the soil increased the amount of P taken up by maize.

Síndrome de prune belly: presentación de caso Prune belly syndrome: a case report

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María Elena Toledo Lamela

2008-03-01

Full Text Available El síndrome de prune belly es una rara enfermedad congénita de causa desconocida. Se presenta el caso de un recién nacido a término, del sexo masculino y de un día de nacido, que fue remitido al servicio de urología pediátrica por presentar ausencia de los músculos de la pared anterior del abdomen (rectos anteriores, criptorquidia bilateral y gran globo vesical. A partir de los hallazgos del examen físico se planteó el diagnóstico de síndrome de prune belly. Se encontraron anomalías asociadas como escoliosis y agenesia del pie derecho. En el estudio radiológico del tracto urinario se confirmaron malformaciones congénitas como valva de uretra posterior y megavejiga con uretero-hidronefrosis bilateral. Los análisis de laboratorio confirmaron la afectación de la función renal y una infección urinaria asociada. Se practicó una cistostomía a cielo abierto. El paciente falleció a los 10 días a causa de las complicaciones de la insuficiencia renalThe prune belly syndrome is a congenital rare disease of unknown origin. The case of a one-day-old full- term male newborn infant that was referred to the pediatric urology service for presenting absence of the muscles of the anterior abdomen wall (anterior rectus muscle, bilateral cryptochordism and big vesical globe, was presented. Starting from the findings of the physical examination, the prune belly syndrome was diagnosed. Associated abnormalities such as scoliosis and agenesis of the right leg were found. In the radiological study of the urinary tract, congenital malformations as posterior urethra valve and megabladder with bilateral ureterohydronephrosis were confirmed. The lab tests corroborated the affectation of the renal function and an associated urinary infection. The patient died at 10 days as a result of the complications of renal failure

Unusual presentation of prune belly syndrome: a case report.

Science.gov (United States)

Demisse, Abayneh Girma; Berhanu, Ashenafi; Tadesse, Temesgen

2017-12-04

Prune belly syndrome is a rare congenital malformation of unknown etiology, with the following triad of findings: abdominal muscle wall weakness, undescended testes, and urinary tract abnormalities. In most cases, detection of prune belly syndrome occurs during neonatal or infancy period. In this case report, we describe a 12-year-old boy from Ethiopia with the triad of findings of prune belly syndrome along with skeletal malformations. We are unaware of any previous report of prune belly syndrome in Ethiopia. A 12-year-old Amhara boy from the Northwest Gondar Amhara regional state presented to our referral hospital with a complaint of swelling over his left flank for the past 3 months. Maternal pregnancy course and medical history were noncontributory, and he had an attended birth at a health center. He has seven siblings, none of whom had similar symptoms. On examination he had a distended abdomen, asymmetric with bulging left flank, visible horizontal line, upward umbilical slit, and absent rectus abdominis muscles. His abdomen was soft with a tender cystic, bimanually palpable mass on the left flank measuring 13 × 11 cm. Both testes were undescended and he also has developmental dysplasia of the hips. An abdominal ultrasound revealed a large cystic mass in his left kidney area with echo debris and a hip X-ray showed bilateral developmental dysplasia of the hip. Intraoperative findings were cystic left kidney, both testes were intraperitoneal, tortuous left renal vein, enlarged bladder reaching above umbilicus, and left megaureter. bilateral orchidectomy and left nephrectomy were done. He was given intravenously administered antibiotics for treatment of pyelonephritis and discharged home with an appointment for follow up and possible abdominoplasty. In the current report delayed presentation contributed to testicular atrophy and decision for orchidectomy. Furthermore, he will be at potential risk for sex hormone abnormality. Therefore, diagnosis of prune

Synaptic Cell Adhesion

OpenAIRE

Missler, Markus; Südhof, Thomas C.; Biederer, Thomas

2012-01-01

Chemical synapses are asymmetric intercellular junctions that mediate synaptic transmission. Synaptic junctions are organized by trans-synaptic cell adhesion molecules bridging the synaptic cleft. Synaptic cell adhesion molecules not only connect pre- and postsynaptic compartments, but also mediate trans-synaptic recognition and signaling processes that are essential for the establishment, specification, and plasticity of synapses. A growing number of synaptic cell adhesion molecules that inc...

Temporal requirements of the fragile X mental retardation protein in modulating circadian clock circuit synaptic architecture

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Cheryl L Gatto

2009-08-01

Full Text Available Loss of fragile X mental retardation 1 (FMR1 gene function is the most common cause of inherited mental retardation and autism spectrum disorders, characterized by attention disorder, hyperactivity and disruption of circadian activity cycles. Pursuit of effective intervention strategies requires determining when the FMR1 product (FMRP is required in the regulation of neuronal circuitry controlling these behaviors. In the well-characterized Drosophila disease model, loss of the highly conserved dFMRP causes circadian arrhythmicity and conspicuous abnormalities in the circadian clock circuitry. Here, a novel Sholl Analysis was used to quantify over-elaborated synaptic architecture in dfmr1-null small ventrolateral neurons (sLNvs, a key subset of clock neurons. The transgenic Gene-Switch system was employed to drive conditional neuronal dFMRP expression in the dfmr1-null mutant background in order to dissect temporal requirements within the clock circuit. Introduction of dFMRP during early brain development, including the stages of neurogenesis, neuronal fate specification and early pathfinding, provided no rescue of dfmr1 mutant phenotypes. Similarly, restoring normal dFMRP expression in the adult failed to restore circadian circuit architecture. In sharp contrast, supplying dFMRP during a transient window of very late brain development, wherein synaptogenesis and substantial subsequent synaptic reorganization (e.g. use-dependent pruning occur, provided strong morphological rescue to reestablish normal sLNvs synaptic arbors. We conclude that dFMRP plays a developmentally restricted role in sculpting synaptic architecture in these neurons that cannot be compensated for by later reintroduction of the protein at maturity.

7 CFR 993.5 - Prunes.

Science.gov (United States)

2010-01-01

... the Food Technology Division, College of Agriculture, University of California, for the specialty pack... 7 Agriculture 8 2010-01-01 2010-01-01 false Prunes. 993.5 Section 993.5 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and...

Pruning management of Chardonnay grapevines at high altitude in Brazilian southeast

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Tania dos Reis Mendonça

2016-03-01

Full Text Available ABSTRACT The agronomical responses of Chardonnay, a variety indicated for sparkling wine production, is influenced by the vineyard management and the edaphoclimatic conditions of the region. The objective of this study was to evaluate the effects of two pruning types (Royat and double Guyot on vegetative and reproductive development of Chardonnay vine growing at high altitude in the Brazilian southeastern region. The experiment was carried out in a commercial vineyard located at 1,280 m of altitude in Divinolândia, São Paulo State, Brazil. The Chardonnay vines (clone 96, grafted onto 1103 Paulsen rootstock and trained in a vertical shoot positioning trellis system, were assessed. Vegetative vigor, bud fruitfulness, production and physicochemical composition of grapes were evaluated during 2014 and 2015 growing seasons. The Royat pruning induced higher vegetative vigor and increased the bud fruitfulness, the cluster number and the productivity of Chardonnay vine when compared to Guyot pruning. Even though the increase on yield was observed, there was no effect of pruning type on grape final quality. Therefore, the choice of pruning method in function of variety genetic characteristics and their interaction with environment can optimize the vineyard profitability. In the Brazilian southeast, the Royat system is the most suitable one to grow Chardonnay for sparkling wines production.

Source-Sink Relations in Fruits VII. Effects of Pruning in Sour Cherry and Plum

DEFF Research Database (Denmark)

Toldam-Andersen, Torben Bo; Hansen, P.

1993-01-01

Sour cherries cv. 'Stevnsbær' and plums cv. 'Victoria' were heavily pruned in 1987. Fruit samples were collected during the growing season and concentrations of different quality components were determined. Pruning resulted in a small increase in fruit size, the effect being greater on the older...... trees (sour cherries) or at the lower crop load (plum). Additionally, pruning decreased the con­centrations of total and soluble dry matter and of anthocya­nins ('Stevnsbær'), while titratable acids showed an increas­ing tendency. The effects of pruning are discussed based on influences on root...

Influence of coffee pruning on the severity of frost damage

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Armando Androcioli Filho

2000-01-01

Full Text Available Frost damages in a field experiment of pruning types and systems for the cultivars of Coffea arabica Catuaí and Mundo Novo, were evaluated at Londrina (23º22’S, 52º10´W, State of Parana, southern Brazil, during the winter of 1990 and 1994. Pruning types evaluated were ‘esqueletamento’ (cutting off all plagiotropic branches at 20-30 cm from the orthotropic branch, ‘decote’ (cutting off the orthotropic branch at 1.5 m and 2.0 m above ground and ‘recepa’ (cutting off the orthotropic branch at 0.8 m above ground, performed on all rows and on alternate rows, and on different sections of the plant. Results indicated that frost damage could increase according to the type and height of pruning. The pruning type ‘esqueletamento’ and prunings at higher levels were more suitable for regions with frost risk. Under severe frost condition, pruning type did not affect the damage in anyone of the treatments evaluated.Foram avaliados os danos causados pelas geadas ocorridas em 1990 e 1994 em cafeeiros de duas cultivares de Coffea arabica L., Catuaí e Mundo Novo, conduzidos em Londrina-PR. Os tipos e sistemas de podas aplicados foram o esqueletamento a 20-30 cm do tronco, decote a 1,5 m e 2,0 m de altura e recepa a 0,80 m de altura. As podas foram feitas em área total e em linhas alternadas e em diferentes partes da planta. Os dados obtidos indicaram que os danos por geada podem ser intensificados em função do tipo e altura da poda. A poda do tipo esqueletamento e as podas altas são mais indicadas para o manejo das lavouras nas regiões mais sujeitas ao fenômeno de geada. No caso de geada severa, todos os cafeeiros foram afetados, independente do tipo de poda.

Partial prune belly syndrome: A rare case report

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Aditya Pratap Singh

2017-01-01

Full Text Available Prune belly syndrome (PBS is characterized by deficient development of abdominal muscles that causes the skin of the abdomen to wrinkle like a prune, bilateral cryptorchidism, abnormalities of the urinary tract. The etiology of PBS is unclear and possible familial genetic inheritance was reported in some of the studies. We are presenting here a case with the absence of the muscle in the right side of the abdomen as hernia, thinning of the muscle on left side with bilateral cryptorchidism, and abnormalities of the urinary tract. It is the partial presentation of the PBS.

Pruning for crop regulation in high density guava (Psidium guajava L.) plantation

Energy Technology Data Exchange (ETDEWEB)

Thakre, M.; Lal, S.; Uniyal, S.; Goswami, A.K. Prakash. P.

2016-11-01

High density management and crop regulation are two important aspects in guava (Psidium guajava L.) production. Therefore, to find out the economic way of managing high density planting and crop regulation, the present work was carried out on 6-year-old guava trees of cv. Pant Prabhat under double-hedge row system of planting during 2009-10 and 2010-11. Seven different forms of pruning [FBT: flower bud thinning by hand, FBTT: flower bud thinning by hand followed by removal of terminal one leaf pair, RLFO: removal of leaves and flower buds by hand, retaining one leaf pair at the top, RLF: removal of all leaves and flowers by hand, OLPS: one leaf pair shoot pruning, FSP: full shoot pruning, OLPF: one leaf pair pruning of fruited shoots only] were studied along with control (C).Minimum annual increase in tree volume (6.764 m3) was recorded with the treatment OLPF, which was 2.31 times less than the control (15.682 m3). Highest yield during winter season (55.30 kg/tree) and total yield (59.87 kg/tree) was obtained from treatment OLPF. One leaf pair pruning of fruited shoots only (OLPF) was also found profitable among other treatments by recording cost:benefit ratio of 1:2.96. This treatment also recorded the highest return distributed in rainy as well as in winter season. On the basis of findings it can be concluded that one leaf pair pruning of fruited shoots only is suitable for profitable high density management as well as crop regulation of guava in farmer friendly manner. (Author)

EVALUATION OF TEMPORALVARIATIONS IN MOISTURE AND CALORIFIC VALUE OF VINE AND OLIVE PRUNING

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Pier Riccardo Porceddu

2012-06-01

Full Text Available In Italy arboreal crops, in particular vine and olive, cover a surface area of around 19.6×109 m2 from which about 4.6×109 kg of pruning are cut. These by-products are currently ploughed into the soil or else harvested and burned in open fields. On the other hand such materials would be more useful as an energy source. If these materials are to be used as fuel, it is important to know their calorific value. The calorific value is significantly influenced by the moisture content of wood. This work has evaluated the changes in moisture content and calorific value with time for different harvesting and storage systems of vine and olive pruning. The observed decrease in the moisture content of the vine and olive pruning depended on the storage system utilized, in particular on the product compression ratio and air circulation. Some differences were observed between the results obtained for vine and olive pruning. The time required for these materials to obtain their best energetic performance was identified at 32 weeks from their harvesting. Harvesting with balers and forwarding costs are about 6.21×10-2 €/kg for vine pruning and 4.64×10-2 €/kg for olive pruning. They are very similar to the price currently offered for energy biomass in Italy (5.00×10-2 €/kg. While the cost actually paid to plough pruning into the soil amounts to about 2.50×10-2 €/kg. Therefore the energy chain encourages a cost-and-benefit analysis.

Effect of main stem pruning and fruit thinning on the postharvest conservation of melon

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Rafaella M. de A. Ferreira

Full Text Available ABSTRACT Main stem pruning and fruit thinning are cultivation practices that can influence the yield and quality of the fruit. This study aimed to evaluate the effects of main stem pruning and fruit thinning on the postharvest conservation of Charentais Banzai melons. In the field, the plants were subjected to main stem pruning and fruit thinning, with harvesting done 74 days after sowing (DAS. The fruits were transported to the laboratory where they were cleaned, characterized, and stored in a cold chamber (5 °C and 90 ± 2% RH. In the field, the experiment was designed as a split-plot using a 2 × 4 + 1 factorial design, with two levels of main stem pruning (pruned and unpruned, four levels of thinning times (42, 45, 48, and 51 DAS, and a control (unpruned and unthinned. The sub-plot consisted of storage times (0, 7, 14, 21, and 28 days, with four blocks. The preharvest treatments did not significantly influence the production characteristics of the Banzai hybrid. The treatment without pruning increased the titratable acidity of fruit, and the thinning at 51 days after sowing (DAS reduced soluble sugars. There was a decline in pulp firmness, titratable acidity, reducing sugars, and an increase in soluble solids, total soluble sugar, and non-reducing sugars during storage. Pruning the main melon stem reduced the weight loss of the fruit after 28 days of storage.

Effect of Shoot Pruning and Flower Thinning on Quality and Quantity of Semi-Determinate Tomato (Lycopersicon esculentum Mill.

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Abdolali HESAMI

2012-02-01

Full Text Available There are many constraints of space, light and availability of fruits to harvest in tomatoes greenhouse. Therefore, two experiments were carried out to determine the effect of shoot pruning and flower thinning on quality and quantity of fruits of semi-determinate tomato in a greenhouse of the Faculty of Agriculture and Natural Resources, Persian Gulf University of Bushehr. Experimental design was randomized complete block designs in which the effect of shoot pruning (single branch pruning, double branch pruning, pyramidal pruning and control or flower thinning (Cluster with 4 and 5 remained flowers and control were studied separately. Results showed that, leaf area and plants yield were higher in treatments which were pruned than control. Yields from pyramidal pruning and cluster thinning with 5 remaining flowers were significantly higher than other treatments. On the other hand, qualitative study identified that pyramidal pruning increases vitamin C in fruits, but had no significant effect on total soluble solids.

Cane pruning on Chardonnay grapevine in the high-altitude regions of Southern Brazil

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Filho José Luiz Marcon

2016-01-01

Full Text Available High-altitude regions of southern Brazil, located above 900 m above sea level, the cordon training with spur pruning is widely used because of easier application. In these regions, Chardonnay wine grape shows potential to produce quality wines, however, in commercial vineyards, the training system used has not provided productivities that makes economically viable the cultivation of this variety. Given this, the present study aimed to evaluate the effect of different cane-pruning systems on the vegetative, productive and enological potential of Chardonnay grapevines grown in the high-altitude region of Southern Brazil. The experiment was conducted in a commercial Chardonnay vineyard, located in São Joaquim – Santa Catarina State (28o17 ′39”S and 49∘ 55′56” W, to 1230 m a.s.l during 2015 and 2016 vintages. Chardonnay vines (grafted on 1103 Paulsen were planted in 2010, with a 3.0 m (row × 1.0 m (vine spacing. The treatments consisted of different cane-pruning systems: Cordon spur-pruning (control; Sylvoz; Cazenave; Capovolto; single Guyot and double Guyot. Pruning was performed in August of each year when the buds were in the green tip developmental stage. Data was analyzed by Scott Knott test (p < 0.05 following a randomized block design with four replicates, each consisting of 12 vines per plot. We observed higher yield in the Cazenave and double Guyot training system with three and two more tons of grapes than spur-pruning respectively. The bud fertility was higher in plants trained in double Guyot. Vines spur-pruned showed higher relation of leaf area: production, with values above 100 cm2 g−1 grape at 2016 vintage. Commercial maturity of grapes (soluble solids, acidity and polyphenols did not differ among training systems studied. The results suggest that cane-pruning systems could be an alternative to increase production efficiency of Chardonnay in high-altitude region of southern Brazil.

Grafting, pruning, and the antipodal map on measured laminations

OpenAIRE

Dumas, David

2006-01-01

Grafting a measured lamination on a hyperbolic surface defines a self-map of Teichmuller space, which is a homeomorphism by a result of Scannell and Wolf. In this paper we study the large-scale behavior of pruning, which is the inverse of grafting. Specifically, for each conformal structure $X \\in \\T(S)$, pruning $X$ gives a map $\\ML(S) \\to \\T(S)$. We show that this map extends to the Thurston compactification of $\\T(S)$, and that its boundary values are the natural antipodal involution relat...

Pruning for crop regulation in high density guava (Psidium guajava L. plantation

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Madhubala Thakre

2016-06-01

Full Text Available High density management and crop regulation are two important aspects in guava (Psidium guajava L. production. Therefore, to find out the economic way of managing high density planting and crop regulation, the present work was carried out on 6-year-old guava trees of cv. Pant Prabhat under double-hedge row system of planting during 2009-10 and 2010-11. Seven different forms of pruning [FBT: flower bud thinning by hand, FBTT: flower bud thinning by hand followed by removal of terminal one leaf pair, RLFO: removal of leaves and flower buds by hand, retaining one leaf pair at the top, RLF: removal of all leaves and flowers by hand, OLPS: one leaf pair shoot pruning, FSP: full shoot pruning, OLPF: one leaf pair pruning of fruited shoots only] were studied along with control (C.Minimum annual increase in tree volume (6.764 m3 was recorded with the treatment OLPF, which was 2.31 times less than the control (15.682 m3. Highest yield during winter season (55.30 kg/tree and total yield (59.87 kg/tree was obtained from treatment OLPF. One leaf pair pruning of fruited shoots only (OLPF was also found profitable among other treatments by recording cost:benefit ratio of 1:2.96. This treatment also recorded the highest return distributed in rainy as well as in winter season. On the basis of findings it can be concluded that one leaf pair pruning of fruited shoots only is suitable for profitable high density management as well as crop regulation of guava in farmer friendly manner.

Factors affecting branch wound occlusion and associated decay following pruning – a case study with wild cherry (Prunus avium L.

Directory of Open Access Journals (Sweden)

Jonathan Sheppard

2016-11-01

Full Text Available Pruning wild cherry (Prunus avium L. is a common silvicultural practice carried out to produce valuable timber at a veneer wood quality. Sub-optimal pruning treatments can permit un-occluded pruning wounds to develop devaluing decay. The aim of this study is to determine relevant branch, tree and pruning characteristics affecting the occlusion process of pruning wounds. Important factors influencing occlusion time for an optimised pruning treatment for valuable timber production utilising wild cherry are derived. 85 artificially pruned branches originating from ten wild cherry trees were retrospectively analysed. Branch stub length, branch diameter and radial stem increment during occlusion were found to be significant predictors for occlusion time. From the results it could be concluded that for the long term success of artificial pruning of wild cherry it is crucial to (i keep branch stubs short (while avoiding damage to the branch collar, (ii to enable the tree to maintain significant radial growth after pruning, (iii to avoid large pruning wounds (>2.5 cm by removing steeply angled and fast growing branches at an early stage.

Yield and crop cycle time of peaches cultivated in subtropical climates and subjected to different pruning times

Directory of Open Access Journals (Sweden)

Rafael Augusto Ferraz

2015-12-01

Full Text Available The cultivation of peaches in regions of subtropical and tropical climate is currently achieved through a set of practices such as using less demanding cultivars in cold conditions, applying plant growth regulators to break dormancy, and performing specific pruning, like production and renewal pruning. Research on the climate adaptation of cultivars is of great importance in establishing a crop in a given region. Therefore, the objective of this study was to evaluate the agronomic performance of three cultivars subjected to different production pruning times in Botucatu/SP, where 2-year old peach trees were evaluated, grown at a spacing of 6.0 x 4.0 meters. The experimental design was a split plot design with four blocks, using the cultivars Douradão, BRS Kampai and BRS Rubimel, and the subplots corresponded to pruning times in May, June, July and August. Ten plants were used per plot, with the four central plants considered useful and the remaining considered as margins. Pruning in June and July showed the best results in terms of percentage of fruit set and production. The cultivar BRS Rubimel showed the best percentage of fruit set when pruned in June (44.96%, and best fruit production when pruned in July (18.7 kg plant-1. Pruning in May anticipated the harvest of cultivar BRS Rubimel by 13 days whereas pruning carried out in July and August provided late harvests for cultivars Douradão and BRS Kampai.

Density based pruning for identification of differentially expressed genes from microarray data

Directory of Open Access Journals (Sweden)

Xu Jia

2010-11-01

Full Text Available Abstract Motivation Identification of differentially expressed genes from microarray datasets is one of the most important analyses for microarray data mining. Popular algorithms such as statistical t-test rank genes based on a single statistics. The false positive rate of these methods can be improved by considering other features of differentially expressed genes. Results We proposed a pattern recognition strategy for identifying differentially expressed genes. Genes are mapped to a two dimension feature space composed of average difference of gene expression and average expression levels. A density based pruning algorithm (DB Pruning is developed to screen out potential differentially expressed genes usually located in the sparse boundary region. Biases of popular algorithms for identifying differentially expressed genes are visually characterized. Experiments on 17 datasets from Gene Omnibus Database (GEO with experimentally verified differentially expressed genes showed that DB pruning can significantly improve the prediction accuracy of popular identification algorithms such as t-test, rank product, and fold change. Conclusions Density based pruning of non-differentially expressed genes is an effective method for enhancing statistical testing based algorithms for identifying differentially expressed genes. It improves t-test, rank product, and fold change by 11% to 50% in the numbers of identified true differentially expressed genes. The source code of DB pruning is freely available on our website http://mleg.cse.sc.edu/degprune

Prune belly syndrome: A report of 15 cases from Sudan.

Science.gov (United States)

Kheir, Abdelmoneim E M; Ali, Eltigani M A; Medani, Safaa A; Maaty, Huda S

2017-01-01

Prune belly syndrome is a rare congenital malformation of unknown aetiology, composed of a triad of deficient abdominal wall muscle, cryptorchidism and urinary tract anomalies. The majority of patients have associated pulmonary, skeletal, cardiac, and gastrointestinal defects. This was a prospective, case finding study that was conducted in the main paediatric hospitals in Khartoum state, during the period December 2015 to September 2016. A total of 15 patients with prune belly syndrome were collected. Patients' characteristics were noted including socio-demographic data, laboratory and radiological investigations and any medical or surgical intervention. There were 12 males and 3 females with a male to female ratio of 4:1. Most of the patients (80%) had hydronephrosis and hydroureter. The study revealed that 60% of the patients had associated anomalies, there were 4 (26.6%) with cardiac defects, 3 (20%) with orthopaedic defects one patient with small bowel volvulus and one patient with cleft lip. 6 (40%) patients received medical intervention and 8 (53%) patients underwent surgical procedures. At the last follow up visit, 2 (13.4%) patients had normal renal function tests, 8 (53.3%) ended with chronic kidney disease, and 5 died with a mortality rate of 33.3%. Prune belly syndrome is a rare entity with wide variability in severity and clinical manifestations. The mortality in prune belly syndrome remains high despite medical and surgical interventions.

Dynamic abdominoplasty for the treatment of prune belly syndrome.

Science.gov (United States)

Fearon, Jeffrey A; Varkarakis, George

2012-09-01

The deficient abdominal wall musculature associated with prune belly syndrome often results in numerous functional disabilities, including diminished cough, impaired bladder and bowel function, and poor posture and balance. Traditional abdominoplasties focus on static fascial excisions or plications. The authors sought to assess their preliminary experience with a new abdominoplasty technique that incorporates standard fascial tightening with bilateral pedicled rectus femoris muscle transfers. This case series review included all patients treated with prune belly syndrome at the authors' center. Physical presentation, operative procedures, hospitalization, complications, and postoperative functional status were assessed, and a systematic analysis of published surgical series was performed. Over a 16-year period, the authors treated 13 patients with prune belly syndrome. All underwent standard "vest over pants" fascial plications, with 11 of 13 undergoing additional rectus femoris muscle transpositions at a mean age of 4 years (range, 12 months to 13 years). Hospitalization averaged 9.3 days, and the average follow-up was over 1.5 years. The authors identified three minor complications (chylous leak, fungal urinary tract infection, and partial umbilical necrosis), yielding a complication rate similar to those identified in our systematic analysis of published standard abdominoplasties. Postoperatively, all transposed muscles were palpably functional, one patient was successfully weaned off a ventilator, and all demonstrated improvements with balance and ambulation. The authors' preliminary review suggests that this new procedure, which supplements the standard prune belly abdominoplasty with bilateral rectus femoris transposition flaps, is not associated with substantially higher complication rates yet does appear to have the potential to provide functional improvements.

Evaluation of soil carbon pools after the addition of prunings in subtropical orchards placed in terraces

Science.gov (United States)

Márquez San Emeterio, Layla; Martín Reyes, Marino Pedro; Ortiz Bernad, Irene; Fernández Ondoño, Emilia; Sierra Aragón, Manuel

2017-04-01

The amount of carbon that can be stored in a soil depends on many factors, such as the type of soil, the chemical composition of plant rests and the climate, and is also highly affected by land use and soil management. Agricultural ecosystems are proved to absorb a large amount of CO2 from the atmosphere through several sustainable management practices. In addition, organic materials such as leaves, grass, prunings, etc., comprise a significant type of agricultural practices as a result of waste recycling. The aim of this research was to evaluate the effects of the addition of different organic prunings on the potential for carbon sequestration in agricultural soils placed in terraces. Three subtropical orchards were sampled in Almuñécar (Granada, S Spain): mango (Mangifera indica L.), avocado (Persea americana Mill.) and cherimoya (Annonacherimola Mill.). The predominant climate is Subtropical Mediterranean and the soil is an Eutric Anthrosol. The experimental design consisted in the application of prunings from avocado, cherimoya and mango trees, placed on the surface soil underneath their correspondent trees, as well as garden prunings from the green areas surrounding the town center on the surface soils under the three orchard trees. Control experiences without the addition of prunings were also evaluated. These experiences were followed for three years. Soil samples were taken at4 cm depth. They were dried for 3-4 days and then sieved (<2 mm).Total soil organic C, water-soluble soil organic C, mineral-associated organic C and non-oxidable C were analyzed and expressed as carbon pools (Mg C ha-1for total soil organic C, or Kg C ha-1for the others). The results showed an increase of all organic carbon pools in all pruning treatments compared to the control experiences. Differences in total organic carbon pool were statistically significant between soils under avocado prunings and their control soil, and between soils under garden prunings with cherimoya and

An Integrated Pruning Criterion for Ensemble Learning Based on Classification Accuracy and Diversity

DEFF Research Database (Denmark)

Fu, Bin; Wang, Zhihai; Pan, Rong

2013-01-01

be further considered while designing a pruning criterion is presented, and then an effective definition of diversity is proposed. The experimental results have validated that the given pruning criterion could single out the subset of classifiers that show better performance in the process of hill...

The potential of legume tree prunings as organic matters for improving phosphorus availability in an acid soil

Directory of Open Access Journals (Sweden)

I Wahyudi

2015-01-01

Full Text Available A study that was aimed to elucidate roles of Gliricidia sepium and Tithonia diversifolia prunings and their extracted humic and fulvic acids on improving phosphorus availability and decreasing aluminum concentration in an Ultisol was conducted in a glasshouse. Thirteen treatments consisting of two prunings, six rates of pruning application (5, 7.5, 10, 20, 40 and 80 t/ha and one control (no added prunings were arranged in a randomized block design with four replicates. Each mixture of prunings and soil was placed in a pot containing 8 kg of soil and maize of Srikandi cultivar was grown on it for 45 days. At harvest, soil pH, P content and aluminium concentration were measured. Results of the glasshouse experiment showed that application of Gliricidia and Tithonia prunings significantly increased soil pH, reduced Alo concentration, increased Alp content, increased P availability, and increased P taken up by maize grown for 45 days. The optimum rate of both Gliricidia and Tithonia pruning should be 40 t/ha. However, at the same rate, optimum production gained by Tithonia would be higher than that of Gliricidia.

Spindle-F Is the Central Mediator of Ik2 Kinase-Dependent Dendrite Pruning in Drosophila Sensory Neurons.

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Tzu Lin

2015-11-01

Full Text Available During development, certain Drosophila sensory neurons undergo dendrite pruning that selectively eliminates their dendrites but leaves the axons intact. How these neurons regulate pruning activity in the dendrites remains unknown. Here, we identify a coiled-coil protein Spindle-F (Spn-F that is required for dendrite pruning in Drosophila sensory neurons. Spn-F acts downstream of IKK-related kinase Ik2 in the same pathway for dendrite pruning. Spn-F exhibits a punctate pattern in larval neurons, whereas these Spn-F puncta become redistributed in pupal neurons, a step that is essential for dendrite pruning. The redistribution of Spn-F from puncta in pupal neurons requires the phosphorylation of Spn-F by Ik2 kinase to decrease Spn-F self-association, and depends on the function of microtubule motor dynein complex. Spn-F is a key component to link Ik2 kinase to dynein motor complex, and the formation of Ik2/Spn-F/dynein complex is critical for Spn-F redistribution and for dendrite pruning. Our findings reveal a novel regulatory mechanism for dendrite pruning achieved by temporal activation of Ik2 kinase and dynein-mediated redistribution of Ik2/Spn-F complex in neurons.

Evaluation of biocontrol agents for grapevine pruning wound protection against trunk pathogen infection.

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Charl KOTZE

2011-12-01

Full Text Available Trunk diseases of grapevine are caused by numerous pathogens, including Eutypa lata, Phaeomoniella chlamydospora, and species of Botryosphaeriaceae (incl. Botryosphaeria and aggregate genera, Phomopsis and Phaeoacremonium. Since infections occur mainly through pruning wounds, that have been shown by previous research to stay susceptible for up to 16 weeks after pruning, long-term pruning wound protection is required for prevention of infection. This study evaluated several biocontrol agents against a range of trunk disease pathogens in dual plate laboratory trials to determine macroscopic and microscopic interactions. The biocontrol agents had a substantial effect on all the pathogens, with a wide range of macroscopic and microscopic interactions observed. The best performing biocontrol agents were tested in two field trials. Fresh pruning wounds were treated with benomyl, Trichoderma products (Biotricho®, Vinevax® and ECO 77® and isolates (USPP-T1 and -T2, identified as T. atroviride and Bacillus subtilis. Seven days after treatment the pruning wounds were inoculated by spraying with spore suspensions of Neofusicoccum australe, N. parvum, Diplodia seriata, Lasiodiplodia theobromae, Eutypa lata, Phaeomoniella chlamydospora or Phomopsis viticola. Eight months after inoculation, the treatments were evaluated by isolation onto potato dextrose agar. The efficacy of the biocontrol agents was in most cases similar or superior to that observed for benomyl. Isolate USPP-T1, in particular, was very effective, reducing incidence of Ph. viticola, E. lata, Pa. chlamydospora, N. australe, N. parvum, D. seriata and L. theobromae by 69, 76, 77, 78, 80, 85 and 92%, respectively. This is the first report of biological protection of grapevine pruning wounds against this group of grapevine trunk disease pathogens.

It's not All Doom and Gloom: Prune Belly Syndrome Associated with VACTERL.

Science.gov (United States)

Awad, Karim; Lall, Anupam

2016-01-01

Prune belly syndrome is a rare abnormality; its association with VACTERL is even rarer. This association has been reported in literature a few times since first reported in 1993 and so far the majority have either been stillbirths or died shortly after birth. We present a case of Prune belly syndrome associated with VACTERL who is now one year old.

Congenital megalourethra in 2 weeks old boy associated with Prune-Belly syndrome

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Lawal Barau Abdullahi

2015-02-01

Full Text Available The megalourethra is a rare congenital anomaly of the penile urethra. It is characterized by the congenital absence of the corpus spongiosum and/or corpus cavernosum. It is especially common associated with Prune-Belly syndrome, and with upper tract abnormalities. We present a 2 weeks old boy with congenital megalourethra because of its association with the Prune-Belly syndrome.

Radiation processing of fruits: application to strawberries and prunes

International Nuclear Information System (INIS)

Levillain, M.

1986-10-01

Extending the shelf-life of fresh fruit by means of low-dose irradiation (radurization) is not a new idea: experiments in that field started in the early sixties. These experiments have actually proved that, in some cases, irradiation can achieve shelf-life extension, either through a delay in ripening (bananas), or through rot inhibition (soft cherries, apricots, tomatoes, strawberries). Alas, they have also highlighted the intolerance showed by a number of fruits when radurized: irradiation is apt to have them ripen more rapidly (peaches, nectarines) or to soften them too much (pears, table grapes, oranges, apples, plums, grapefruit, melons, honeydew melons). Even in those cases where irradiation results in a benefit, this benefit varies depending on the variety of fruit involved, as can be seen from a deep survey of the irradiation of strawberries. Preservation of dehydrated fruit is a different matter. Prunes, for instance, would be contamined by molds, wasn't it for the addition of sorbic acid during the fabrication process. Ionization of prunes can allow producers to avoid the use of a chemical, and to keep the prunes at a greater degree of humidity [fr

Influence of coffee pruning on the severity of frost damage

OpenAIRE

Androcioli Filho,Armando; Caramori,Paulo Henrique

2000-01-01

Frost damages in a field experiment of pruning types and systems for the cultivars of Coffea arabica Catuaí and Mundo Novo, were evaluated at Londrina (23º22’S, 52º10´W), State of Parana, southern Brazil, during the winter of 1990 and 1994. Pruning types evaluated were ‘esqueletamento’ (cutting off all plagiotropic branches at 20-30 cm from the orthotropic branch), ‘decote’ (cutting off the orthotropic branch at 1.5 m and 2.0 m above ground) and ‘recepa’ (cutting off the orthotropic branch at...

21 CFR 145.190 - Canned prunes.

Science.gov (United States)

2010-04-01

... of a mixture of brown sugar and honey, an appropriate statement would be “___ sirup of brown sugar... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Canned prunes. 145.190 Section 145.190 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN...

Maternal dietary loads of alpha-tocopherol increase synapse density and glial synaptic coverage in the hippocampus of adult offspring

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S. Salucci

2014-05-01

Full Text Available An increased intake of the antioxidant α-Tocopherol (vitamin E is recommended in complicated pregnancies, to prevent free radical damage to mother and fetus. However, the anti-PKC and antimitotic activity of α-Tocopherol raises concerns about its potential effects on brain development. Recently, we found that maternal dietary loads of α-Tocopherol through pregnancy and lactation cause developmental deficit in hippocampal synaptic plasticity in rat offspring. The defect persisted into adulthood, with behavioral alterations in hippocampus-dependent learning. Here, using the same rat model of maternal supplementation, ultrastructural morphometric studies were carried out to provide mechanistic interpretation to such a functional impairment in adult offspring by the occurrence of long-term changes in density and morphological features of hippocampal synapses. Higher density of axo-spinous synapses was found in CA1 stratum radiatum of α-Tocopherol-exposed rats compared to controls, pointing to a reduced synapse pruning. No morphometric changes were found in synaptic ultrastructural features, i.e., perimeter of axon terminals, length of synaptic specializations, extension of bouton-spine contact. Glia-synapse anatomical relationship was also affected. Heavier astrocytic coverage of synapses was observed in Tocopherol-treated offspring, notably surrounding axon terminals; moreover, the percentage of synapses contacted by astrocytic endfeet at bouton-spine interface (tripartite synapses was increased. These findings indicate that gestational and neonatal exposure to supranutritional tocopherol intake can result in anatomical changes of offspring hippocampus that last through adulthood. These include a surplus of axo-spinous synapses and an aberrant glia-synapse relationship, which may represent the morphological signature of previously described alterations in synaptic plasticity and hippocampus-dependent learning.

Towards an Efficient Artificial Neural Network Pruning and Feature Ranking Tool

KAUST Repository

AlShahrani, Mona

2015-01-01

Artificial Neural Networks (ANNs) are known to be among the most effective and expressive machine learning models. Their impressive abilities to learn have been reflected in many broad application domains such as image recognition, medical diagnosis, online banking, robotics, dynamic systems, and many others. ANNs with multiple layers of complex non-linear transformations (a.k.a Deep ANNs) have shown recently successful results in the area of computer vision and speech recognition. ANNs are parametric models that approximate unknown functions in which parameter values (weights) are adapted during training. ANN’s weights can be large in number and thus render the trained model more complex with chances for “overfitting” training data. In this study, we explore the effects of network pruning on performance of ANNs and ranking of features that describe the data. Simplified ANN model results in fewer parameters, less computation and faster training. We investigate the use of Hessian-based pruning algorithms as well as simpler ones (i.e. non Hessian-based) on nine datasets with varying number of input features and ANN parameters. The Hessian-based Optimal Brain Surgeon algorithm (OBS) is robust but slow. Therefore a faster parallel Hessian- approximation is provided. An additional speedup is provided using a variant we name ‘Simple n Optimal Brain Surgeon’ (SNOBS), which represents a good compromise between robustness and time efficiency. For some of the datasets, the ANN pruning experiments show on average 91% reduction in the number of ANN parameters and about 60% - 90% in the number of ANN input features, while maintaining comparable or better accuracy to the case when no pruning is applied. Finally, we show through a comprehensive comparison with seven state-of-the art feature filtering methods that the feature selection and ranking obtained as a byproduct of the ANN pruning is comparable in accuracy to these methods.

Towards an Efficient Artificial Neural Network Pruning and Feature Ranking Tool

KAUST Repository

AlShahrani, Mona

2015-05-24

Artificial Neural Networks (ANNs) are known to be among the most effective and expressive machine learning models. Their impressive abilities to learn have been reflected in many broad application domains such as image recognition, medical diagnosis, online banking, robotics, dynamic systems, and many others. ANNs with multiple layers of complex non-linear transformations (a.k.a Deep ANNs) have shown recently successful results in the area of computer vision and speech recognition. ANNs are parametric models that approximate unknown functions in which parameter values (weights) are adapted during training. ANN’s weights can be large in number and thus render the trained model more complex with chances for “overfitting” training data. In this study, we explore the effects of network pruning on performance of ANNs and ranking of features that describe the data. Simplified ANN model results in fewer parameters, less computation and faster training. We investigate the use of Hessian-based pruning algorithms as well as simpler ones (i.e. non Hessian-based) on nine datasets with varying number of input features and ANN parameters. The Hessian-based Optimal Brain Surgeon algorithm (OBS) is robust but slow. Therefore a faster parallel Hessian- approximation is provided. An additional speedup is provided using a variant we name ‘Simple n Optimal Brain Surgeon’ (SNOBS), which represents a good compromise between robustness and time efficiency. For some of the datasets, the ANN pruning experiments show on average 91% reduction in the number of ANN parameters and about 60% - 90% in the number of ANN input features, while maintaining comparable or better accuracy to the case when no pruning is applied. Finally, we show through a comprehensive comparison with seven state-of-the art feature filtering methods that the feature selection and ranking obtained as a byproduct of the ANN pruning is comparable in accuracy to these methods.

Cover crops and pruning in Bobal and Tempranillo vineyards have little influence on grapevine nutrition

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Pedro Pérez-Bermúdez

2016-06-01

Full Text Available ABSTRACT Cover crops may improve vineyard soil properties, grapevine nutrient status and berry composition, however, factors such as cover crop type, annual rainfall, climate and irrigation may change their effects on vineyards. From 2008 to 2011, the effects of a non-permanent cover crop and two pruning techniques on soil as well as vine nutrients and grapevine performance of two vineyards (cv. Tempranillo and cv. Bobal were evaluated. For that purpose, two legumes were sown in inter-rows of hand-pruned vines in February and were tilled at flowering. Soil tillage, or cover cropping, was combined with either light pruning or severe pruning to study foliar nutrient variations. Soil N, P, K and total organic carbon (TOC were determined in samples taken from the Ap1 horizon in January prior to vine pruning. Foliar N, P, K contents were measured in leaves sampled upon grape veraison. The differences between vineyards with cover cropping and bare soils suggest that legumes positively affected soil N (1.55 vs. 1.68 g kg−1 and 1.49 vs. 1.76 g kg−1 in Bobal and Tempranillo vineyards, respectively and soil organic matter (SOM (12.5 vs. 15.5 g kg−1 and 12.9 vs. 17.2 g kg−1 in Bobal and Tempranillo vineyards, respectively. The use of cover crops did not affect grapevine yields nor quality of Bobal and Tempranillo berry . Cover crops, or light pruning, did not alter the foliar N, P, K contents of both cultivars since their concentrations were similar to those found in the leaves from vineyards with soil tillage or severe pruning.

Enhanced Context Recognition by Sensitivity Pruned Vocabularies

DEFF Research Database (Denmark)

Madsen, Rasmus Elsborg; Sigurdsson, Sigurdur; Hansen, Lars Kai

2004-01-01

a latent semantic indexing representation and a probabilistic neural network classifier. Pruning the vocabularies to approximately 20% of the original size, we find consistent context recognition enhancement for two mid size data-sets for a range of training set sizes. We also study the applicability...

Mechanisms of glycine release, which build up synaptic and extrasynaptic glycine levels: the role of synaptic and non-synaptic glycine transporters.

Science.gov (United States)

Harsing, Laszlo G; Matyus, Peter

2013-04-01

Glycine is an amino acid neurotransmitter that is involved in both inhibitory and excitatory neurochemical transmission in the central nervous system. The role of glycine in excitatory neurotransmission is related to its coagonist action at glutamatergic N-methyl-D-aspartate receptors. The glycine levels in the synaptic cleft rise many times higher during synaptic activation assuring that glycine spills over into the extrasynaptic space. Another possible origin of extrasynaptic glycine is the efflux of glycine occurring from astrocytes associated with glutamatergic synapses. The release of glycine from neuronal or glial origins exhibits several differences compared to that of biogenic amines or other amino acid neurotransmitters. These differences appear in an external Ca(2+)- and temperature-dependent manner, conferring unique characteristics on glycine as a neurotransmitter. Glycine transporter type-1 at synapses may exhibit neural and glial forms and plays a role in controlling synaptic glycine levels and the spill over rate of glycine from the synaptic cleft into the extrasynaptic biophase. Non-synaptic glycine transporter type-1 regulates extrasynaptic glycine concentrations, either increasing or decreasing them depending on the reverse or normal mode operation of the carrier molecule. While we can, at best, only estimate synaptic glycine levels at rest and during synaptic activation, glycine concentrations are readily measurable via brain microdialysis technique applied in the extrasynaptic space. The non-synaptic N-methyl-D-aspartate receptor may obtain glycine for activation following its spill over from highly active synapses or from its release mediated by the reverse operation of non-synaptic glycine transporter-1. The sensitivity of non-synaptic N-methyl-D-aspartate receptors to glutamate and glycine is many times higher than that of synaptic N-methyl-D-aspartate receptors making the former type of receptor the primary target for drug action. Synaptic

The association between prune belly syndrome and dental anomalies: a case report.

Science.gov (United States)

Basso, Maria Daniela; Favretto, Carla Oliveira; Cunha, Robson Frederico

2012-12-18

Prune belly syndrome is a rare condition produced by an early mesodermal defect that causes abdominal abnormalities. However, the literature indicates that disturbances related to ectodermal development may also be present. This is the first case report in the literature to suggest that dental abnormalities are part of the broad spectrum of clinical features of prune belly syndrome. Because the syndrome causes many serious medical problems, early diagnosis of abnormalities involving the primary and permanent dentitions are encouraged. The authors report the clinical case of a 4-year-old Caucasian boy with prune belly syndrome. In addition to the triad of abdominal muscle deficiency, abnormalities of the gastrointestinal and urinary tracts, and cryptorchidism, a geminated mandibular right central incisor, agenesis of a mandibular permanent left incisor, and congenitally missing primary teeth (namely, the mandibular right and left lateral incisors) were noted. This original case report about prune belly syndrome highlights the possibility that dental abnormalities are a part of the broad spectrum of clinical features of the syndrome. Therefore, an accurate intra-oral clinical examination and radiographic evaluation are required for patients with this syndrome in order to provide an early diagnosis of abnormalities involving the primary and permanent dentitions.

The association between prune belly syndrome and dental anomalies: a case report

Directory of Open Access Journals (Sweden)

Basso Maria Daniela

2012-12-01

Full Text Available Abstract Background Prune belly syndrome is a rare condition produced by an early mesodermal defect that causes abdominal abnormalities. However, the literature indicates that disturbances related to ectodermal development may also be present. This is the first case report in the literature to suggest that dental abnormalities are part of the broad spectrum of clinical features of prune belly syndrome. Because the syndrome causes many serious medical problems, early diagnosis of abnormalities involving the primary and permanent dentitions are encouraged. Case presentation The authors report the clinical case of a 4-year-old Caucasian boy with prune belly syndrome. In addition to the triad of abdominal muscle deficiency, abnormalities of the gastrointestinal and urinary tracts, and cryptorchidism, a geminated mandibular right central incisor, agenesis of a mandibular permanent left incisor, and congenitally missing primary teeth (namely, the mandibular right and left lateral incisors were noted. Conclusion This original case report about prune belly syndrome highlights the possibility that dental abnormalities are a part of the broad spectrum of clinical features of the syndrome. Therefore, an accurate intra-oral clinical examination and radiographic evaluation are required for patients with this syndrome in order to provide an early diagnosis of abnormalities involving the primary and permanent dentitions.

Suspected Urine Leak in a Pediatric Renal Transplant Patient With Prune Belly Syndrome.

Science.gov (United States)

Liu, Bin; Kaplan, Summer L; Zhuang, Hongming

2016-03-01

Patients with prune belly syndrome usually have tortuous ureters, which can cause difficulty in the interpretation of renal scan used to evaluate possible urine leak after renal transplant. We reported a renal scan finding in a pediatric renal transplant patient with prune belly syndrome. The radioactivity in the dilated ureter, which was lateral to the renal transplant, appears to be urine leak.

Metabolic Turnover of Synaptic Proteins: Kinetics, Interdependencies and Implications for Synaptic Maintenance

Science.gov (United States)

Cohen, Laurie D.; Zuchman, Rina; Sorokina, Oksana; Müller, Anke; Dieterich, Daniela C.; Armstrong, J. Douglas; Ziv, Tamar; Ziv, Noam E.

2013-01-01

Chemical synapses contain multitudes of proteins, which in common with all proteins, have finite lifetimes and therefore need to be continuously replaced. Given the huge numbers of synaptic connections typical neurons form, the demand to maintain the protein contents of these connections might be expected to place considerable metabolic demands on each neuron. Moreover, synaptic proteostasis might differ according to distance from global protein synthesis sites, the availability of distributed protein synthesis facilities, trafficking rates and synaptic protein dynamics. To date, the turnover kinetics of synaptic proteins have not been studied or analyzed systematically, and thus metabolic demands or the aforementioned relationships remain largely unknown. In the current study we used dynamic Stable Isotope Labeling with Amino acids in Cell culture (SILAC), mass spectrometry (MS), Fluorescent Non–Canonical Amino acid Tagging (FUNCAT), quantitative immunohistochemistry and bioinformatics to systematically measure the metabolic half-lives of hundreds of synaptic proteins, examine how these depend on their pre/postsynaptic affiliation or their association with particular molecular complexes, and assess the metabolic load of synaptic proteostasis. We found that nearly all synaptic proteins identified here exhibited half-lifetimes in the range of 2–5 days. Unexpectedly, metabolic turnover rates were not significantly different for presynaptic and postsynaptic proteins, or for proteins for which mRNAs are consistently found in dendrites. Some functionally or structurally related proteins exhibited very similar turnover rates, indicating that their biogenesis and degradation might be coupled, a possibility further supported by bioinformatics-based analyses. The relatively low turnover rates measured here (∼0.7% of synaptic protein content per hour) are in good agreement with imaging-based studies of synaptic protein trafficking, yet indicate that the metabolic load

Nitrogen fixation in Leucaena leucocephala and effects of pruning s on cereal yields

International Nuclear Information System (INIS)

Bekunda, M.

1998-01-01

Leucaena leucocephala was interplanted with reference tree species, Cassia siamea and Cassia spectabilis, and estimates of percent N derived from N 2 fixation (%Ndfa) were made, by the isotope-dilution method, at 4, 6, 14, 20 and 30 months after transplanting. The %Ndfa values were low and variable throughout the growth period, except after thinning at 14 months when there was a five-fold increase. The two non-fixing reference species outperformed the N 2 -fixing Leucaena in above-ground vegetative production, and provided different fixed-N estimates. Prunings from the L. leucocephala and C. Siamea trees were applied separately to soil as green manure. Maize was planted to test the effects of the Leucaena green manure on soil fertility, and millet was the test crop for the Cassia. Whether surface-applied or incorporated, the prunings significantly improved yields, which were generally similar among rates and methods of application. The proportions of cereal N obtained from prunings ranged from 8 to 33%, with no cereal-yield correlation. The data indicate that multipurpose tree prunings are of potential use to farmers as organic sources of nutrients, even at relatively low application rates, without need for incorporation into the soil. (author)

Isolation of Synaptosomes, Synaptic Plasma Membranes, and Synaptic Junctional Complexes.

Science.gov (United States)

Michaelis, Mary L; Jiang, Lei; Michaelis, Elias K

2017-01-01

Isolation of synaptic nerve terminals or synaptosomes provides an opportunity to study the process of neurotransmission at many levels and with a variety of approaches. For example, structural features of the synaptic terminals and the organelles within them, such as synaptic vesicles and mitochondria, have been elucidated with electron microscopy. The postsynaptic membranes are joined to the presynaptic "active zone" of transmitter release through cell adhesion molecules and remain attached throughout the isolation of synaptosomes. These "post synaptic densities" or "PSDs" contain the receptors for the transmitters released from the nerve terminals and can easily be seen with electron microscopy. Biochemical and cell biological studies with synaptosomes have revealed which proteins and lipids are most actively involved in synaptic release of neurotransmitters. The functional properties of the nerve terminals, such as responses to depolarization and the uptake or release of signaling molecules, have also been characterized through the use of fluorescent dyes, tagged transmitters, and transporter substrates. In addition, isolated synaptosomes can serve as the starting material for the isolation of relatively pure synaptic plasma membranes (SPMs) that are devoid of organelles from the internal environment of the nerve terminal, such as mitochondria and synaptic vesicles. The isolated SPMs can reseal and form vesicular structures in which transport of ions such as sodium and calcium, as well as solutes such as neurotransmitters can be studied. The PSDs also remain associated with the presynaptic membranes during isolation of SPM fractions, making it possible to isolate the synaptic junctional complexes (SJCs) devoid of the rest of the plasma membranes of the nerve terminals and postsynaptic membrane components. Isolated SJCs can be used to identify the proteins that constitute this highly specialized region of neurons. In this chapter, we describe the steps involved

At the centre of neuronal, synaptic and axonal pathology in murine prion disease: degeneration of neuroanatomically linked thalamic and brainstem nuclei

Science.gov (United States)

Reis, Renata; Hennessy, Edel; Murray, Caoimhe; Griffin, Éadaoin W.

2015-01-01

Aims The processes by which neurons degenerate in chronic neurodegenerative diseases remain unclear. Synaptic loss and axonal pathology frequently precede neuronal loss and protein aggregation demonstrably spreads along neuroanatomical pathways in many neurodegenerative diseases. The spread of neuronal pathology is less studied. Methods We previously demonstrated severe neurodegeneration in the posterior thalamus of multiple prion disease strains. Here we used the ME7 model of prion disease to examine the nature of this degeneration in the posterior thalamus and the major brainstem projections into this region. Results We objectively quantified neurological decline between 16 and 18 weeks post‐inoculation and observed thalamic subregion‐selective neuronal, synaptic and axonal pathology while demonstrating relatively uniform protease‐resistant prion protein (PrP) aggregation and microgliosis across the posterior thalamus. Novel amyloid precursor protein (APP) pathology was particularly prominent in the thalamic posterior (PO) and ventroposterior lateral (VPL) nuclei. The brainstem nuclei forming the major projections to these thalamic nuclei were examined. Massive neuronal loss in the PO was not matched by significant neuronal loss in the interpolaris (Sp5I), while massive synaptic loss in the ventral posteromedial nucleus (VPM) did correspond with significant neuronal loss in the principal trigeminal nucleus. Likewise, significant VPL synaptic loss was matched by significant neuronal loss in the gracile and cuneate nuclei. Conclusion These findings demonstrate significant spread of neuronal pathology from the thalamus to the brainstem in prion disease. The divergent neuropathological features in adjacent neuronal populations demonstrates that there are discrete pathways to neurodegeneration in different neuronal populations. PMID:25727649

Pruning affects the vegetative balance of the wine grape (Vitis vinifera L.

Directory of Open Access Journals (Sweden)

Pedro José Almanza-Merchán

2014-08-01

Full Text Available Grape cultivation for wine production at altitudes between 2,200 and 2,600 m a.s.l. started in the department of Boyaca in 1982. Quality wines are produced by the AinKarim Vineyard in Ricaurte High. Wine grapes have to possess suitable organoleptic compounds at harvest in order to guarantee quality grape must that can be converted into wine. Therefore, it is necessary to maintain a suitable ratio the sources and the sinks and to guarantee production, quality and vegetative sustainability over time, conserving the equilibrium and benefiting the productive potential of the vineyard. The aim of this study was to evaluate the productive and vegetative balance effect in the wine grape varieties Cabernet Sauvignon and Sauvignon Blanc in Sutamarchan-Boyaca, considering different pruning types (short, long, and mixed. A bifactorial, completely random statistical design was used. At the time of harvest, the fruit production and pruned wood were evaluated. The long-pruned vines showed the best behavior and the most balanced source/sink relationship,, while Sauvignon Blanc demonstrated a better productive yield. Meanwhile, the short and mixed prunings had the better values for the Ravaz index (balance between fruit production and vegetative growth, indicating that they are more suitable for the conditions of the region, allowing for sustainability during the productive cycles of the wine grapes.

Involvements of PCD and changes in gene expression profile during self-pruning of spring shoots in sweet orange (Citrus sinensis).

Science.gov (United States)

Zhang, Jin-Zhi; Zhao, Kun; Ai, Xiao-Yan; Hu, Chun-Gen

2014-10-13

Citrus shoot tips abscise at an anatomically distinct abscission zone (AZ) that separates the top part of the shoots into basal and apical portions (citrus self-pruning). Cell separation occurs only at the AZ, which suggests its cells have distinctive molecular regulation. Although several studies have looked into the morphological aspects of self-pruning process, the underlying molecular mechanisms remain unknown. In this study, the hallmarks of programmed cell death (PCD) were identified by TUNEL experiments, transmission electron microscopy (TEM) and histochemical staining for reactive oxygen species (ROS) during self-pruning of the spring shoots in sweet orange. Our results indicated that PCD occurred systematically and progressively and may play an important role in the control of self-pruning of citrus. Microarray analysis was used to examine transcriptome changes at three stages of self-pruning, and 1,378 differentially expressed genes were identified. Some genes were related to PCD, while others were associated with cell wall biosynthesis or metabolism. These results strongly suggest that abscission layers activate both catabolic and anabolic wall modification pathways during the self-pruning process. In addition, a strong correlation was observed between self-pruning and the expression of hormone-related genes. Self-pruning plays an important role in citrus floral bud initiation. Therefore, several key flowering homologs of Arabidopsis and tomato shoot apical meristem (SAM) activity genes were investigated in sweet orange by real-time PCR and in situ hybridization, and the results indicated that these genes were preferentially expressed in SAM as well as axillary meristem. Based on these findings, a model for sweet orange spring shoot self-pruning is proposed, which will enable us to better understand the mechanism of self-pruning and abscission.

REM sleep selectively prunes and maintains new synapses in development and learning.

Science.gov (United States)

Li, Wei; Ma, Lei; Yang, Guang; Gan, Wen-Biao

2017-03-01

The functions and underlying mechanisms of rapid eye movement (REM) sleep remain unclear. Here we show that REM sleep prunes newly formed postsynaptic dendritic spines of layer 5 pyramidal neurons in the mouse motor cortex during development and motor learning. This REM sleep-dependent elimination of new spines facilitates subsequent spine formation during development and when a new motor task is learned, indicating a role for REM sleep in pruning to balance the number of new spines formed over time. Moreover, REM sleep also strengthens and maintains newly formed spines, which are critical for neuronal circuit development and behavioral improvement after learning. We further show that dendritic calcium spikes arising during REM sleep are important for pruning and strengthening new spines. Together, these findings indicate that REM sleep has multifaceted functions in brain development, learning and memory consolidation by selectively eliminating and maintaining newly formed synapses via dendritic calcium spike-dependent mechanisms.

Bonsai trees in your head: how the pavlovian system sculpts goal-directed choices by pruning decision trees.

Directory of Open Access Journals (Sweden)

Quentin J M Huys

Full Text Available When planning a series of actions, it is usually infeasible to consider all potential future sequences; instead, one must prune the decision tree. Provably optimal pruning is, however, still computationally ruinous and the specific approximations humans employ remain unknown. We designed a new sequential reinforcement-based task and showed that human subjects adopted a simple pruning strategy: during mental evaluation of a sequence of choices, they curtailed any further evaluation of a sequence as soon as they encountered a large loss. This pruning strategy was Pavlovian: it was reflexively evoked by large losses and persisted even when overwhelmingly counterproductive. It was also evident above and beyond loss aversion. We found that the tendency towards Pavlovian pruning was selectively predicted by the degree to which subjects exhibited sub-clinical mood disturbance, in accordance with theories that ascribe Pavlovian behavioural inhibition, via serotonin, a role in mood disorders. We conclude that Pavlovian behavioural inhibition shapes highly flexible, goal-directed choices in a manner that may be important for theories of decision-making in mood disorders.

Prune belly syndrome in an Egyptian infant with Down syndrome: A case report

Directory of Open Access Journals (Sweden)

Metwalley Kotb A

2008-10-01

Full Text Available Abstract Introduction Prune belly syndrome is a rare congenital anomaly of uncertain aetiology almost exclusive to males. The association between prune belly syndrome and Down syndrome is very rare. Case presentation A 4-month-old Egyptian boy was admitted to our institute for management of acute bronchiolitis. He was born at full term by normal vaginal delivery. His mother, a 42-year-Egyptian villager with six other children, had no antenatal or prenatal care. On examination, the boy was found to be hypotonic. In addition to features of Down syndrome, karyotyping confirmed the diagnosis of trisomy 21. Ultrasound examination of the abdomen showed bilateral gross hydronephrosis with megaureter. Micturating cystourethrography showed grade V vesicoureteric reflux bilaterally with no urethral obstruction. Serum creatinine concentration was 90 μmol/litre, serum sodium was 132 mmol/litre and serum potassium was 5.9 mmol/litre. Conclusion We report an Egyptian infant with Down syndrome and prune belly syndrome. The incidence of this association is unknown. Routine antenatal ultrasonography will help in discovering renal anomalies which can be followed postnatally. Postnatal detection of prune belly syndrome necessitates full radiological investigation to detect any renal anomalies. Early diagnosis of this syndrome and determining its optimal treatment are very important in helping to avoid its fatal course.

Prune belly syndrome in an Egyptian infant with Down syndrome: a case report.

Science.gov (United States)

Metwalley, Kotb A; Farghalley, Hekma S; Abd-Elsayed, Alaa A

2008-10-02

Prune belly syndrome is a rare congenital anomaly of uncertain aetiology almost exclusive to males. The association between prune belly syndrome and Down syndrome is very rare. A 4-month-old Egyptian boy was admitted to our institute for management of acute bronchiolitis. He was born at full term by normal vaginal delivery. His mother, a 42-year-Egyptian villager with six other children, had no antenatal or prenatal care. On examination, the boy was found to be hypotonic. In addition to features of Down syndrome, karyotyping confirmed the diagnosis of trisomy 21. Ultrasound examination of the abdomen showed bilateral gross hydronephrosis with megaureter. Micturating cystourethrography showed grade V vesicoureteric reflux bilaterally with no urethral obstruction. Serum creatinine concentration was 90 mumol/litre, serum sodium was 132 mmol/litre and serum potassium was 5.9 mmol/litre. We report an Egyptian infant with Down syndrome and prune belly syndrome. The incidence of this association is unknown. Routine antenatal ultrasonography will help in discovering renal anomalies which can be followed postnatally. Postnatal detection of prune belly syndrome necessitates full radiological investigation to detect any renal anomalies. Early diagnosis of this syndrome and determining its optimal treatment are very important in helping to avoid its fatal course.

Sensitivity of directed networks to the addition and pruning of edges and vertices

Science.gov (United States)

Goltsev, A. V.; Timár, G.; Mendes, J. F. F.

2017-08-01

Directed networks have various topologically different extensive components, in contrast to a single giant component in undirected networks. We study the sensitivity (response) of the sizes of these extensive components in directed complex networks to the addition and pruning of edges and vertices. We introduce the susceptibility, which quantifies this sensitivity. We show that topologically different parts of a directed network have different sensitivity to the addition and pruning of edges and vertices and, therefore, they are characterized by different susceptibilities. These susceptibilities diverge at the critical point of the directed percolation transition, signaling the appearance (or disappearance) of the giant strongly connected component in the infinite size limit. We demonstrate this behavior in randomly damaged real and synthetic directed complex networks, such as the World Wide Web, Twitter, the Caenorhabditis elegans neural network, directed Erdős-Rényi graphs, and others. We reveal a nonmonotonic dependence of the sensitivity to random pruning of edges or vertices in the case of C. elegans and Twitter that manifests specific structural peculiarities of these networks. We propose the measurements of the susceptibilities during the addition or pruning of edges and vertices as a new method for studying structural peculiarities of directed networks.

Carbon footprint associated with four disposal scenarios for urban pruning waste.

Science.gov (United States)

Araújo, Yuri Rommel Vieira; de Góis, Monijany Lins; Junior, Luiz Moreira Coelho; Carvalho, Monica

2018-01-01

The inadequate disposal of urban pruning residues can cause significant environmental impacts. The objective of the study presented herein was to quantify the carbon footprint and analyze four disposal scenarios for the urban pruning waste of the city of Joao Pessoa (Northeast Brazil). Software SimaPro was utilized for the quantification of the carbon footprint, with the IPCC 2013 GWP 100y impact evaluation method. The end-of-life treatments considered were sanitary landfilling (with and without collection of methane), simple municipal incineration, and reutilization of wood (transformation into briquettes). The results indicated that simple disposal in sanitary landfill generated 136.34 kg CO 2 /t urban pruning waste collected (highest carbon footprint), sanitary landfill with methane collection emitted 113.43 kg CO 2 /t waste, municipal incineration generated 71.31 kg CO 2 /t waste, and reutilization of woody residues was the scenario with the lowest carbon footprint, with 27.82 kg CO 2 /t waste. This study demonstrated that reutilization of biomass, besides being environmentally viable, presents the potential to contribute to the city's environmental quality, including the possibility of being used to obtain carbon credits.

Synaptic electronics: materials, devices and applications.

Science.gov (United States)

Kuzum, Duygu; Yu, Shimeng; Wong, H-S Philip

2013-09-27

In this paper, the recent progress of synaptic electronics is reviewed. The basics of biological synaptic plasticity and learning are described. The material properties and electrical switching characteristics of a variety of synaptic devices are discussed, with a focus on the use of synaptic devices for neuromorphic or brain-inspired computing. Performance metrics desirable for large-scale implementations of synaptic devices are illustrated. A review of recent work on targeted computing applications with synaptic devices is presented.

Synaptic electronics: materials, devices and applications

International Nuclear Information System (INIS)

Kuzum, Duygu; Yu, Shimeng; Philip Wong, H-S

2013-01-01

In this paper, the recent progress of synaptic electronics is reviewed. The basics of biological synaptic plasticity and learning are described. The material properties and electrical switching characteristics of a variety of synaptic devices are discussed, with a focus on the use of synaptic devices for neuromorphic or brain-inspired computing. Performance metrics desirable for large-scale implementations of synaptic devices are illustrated. A review of recent work on targeted computing applications with synaptic devices is presented. (topical review)

Using a pruned, nondirect product basis in conjunction with the multi-configuration time-dependent Hartree (MCTDH) method

Energy Technology Data Exchange (ETDEWEB)

Wodraszka, Robert, E-mail: Robert.Wodraszka@chem.queensu.ca; Carrington, Tucker, E-mail: Tucker.Carrington@queensu.ca [Department of Chemistry, Queen’s University, Kingston, Ontario K7L 3N6 (Canada)

2016-07-28

In this paper, we propose a pruned, nondirect product multi-configuration time dependent Hartree (MCTDH) method for solving the Schrödinger equation. MCTDH uses optimized 1D basis functions, called single particle functions, but the size of the standard direct product MCTDH basis scales exponentially with D, the number of coordinates. We compare the pruned approach to standard MCTDH calculations for basis sizes small enough that the latter are possible and demonstrate that pruning the basis reduces the CPU cost of computing vibrational energy levels of acetonitrile (D = 12) by more than two orders of magnitude. Using the pruned method, it is possible to do calculations with larger bases, for which the cost of standard MCTDH calculations is prohibitive. Pruning the basis complicates the evaluation of matrix-vector products. In this paper, they are done term by term for a sum-of-products Hamiltonian. When no attempt is made to exploit the fact that matrices representing some of the factors of a term are identity matrices, one needs only to carefully constrain indices. In this paper, we develop new ideas that make it possible to further reduce the CPU time by exploiting identity matrices.

Banach Synaptic Algebras

Science.gov (United States)

Foulis, David J.; Pulmannov, Sylvia

2018-04-01

Using a representation theorem of Erik Alfsen, Frederic Schultz, and Erling Størmer for special JB-algebras, we prove that a synaptic algebra is norm complete (i.e., Banach) if and only if it is isomorphic to the self-adjoint part of a Rickart C∗-algebra. Also, we give conditions on a Banach synaptic algebra that are equivalent to the condition that it is isomorphic to the self-adjoint part of an AW∗-algebra. Moreover, we study some relationships between synaptic algebras and so-called generalized Hermitian algebras.

7 CFR 457.133 - Prune crop insurance provisions.

Science.gov (United States)

2010-01-01

... roadside stand, farmer's market, and permitting the general public to enter the field for the purpose of... (except where otherwise provided in the Special Provisions); (d) That are grown in an orchard that, if... not been controlled or pruning debris has not been removed from the orchard; (3) Wildlife; (4...

Vocabulary Pruning for Improved Context Recognition

DEFF Research Database (Denmark)

Madsen, Rasmus Elsborg; Sigurdsson, Sigurdur; Hansen, Lars Kai

2004-01-01

Language independent `bag-of-words' representations are surprisingly effective for text classification. The representation is high dimensional though, containing many non-consistent words for text categorization. These non-consistent words result in reduced generalization performance of subsequent...... of term relevancy, when pruning the vocabularies. With reduced vocabularies documents are classified using a latent semantic indexing representation and a probabilistic neural network classifier. Reducing the bag-of-words vocabularies with 90%-98%, we find consistent classification improvement using two...

Prune belly syndrome: Early management outcome of nine ...

African Journals Online (AJOL)

Background: Prune belly syndrome (PBS) is a rare congenital malformation of unclear etiology. The disease progress and outcome in developing countries are not clear as most reports are isolated case reports. Materials and Methods: A review of 9 patients managed for PBS in 5 years. Results: There were 7 males and 2 ...

Prune belly syndrome associated with bilateral multicystic dysplastic kidneys and urethral obstruction: A case report

Directory of Open Access Journals (Sweden)

Arzu Akdag

2015-06-01

Full Text Available Prune belly syndrome is a rare congenital disorder defined by a characteristic clinical triad: Abdominal muscle deficiency, severe urinary tract abnormalities, and bilateral cryptorchidism. We describe a preterm neonate of Prune Belly syndrome who had abdominal muscle deficiency, multicystic dysplastic kidney, urethral hypoplasia and pulmonary hypoplasia. We presented this rare case with the data gathered from the literatüre.

Deletion of hepatocyte nuclear factor-1-beta in an infant with prune belly syndrome.

Science.gov (United States)

Haeri, Sina; Devers, Patricia L; Kaiser-Rogers, Kathleen A; Moylan, Vincent J; Torchia, Beth S; Horton, Amanda L; Wolfe, Honor M; Aylsworth, Arthur S

2010-08-01

Prune belly syndrome is a rare congenital disorder characterized by deficiency of abdominal wall muscles, cryptorchidism, and urinary tract anomalies. We have had the opportunity to study a baby with prune belly syndrome associated with an apparently de novo 1.3-megabase interstitial 17q12 microdeletion that includes the hepatocyte nuclear factor-1-beta gene at 17q12. One previous patient, an adult, has been reported with prune belly syndrome and a hepatocyte nuclear factor-1-beta microdeletion. Hepatocyte nuclear factor-1-beta is a widely expressed transcription factor that regulates tissue-specific gene expression and is expressed in numerous tissues including mesonephric duct derivatives, the renal tubule of the metanephros, and the developing prostate of the mouse. Mutations in hepatocyte nuclear factor-1-beta cause the "renal cysts and diabetes syndrome," isolated renal cystic dysplasia, and a variety of other malformations. Based on its expression pattern and the observation of two affected cases, we propose that haploinsufficiency of hepatocyte nuclear factor-1-beta may be causally related to the production of the prune belly syndrome phenotype through a mechanism of prostatic and ureteral hypoplasia that results in severe obstructive uropathy with urinary tract and abdominal distension. Copyright Thieme Medical Publishers.

An Artificial Neural Network Modeling for Force Control System of a Robotic Pruning Machine

Directory of Open Access Journals (Sweden)

Ali Hashemi

2014-06-01

Full Text Available Nowadays, there has been an increasing application of pruning robots for planted forests due to the growing concern on the efficiency and safety issues. Power consumption and working time of agricultural machines have become important issues due to the high value of energy in modern world. In this study, different multi-layer back-propagation networks were utilized for mapping the complex and highly interactive of pruning process parameters and to predict power consumption and cutting time of a force control equipped robotic pruning machine by knowing input parameters such as: rotation speed, stalk diameter, and sensitivity coefficient. Results showed significant effects of all input parameters on output parameters except rotational speed on cutting time. Therefore, for reducing the wear of cutting system, a less rotational speed in every sensitivity coefficient should be selected.

EDITORIAL: Synaptic electronics Synaptic electronics

Science.gov (United States)

Demming, Anna; Gimzewski, James K.; Vuillaume, Dominique

2013-09-01

Conventional computers excel in logic and accurate scientific calculations but make hard work of open ended problems that human brains handle easily. Even von Neumann—the mathematician and polymath who first developed the programming architecture that forms the basis of today's computers—was already looking to the brain for future developments before his death in 1957 [1]. Neuromorphic computing uses approaches that better mimic the working of the human brain. Recent developments in nanotechnology are now providing structures with very accommodating properties for neuromorphic approaches. This special issue, with guest editors James K Gimzewski and Dominique Vuillaume, is devoted to research at the serendipitous interface between the two disciplines. 'Synaptic electronics', looks at artificial devices with connections that demonstrate behaviour similar to synapses in the nervous system allowing a new and more powerful approach to computing. Synapses and connecting neurons respond differently to incident signals depending on the history of signals previously experienced, ultimately leading to short term and long term memory behaviour. The basic characteristics of a synapse can be replicated with around ten simple transistors. However with the human brain having around 1011 neurons and 1015 synapses, artificial neurons and synapses from basic transistors are unlikely to accommodate the scalability required. The discovery of nanoscale elements that function as 'memristors' has provided a key tool for the implementation of synaptic connections [2]. Leon Chua first developed the concept of the 'The memristor—the missing circuit element' in 1971 [3]. In this special issue he presents a tutorial describing how memristor research has fed into our understanding of synaptic behaviour and how they can be applied in information processing [4]. He also describes, 'The new principle of local activity, which uncovers a minuscule life-enabling "Goldilocks zone", dubbed the

Influence of Pre- and Postharvest Summer Pruning on the Growth, Yield, Fruit Quality, and Carbohydrate Content of Early Season Peach Cultivars

Science.gov (United States)

Ikinci, Ali

2014-01-01

Winter and summer pruning are widely applied processes in all fruit trees, including in peach orchard management. This study was conducted to determine the effects of summer prunings (SP), as compared to winter pruning (WP), on shoot length, shoot diameter, trunk cross sectional area (TCSA) increment, fruit yield, fruit quality, and carbohydrate content of two early ripening peach cultivars (“Early Red” and “Maycrest”) of six years of age, grown in semiarid climate conditions, in 2008 to 2010. The trees were grafted on GF 677 rootstocks, trained with a central leader system, and spaced 5 × 5 m apart. The SP carried out after harvesting in July and August decreased the shoot length significantly; however, it increased its diameter. Compared to 2009, this effect was more marked in year 2010. In general, control and winter pruned trees of both cultivars had the highest TCSA increment and yield efficiency. The SP increased the average fruit weight and soluble solids contents (SSC) more than both control and WP. The titratable acidity showed no consistent response to pruning time. The carbohydrate accumulation in shoot was higher in WP and in control than in SP trees. SP significantly affected carbohydrate accumulation; postharvest pruning showed higher carbohydrate content than preharvest pruning. PMID:24737954

Effects of root pruning on the growth and rhizosphere soil characteristics of short-rotation closed-canopy poplar

Energy Technology Data Exchange (ETDEWEB)

Du, Z. Y.; Xing, S. J.; Ma, B. Y.; Liu, F. C.; Ma, H. L.; Wang, Q. H.

2012-11-01

When poplar trees planted at a high density are canopy-closed in plantation after 4-5 years of growth, the roots of adjacent trees will inevitably intermingle together, which possibly restricts the nutrient uptake by root system. Root pruning might stimulate the emergence of fine roots and benefit the tree growth of short-rotation poplar at the stage of canopy closing. The aim of this study is to evaluate the effects of root pruning on DBH (diameter at breast height, 1.3 m), tree height, nutrients (N, P and K) and hormones (indoleacetic acid and cytokinin) in poplar leaves, gas exchange variables (photosynthetic rate and stomatal conductance), and rhizosphere soil characteristics. Field experiment was carried out with four-yearold poplar (Populus × euramericana cv. ‘Neva’) planted in a fluvo-aquic loam soil in Shandong province, China in early April, 2008. Three root pruning treatments (severe, moderate and light degree) were conducted at the distances of 6, 8 and 10 times DBH on both inter-row sides of the trees to the depth of 30 cm, respectively. The results showed that the growth performance was obtained in the following order of treatments: moderate > light = control > severe. In the rhizophere soil, moderate and light pruning increased the microbial populations, enzymatic activities, and the concentrations of available N, P, K and organic matter. Generally, root pruning to improve tree growth and rhizosphere soil fertility can be recommended in canopy-closed poplar plantation. The appropriate selection of root pruning intensity is a pivotal factor for the effectiveness of this technique. (Author) 35 refs.

Field performance of Quercus bicolor established as repeatedly air-root-pruned container and bareroot planting stock

Science.gov (United States)

J.W." Jerry" Van Sambeek; Larry D. Godsey; William D. Walter; Harold E. Garrett; John P. Dwyer

2016-01-01

Benefits of repeated air-root-pruning of seedlings when stepping up to progressively larger containers include excellent lateral root distribution immediately below the root collar and an exceptionally fibrous root ball. To evaluate long-term field performance of repeatedly air-root-pruned container stock, three plantings of swamp white oak (Quercus bicolor...

First steps in translating human cognitive processes of cane pruning grapevines into AI rules for automated robotic pruning

Directory of Open Access Journals (Sweden)

Saxton Valerie

2014-01-01

Full Text Available Cane pruning of grapevines is a skilled task for which, internationally, there is a dire shortage of human pruners. As part of a larger project developing an automated robotic pruner, we have used artificial intelligence (AI algorithms to create an expert system for selecting new canes and cutting off unwanted canes. A domain and ontology has been created for AI, which reflects the expertise of expert human pruners. The first step in the creation of an expert system was to generate virtual vines, which were then ‘pruned’ by human pruners and also by the expert system in its infancy. Here we examined the decisions of 12 human pruners, for consistency of decision, on 60 virtual vines. 96.7% of the 12 pruners agreed on at least one cane choice after which there was diminishing agreement on which further canes to select for laying. Our results indicate that techniques developed in computational intelligence can be used to co-ordinate and synthesise the expertise of human pruners into a best practice format. This paper describes first steps in this knowledge elicitation process, and discusses the fit between cane pruning expertise and the expertise that can be elicited using AI based expert system techniques.

Encapsulating peritoneal sclerosis in a peritoneal dialysis patient with prune-belly syndrome: a case report.

Science.gov (United States)

Geurts, N; Hubens, G; Wojciechowski, M; Vaneerdeweg, W

2010-01-01

This case describes a prune-belly syndrome patient who had a kidney transplantation and was diagnosed with Encapsulating Peritoneal Sclerosis (EPS), a rare but potentially fatal condition, mostly associated with Peritoneal Dialysis (PD). The definition of EPS is based on the clinical findings linked to bowel obstruction and on the demonstration of peritoneal thickening. Surgical treatment is the only established basic treatment for the condition. Prune-belly syndrome is characterized by the triad of deficient abdominal musculature, urinary tract abnormality and cryptorchidism. Because it is often associated with end-stage renal disease, PD is essential in the treatment of patients with prune-belly syndrome. The aetiology of EPS follows a 'two-hit theory': the first 'hit' is peritoneal deterioration, caused by long-time exposure to PD. This causes peritoneal disruption which predisposes the patient to a second hit. In our patient, PD discontinuation and renal transplantation are possible 'second hits' that triggered the development of EPS. This case of prune-belly syndrome has all the necessary elements for the development of EPS, and we felt we should report it as the peroperative diagnosis was unexpected.

7 CFR 52.3188 - Work sheet for dried prunes.

Science.gov (United States)

2010-01-01

... for dried prunes. Size and kind of container Container mark or identification Label or brand Varietal... fermentation, scars, heat damage, insect injury, other means, mold, dirt, foreign material, insect infestation... fermentation, scars, heat damage, insect injury, other means, mold, dirt, foreign material, insect infestation...

Synaptic transmission modulates while non-synaptic processes govern the transition from pre-ictal to seizure activity in vitro

OpenAIRE

Jefferys, John; Fox, John; Jiruska, Premysl; Kronberg, Greg; Miranda, Dolores; Ruiz-Nuño, Ana; Bikson, Marom

2018-01-01

It is well established that non-synaptic mechanisms can generate electrographic seizures after blockade of synaptic function. We investigated the interaction of intact synaptic activity with non-synaptic mechanisms in the isolated CA1 region of rat hippocampal slices using the 'elevated-K+' model of epilepsy. Elevated K+ ictal bursts share waveform features with other models of electrographic seizures, including non-synaptic models where chemical synaptic transmission is suppressed, such as t...

Dynamic Control of Synaptic Adhesion and Organizing Molecules in Synaptic Plasticity

Energy Technology Data Exchange (ETDEWEB)

Rudenko, Gabby (Texas-MED)

2017-01-01

Synapses play a critical role in establishing and maintaining neural circuits, permitting targeted information transfer throughout the brain. A large portfolio of synaptic adhesion/organizing molecules (SAMs) exists in the mammalian brain involved in synapse development and maintenance. SAMs bind protein partners, formingtrans-complexes spanning the synaptic cleft orcis-complexes attached to the same synaptic membrane. SAMs play key roles in cell adhesion and in organizing protein interaction networks; they can also provide mechanisms of recognition, generate scaffolds onto which partners can dock, and likely take part in signaling processes as well. SAMs are regulated through a portfolio of different mechanisms that affect their protein levels, precise localization, stability, and the availability of their partners at synapses. Interaction of SAMs with their partners can further be strengthened or weakened through alternative splicing, competing protein partners, ectodomain shedding, or astrocytically secreted factors. Given that numerous SAMs appear altered by synaptic activity, in vivo, these molecules may be used to dynamically scale up or scale down synaptic communication. Many SAMs, including neurexins, neuroligins, cadherins, and contactins, are now implicated in neuropsychiatric and neurodevelopmental diseases, such as autism spectrum disorder, schizophrenia, and bipolar disorder and studying their molecular mechanisms holds promise for developing novel therapeutics.

Effect of pruning height on the architecture of plants of camu camu (Myrciaria dubia HBK Mc Vaugh in the experimental station of IIAP, Ucayali, Peru.

Directory of Open Access Journals (Sweden)

Carlos Abanto

2011-06-01

Full Text Available In order to evaluate the response camu camu’s plants in plantations initial undergoing training pruning, an experiment was installed in EE - IIAP-Ucayali, under a design randomized complete block, with 3 replications, making use of 20 plants per experimental unit. The pruning treatments were performing at different heights from the base of the stem, it was considered T0 [witness without pruning], T1 [pruning to 10 cm from the base], T2 [pruning to 20 cm from the base] and T3 [pruning to 40 cm from the base] in plants of known provenance. The investigation was directed to evaluate the number of shoots, shoot growth, plant height, basal diameter, crown diameter and number of branches. After of 9 months of evaluation was found significant differences between the variables except in top diameter. In the variable Height, treatment T0 [witness without pruning] outstanding because they were not pruned, among the remaining treatments has similarly behaved, surpassing the control treatment by 267 %. In addition to this, the basal diameter was found that T1 [pruning to 10 cm from the base] has a better performed with an average value of 1.96 cm compared with the control (1.7cm. The pruning had a positive influence in the number of branches, with an average of 13.4 branches compared with T0 that get 3.1 branches on average, its shows that the pruning can increased up the production of branches to 432.3%.

Fully parallel write/read in resistive synaptic array for accelerating on-chip learning

Science.gov (United States)

Gao, Ligang; Wang, I.-Ting; Chen, Pai-Yu; Vrudhula, Sarma; Seo, Jae-sun; Cao, Yu; Hou, Tuo-Hung; Yu, Shimeng

2015-11-01

A neuro-inspired computing paradigm beyond the von Neumann architecture is emerging and it generally takes advantage of massive parallelism and is aimed at complex tasks that involve intelligence and learning. The cross-point array architecture with synaptic devices has been proposed for on-chip implementation of the weighted sum and weight update in the learning algorithms. In this work, forming-free, silicon-process-compatible Ta/TaO x /TiO2/Ti synaptic devices are fabricated, in which >200 levels of conductance states could be continuously tuned by identical programming pulses. In order to demonstrate the advantages of parallelism of the cross-point array architecture, a novel fully parallel write scheme is designed and experimentally demonstrated in a small-scale crossbar array to accelerate the weight update in the training process, at a speed that is independent of the array size. Compared to the conventional row-by-row write scheme, it achieves >30× speed-up and >30× improvement in energy efficiency as projected in a large-scale array. If realistic synaptic device characteristics such as device variations are taken into an array-level simulation, the proposed array architecture is able to achieve ∼95% recognition accuracy of MNIST handwritten digits, which is close to the accuracy achieved by software using the ideal sparse coding algorithm.

Fully parallel write/read in resistive synaptic array for accelerating on-chip learning

International Nuclear Information System (INIS)

Gao, Ligang; Chen, Pai-Yu; Seo, Jae-sun; Cao, Yu; Yu, Shimeng; Wang, I-Ting; Hou, Tuo-Hung; Vrudhula, Sarma

2015-01-01

A neuro-inspired computing paradigm beyond the von Neumann architecture is emerging and it generally takes advantage of massive parallelism and is aimed at complex tasks that involve intelligence and learning. The cross-point array architecture with synaptic devices has been proposed for on-chip implementation of the weighted sum and weight update in the learning algorithms. In this work, forming-free, silicon-process-compatible Ta/TaO_x/TiO_2/Ti synaptic devices are fabricated, in which >200 levels of conductance states could be continuously tuned by identical programming pulses. In order to demonstrate the advantages of parallelism of the cross-point array architecture, a novel fully parallel write scheme is designed and experimentally demonstrated in a small-scale crossbar array to accelerate the weight update in the training process, at a speed that is independent of the array size. Compared to the conventional row-by-row write scheme, it achieves >30× speed-up and >30× improvement in energy efficiency as projected in a large-scale array. If realistic synaptic device characteristics such as device variations are taken into an array-level simulation, the proposed array architecture is able to achieve ∼95% recognition accuracy of MNIST handwritten digits, which is close to the accuracy achieved by software using the ideal sparse coding algorithm. (paper)

Long-term avoidance memory formation is associated with a transient increase in mushroom body synaptic complexes in leaf-cutting ants

Directory of Open Access Journals (Sweden)

Agustina eFalibene

2015-04-01

Full Text Available Long-term behavioral changes related to learning and experience have been shown to be associated with structural remodeling in the brain. Leaf-cutting ants learn to avoid previously preferred plants after they have proved harmful for their symbiotic fungus, a process that involves long-term olfactory memory. We studied the dynamics of brain microarchitectural changes after long-term olfactory memory formation following avoidance learning in Acromyrmex ambiguus. After performing experiments to control for possible neuronal changes related to age and body size, we quantified synaptic complexes (microglomeruli, MG in olfactory regions of the mushroom bodies (MB at different times after learning. Long-term avoidance memory formation was associated with a transient change in MG densities. Two days after learning, MG density was higher than before learning. At days 4 and 15 after learning — when ants still showed plant avoidance — MG densities had decreased to the initial state. The structural reorganization of MG triggered by long-term avoidance memory formation clearly differed from changes promoted by pure exposure to and collection of novel plants with distinct odors. Sensory exposure by the simultaneous collection of several, instead of one, non-harmful plant species resulted in a decrease in MG densities in the olfactory lip. We hypothesize that while sensory exposure leads to MG pruning in the MB olfactory lip, the formation of long-term avoidance memory involves an initial growth of new MG followed by subsequent pruning.

Long-term avoidance memory formation is associated with a transient increase in mushroom body synaptic complexes in leaf-cutting ants.

Science.gov (United States)

Falibene, Agustina; Roces, Flavio; Rössler, Wolfgang

2015-01-01

Long-term behavioral changes related to learning and experience have been shown to be associated with structural remodeling in the brain. Leaf-cutting ants learn to avoid previously preferred plants after they have proved harmful for their symbiotic fungus, a process that involves long-term olfactory memory. We studied the dynamics of brain microarchitectural changes after long-term olfactory memory formation following avoidance learning in Acromyrmex ambiguus. After performing experiments to control for possible neuronal changes related to age and body size, we quantified synaptic complexes (microglomeruli, MG) in olfactory regions of the mushroom bodies (MBs) at different times after learning. Long-term avoidance memory formation was associated with a transient change in MG densities. Two days after learning, MG density was higher than before learning. At days 4 and 15 after learning-when ants still showed plant avoidance-MG densities had decreased to the initial state. The structural reorganization of MG triggered by long-term avoidance memory formation clearly differed from changes promoted by pure exposure to and collection of novel plants with distinct odors. Sensory exposure by the simultaneous collection of several, instead of one, non-harmful plant species resulted in a decrease in MG densities in the olfactory lip. We hypothesize that while sensory exposure leads to MG pruning in the MB olfactory lip, the formation of long-term avoidance memory involves an initial growth of new MG followed by subsequent pruning.

Prune Belly Syndrome: A case Report | Ezeaka | Nigerian Quarterly ...

African Journals Online (AJOL)

The Prune Belly Syndrome (PBS) is a anomaly. It comprises of a lax abdominal wall musculature, urinary tract anomalies, and cryptorchidism. Our patients had urinary tract infection and renal failure. These are well described consequences of the syndrome and are poor prognostic indices. This case report was undertaken ...

Prune-belly syndrome in two children and review of the literature.

Science.gov (United States)

Bogart, Megan M; Arnold, Holly E; Greer, Kenneth E

2006-01-01

Prune-belly syndrome is a congenital disorder characterized by abdominal wall musculature deficiency, urinary tract anomalies, and bilateral cryptorchidism. Because of the defect in the musculature, the abdominal skin has a peculiar wrinkled appearance. The syndrome is commonly associated with pulmonary, skeletal, cardiac, and gastrointestinal defects. Developmental delays and growth retardation have also been reported. The incidence of prune belly syndrome is approximately 1:40,000 live births. Over 95% of patients are men. Urinary tract disease is the major prognostic factor, with the complications of pulmonary hypoplasia and end stage renal disease resulting in a mortality rate of 60%. Treatment involves surgical correction of the abdominal wall defect and urinary tract abnormalities, early orchiopexy, and supportive management of associated defects.

The improved Apriori algorithm based on matrix pruning and weight analysis

Science.gov (United States)

Lang, Zhenhong

2018-04-01

This paper uses the matrix compression algorithm and weight analysis algorithm for reference and proposes an improved matrix pruning and weight analysis Apriori algorithm. After the transactional database is scanned for only once, the algorithm will construct the boolean transaction matrix. Through the calculation of one figure in the rows and columns of the matrix, the infrequent item set is pruned, and a new candidate item set is formed. Then, the item's weight and the transaction's weight as well as the weight support for items are calculated, thus the frequent item sets are gained. The experimental result shows that the improved Apriori algorithm not only reduces the number of repeated scans of the database, but also improves the efficiency of data correlation mining.

Síndrome de Prune Belly

Directory of Open Access Journals (Sweden)

Roni Leonardo Teixeira

Full Text Available Prune Belly Syndrome is a fetal uropathy of unknown etiology with incidence of 1/35000 to 1/50000 alive been born, characterized by a classical triad: abdominal musculature congenital deficiency, bilateral criptorquidia and urinary tract malformations. The authors present a case of this rare pathology associated with a patent urachus. After complementary exams confirmed urinary tract alterations (bilateral ureterohidronefrosis and vesicoureteral reflux degree 5, besides urinary infection, the surgical approach was vesicostomy to decrease urinary infections and sepsis. Definitve surgery should be accomplished around the 12th month of life. Nowadays, the child is asymptomatic , with follow-up every two months, with return consultation bimonthly.

Familial prune belly syndrome in a Nigerian family.

Science.gov (United States)

Ibadin, Michael Okoeguale; Ademola, Ade Adeyekun; Ofovwe, Gabriel Egberue

2012-03-01

A case of Prune Belly Syndrome in an infant, the second in a middle class family with both parents in their late thirties, is presented because of its rarity. Constraints in the management are discussed and relevant literature reviewed. This is intended to awaken interest and sharpen indices of suspicion that would facilitate early diagnosis, enhance management, and mitigate prejudices.

Induction and pruning of classification rules for prediction of microseismic hazards in coal mines

Energy Technology Data Exchange (ETDEWEB)

Sikora, M. [Silesian Technical University, Gliwice (Poland)

2011-06-15

The paper presents results of application of a rule induction and pruning algorithm for classification of a microseismic hazard state in coal mines. Due to imbalanced distribution of examples describing states 'hazardous' and 'safe', the special algorithm was used for induction and rule pruning. The algorithm selects optimal parameters' values influencing rule induction and pruning based on training and tuning sets. A rule quality measure which decides about a form and classification abilities of rules that are induced is the basic parameter of the algorithm. The specificity and sensitivity of a classifier were used to evaluate its quality. Conducted tests show that the admitted method of rules induction and classifier's quality evaluation enables to get better results of classification of microseismic hazards than by methods currently used in mining practice. Results obtained by the rules-based classifier were also compared with results got by a decision tree induction algorithm and by a neuro-fuzzy system.

Prune-belly syndrome detected by ultrasound in the first trimester and the usefulness of vesicocentesis as a modality of treatment.

Science.gov (United States)

Byon, Mina; Kim, Gwang Jun

2013-07-01

Prune-belly syndrome may be related to lower urinary tract obstruction (LUTO). LUTO in the early gestational age exacerbates fetal renal function and may require intrauterine intervention. If early developed LUTO causes bladder distension and abdominal musculature deficiency, it will result in prune belly syndrome. Therefore, early detection of the disease and proper treatment before the renal impairment is important. However, there are few literatures concerning the treatment of prune belly syndrome in the first trimester. We report a case of prune belly syndrome diagnosed at 11+6 weeks of gestation and the value of vesicocentesis as a modality of treatment. Ultrasound showed dilated fetal bladder and vesicocentesis was successful in reducing the volume of the bladder. However, the pregnancy was terminated upon request.

Traceability System for Improved Utilization of Solid Biofuel from Agricultural Prunings

Directory of Open Access Journals (Sweden)

Techane Bosona

2018-01-01

Full Text Available Biomass production and supply for renewable energy generation should be managed well and carried out in a sustainable manner. An effective traceability system (TS is required to provide sufficient information and assure the quality of the biomass. The objective of this study is to define and develop a TS to assure the pruning biomass quality for the production of solid biofuels and to provide guarantee to the final user that the biomass is in good condition according to recommended quality criteria. It is designed for an agricultural pruning supply chain in which farmers, biomass traders, transporters, and end users are major actors. It is based on the biofuel quality requirements required by final users and other standards such as the new European standards EN 14961-1, EN15234:1-2011, and EN14961-1:2010, which describe solid fuel quality parameters. Traceable quality parameters include origin and source of product, traded form, bale dimension, chips size distribution, moisture content, ash content, and density of biomass. In this TS, a unique product label is introduced and integrated into a smart logistics system (SLS. The TS uses information captured at different stages of the product supply chain. It enables the management of the whole pruning biomass supply chain with the support of a centralized web-based information platform, an integral part of the SLS.

Characterization and extraction of the synaptic apposition surface for synaptic geometry analysis

Science.gov (United States)

Morales, Juan; Rodríguez, Angel; Rodríguez, José-Rodrigo; DeFelipe, Javier; Merchán-Pérez, Angel

2013-01-01

Geometrical features of chemical synapses are relevant to their function. Two critical components of the synaptic junction are the active zone (AZ) and the postsynaptic density (PSD), as they are related to the probability of synaptic release and the number of postsynaptic receptors, respectively. Morphological studies of these structures are greatly facilitated by the use of recent electron microscopy techniques, such as combined focused ion beam milling and scanning electron microscopy (FIB/SEM), and software tools that permit reconstruction of large numbers of synapses in three dimensions. Since the AZ and the PSD are in close apposition and have a similar surface area, they can be represented by a single surface—the synaptic apposition surface (SAS). We have developed an efficient computational technique to automatically extract this surface from synaptic junctions that have previously been three-dimensionally reconstructed from actual tissue samples imaged by automated FIB/SEM. Given its relationship with the release probability and the number of postsynaptic receptors, the surface area of the SAS is a functionally relevant measure of the size of a synapse that can complement other geometrical features like the volume of the reconstructed synaptic junction, the equivalent ellipsoid size and the Feret's diameter. PMID:23847474

The effects of pruning and nodal adventitious roots on polychlorinated biphenyl uptake by Cucurbita pepo grown in field conditions

Energy Technology Data Exchange (ETDEWEB)

Low, Jennifer E.; Whitfield Aslund, Melissa L. [Department of Chemistry and Chemical Engineering, Royal Military College of Canada, PO Box 17000 Station Forces, Kingston, ON, K7K 7B4 (Canada); Rutter, Allison [School of Environmental Studies, Rm 0626 Biosciences Complex, Queen' s University, 116 Barrie St., Kingston, ON, K7L 3N6 (Canada); Zeeb, Barbara A., E-mail: zeeb-b@rmc.ca [Department of Chemistry and Chemical Engineering, Royal Military College of Canada, PO Box 17000 Station Forces, Kingston, ON, K7K 7B4 (Canada)

2011-03-15

Two cultivation techniques (i-pruning and ii-nodal adventitious root encouragement) were investigated for their ability to increase PCB phytoextraction by Cucurbita pepo ssp pepo cv. Howden (pumpkin) plants in situ at a contaminated industrial site in Ontario (Aroclor 1248, mean soil [PCB] = 5.6 {mu}g g{sup -1}). Pruning was implemented to increase plant biomass close to the root where PCB concentration is known to be highest. This treatment was found to have no effect on final shoot biomass or PCB concentration. However, material pruned from the plant is not included in the final shoot biomass. The encouragement of nodal adventitious roots at stem nodes did significantly increase the PCB concentration in the primary stem, while not affecting shoot biomass. Both techniques are easily applied cultivation practices that may be implemented to decrease phytoextraction treatment time. - Research highlights: > Presence of nodal adventitious roots do increase phytoextraction efficiency. > Pruning may increase the biomass of pumpkin plants during phytoextraction. > [Aroclor 1248] decreases in plant tissue with increasing distance from the root. - The application of cultivation practices (pruning and nodal adventitious root encouragement) increases phytoextraction of PCBs in C. pepo.

The effects of pruning and nodal adventitious roots on polychlorinated biphenyl uptake by Cucurbita pepo grown in field conditions

International Nuclear Information System (INIS)

Low, Jennifer E.; Whitfield Aslund, Melissa L.; Rutter, Allison; Zeeb, Barbara A.

2011-01-01

Two cultivation techniques (i-pruning and ii-nodal adventitious root encouragement) were investigated for their ability to increase PCB phytoextraction by Cucurbita pepo ssp pepo cv. Howden (pumpkin) plants in situ at a contaminated industrial site in Ontario (Aroclor 1248, mean soil [PCB] = 5.6 μg g -1 ). Pruning was implemented to increase plant biomass close to the root where PCB concentration is known to be highest. This treatment was found to have no effect on final shoot biomass or PCB concentration. However, material pruned from the plant is not included in the final shoot biomass. The encouragement of nodal adventitious roots at stem nodes did significantly increase the PCB concentration in the primary stem, while not affecting shoot biomass. Both techniques are easily applied cultivation practices that may be implemented to decrease phytoextraction treatment time. - Research highlights: → Presence of nodal adventitious roots do increase phytoextraction efficiency. → Pruning may increase the biomass of pumpkin plants during phytoextraction. → [Aroclor 1248] decreases in plant tissue with increasing distance from the root. - The application of cultivation practices (pruning and nodal adventitious root encouragement) increases phytoextraction of PCBs in C. pepo.

Synaptic Plasticity and Nociception

Institute of Scientific and Technical Information of China (English)

ChenJianguo

2004-01-01

Synaptic plasticity is one of the fields that progresses rapidly and has a lot of success in neuroscience. The two major types of synaptie plasticity: long-term potentiation ( LTP and long-term depression (LTD are thought to be the cellular mochanisms of learning and memory. Recently, accumulating evidence suggests that, besides serving as a cellular model for learning and memory, the synaptic plasticity involves in other physiological or pathophysiological processes, such as the perception of pain and the regulation of cardiovascular system. This minireview will focus on the relationship between synaptic plasticity and nociception.

Fast Parsing using Pruning and Grammar Specialization

OpenAIRE

Rayner, Manny; Carter, David

1996-01-01

We show how a general grammar may be automatically adapted for fast parsing of utterances from a specific domain by means of constituent pruning and grammar specialization based on explanation-based learning. These methods together give an order of magnitude increase in speed, and the coverage loss entailed by grammar specialization is reduced to approximately half that reported in previous work. Experiments described here suggest that the loss of coverage has been reduced to the point where ...

Longleaf Pine Root System Development and Seedling Quality in Response to Copper Root Pruning and Cavity Size

Science.gov (United States)

Mary Anne Sword Sayer; Shi-Jean Susana Sung; James D. Haywood

2011-01-01

Cultural practices that modify root system structure in the plug of container-grown seedlings have the potential to improve root system function after planting. Our objective was to assess how copper root pruning affects the quality and root system development of longleaf pine seedlings grown in three cavity sizes in a greenhouse. Copper root pruning increased seedling...

Familial prune belly syndrome in a Nigerian family

Directory of Open Access Journals (Sweden)

Michael Okoeguale Ibadin

2012-01-01

Full Text Available A case of Prune Belly Syndrome in an infant, the second in a middle class family with both parents in their late thirties, is presented because of its rarity. Constraints in the manage-ment are discussed and relevant literature reviewed. This is intended to awaken interest and sharpen indices of suspicion that would facilitate early diagnosis, enhance management, and mitigate prejudices.

Combustion of a Pb(II)-loaded olive tree pruning used as biosorbent.

Science.gov (United States)

Ronda, A; Della Zassa, M; Martín-Lara, M A; Calero, M; Canu, P

2016-05-05

The olive tree pruning is a specific agroindustrial waste that can be successfully used as adsorbent, to remove Pb(II) from contaminated wastewater. Its final incineration has been studied in a thermobalance and in a laboratory flow reactor. The study aims at evaluating the fate of Pb during combustion, at two different scales of investigation. The flow reactor can treat samples approximately 10(2) larger than the conventional TGA. A detailed characterization of the raw and Pb(II)-loaded waste, before and after combustion is presented, including analysis of gas and solids products. The Pb(II)-loaded olive tree pruning has been prepared by a previous biosorption step in a lead solution, reaching a concentration of lead of 2.3 wt%. Several characterizations of the ashes and the mass balances proved that after the combustion, all the lead presents in the waste remained in ashes. Combustion in a flow reactor produced results consistent with those obtained in the thermobalance. It is thus confirmed that the combustion of Pb(II)-loaded olive tree pruning is a viable option to use it after the biosorption process. The Pb contained in the solid remained in the ashes, preventing possible environmental hazards. Copyright © 2016 Elsevier B.V. All rights reserved.

Corset Usage for Gastrointestinal and Respiratory Problems in a Newborn with Prune Belly Syndrome.

Science.gov (United States)

Satar, Mehmet; Özlü, Ferda; Yapıcıoğlu, Hacer; İskit, Serdar

2016-07-01

Prune Belly syndrome (PBS), comprises a triad of anomalies that include abdominal wall flaccidity, urologic anomalies and bilateral cryptorchidism in males. The abdominal musculature hypoplasia predisposes to respiratory problems, respiratory infections secondary to impaired cough mechanism, and cause chronic constipation secondary to ineffective valsalva ability. Here, the authors present a newborn baby with Prune Belly syndrome who had respiratory and gastrointestinal problems which resolved after corset use. To the authors knowledge, this is the first case of corset usage in the treatment of PBS in a newborn infant.

Bioavailability of Compounds Susceptible to Enzymatic Oxidation Enhances Growth of Shiitake Medicinal Mushroom (Lentinus edodes) in Solid-State Fermentation with Vineyard Prunings.

Science.gov (United States)

Cabrera, Rosina; López-Peña, Damian; Asaff, Ali; Esqueda, Martín; Valenzuela-Soto, Elisa M

2018-01-01

Grapes are widely produced in northwestern Mexico, generating many wood trimmings (vineyard prunings) that have no further local use. This makes vineyard prunings a very attractive alternative for the cultivation of white-rot medicinal mushrooms such as Lentinus edodes. This type of wood can also offer a model for the evaluation of oxidative enzyme production during the fermentation process. We tested the effect of wood from vineyard prunings on the vegetative growth of and production of ligninolytic enzymes in L. edodes in solid-state fermentation and with wheat straw as the control substrate. The specific growth rate of the fungus was 2-fold higher on vineyard pruning culture (μM = 0.95 day-1) than on wheat straw culture (μM = 0.47 day-1). Laccase-specific production was 4 times higher in the vineyard prunings culture than on wheat straw (0.34 and 0.08 mU · mg protein-1 · ppm CO2-1, respectively), and manganese peroxidase production was 3.7 times higher on wheat straw culture than on vineyard prunings (2.21 and 0.60 mU · mg protein-1 · ppm CO2-1, respectively). To explain accurately these differences in growth and ligninolytic enzyme activity, methanol extracts were obtained from each substrate and characterized. Resveratrol and catechins were the main compounds identified in vineyard prunings, whereas epigallocatechin was the only one detected in wheat straw. Compounds susceptible to enzymatic oxidation are more bioavailable in vineyard prunings than in wheat straw, and thus the highest L. edodes growth rate is associated with the presence of these compounds.

Qualidade de frutos da tangerina 'Ponkan' após poda de recuperação Quality of 'Ponkan' tangerine tree after recovering pruning

Directory of Open Access Journals (Sweden)

Vander Mendonça

2006-04-01

Full Text Available Objetivou-se com esta pesquisa avaliar a qualidade de frutos de tangerineira 'Ponkan' em três safras subseqüentes aos tratamentos: poda de topo no rebaixamento da copa e poda da parte baixa da planta (saia. O experimento foi conduzido na Fazenda Vito Crincoli, localizada no município de Perdões - MG. O delineamento experimental utilizado foi em blocos ao acaso, em esquema fatorial 4 x 2, sendo poda do topo (sem poda, poda a 3,0; 2,5 e 2,0 m e poda da saia (sem e com a poda com quatro repetições e três plantas úteis por parcela. Os diferentes tipos de poda não prejudicaram a qualidade de frutos de tangerineira 'Ponkan' nas três safras subseqüente as podas. Após o terceiro ano as plantas que sofreram podas mais severas produziram frutos com peso superiores, demonstrando a viabilidade da poda na recuperação da qualidade dos frutos.This research aimed to test top pruning effect on lowering the top canopy and pruning the lower part of the plant on the recovering of 12 years old 'Ponkan' tangerine tree. Plants were four meters height, 6x4 spacing, grafted on 'Cravo' lemon tree. This experiment was carried out at Vito Crincoli' s Farm in Perdões, MG, Brazil . It was used a randomized block experimental design in a factorial scheme of 4x2, top pruning (without pruning, pruning at 3.0; 2.5 and 2.0m from soil level and circumference pruning (with and without pruning with four replications. The useful plot was constituted of three tangerine plants. After third year of treatment plants that had been under more severe pruning gave higher fruit weight. Indicating the used of pruning to recover fruit quality.

On the use of a pruning prior for neural networks

DEFF Research Database (Denmark)

Goutte, Cyril

1996-01-01

We address the problem of using a regularization prior that prunes unnecessary weights in a neural network architecture. This prior provides a convenient alternative to traditional weight-decay. Two examples are studied to support this method and illustrate its use. First we use the sunspots...

Spine Calcium Transients Induced by Synaptically-Evoked Action Potentials Can Predict Synapse Location and Establish Synaptic Democracy

Science.gov (United States)

Meredith, Rhiannon M.; van Ooyen, Arjen

2012-01-01

CA1 pyramidal neurons receive hundreds of synaptic inputs at different distances from the soma. Distance-dependent synaptic scaling enables distal and proximal synapses to influence the somatic membrane equally, a phenomenon called “synaptic democracy”. How this is established is unclear. The backpropagating action potential (BAP) is hypothesised to provide distance-dependent information to synapses, allowing synaptic strengths to scale accordingly. Experimental measurements show that a BAP evoked by current injection at the soma causes calcium currents in the apical shaft whose amplitudes decay with distance from the soma. However, in vivo action potentials are not induced by somatic current injection but by synaptic inputs along the dendrites, which creates a different excitable state of the dendrites. Due to technical limitations, it is not possible to study experimentally whether distance information can also be provided by synaptically-evoked BAPs. Therefore we adapted a realistic morphological and electrophysiological model to measure BAP-induced voltage and calcium signals in spines after Schaffer collateral synapse stimulation. We show that peak calcium concentration is highly correlated with soma-synapse distance under a number of physiologically-realistic suprathreshold stimulation regimes and for a range of dendritic morphologies. Peak calcium levels also predicted the attenuation of the EPSP across the dendritic tree. Furthermore, we show that peak calcium can be used to set up a synaptic democracy in a homeostatic manner, whereby synapses regulate their synaptic strength on the basis of the difference between peak calcium and a uniform target value. We conclude that information derived from synaptically-generated BAPs can indicate synapse location and can subsequently be utilised to implement a synaptic democracy. PMID:22719238

Oral manifestations associated with systemic complications of prune belly syndrome.

Science.gov (United States)

Pessoa, Larissa; Galvão, Virgilio

2013-01-01

Prune belly syndrome (PBS) is a rare congenital malformation of unknown etiology characterized by congenital abnormalities including abdominal wall flaccidity, urinary tract alterations, and bilateral cryptorchidism. The incidence of the syndrome is between 1/35000 and 1/50000 live births and there is little information about the oral findings. The present case describes the oral manifestations of a 15-year-old boy diagnosed with PBS. The findings include enamel hypoplasia associated with generalized hypocalcemic dental lines. In the radiographic exam, pronounced demineralization of the trabecular bone of the jaws, loss of lamina dura in all the teeth, and discontinuity of the mandibular cortical bone were observed. Prune belly syndrome is a rare disease, whose clinical dental aspects are not pathognomonic of the syndrome. The comprehension of the systemic mechanism of PBS and its comorbidities enable an understanding of the systemic etiologic factors associated with oral manifestations. Copyright © 2013 Elsevier Inc. All rights reserved.

Chemical composition of biomass generated in the guava tree pruning

Science.gov (United States)

Camarena-Tello, Julio César; Rocha-Guzmán, Nuria Elizabeth; Gallegos-Infante, José Alberto; González-Laredo, Rubén Francisco; Pedraza-Bucio, Fabiola Eugenia; López-Albarrán, Pablo; Herrera-Bucio, Rafael; Rutiaga-Quiñones, José Guadalupe

2015-01-01

Psidium guajava L. (Myrtaceae) is a native plant of Central America and is now widely cultivated in many tropical regions of the world for the fruit production. In Mexico, in the guava orchards common practices to control fruit production are: water stress, defoliation and pruning. In this study, we report the chemical composition of the biomass (branches and leaves) generated in the pruning practices. The results ranged as follows: pH (4.98-5.88), soda solubility (39.01-70.49 %), ash (1.87-8.20 %); potassium and calcium were the major inorganic elements in ash. No heavy metals were detected in the studied samples; total solubility (15.21-46.60 %), Runkel lignin (17.77-35.26 %), holocellulose (26.56 -69.49 %), α-cellulose (15.53-35.36 %), hemicelluloses (11.02-34.12 %), tannins in aqueous extracts (3.81-9.06 %), and tannins in ethanolic extracts (3.42-15.24 %). PMID:26417359

Produção da tangerineira 'ponkan' após poda de recuperação Production of 'ponkan' tangerine tree after pruning recovery

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Vander Mendonça

2008-02-01

Full Text Available Objetivou esta pesquisa testar o efeito da poda de topo no rebaixamento da copa e poda da saia, na recuperação da tangerineira 'Ponkan' com 12 anos de idade, altura de 4 metros, espaçadas de 6 x 4 m e enxertadas sobre limoeiro 'Cravo'. O experimento foi conduzido na Fazenda Vito Crincoli localizada no município de Perdões, MG. O delineamento experimental utilizado foi em blocos ao acaso, em esquema fatorial 4 x 2, sendo poda do topo (sem poda, poda a 3,0; 2,5 e 2,0m e poda da saia (sem e com a poda com quatro repetições. A parcela útil foi constituída de três plantas. As podas drásticas de topo prejudicaram a primeira produção, contudo a partir do segundo ano após a poda, as plantas apresentaram boa recuperação. Esse comportamento foi confirmado na terceira colheita, quando os diferentes tipos de podas do topo não se diferenciaram na produtividade, sendo que o tratamento com poda da saia foi superior ao sem poda.This research aimed to test top pruning effect on the lowering of plant canopy, pruning the lower canopy on the recover of 12 years old 'Ponkan' tangerine tree, 4 meters height, 6 x 4 spaced and grafted on 'Cravo' lemon rootstock. This experiment was carried out at Vito Crincoli's Farm in Perdões, MG. It was carried out under randomized plots in a factorial scheme of 4x2, top pruning (without pruning, pruning at 3.0; 2.5 and 2.0 m and skirt pruning (with and without pruning with 4 replications. Plot size was composed by three plants. Heavy pruning of the top canopy lowered the first tree yield, however, and in the begining of the second year, the plants showed a very good recover. The same behavior was seem for the third harvest when several kinds of top pruning did not differ in the yield. Skirt pruning treatment was superior to that without any pruning.

Combining soft decision algorithms and scale-sequential hypotheses pruning for object recognition

Energy Technology Data Exchange (ETDEWEB)

Kumar, V.P.; Manolakos, E.S. [Northeastern Univ., Boston, MA (United States)

1996-12-31

This paper describes a system that exploits the synergy of Hierarchical Mixture Density (HMD) estimation with multiresolution decomposition based hypothesis pruning to perform efficiently joint segmentation and labeling of partially occluded objects in images. First we present the overall structure of the HMD estimation algorithm in the form of a recurrent neural network which generates the posterior probabilities of the various hypotheses associated with the image. Then in order to reduce the large memory and computation requirement we propose a hypothesis pruning scheme making use of the orthonormal discrete wavelet transform for dimensionality reduction. We provide an intuitive justification for the validity of this scheme and present experimental results and performance analysis on real and synthetic images to verify our claims.

Synaptic consolidation across multiple timescales

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Lorric Ziegler

2014-03-01

Full Text Available The brain is bombarded with a continuous stream of sensory events, but retains only a small subset in memory. The selectivity of memory formation prevents our memory from being overloaded with irrelevant items that would rapidly bring the brain to its storage limit; moreover, selectivity also prevents overwriting previously formed memories with new ones. Memory formation in the hippocampus, as well as in other brain regions, is thought to be linked to changes in the synaptic connections between neurons. In this view, sensory events imprint traces at the level of synapses that reflect potential memory items. The question of memory selectivity can therefore be reformulated as follows: what are the reasons and conditions that some synaptic traces fade away whereas others are consolidated and persist? Experimentally, changes in synaptic strength induced by 'Hebbian' protocols fade away over a few hours (early long-term potentiation or e-LTP, unless these changes are consolidated. The experiments and conceptual theory of synaptic tagging and capture (STC provide a mechanistic explanation for the processes involved in consolidation. This theory suggests that the initial trace of synaptic plasticity sets a tag at the synapse, which then serves as a marker for potential consolidation of the changes in synaptic efficacy. The actual consolidation processes, transforming e-LTP into late LTP (l-LTP, require the capture of plasticity-related proteins (PRP. We translate the above conceptual model into a compact computational model that accounts for a wealth of in vitro data including experiments on cross-tagging, tag-resetting and depotentiation. A central ingredient is that synaptic traces are described with several variables that evolve on different time scales. Consolidation requires the transmission of information from a 'fast' synaptic trace to a 'slow' one through a 'write' process, including the formation of tags and the production of PRP for the

Degree Associated Edge Reconstruction Number of Graphs with Regular Pruned Graph

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P. Anusha Devi

2015-10-01

Full Text Available An ecard of a graph $G$ is a subgraph formed by deleting an edge. A da-ecard specifies the degree of the deleted edge along with the ecard. The degree associated edge reconstruction number of a graph $G,~dern(G,$ is the minimum number of da-ecards that uniquely determines $G.$  The adversary degree associated edge reconstruction number of a graph $G, adern(G,$ is the minimum number $k$ such that every collection of $k$ da-ecards of $G$ uniquely determines $G.$ The maximal subgraph without end vertices of a graph $G$ which is not a tree is the pruned graph of $G.$ It is shown that $dern$ of complete multipartite graphs and some connected graphs with regular pruned graph is $1$ or $2.$ We also determine $dern$ and $adern$ of corona product of standard graphs.

An Adaptive Pruning Algorithm for the Discrete L-Curve Criterion

DEFF Research Database (Denmark)

Hansen, Per Christian; Jensen, Toke Koldborg; Rodriguez, Giuseppe

2004-01-01

SVD or regularizing CG iterations). Our algorithm needs no pre-defined parameters, and in order to capture the global features of the curve in an adaptive fashion, we use a sequence of pruned L-curves that correspond to considering the curves at different scales. We compare our new algorithm...

proBDNF Negatively Regulates Neuronal Remodeling, Synaptic Transmission, and Synaptic Plasticity in Hippocampus

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Jianmin Yang

2014-05-01

Full Text Available Experience-dependent plasticity shapes postnatal development of neural circuits, but the mechanisms that refine dendritic arbors, remodel spines, and impair synaptic activity are poorly understood. Mature brain-derived neurotrophic factor (BDNF modulates neuronal morphology and synaptic plasticity, including long-term potentiation (LTP via TrkB activation. BDNF is initially translated as proBDNF, which binds p75NTR. In vitro, recombinant proBDNF modulates neuronal structure and alters hippocampal long-term plasticity, but the actions of endogenously expressed proBDNF are unclear. Therefore, we generated a cleavage-resistant probdnf knockin mouse. Our results demonstrate that proBDNF negatively regulates hippocampal dendritic complexity and spine density through p75NTR. Hippocampal slices from probdnf mice exhibit depressed synaptic transmission, impaired LTP, and enhanced long-term depression (LTD in area CA1. These results suggest that proBDNF acts in vivo as a biologically active factor that regulates hippocampal structure, synaptic transmission, and plasticity, effects that are distinct from those of mature BDNF.

Synaptic remodeling, synaptic growth and the storage of long-term memory in Aplysia.

Science.gov (United States)

Bailey, Craig H; Kandel, Eric R

2008-01-01

Synaptic remodeling and synaptic growth accompany various forms of long-term memory. Storage of the long-term memory for sensitization of the gill-withdrawal reflex in Aplysia has been extensively studied in this respect and is associated with the growth of new synapses by the sensory neurons onto their postsynaptic target neurons. Recent time-lapse imaging studies of living sensory-to-motor neuron synapses in culture have monitored both functional and structural changes simultaneously so as to follow remodeling and growth at the same specific synaptic connections continuously over time and to examine the functional contribution of these learning-related structural changes to the different time-dependent phases of memory storage. Insights provided by these studies suggest the synaptic differentiation and growth induced by learning in the mature nervous system are highly dynamic and often rapid processes that can recruit both molecules and mechanisms used for de novo synapse formation during development.

Diacylglycerol kinases in the coordination of synaptic plasticity

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Dongwon Lee

2016-08-01

Full Text Available Synaptic plasticity is activity-dependent modification of the efficacy of synaptic transmission. Although detailed mechanisms underlying synaptic plasticity are diverse and vary at different types of synapses, diacylglycerol (DAG-associated signaling has been considered as an important regulator of many forms of synaptic plasticity, including long-term potentiation (LTP and long-term depression (LTD. Recent evidence indicate that DAG kinases (DGKs, which phosphorylate DAG to phosphatidic acid to terminate DAG signaling, are important regulators of LTP and LTD, as supported by the results from mice lacking specific DGK isoforms. This review will summarize these studies and discuss how specific DGK isoforms distinctly regulate different forms of synaptic plasticity at pre- and postsynaptic sites. In addition, we propose a general role of DGKs as coordinators of synaptic plasticity that make local synaptic environments more permissive for synaptic plasticity by regulating DAG concentration and interacting with other synaptic proteins.

Can early thinning and pruning lessen the impact of pine plantations ...

African Journals Online (AJOL)

dwelling insects found in pine tree plantations in Patagonia. We compared the abundance, species richness and composition of the beetle and ant assemblages within 16-year-old pine stands (n = 10) subjected to early pruning and thinning (i.e. ...

Outcomes of renal replacement therapy in boys with prune belly syndrome

DEFF Research Database (Denmark)

Yalcinkaya, Fatos; Bonthuis, Marjolein; Erdogan, Beyza Doganay

2018-01-01

BACKGROUND: As outcome data for prune belly syndrome (PBS) complicated by end-stage renal disease are scarce, we analyzed characteristics and outcomes of children with PBS using the European Society for Pediatric Nephrology/European Renal Association-European Dialysis and Transplant Association...

Outcomes of renal replacement therapy in boys with prune belly syndrome

DEFF Research Database (Denmark)

Yalcinkaya, Fatos; Bonthuis, Marjolein; Erdogan, Beyza Doganay

2018-01-01

BACKGROUND: As outcome data for prune belly syndrome (PBS) complicated by end-stage renal disease are scarce, we analyzed characteristics and outcomes of children with PBS using the European Society for Pediatric Nephrology/European Renal Association-European Dialysis and Transplant Association (...

Nitrogen fixation and effects of pruning on Gliricidia sepium and Leucaena leucocephala

International Nuclear Information System (INIS)

Liyanage, M.S. de

1998-01-01

This 7-year study examined genetic variability in N 2 fixation by Gliricidia sepium and the N 2 -fixing capacity in G. sepium and Leucaena leucocephala as influenced by frequency of pruning, age, and shade from coconut. The 15 N-dilution method was used with the non-nodulating tree legume Senna siamea as the non-fixing reference. There were significant differences in total dry matter, N yield and N 2 -fixation capacity among four G. sepium provenances. Gliricidia had higher values than Leucaena for dry matter, N yield, and amount of N fixed; %Ndfa was comparable in both species (47-55%). A substantial amount (18%) of fixed N 2 was present in the roots of both species. In a long-term study aimed at comparing the effect of pruning practices and age of trees, G. sepium grown under coconut outperformed L. leucocephala in terms of dry matter, N yield and amounts of N 2 fixation. Coconut saplings supplied with G. sepium and L. leucocephala prunings as green manure grew better than those supplied with S. siamea; the fraction of coconut-sapling N obtained from Gliricidia and Leucaena was 40 and 36%, respectively. These results suggest that G. sepium, which demonstrated a high potential for biomass production and N 2 fixation, is appropriate for interplanting with coconut palms. Also, S. Siamea was found to be a suitable reference species. (author)

Effect of root pruning and irrigation regimes on leaf water relations and xylem ABA and ionic concentrations in pear trees

DEFF Research Database (Denmark)

Wang, Yufei; Bertelsen, Marianne G.; Petersen, Karen Koefoed

2014-01-01

relation characteristics, stomatal conductance and xylem sap abscisic acid (ABA) and ionic concentrations. Results showed that leaf water potential, leaf turgor and stomatal conductance of root pruning (RP) treatment was significantly lower than those of non-root pruning (NP) treatment indicating that root...

Should Pruning be a Pre-Processor of any Linear System?

Science.gov (United States)

Sen, Syamal K.; Ramakrishnan, Suja; Agarwal, Ravi P.; Shaykhian, Gholam Ali

2011-01-01

There are many real-world problems whose mathematical models turn out to be linear systems Ax = b, where A is an m x n matrix. Each equation of the linear system is an information. An information, in a physical problem, such as 4 mangoes, 6 bananas, and 5 oranges cost $10, is mathematically modeled as an equation 4x(sub 1) + 6x(sub 2) + 5x(sub 3) = 10 , where x(sub 1), x(sub 2), x(sub 3) are each cost of one mango, that of one banana, and that of one orange, respectively. All the information put together in a specified context, constitutes the physical problem and need not be all distinct. Some of these could be redundant, which cannot be readily identified by inspection. The resulting mathematical model will thus have equations corresponding to this redundant information and hence are linearly dependent and thus superfluous. Consequently, these equations once identified should be better pruned in the process of solving the system. The benefits are (i) less computation and hence less error and consequently a better quality of solution and (ii) reduced storage requirements. In literature, the pruning concept is not in vogue so far although it is most desirable. It is assumed that at least one information, i.e. one equation is known to be correct and which will be our first equation. In a numerical linear system, the system could be slightly inconsistent or inconsistent of varying degree. If the system is too inconsistent, then we should fall back on to the physical problem (PP), check the correctness of the PP derived from the material universe, modify it, if necessary, and then check the corresponding mathematical model (MM) and correct it. In nature/material universe, inconsistency is completely nonexistent. If the MM becomes inconsistent, it could be due to error introduced by the concerned measuring device and/or due to assumptions made on the PP to obtain an MM which is relatively easily solvable or simply due to human error. No measuring device can usually

78 FR 63128 - Dried Prunes Produced in California; Increased Assessment Rate

Science.gov (United States)

2013-10-23

...; Increased Assessment Rate AGENCY: Agricultural Marketing Service, USDA. ACTION: Proposed rule. SUMMARY: This... the Regulatory Flexibility Act (RFA) (5 U.S.C. 601-612), the Agricultural Marketing Service (AMS) has... prunes. Dated: October 17, 2013. Rex A. Barnes, Associate Administrator, Agricultural Marketing Service...

The importance of pruning to the quality of wine grape fruits (Vitis vinifera L. cultivated under high-altitude tropical conditions

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Pedro José Almanza-Merchán

2014-12-01

Full Text Available Since 1998, the Ain-Karim Vineyard has been growing different grape varieties for the production of high-altitude tropical wines in the municipality of Sutamarchan, located in the Alto Ricaurte region of Boyaca (Colombia. Pruning is used to limit the number and length of branches, generating a suitable balance between plant vigor and production; thereby, regulating fruit quantity and quality and ensuring reserves for the subsequent production. This study aimed to evaluate the effect of three pruning types (short = two buds on two spurs; long = five buds on three spurs and mixed = combination of short and long pruning types on the fruit quality of V. vinifera, Cabernet Sauvignon and Sauvignon Blanc varieties. To accomplish this, a completely randomized two-factor design was used. Physicochemical variables of fruit quality (fresh cluster weight, water content, total soluble solids (TSS, total titratable acidity (TTA, technical maturity index (TMI, and pH were determined at harvest. The long pruning type presented the highest values for the fresh cluster weight and TSS of the fruits from both varieties and a higher TMI in the Cabernet Sauvignon variety. These results indicate that, under the conditions of the vineyard, long pruning is the most suitable.

Jatropha curcas, L. Pruning Residues for Energy: Characteristics of an Untapped By-Product

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Luigi Pari

2018-06-01

Full Text Available Jatropha (Jatropha curcas, L. is an energy crop mainly cultivated for the oil-seed, and the oil is usually used as bio-fuel. However, few studies have reported information about the utilization of the wood as a fuel for boiler heating systems. With 2500 jatropha trees per hectare, it is possible to produce about 3 t·ha−1·y−1 of woody biomass from pruning. In addition, jatropha trees are commonly cut down to a height of 45 cm once every 10 years, with a production of 80 t·ha−1 of dry matter of woody biomass. The use of this biomass has not yet been investigated. During the European project JatroMed, woody biomass from jatropha pruning was collected in Morocco. Chemical and physical characteristics of the wood were conducted according to UNI EN ISO standards. The following jatropha wood characteristics have been analyzed: Moisture and ash contents, the ash melting point, heating value, and concentrations of C, H, N, and S. This research focused on the evaluation of the potential use of jatropha pruning for energy production, and the results represent critical data that is useful for future studies and business potential.

Using Multi-Spectral UAV Imagery to Extract Tree Crop Structural Properties and Assess Pruning Effects

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Kasper Johansen

2018-06-01

Full Text Available Unmanned aerial vehicles (UAV provide an unprecedented capacity to monitor the development and dynamics of tree growth and structure through time. It is generally thought that the pruning of tree crops encourages new growth, has a positive effect on fruiting, makes fruit-picking easier, and may increase yield, as it increases light interception and tree crown surface area. To establish the response of pruning in an orchard of lychee trees, an assessment of changes in tree structure, i.e., tree crown perimeter, width, height, area and Plant Projective Cover (PPC, was undertaken using multi-spectral UAV imagery collected before and after a pruning event. While tree crown perimeter, width and area could be derived directly from the delineated tree crowns, height was estimated from a produced canopy height model and PPC was most accurately predicted based on the NIR band. Pre- and post-pruning results showed significant differences in all measured tree structural parameters, including an average decrease in tree crown perimeter of 1.94 m, tree crown width of 0.57 m, tree crown height of 0.62 m, tree crown area of 3.5 m2, and PPC of 14.8%. In order to provide guidance on data collection protocols for orchard management, the impact of flying height variations was also examined, offering some insight into the influence of scale and the scalability of this UAV-based approach for larger orchards. The different flying heights (i.e., 30, 50 and 70 m produced similar measurements of tree crown width and PPC, while tree crown perimeter, area and height measurements decreased with increasing flying height. Overall, these results illustrate that routine collection of multi-spectral UAV imagery can provide a means of assessing pruning effects on changes in tree structure in commercial orchards, and highlight the importance of collecting imagery with consistent flight configurations, as varying flying heights may cause changes to tree structural measurements.

Using Multi-Spectral UAV Imagery to Extract Tree Crop Structural Properties and Assess Pruning Effects

KAUST Repository

Johansen, Kasper

2018-04-18

Unmanned aerial vehicles (UAV) provide an unprecedented capacity to monitor the development and dynamics of tree growth and structure through time. It is generally thought that the pruning of tree crops encourages new growth, has a positive effect on fruiting, makes fruit-picking easier, and may increase yield, as it increases light interception and tree crown surface area. To establish the response of pruning in an orchard of lychee trees, an assessment of changes in tree structure, i.e. tree crown perimeter, width, height, area and Plant Projective Cover (PPC), was undertaken using multi-spectral UAV imagery collected before and after a pruning event. While tree crown perimeter, width and area could be derived directly from the delineated tree crowns, height was estimated from a produced canopy height model and PPC was most accurately predicted based on the NIR band. Pre- and post-pruning results showed significant differences in all measured tree structural parameters, including an average decrease in tree crown perimeter of 1.94 m, tree crown width of 0.57 m, tree crown height of 0.62 m, tree crown area of 3.5 m2, and PPC of 14.8%. In order to provide guidance on data collection protocols for orchard management, the impact of flying height variations was also examined, offering some insight into the influence of scale and the scalability of this UAV based approach for larger orchards. The different flying heights (i.e. 30, 50 and 70 m) produced similar measurements of tree crown width and PPC, while tree crown perimeter, area and height measurements decreased with increasing flying height. Overall, these results illustrate that routine collection of multi-spectral UAV imagery can provide a means of assessing pruning effects on changes in tree structure in commercial orchards, and highlight the importance of collecting imagery with consistent flight configurations, as varying flying heights may cause changes to tree structural measurements.

Characterizing synaptic protein development in human visual cortex enables alignment of synaptic age with rat visual cortex

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Joshua G.A Pinto

2015-02-01

Full Text Available Although many potential neuroplasticity based therapies have been developed in the lab, few have translated into established clinical treatments for human neurologic or neuropsychiatric diseases. Animal models, especially of the visual system, have shaped our understanding of neuroplasticity by characterizing the mechanisms that promote neural changes and defining timing of the sensitive period. The lack of knowledge about development of synaptic plasticity mechanisms in human cortex, and about alignment of synaptic age between animals and humans, has limited translation of neuroplasticity therapies. In this study, we quantified expression of a set of highly conserved pre- and post-synaptic proteins (Synapsin, Synaptophysin, PSD-95, Gephyrin and found that synaptic development in human primary visual cortex continues into late childhood. Indeed, this is many years longer than suggested by neuroanatomical studies and points to a prolonged sensitive period for plasticity in human sensory cortex. In addition, during childhood we found waves of inter-individual variability that are different for the 4 proteins and include a stage during early development (<1 year when only Gephyrin has high inter-individual variability. We also found that pre- and post-synaptic protein balances develop quickly, suggesting that maturation of certain synaptic functions happens within the first year or two of life. A multidimensional analysis (principle component analysis showed that most of the variance was captured by the sum of the 4 synaptic proteins. We used that sum to compare development of human and rat visual cortex and identified a simple linear equation that provides robust alignment of synaptic age between humans and rats. Alignment of synaptic ages is important for age-appropriate targeting and effective translation of neuroplasticity therapies from the lab to the clinic.

Postnatal Ablation of Synaptic Retinoic Acid Signaling Impairs Cortical Information Processing and Sensory Discrimination in Mice.

Science.gov (United States)

Park, Esther; Tjia, Michelle; Zuo, Yi; Chen, Lu

2018-06-06

Retinoic acid (RA) and its receptors (RARs) are well established essential transcriptional regulators during embryonic development. Recent findings in cultured neurons identified an independent and critical post-transcriptional role of RA and RARα in the homeostatic regulation of excitatory and inhibitory synaptic transmission in mature neurons. However, the functional relevance of synaptic RA signaling in vivo has not been established. Here, using somatosensory cortex as a model system and the RARα conditional knock-out mouse as a tool, we applied multiple genetic manipulations to delete RARα postnatally in specific populations of cortical neurons, and asked whether synaptic RA signaling observed in cultured neurons is involved in cortical information processing in vivo Indeed, conditional ablation of RARα in mice via a CaMKIIα-Cre or a layer 5-Cre driver line or via somatosensory cortex-specific viral expression of Cre-recombinase impaired whisker-dependent texture discrimination, suggesting a critical requirement of RARα expression in L5 pyramidal neurons of somatosensory cortex for normal tactile sensory processing. Transcranial two-photon imaging revealed a significant increase in dendritic spine elimination on apical dendrites of somatosensory cortical layer 5 pyramidal neurons in these mice. Interestingly, the enhancement of spine elimination is whisker experience-dependent as whisker trimming rescued the spine elimination phenotype. Additionally, experiencing an enriched environment improved texture discrimination in RARα-deficient mice and reduced excessive spine pruning. Thus, RA signaling is essential for normal experience-dependent cortical circuit remodeling and sensory processing. SIGNIFICANCE STATEMENT The importance of synaptic RA signaling has been demonstrated in in vitro studies. However, whether RA signaling mediated by RARα contributes to neural circuit functions in vivo remains largely unknown. In this study, using a RARα conditional

Modulation of synaptic plasticity by stress hormone associates with plastic alteration of synaptic NMDA receptor in the adult hippocampus.

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Yiu Chung Tse

Full Text Available Stress exerts a profound impact on learning and memory, in part, through the actions of adrenal corticosterone (CORT on synaptic plasticity, a cellular model of learning and memory. Increasing findings suggest that CORT exerts its impact on synaptic plasticity by altering the functional properties of glutamate receptors, which include changes in the motility and function of α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid subtype of glutamate receptor (AMPAR that are responsible for the expression of synaptic plasticity. Here we provide evidence that CORT could also regulate synaptic plasticity by modulating the function of synaptic N-methyl-D-aspartate receptors (NMDARs, which mediate the induction of synaptic plasticity. We found that stress level CORT applied to adult rat hippocampal slices potentiated evoked NMDAR-mediated synaptic responses within 30 min. Surprisingly, following this fast-onset change, we observed a slow-onset (>1 hour after termination of CORT exposure increase in synaptic expression of GluN2A-containing NMDARs. To investigate the consequences of the distinct fast- and slow-onset modulation of NMDARs for synaptic plasticity, we examined the formation of long-term potentiation (LTP and long-term depression (LTD within relevant time windows. Paralleling the increased NMDAR function, both LTP and LTD were facilitated during CORT treatment. However, 1-2 hours after CORT treatment when synaptic expression of GluN2A-containing NMDARs is increased, bidirectional plasticity was no longer facilitated. Our findings reveal the remarkable plasticity of NMDARs in the adult hippocampus in response to CORT. CORT-mediated slow-onset increase in GluN2A in hippocampal synapses could be a homeostatic mechanism to normalize synaptic plasticity following fast-onset stress-induced facilitation.

Evaluation of fungicides to protect pruning wounds from Botryosphaeriaceae species infections on almond trees

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Diego OLMO

2017-05-01

Full Text Available In vitro efficacy of ten fungicides was evaluated against four Botryosphaeriaceae spp. (Diplodia seriata, Neofusicoccum luteum, N. mediterraneum and N. parvum associated with branch cankers on almond trees. Cyproconazole, pyraclostrobin, tebuconazole, and thiophanate-methyl were effective for the inhibition of mycelial growth of most of these fungi. An experiment on 3-year-old almond trees evaluated boscalid, mancozeb, thiophanate-methyl, pyraclostrobin and tebuconazole for preventative ability against infections caused by the four pathogens. Five months after pruning and fungicide application, lesion length measurements and isolation percentages showed no significant differences among the four pathogens after they were inoculated onto the trees, and also between the two inoculation times tested (1 or 7 d after fungicide application. Thiophanate-methyl was the most effective fungicide, resulting in the shortest lesion lengths and the lowest isolation percentages from artificially inoculated pruning wounds. This chemical is therefore a candidate for inclusion in integrated disease management, to protect pruning wounds from infections caused by species of Botryosphaeriaceae. This study represents the first approach to development of chemical control strategies for the management of canker diseases caused by Botryosphaeriaceae fungi on almond trees. 

Effect of irradiation, pruning and removal of in vitro formed roots on ex vitro growth in micropropagated grape

International Nuclear Information System (INIS)

Charbaji, T.; Ayyoubi, Z.

2002-06-01

In vitro rootstock (Ru 140) and Helwani variety were cultured on DSD1 media, were irradiated at low doses of gamma irradiation before acclimatization. Ru 140 were exposed to 0-5 Gy, while Helwani was exposed to 0-7 Gy. Then, the plants were divided into three different groups: in the first group the plant roots were pruned, in the second the plant roots were completely removed and in the third group the plant roots were kept intact (control). The ex vitro plants were observed after 45 days of planting. Shoots groeth, leaf number and dry weight of Ru 140 were significantly higher than those of the control when roots were pruned and 5 Gy was applied. Those parameters were negatively affected by root removal. Gamma irradiation had a positive effect on the control comparing to unirradiated plants. Root pruning had positive effects on shoot growth, leaf number and dry weight of helwani veriety, while root removal had a contrary effect on this variety. Gamma irradiation positively affected shoot growth and dry weight of control comparing to unirradiated plants, similar effect was observed on leaf number of control and pruned plant of Helwani. (author)

Effect of Irradiation, Pruning and Removal of In Vitro Formed Roots on Ex Vitro Growth in Micropropagated Grape

International Nuclear Information System (INIS)

Charabaji, T.; Ayyoubi, Z.; Karajoly, I

2007-01-01

In vitro rootstock (Ru 140) and Helwani variety were cultured on DSD1 media, were irradiated at low doses of gamma irradiation before acclimatization. Ru 140 was exposed to 0-5 Gy, while Helwani was exposed to 0-7 Gy. Then, the plants were divided into three different procedures, 1)- the plant roots were pruned, 2)- the plant roots were completely removed, 3)- the plant roots were kept intact (control). The ex vitro plants were observed after 45 days of planting. Shoots growth, leaf number and dry weight of Ru 140 were significantly higher than those of the control when roots were pruned and 5 Gy was applied. Those parameters were negatively affected by root removal. Gamma irradiation had a positive effect on the control comparing to unirradiated plants. Root pruning had positive effects on shoot growth, leaf number and dry weight of Helwani variety, while root removal had a contrary effect on this variety. Gamma irradiation positively affected shoot growth and dry weight of control comparing to unirradiated plants, similar effect was observed on leaf number of control and pruned plant of Helwani.

75 FR 67607 - Dried Prunes Produced in California; Increased Assessment Rate

Science.gov (United States)

2010-11-03

... Order 12988, Civil Justice Reform. Under the marketing order now in effect, California dried prune... DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 993 [Doc. No. AMS-FV-10-0057... Marketing Service, USDA. ACTION: Final rule. SUMMARY: This rule increases the assessment rate established...

Cerebellar plasticity and motor learning deficits in a copy-number variation mouse model of autism.

Science.gov (United States)

Piochon, Claire; Kloth, Alexander D; Grasselli, Giorgio; Titley, Heather K; Nakayama, Hisako; Hashimoto, Kouichi; Wan, Vivian; Simmons, Dana H; Eissa, Tahra; Nakatani, Jin; Cherskov, Adriana; Miyazaki, Taisuke; Watanabe, Masahiko; Takumi, Toru; Kano, Masanobu; Wang, Samuel S-H; Hansel, Christian

2014-11-24

A common feature of autism spectrum disorder (ASD) is the impairment of motor control and learning, occurring in a majority of children with autism, consistent with perturbation in cerebellar function. Here we report alterations in motor behaviour and cerebellar synaptic plasticity in a mouse model (patDp/+) for the human 15q11-13 duplication, one of the most frequently observed genetic aberrations in autism. These mice show ASD-resembling social behaviour deficits. We find that in patDp/+ mice delay eyeblink conditioning--a form of cerebellum-dependent motor learning--is impaired, and observe deregulation of a putative cellular mechanism for motor learning, long-term depression (LTD) at parallel fibre-Purkinje cell synapses. Moreover, developmental elimination of surplus climbing fibres--a model for activity-dependent synaptic pruning--is impaired. These findings point to deficits in synaptic plasticity and pruning as potential causes for motor problems and abnormal circuit development in autism.

Urachal catheter provides new choice for long-term urinary diversion in prune belly syndrome.

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Chen, I-Lun; Huang, Hsin-Chun; Lee, Shin-Yi; Liu, Chieh-An; Tain, You-Lin; Ou-Yang, Mei-Chen; Chao, Pei-Hsin

2011-02-01

Prune belly syndrome has been identified as a clinical triad of abdominal muscle deficiency, bilateral cryptorchidism, and urologic abnormalities. We present the case of a discordant monozygotic twin with prune belly syndrome and voiding dysfunction that was relieved by long-term urinary catheterization by way of the urachus. To the best of our knowledge, this alternative method has not been previously reported. We suggest that for newborn infants with long-term voiding dysfunction, if the urachus retains patency, urinary catheterization through the urachus could be a choice for urine drainage instead of cystostomy, providing a better cosmetic appearance and quality of life. Copyright © 2011 Elsevier Inc. All rights reserved.

DNA hypomethylation, transient neonatal diabetes, and prune belly sequence in one of two identical twins.

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Laborie, Lene Bjerke; Mackay, Deborah J G; Temple, I Karen; Molven, Anders; Søvik, Oddmund; Njølstad, Pål Rasmus

2010-02-01

One known genetic mechanism for transient neonatal diabetes is loss of methylation at 6q24. The etiology of prune belly sequence is unknown but a genetic defect, affecting the mesoderm from which the triad abdominal muscle hypoplasia, urinary tract abnormalities, and cryptorchidism develop, has been suggested. We investigated a family, including one twin, with transient neonatal diabetes and prune belly sequence. Autoantibody tests excluded type 1 diabetes. Microsatellite marker analysis confirmed the twins being monozygotic. We identified no mutations in ZFP57, KCNJ11, ABCC8, GCK, HNF1A, HNF1B, HNF3B, IPF1, PAX4, or ZIC3. The proband had loss of methylation at the 6q24 locus TNDM and also at the loci IGF2R, DIRAS3, and PEG1, while the other family members, including the healthy monozygotic twin, had normal findings. The loss of methylation on chromosome 6q24 and elsewhere may indicate a generalized maternal hypomethylation syndrome, which accounts for both transient neonatal diabetes and prune belly sequence.

Stock Picking via Nonsymmetrically Pruned Binary Decision Trees

OpenAIRE

Anton Andriyashin

2008-01-01

Stock picking is the field of financial analysis that is of particular interest for many professional investors and researchers. In this study stock picking is implemented via binary classification trees. Optimal tree size is believed to be the crucial factor in forecasting performance of the trees. While there exists a standard method of tree pruning, which is based on the cost-complexity tradeoff and used in the majority of studies employing binary decision trees, this paper introduces a no...

Effects of long-term pruning, meristem origin, and branch order on the rooting of Douglas-fir stem cuttings.

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D.L. Copes

1992-01-01

The rooting percentages of 14 Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) clones were examined annually from 1974 to 1988. The trees were 10 and 13 years old in 1974 and were pruned to 2.0 m in 1978 and 1979 and then recut annually to 0.5, 1.0, or 1.5 m, starting in 1983. The pruned trees showed no evidence of decreased rooting percentage...

Synaptic plasticity in drug reward circuitry.

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Winder, Danny G; Egli, Regula E; Schramm, Nicole L; Matthews, Robert T

2002-11-01

Drug addiction is a major public health issue worldwide. The persistence of drug craving coupled with the known recruitment of learning and memory centers in the brain has led investigators to hypothesize that the alterations in glutamatergic synaptic efficacy brought on by synaptic plasticity may play key roles in the addiction process. Here we review the present literature, examining the properties of synaptic plasticity within drug reward circuitry, and the effects that drugs of abuse have on these forms of plasticity. Interestingly, multiple forms of synaptic plasticity can be induced at glutamatergic synapses within the dorsal striatum, its ventral extension the nucleus accumbens, and the ventral tegmental area, and at least some of these forms of plasticity are regulated by behaviorally meaningful administration of cocaine and/or amphetamine. Thus, the present data suggest that regulation of synaptic plasticity in reward circuits is a tractable candidate mechanism underlying aspects of addiction.

Effect of pruning history on growth and dry mass partitioning of jatropha on a plantation site in Madagascar

International Nuclear Information System (INIS)

Rajaona, Arisoa M.; Brueck, Holger; Asch, Folkard

2011-01-01

While technical aspects of oil processing of seeds of jatropha are under intensive investigation, comparably little is known about the performance of jatropha in the field. We investigated the effects of water availability (rainfed versus irrigated) and pruning-induced differences in plant stature on growth, biomass partitioning, and canopy size at a plantation site in Madagascar in 2010. Plants of different pruning types differed in trunk height (43 versus 29 cm) and primary branches total length (171 versus 310 cm). The two pruning types had effects on dry mass formation and leaf area projection (LAP) during the vegetation period. Trees which had a shorter trunk and longer lateral branches produced more biomass and had a higher LAP. Total dry mass formation varied from 489 to 912 g m −2 and LAP from 3.26 to 7.37. Total aboveground biomass increased from 2.3 ± 0.5 to 4.89 ± 1.4 kg tree −1 and from 4.6 ± 1.8 to 8.9 ± 1.0 kg tree −1 for the pruning types with shorter and longer lateral branches, respectively. Growth of twigs and leaves was positively correlated with total length of branches. Relative dry mass allocation to branches, twigs and leaves, length of twigs per cm of branches and specific leaf area (13.57 ± 0.72 m 2 kg −1 ) were not affected by pruning and water supply. Trees with shorter branches had higher LAD. Results indicate that pruning type should be considered as a management tool to optimize biomass production. Detailed studies on effects of canopy size and shape on radiation interception and growth are required to improve the productivity of jatropha. -- Highlights: ▶ Correlation between branch length and newly formed twigs and leaves. ▶ Comparison of LAI and leaf area density in the field. ▶ Twigs per unit length of branches.

A Ca2+-based computational model for NDMA receptor-dependent synaptic plasticity at individual post-synaptic spines in the hippocampus

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Owen Rackham

2010-07-01

Full Text Available Associative synaptic plasticity is synapse specific and requires coincident activity in presynaptic and postsynaptic neurons to activate NMDA receptors (NMDARs. The resultant Ca2+ influx is the critical trigger for the induction of synaptic plasticity. Given its centrality for the induction of synaptic plasticity, a model for NMDAR activation incorporating the timing of presynaptic glutamate release and postsynaptic depolarization by back-propagating action potentials could potentially predict the pre- and post-synaptic spike patterns required to induce synaptic plasticity. We have developed such a model by incorporating currently available data on the timecourse and amplitude of the postsynaptic membrane potential within individual spines. We couple this with data on the kinetics of synaptic NMDARs and then use the model to predict the continuous spine [Ca2+] in response to regular or irregular pre- and post-synaptic spike patterns. We then incorporate experimental data from synaptic plasticity induction protocols by regular activity patterns to couple the predicted local peak [Ca2+] to changes in synaptic strength. We find that our model accurately describes [Ca2+] in dendritic spines resulting from NMDAR activation during presynaptic and postsynaptic activity when compared to previous experimental observations. The model also replicates the experimentally determined plasticity outcome of regular and irregular spike patterns when applied to a single synapse. This model could therefore be used to predict the induction of synaptic plasticity under a variety of experimental conditions and spike patterns.

76 FR 53813 - Dried Prunes Produced in California; Decreased Assessment Rate

Science.gov (United States)

2011-08-30

... Reform. Under the marketing order now in effect, California dried prune handlers are subject to... DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 993 [Doc. No. AMS-FV-11-0068... Marketing Service, USDA. ACTION: Interim rule with request for comments. SUMMARY: This rule decreases the...

Synaptic Effects of Electric Fields

Science.gov (United States)

Rahman, Asif

Learning and sensory processing in the brain relies on the effective transmission of information across synapses. The strength and efficacy of synaptic transmission is modifiable through training and can be modulated with noninvasive electrical brain stimulation. Transcranial electrical stimulation (TES), specifically, induces weak intensity and spatially diffuse electric fields in the brain. Despite being weak, electric fields modulate spiking probability and the efficacy of synaptic transmission. These effects critically depend on the direction of the electric field relative to the orientation of the neuron and on the level of endogenous synaptic activity. TES has been used to modulate a wide range of neuropsychiatric indications, for various rehabilitation applications, and cognitive performance in diverse tasks. How can a weak and diffuse electric field, which simultaneously polarizes neurons across the brain, have precise changes in brain function? Designing therapies to maximize desired outcomes and minimize undesired effects presents a challenging problem. A series of experiments and computational models are used to define the anatomical and functional factors leading to specificity of TES. Anatomical specificity derives from guiding current to targeted brain structures and taking advantage of the direction-sensitivity of neurons with respect to the electric field. Functional specificity originates from preferential modulation of neuronal networks that are already active. Diffuse electric fields may recruit connected brain networks involved in a training task and promote plasticity along active synaptic pathways. In vitro, electric fields boost endogenous synaptic plasticity and raise the ceiling for synaptic learning with repeated stimulation sessions. Synapses undergoing strong plasticity are preferentially modulated over weak synapses. Therefore, active circuits that are involved in a task could be more susceptible to stimulation than inactive circuits

Feasibility and early outcomes of robotic-assisted laparoscopic Mitrofanoff appendicovesicostomy in patients with prune belly syndrome.

Science.gov (United States)

Wille, Mark A; Jayram, Gautam; Gundeti, Mohan S

2012-01-01

To evaluate the feasibility and report our initial experience with Robotic-Assisted Laparoscopic Mitrofanoff Appendicovesicostomy (RALMA) in patients with prune belly syndrome. The Mitrofanoff appendicovesicostomy procedure uses the appendix to create an easily accessible continent, catheterizable channel into the urinary bladder. Historically, the procedure is performed by an open surgical approach in prune belly patients. We describe our initial experience herein. Between October 2008 and February 2010 three patients with prune belly syndrome underwent RALMA. The appendicovesicostomy anastomosis was performed on the anterior bladder wall and the stoma was brought to the umbilical site or right lower quadrant. At least 4 cm of detrusor backing was ensured. The appendicovesicostomy stent was left in place for 4 weeks postoperatively before initiation of catheterization. Mean age at surgery was 9.7 years (range 5-14 years). Blood loss volume was 20 mL in each case. Overall mean operative time was 352 min (range 319-402 min). There were no intraoperative complications and no open conversions. There was one postoperative complication in the form of wound infection. All patients are catheterizing their stomas and are continent at an average follow-up of 14.7 months (range 5-21 months). In our initial experience, RALMA is a feasible option with encouraging early experience for creating a continent catheterizable channel into the urinary bladder in patients with prune belly syndrome. © 2011 THE AUTHORS. BJU INTERNATIONAL © 2011 BJU INTERNATIONAL.

Flexible Proton-Gated Oxide Synaptic Transistors on Si Membrane.

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Zhu, Li Qiang; Wan, Chang Jin; Gao, Ping Qi; Liu, Yang Hui; Xiao, Hui; Ye, Ji Chun; Wan, Qing

2016-08-24

Ion-conducting materials have received considerable attention for their applications in fuel cells, electrochemical devices, and sensors. Here, flexible indium zinc oxide (InZnO) synaptic transistors with multiple presynaptic inputs gated by proton-conducting phosphorosilicate glass-based electrolyte films are fabricated on ultrathin Si membranes. Transient characteristics of the proton gated InZnO synaptic transistors are investigated, indicating stable proton-gating behaviors. Short-term synaptic plasticities are mimicked on the proposed proton-gated synaptic transistors. Furthermore, synaptic integration regulations are mimicked on the proposed synaptic transistor networks. Spiking logic modulations are realized based on the transition between superlinear and sublinear synaptic integration. The multigates coupled flexible proton-gated oxide synaptic transistors may be interesting for neuroinspired platforms with sophisticated spatiotemporal information processing.

Mycotoxin risks and toxigenic fungi in date, prune and dried apricot among Mediterranean crops

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Hayrettin OZER

2012-05-01

Full Text Available Dried fruit is fruit that is preserved by removing the original water content naturally, through sun drying or artificially, by the use of specialized dryers or dehydrators. Dried fruit has a long tradition of use dating back to the fourth millennium BC in Mesopotamia and is prized because of its sweet taste, nutritive value and long shelf life. Traditional dried fruits such as raisins, figs, dates, apricots and prunes have been a staple of Mediterranean diets for millennia. The Mediterranean region is very favourable for production of dried fruits, not only with its climatic conditions, but also its exceptional fertile lands. Additionally, proximity to trade routes historically has allowed Mediterranean countries more access to dried fruits than landlocked countries. Today, dried fruit consumption is widespread. Nearly half of the dried fruits sold throughout the world are raisins, followed by dates, prunes (dried plums, figs, apricots, peaches, apples and pears. Dates, prunes, apricots, figs and raisins are the major dried fruits produced in the Mediterranean area. Dried fruits are not perishable but can support mold growth, some of which can produce mycotoxins. Occurence of toxigenic molds and mycotoxins on these dried fruits can be a problem in the Mediterranean basin, as in the other parts of the world, being a health hazard to the population as well as a trade issue for the export of local products. Although the most important mycotoxins occuring in Mediterranean crops are aflatoxins (B1, B2, G1 and G2 and ochratoxin A, the type and level of mycotoxins and toxigenic molds vary by crop and also by country and in some cases geographic location within a country. In this review mycotoxin risks and toxigenic fungi in date, prune and dried apricot among Mediterranean crops are reported and discussed.

Recurrent nephrogenic adenoma in a 10-year-old boy with prune belly syndrome : a case presentation.

Science.gov (United States)

Vemulakonda, Vijaya M; Kopp, Ryan P; Sorensen, Mathew D; Grady, Richard W

2008-05-01

Nephrogenic adenoma is a rare benign lesion of the urinary tract that is associated with a history of irritation or injury of the urothelium. Predisposing factors include infection, calculi, surgery, trauma, and renal transplantation. Nephrogenic adenoma commonly presents with lower urinary tract symptoms or hematuria. We present the case of recurrent nephrogenic adenoma in a 10-year-old boy with a history of prune belly syndrome and discuss management of this disease in the pediatric population. To our knowledge this represents the first reported case of recurrent nephrogenic adenoma associated with prune belly syndrome.

Influence of Synaptic Depression on Memory Storage Capacity

Science.gov (United States)

Otsubo, Yosuke; Nagata, Kenji; Oizumi, Masafumi; Okada, Masato

2011-08-01

Synaptic efficacy between neurons is known to change within a short time scale dynamically. Neurophysiological experiments show that high-frequency presynaptic inputs decrease synaptic efficacy between neurons. This phenomenon is called synaptic depression, a short term synaptic plasticity. Many researchers have investigated how the synaptic depression affects the memory storage capacity. However, the noise has not been taken into consideration in their analysis. By introducing ``temperature'', which controls the level of the noise, into an update rule of neurons, we investigate the effects of synaptic depression on the memory storage capacity in the presence of the noise. We analytically compute the storage capacity by using a statistical mechanics technique called Self Consistent Signal to Noise Analysis (SCSNA). We find that the synaptic depression decreases the storage capacity in the case of finite temperature in contrast to the case of the low temperature limit, where the storage capacity does not change.

Secreted factors as synaptic organizers.

Science.gov (United States)

Johnson-Venkatesh, Erin M; Umemori, Hisashi

2010-07-01

A critical step in synaptic development is the differentiation of presynaptic and postsynaptic compartments. This complex process is regulated by a variety of secreted factors that serve as synaptic organizers. Specifically, fibroblast growth factors, Wnts, neurotrophic factors and various other intercellular signaling molecules are proposed to regulate presynaptic and/or postsynaptic differentiation. Many of these factors appear to function at both the neuromuscular junction and in the central nervous system, although the specific function of the molecules differs between the two. Here we review secreted molecules that organize the synaptic compartments and discuss how these molecules shape synaptic development, focusing on mammalian in vivo systems. Their critical role in shaping a functional neural circuit is underscored by their possible link to a wide range of neurological and psychiatric disorders both in animal models and by mutations identified in human patients. © The Authors (2010). Journal Compilation © Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

MPTP-meditated hippocampal dopamine deprivation modulates synaptic transmission and activity-dependent synaptic plasticity

International Nuclear Information System (INIS)

Zhu Guoqi; Chen Ying; Huang Yuying; Li Qinglin; Behnisch, Thomas

2011-01-01

Parkinson's disease (PD)-like symptoms including learning deficits are inducible by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Therefore, it is possible that MPTP may disturb hippocampal memory processing by modulation of dopamine (DA)- and activity-dependent synaptic plasticity. We demonstrate here that intraperitoneal (i.p.) MPTP injection reduces the number of tyrosine hydroxylase (TH)-positive neurons in the substantia nigra (SN) within 7 days. Subsequently, the TH expression level in SN and hippocampus and the amount of DA and its metabolite DOPAC in striatum and hippocampus decrease. DA depletion does not alter basal synaptic transmission and changes pair-pulse facilitation (PPF) of field excitatory postsynaptic potentials (fEPSPs) only at the 30 ms inter-pulse interval. In addition, the induction of long-term potentiation (LTP) is impaired whereas the duration of long-term depression (LTD) becomes prolonged. Since both LTP and LTD depend critically on activation of NMDA and DA receptors, we also tested the effect of DA depletion on NMDA receptor-mediated synaptic transmission. Seven days after MPTP injection, the NMDA receptor-mediated fEPSPs are decreased by about 23%. Blocking the NMDA receptor-mediated fEPSP does not mimic the MPTP-LTP. Only co-application of D1/D5 and NMDA receptor antagonists during tetanization resembled the time course of fEPSP potentiation as observed 7 days after i.p. MPTP injection. Together, our data demonstrate that MPTP-induced degeneration of DA neurons and the subsequent hippocampal DA depletion alter NMDA receptor-mediated synaptic transmission and activity-dependent synaptic plasticity. - Highlights: → I.p. MPTP-injection mediates death of dopaminergic neurons. → I.p. MPTP-injection depletes DA and DOPAC in striatum and hippocampus. → I.p. MPTP-injection does not alter basal synaptic transmission. → Reduction of LTP and enhancement of LTD after i.p. MPTP-injection. → Attenuation of NMDA-receptors mediated

The Effect of Green Pruning on the Yield and Fruit Quality of the Crawling Grape Vines Cultivar Keshmeshy in the Climatic Conditions of Shirvan

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F. Sadeghian

2016-02-01

Full Text Available Introduction: Green pruning or summer pruning completes winter pruning, and it is conducted during the growing season. The purpose of green pruning is to maximize yield of high quality grapes. Green pruning in fruit trees improves light penetration and increases the quality of fruits. The objectives of this research were to determine the influence of green pruning on fruit quantitative and qualitative attributes in grapevine cultivar 'keshmeshi'. Materials and Methods: The present research was undertaken in Shirvan, Northern Khorasan province. The vines were highly uniform, 17 years old and all had equal vegetative growth strength.The planting distances were 3 × 3 m. The present study was conducted on cultivar 'Keshmeshi' that is considered to be one of the best grapevine cultivars mostly used for raisin production as well as table fresh fruits. In order to evaluate the effect of green pruning on different quantitative and qualitative attributes of fruits in cultivar "keshmeshi", the experiment was carried out in two way randomized complete block design with 12 treatments and three replications. Vines were pruned three times including full bloom, two weeks after full bloom and veraison (eight weeks after full bloom. Pruning was carried out in three levels including tipping after two, four or six nodes above the final cluster. The characteristics studied were cluster weight, berry weight, cluster length and width, berry length and width, number of cluster and berry, vine yield, leaf area, soluble solid, total acidity, pH, berry color, berry sunscald and number of shot berry. The SAS software (SAS, version 9.1 was used for statistical analysis of the recorded data. The mean comparison was performed based on Duncan's multiple range tests at %5 and %1 levels. Results and Discussion: The results of this study indicate that the severity of green pruning has no significant effect on the number and width of berries. This treatment also had no

Effect of irradiation, pruning and removal of in vitro formed roots on ex vitro growth in micro propagated grape

International Nuclear Information System (INIS)

Charbaji, T.; Ayyoubi, Z.

2003-01-01

In vitro rootstock (Ru 140) and Helwani variety were cultured on DSD1 media, were irradiated at low doses of gamma irradiation before acclimatization. Ru 140 were exposed to 0-5 Gy, while Helwani was exposed to 0-7 Gy. Then, the plants were divided into three different groups: in the first group the plant roots were pruned, in the second the plant roots were completely removed and in the third group the plant roots were kept intact (control). The ex vitro plants were observed after 45 days of planting. Shoots growth, leaf number and dry weight of Ru 140 were significantly higher than those of the control when roots were pruned and 5 Gy was applied. Those parameters were negatively affected by root removal. Gamma irradiation had a positive effect on the control comparing to unirradiated plants. Root pruning had positive effects on shoot growth, leaf number and dry weight of Helwani variety, while root removal had a contrary effect on this variety. Gamma irradiation positively affected shoot growth and dry weight of control comparing to unirradiated plants, similar effect was observed on leaf number of control and pruned plant of Helwani. (author)

Prune belly anomaly on prenatal ultrasound as a presenting feature of ectrodactyly-ectodermal dysplasia-clefting syndrome (EEC).

Science.gov (United States)

Janssens, S; Defoort, P; Vandenbroecke, C; Scheffer, H; Mortier, G

2008-01-01

We report on a fetus with prune belly anomaly presenting at 16 weeks gestation. Clinical evaluation after birth revealed other malformations reminiscent of the EEC syndrome. This diagnosis was also suspected in the mother and finally confirmed in both relatives by identification of a heterozygous mutation (p.R204W) in the p63 gene. With this paper we confirm the previously reported occurrence of prune belly anomaly in the EEC syndrome, however here in this family proven by genetic analysis.

Spontaneous Vesicle Recycling in the Synaptic Bouton

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Sven eTruckenbrodt

2014-12-01

Full Text Available The trigger for synaptic vesicle exocytosis is Ca2+, which enters the synaptic bouton following action potential stimulation. However, spontaneous release of neurotransmitter also occurs in the absence of stimulation in virtually all synaptic boutons. It has long been thought that this represents exocytosis driven by fluctuations in local Ca2+ levels. The vesicles responding to these fluctuations are thought to be the same ones that release upon stimulation, albeit potentially triggered by different Ca2+ sensors. This view has been challenged by several recent works, which have suggested that spontaneous release is driven by a separate pool of synaptic vesicles. Numerous articles appeared during the last few years in support of each of these hypotheses, and it has been challenging to bring them into accord. We speculate here on the origins of this controversy, and propose a solution that is related to developmental effects. Constitutive membrane traffic, needed for the biogenesis of vesicles and synapses, is responsible for high levels of spontaneous membrane fusion in young neurons, probably independent of Ca2+. The vesicles releasing spontaneously in such neurons are not related to other synaptic vesicle pools and may represent constitutively releasing vesicles (CRVs rather than bona fide synaptic vesicles. In mature neurons, constitutive traffic is much dampened, and the few remaining spontaneous release events probably represent bona fide spontaneously releasing synaptic vesicles (SRSVs responding to Ca2+ fluctuations, along with a handful of CRVs that participate in synaptic vesicle turnover.

Active hippocampal networks undergo spontaneous synaptic modification.

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Masako Tsukamoto-Yasui

Full Text Available The brain is self-writable; as the brain voluntarily adapts itself to a changing environment, the neural circuitry rearranges its functional connectivity by referring to its own activity. How the internal activity modifies synaptic weights is largely unknown, however. Here we report that spontaneous activity causes complex reorganization of synaptic connectivity without any external (or artificial stimuli. Under physiologically relevant ionic conditions, CA3 pyramidal cells in hippocampal slices displayed spontaneous spikes with bistable slow oscillations of membrane potential, alternating between the so-called UP and DOWN states. The generation of slow oscillations did not require fast synaptic transmission, but their patterns were coordinated by local circuit activity. In the course of generating spontaneous activity, individual neurons acquired bidirectional long-lasting synaptic modification. The spontaneous synaptic plasticity depended on a rise in intracellular calcium concentrations of postsynaptic cells, but not on NMDA receptor activity. The direction and amount of the plasticity varied depending on slow oscillation patterns and synapse locations, and thus, they were diverse in a network. Once this global synaptic refinement occurred, the same neurons now displayed different patterns of spontaneous activity, which in turn exhibited different levels of synaptic plasticity. Thus, active networks continuously update their internal states through ongoing synaptic plasticity. With computational simulations, we suggest that with this slow oscillation-induced plasticity, a recurrent network converges on a more specific state, compared to that with spike timing-dependent plasticity alone.

Characterizing synaptic protein development in human visual cortex enables alignment of synaptic age with rat visual cortex

Science.gov (United States)

Pinto, Joshua G. A.; Jones, David G.; Williams, C. Kate; Murphy, Kathryn M.

2015-01-01

Although many potential neuroplasticity based therapies have been developed in the lab, few have translated into established clinical treatments for human neurologic or neuropsychiatric diseases. Animal models, especially of the visual system, have shaped our understanding of neuroplasticity by characterizing the mechanisms that promote neural changes and defining timing of the sensitive period. The lack of knowledge about development of synaptic plasticity mechanisms in human cortex, and about alignment of synaptic age between animals and humans, has limited translation of neuroplasticity therapies. In this study, we quantified expression of a set of highly conserved pre- and post-synaptic proteins (Synapsin, Synaptophysin, PSD-95, Gephyrin) and found that synaptic development in human primary visual cortex (V1) continues into late childhood. Indeed, this is many years longer than suggested by neuroanatomical studies and points to a prolonged sensitive period for plasticity in human sensory cortex. In addition, during childhood we found waves of inter-individual variability that are different for the four proteins and include a stage during early development (visual cortex and identified a simple linear equation that provides robust alignment of synaptic age between humans and rats. Alignment of synaptic ages is important for age-appropriate targeting and effective translation of neuroplasticity therapies from the lab to the clinic. PMID:25729353

Stochastic lattice model of synaptic membrane protein domains.

Science.gov (United States)

Li, Yiwei; Kahraman, Osman; Haselwandter, Christoph A

2017-05-01

Neurotransmitter receptor molecules, concentrated in synaptic membrane domains along with scaffolds and other kinds of proteins, are crucial for signal transmission across chemical synapses. In common with other membrane protein domains, synaptic domains are characterized by low protein copy numbers and protein crowding, with rapid stochastic turnover of individual molecules. We study here in detail a stochastic lattice model of the receptor-scaffold reaction-diffusion dynamics at synaptic domains that was found previously to capture, at the mean-field level, the self-assembly, stability, and characteristic size of synaptic domains observed in experiments. We show that our stochastic lattice model yields quantitative agreement with mean-field models of nonlinear diffusion in crowded membranes. Through a combination of analytic and numerical solutions of the master equation governing the reaction dynamics at synaptic domains, together with kinetic Monte Carlo simulations, we find substantial discrepancies between mean-field and stochastic models for the reaction dynamics at synaptic domains. Based on the reaction and diffusion properties of synaptic receptors and scaffolds suggested by previous experiments and mean-field calculations, we show that the stochastic reaction-diffusion dynamics of synaptic receptors and scaffolds provide a simple physical mechanism for collective fluctuations in synaptic domains, the molecular turnover observed at synaptic domains, key features of the observed single-molecule trajectories, and spatial heterogeneity in the effective rates at which receptors and scaffolds are recycled at the cell membrane. Our work sheds light on the physical mechanisms and principles linking the collective properties of membrane protein domains to the stochastic dynamics that rule their molecular components.

Self-organised criticality via retro-synaptic signals

Science.gov (United States)

Hernandez-Urbina, Victor; Herrmann, J. Michael

2016-12-01

The brain is a complex system par excellence. In the last decade the observation of neuronal avalanches in neocortical circuits suggested the presence of self-organised criticality in brain networks. The occurrence of this type of dynamics implies several benefits to neural computation. However, the mechanisms that give rise to critical behaviour in these systems, and how they interact with other neuronal processes such as synaptic plasticity are not fully understood. In this paper, we present a long-term plasticity rule based on retro-synaptic signals that allows the system to reach a critical state in which clusters of activity are distributed as a power-law, among other observables. Our synaptic plasticity rule coexists with other synaptic mechanisms such as spike-timing-dependent plasticity, which implies that the resulting synaptic modulation captures not only the temporal correlations between spiking times of pre- and post-synaptic units, which has been suggested as requirement for learning and memory in neural systems, but also drives the system to a state of optimal neural information processing.

A favorable outcome following 32 vesicocentesis and amnioinfusion procedures in a fetus with severe prune belly syndrome.

Science.gov (United States)

Galati, Vincenzo; Beeson, James H; Confer, Stephen D; Frimberger, Dominic; Campbell, Jeffrey B; Ramji, Faridali G; Kropp, Bradley P

2008-04-01

Patients with severe prune belly syndrome rarely survive beyond the first days of life. We present a case of prune belly syndrome that initially presented with severe oligohydramnios, megacystis and associated poor urine biochemistries. Due to an anteriorly located placenta the patient was referred to three major centers, but was turned down because of the unfavorable prognostic findings. Therefore, fetal intervention was performed with 32 vesicocentesis and amnioinfusion procedures. Despite the unfavorable prenatal findings, and having undergone numerous fetal interventions, the birth resulted in a viable infant.

Síndrome de Prune Belly- Relato de caso

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Anna Catarina Rocha Ferreira

2018-03-01

Full Text Available A Síndrome de Prune Belly (SPB é caracterizada por sintomas que se organizam em uma tríade baseada pela ausência, deficiência ou hipoplasia congênita de toda musculatura abdominal além de alterações do trato urinário acompanhada de criptorquidia bilateral.  O objetivo deste estudo foi relatar um caso clínico desta grave síndrome e apresentar um breve protocolo de atendimento Fisioterapêutico. O caso relatado é de um paciente de 03 anos, sexo masculino com criptorquidia bilateral, mal- formação da musculatura abdominal e dificuldade respiratória fazendo uso de traqueostomia e sonda nasoenteral, foi investigado na Faculdade de Ciências e Educação Sena Aires em Valparaiso de Goiás, onde foi submetido a um protocolo fisioterapêutico. Por ser uma síndrome grave é necessário um diagnóstico eficaz para uma rápida intervenção fisioterapêutica, pois assim será possível conhecer as limitações desses pacientes e prestar um atendimento eficaz com o objetivo de melhorar a qualidade de vida e sua inserção na sociedade promovendo o bem-estar da criança, além de servir como norteador de novas pesquisas na área, sobretudo aquelas com poucas evidências. Descritores: Síndrome de Prune Belly; Anormalidades congênitas; Parede abdominal; Criptorquidismo.

Symbiotic nitrogen fixation and yield of Pachyrhizus Erosus (L) urban cultivars and Pachyrhizus Ahipa (WEDD) parodi landraces as affected by flower pruning

DEFF Research Database (Denmark)

Castellanos, J.Z.; Zapata, F.; Badillo, V.

1997-01-01

biomass without N fertiliser application. In some climatic regions P. erosus is reproductively pruned in order to obtain economic yields, but little is known about how the pruning influences the capacity of these tuber legumes to fix nitrogen. Two experiments were carried out to investigate the effect...

Production of fuel ethanol from steam-explosion pretreated olive tree pruning

Energy Technology Data Exchange (ETDEWEB)

Cristobal Cara; Encarnacion Ruiz; Mercedes Ballesteros; Paloma Manzanares; Ma Jose Negro; Eulogio Castro [University of Jaen, Jaen (Spain). Department of Chemical, Environmental and Materials Engineering

2008-05-15

This work deals with the production of fuel ethanol from olive tree pruning. This raw material is a renewable, low cost, largely available, and lacking of economic alternatives agricultural residue. Olive tree pruning was submitted to steam explosion pre-treatment in the temperature range 190-240{sup o}C, with or without previous impregnation by water or sulphuric acid solutions. The influence of both pre-treatment temperature and impregnation conditions on sugar and ethanol yields was investigated by enzymatic hydrolysis and simultaneous saccharification and fermentation on the pretreated solids. Results show that the maximum ethanol yield (7.2 g ethanol/100 g raw material) is obtained from water impregnated, steam pretreated residue at 240{sup o}C. Nevertheless if all sugars solubilized during pre-treatment are taken into account, up to 15.9 g ethanol/100 g raw material may be obtained (pre-treatment conditions: 230{sup o}C and impregnation with 1% w/w sulphuric acid concentration), assuming theoretical conversion of these sugars to ethanol. 29 refs., 2 figs., 5 tabs.

Type V Pouch Colon, Prune Belly Syndrome, and Congenital Anterior Urethrocutaneous Fistula.

Science.gov (United States)

Raj, Prince; Birua, Hirendra

2017-01-01

Congenital pouch colon (CPC) or short colon syndrome is a rare type of anorectal malformation(ARM). Type V is the rarest form of CPC. We present a 1-day-old male child with type V CPC with prune belly syndrome and congenital anterior urethrocutaneous fistula (CAUF).

Formulation of an alginate-vineyard pruning waste composite as a new eco-friendly adsorbent to remove micronutrients from agroindustrial effluents.

Science.gov (United States)

Vecino, X; Devesa-Rey, R; Moldes, A B; Cruz, J M

2014-09-01

The cellulosic fraction of vineyard pruning waste (free of hemicellulosic sugars) was entrapped in calcium alginate beads and evaluated as an eco-friendly adsorbent for the removal of different nutrients and micronutrients (Mg, P, Zn, K, N-NH4, SO4, TN, TC and PO4) from an agroindustrial effluent (winery wastewater). Batch adsorption studies were performed by varying the amounts of cellulosic adsorbent (0.5-2%), sodium alginate (1-5%) and calcium chloride (0.05-0.9M) included in the biocomposite. The optimal formulation of the adsorbent composite varied depending on the target contaminant. Thus, for the adsorption of cationic contaminants (Mg, Zn, K, N-NH4 and TN), the best mixture comprised 5% sodium alginate, 0.05M calcium chloride and 0.5% cellulosic vineyard pruning waste, whereas for removal of anionic compounds (P, SO4 and PO4), the optimal mixture comprised 1% sodium alginate, 0.9M calcium chloride and 0.5% cellulosic vineyard pruning waste. To remove TC from the winery wastewater, the optimal mixture comprised 3% of sodium alginate, 0.475M calcium chloride and 0.5% cellulosic vineyard pruning waste. Copyright © 2014 Elsevier Ltd. All rights reserved.

Lateral regulation of synaptic transmission by astrocytes.

Science.gov (United States)

Covelo, A; Araque, A

2016-05-26

Fifteen years ago the concept of the "tripartite synapse" was proposed to conceptualize the functional view that astrocytes are integral elements of synapses. The signaling exchange between astrocytes and neurons within the tripartite synapse results in the synaptic regulation of synaptic transmission and plasticity through an autocrine form of communication. However, recent evidence indicates that the astrocyte synaptic regulation is not restricted to the active tripartite synapse but can be manifested through astrocyte signaling at synapses relatively distant from active synapses, a process termed lateral astrocyte synaptic regulation. This phenomenon resembles the classical heterosynaptic modulation but is mechanistically different because it involves astrocytes and its properties critically depend on the morphological and functional features of astrocytes. Therefore, the functional concept of the tripartite synapse as a fundamental unit must be expanded to include the interaction between tripartite synapses. Through lateral synaptic regulation, astrocytes serve as an active processing bridge for synaptic interaction and crosstalk between synapses with no direct neuronal connectivity, supporting the idea that neural network function results from the coordinated activity of astrocytes and neurons. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Nephrogenic adenoma of the bladder in a prune belly syndrome patient: case report and review of the literature.

Science.gov (United States)

Broecker, Justine S; Steelman, Charlotte K; Broecker, Bruce H; Shehata, Bahig M

2011-01-01

Nephrogenic adenoma (NA) is a rare lesion of the urinary tract widely considered to be a metaplastic response to urothelial injury. Herein, we present the case of an 8-year-old male with prune belly syndrome who presented with gross hematuria. Investigation revealed a bladder mass; however, upon cystoscopic examination, multiple polypoid lesions were identified. Microscopic examination revealed NA of the bladder. To our knowledge, this is the second reported case of NA of the bladder in association with prune belly syndrome.

Air lateral root pruning affects longleaf pine seedling root system morphology

Science.gov (United States)

Shi-Jean Susana Sung; Dave Haywood

2016-01-01

Longleaf pine (Pinus palustris) seedlings were cultured with air lateral root pruning (side-vented containers, VT) or without (solid-walled containers, SW). Seedling root system morphology and growth were assessed before planting and 8 and 14 months after planting. Although VT seedlings had greater root collar diameter than the SW before planting,...

Planting and care of fine hardwood seedlings: Fertilizing, pruning, and thinning

Science.gov (United States)

James McKenna; Keith Woeste

2004-01-01

This publication outlines the cultural operations of pruning, fertilizing, and thinning that can greatly enhance the timber value of a plantation. This summary is based on the findings of many individuals. While there are alternatives to many of the recommended practices and differences of opinion existing among professionals, our purpose is to give the landowner a...

Dynamical pruning of static localized basis sets in time-dependent quantum dynamics

NARCIS (Netherlands)

McCormack, D.A.

2006-01-01

We investigate the viability of dynamical pruning of localized basis sets in time-dependent quantum wave packet methods. Basis functions that have a very small population at any given time are removed from the active set. The basis functions themselves are time independent, but the set of active

Combustion of a Pb(II)-loaded olive tree pruning used as biosorbent

Energy Technology Data Exchange (ETDEWEB)

Ronda, A., E-mail: alirg@ugr.es [Department of Chemical Engineering, University of Granada, 18071 Granada (Spain); Della Zassa, M. [Department of Industrial Engineering, University of Padua, 35131 Padova (Italy); Martín-Lara, M.A.; Calero, M. [Department of Chemical Engineering, University of Granada, 18071 Granada (Spain); Canu, P. [Department of Industrial Engineering, University of Padua, 35131 Padova (Italy)

2016-05-05

Highlights: • The fate of Pb during combustion at two scales of investigation was studied. • Results from combustion in a flow reactor and in the thermobalance were consistent. • The Pb contained in the solid remained in the ashes. • The Pb does not interfere in the use of OTP as fuel. • The combustion of Pb(II)-loaded OTP does not cause environmental hazards. - Abstract: The olive tree pruning is a specific agroindustrial waste that can be successfully used as adsorbent, to remove Pb(II) from contaminated wastewater. Its final incineration has been studied in a thermobalance and in a laboratory flow reactor. The study aims at evaluating the fate of Pb during combustion, at two different scales of investigation. The flow reactor can treat samples approximately 10{sup 2} larger than the conventional TGA. A detailed characterization of the raw and Pb(II)-loaded waste, before and after combustion is presented, including analysis of gas and solids products. The Pb(II)-loaded olive tree pruning has been prepared by a previous biosorption step in a lead solution, reaching a concentration of lead of 2.3 wt%. Several characterizations of the ashes and the mass balances proved that after the combustion, all the lead presents in the waste remained in ashes. Combustion in a flow reactor produced results consistent with those obtained in the thermobalance. It is thus confirmed that the combustion of Pb(II)-loaded olive tree pruning is a viable option to use it after the biosorption process. The Pb contained in the solid remained in the ashes, preventing possible environmental hazards.

Attractor neural networks with resource-efficient synaptic connectivity

Science.gov (United States)

Pehlevan, Cengiz; Sengupta, Anirvan

Memories are thought to be stored in the attractor states of recurrent neural networks. Here we explore how resource constraints interplay with memory storage function to shape synaptic connectivity of attractor networks. We propose that given a set of memories, in the form of population activity patterns, the neural circuit choses a synaptic connectivity configuration that minimizes a resource usage cost. We argue that the total synaptic weight (l1-norm) in the network measures the resource cost because synaptic weight is correlated with synaptic volume, which is a limited resource, and is proportional to neurotransmitter release and post-synaptic current, both of which cost energy. Using numerical simulations and replica theory, we characterize optimal connectivity profiles in resource-efficient attractor networks. Our theory explains several experimental observations on cortical connectivity profiles, 1) connectivity is sparse, because synapses are costly, 2) bidirectional connections are overrepresented and 3) are stronger, because attractor states need strong recurrence.

The prune belly anomaly: heterogeneity and superficial X-linkage mimicry.

Science.gov (United States)

Riccardi, V M; Grum, C M

1977-01-01

The genetic, clinical, and necropsy findings of 2 brothers with the prune belly anomaly are presented and the literature reviewed. The combined data emphasise the clinical and genetic heterogeneity of the disorder and show that in at least some instances a heritable component may be the primary insult. The most likely heritable explanation involves a two-step autosomal dominant mutation with sex-limited expression that partially mimics X-linkage. PMID:144797

Quadratus lumborum block for post-operative pain relief in patient with Prune belly syndrome.

Science.gov (United States)

Garg, Chitra; Khanna, Sangeeta; Mehta, Yatin

2017-10-01

Abdominal field blocks are commonly used as part of multimodal analgesia for post-operative pain relief in patients undergoing abdominal surgery. Conventionally, transversus abdominis plane block is used, but has the disadvantage of limited spread only to T10-T12 segments, providing only partial pain relief. The new quadratus lumborum (QL) block has the advantage of providing wider sensory block from T6 to L1 and thus has an evolving role in opioid-free anaesthesia. Opioid-induced cough depression, urinary retention, and drowsiness can be problematic in patients with Prune belly syndrome, who have deficient abdominal muscles and myriad of genitourinary problems. We report a case of a young male with Prune belly syndrome, who had a pain-free post-operative period after high inguinal orchidectomy with unilateral QL block.

Application of the pessimistic pruning to increase the accuracy of C4.5 algorithm in diagnosing chronic kidney disease

Science.gov (United States)

Muslim, M. A.; Herowati, A. J.; Sugiharti, E.; Prasetiyo, B.

2018-03-01

A technique to dig valuable information buried or hidden in data collection which is so big to be found an interesting patterns that was previously unknown is called data mining. Data mining has been applied in the healthcare industry. One technique used data mining is classification. The decision tree included in the classification of data mining and algorithm developed by decision tree is C4.5 algorithm. A classifier is designed using applying pessimistic pruning in C4.5 algorithm in diagnosing chronic kidney disease. Pessimistic pruning use to identify and remove branches that are not needed, this is done to avoid overfitting the decision tree generated by the C4.5 algorithm. In this paper, the result obtained using these classifiers are presented and discussed. Using pessimistic pruning shows increase accuracy of C4.5 algorithm of 1.5% from 95% to 96.5% in diagnosing of chronic kidney disease.

MG Travessia: a coffee arabica cultivar productive and responsive to pruning

OpenAIRE

Carvalho, Gladyston Rodrigues; Bartholo, Gabriel Ferreira; Pereira, Antônio Alves; Rezende, Juliana Costa de; Botelho, Cesar Elias; Oliveira, Antônio Carlos Baião de; Silva, Felipe Lopes da

2017-01-01

Abstract This paper presents the results of progeny 1190-1170-2, which was recorded as ‘MGS Travessia’ and selected based on its performance in the state of Minas Gerais. The cultivar has short size, cylindrical canopy, high yield capacity, high vegetative vigor, very satisfactory husk/bean ratio, grain quality compatible to traditional cultivars, and is very responsive to skeleton pruning.

MG Travessia: a coffee arabica cultivar productive and responsive to pruning

Directory of Open Access Journals (Sweden)

Gladyston Rodrigues Carvalho

2017-06-01

Full Text Available This paper presents the results of progeny 1190-1170-2, which was recorded as ‘MGS Travessia’ and selected based on its performance in the state of Minas Gerais. The cultivar has short size, cylindrical canopy, high yield capacity, high vegetative vigor, very satisfactory husk/bean ratio, grain quality compatible to traditional cultivars, and is very responsive to skeleton pruning.

Forebrain deletion of αGDI in adult mice worsens the pre-synaptic deficit at cortico-lateral amygdala synaptic connections.

Directory of Open Access Journals (Sweden)

Veronica Bianchi

Full Text Available The GDI1 gene encodes αGDI, which retrieves inactive GDP-bound RAB from membranes to form a cytosolic pool awaiting vesicular release. Mutations in GDI1 are responsible for X-linked Intellectual Disability. Characterization of the Gdi1-null mice has revealed alterations in the total number and distribution of hippocampal and cortical synaptic vesicles, hippocampal short-term synaptic plasticity and specific short-term memory deficits in adult mice, which are possibly caused by alterations of different synaptic vesicle recycling pathways controlled by several RAB GTPases. However, interpretation of these studies is complicated by the complete ablation of Gdi1 in all cells in the brain throughout development. In this study, we generated conditionally gene-targeted mice in which the knockout of Gdi1 is restricted to the forebrain, hippocampus, cortex and amygdala and occurs only during postnatal development. Adult mutant mice reproduce the short-term memory deficit previously reported in Gdi1-null mice. Surprisingly, the delayed ablation of Gdi1 worsens the pre-synaptic phenotype at cortico-amygdala synaptic connections compared to Gdi1-null mice. These results suggest a pivotal role of αGDI via specific RAB GTPases acting specifically in forebrain regions at the pre-synaptic sites involved in memory formation.

Synapse geometry and receptor dynamics modulate synaptic strength.

Directory of Open Access Journals (Sweden)

Dominik Freche

Full Text Available Synaptic transmission relies on several processes, such as the location of a released vesicle, the number and type of receptors, trafficking between the postsynaptic density (PSD and extrasynaptic compartment, as well as the synapse organization. To study the impact of these parameters on excitatory synaptic transmission, we present a computational model for the fast AMPA-receptor mediated synaptic current. We show that in addition to the vesicular release probability, due to variations in their release locations and the AMPAR distribution, the postsynaptic current amplitude has a large variance, making a synapse an intrinsic unreliable device. We use our model to examine our experimental data recorded from CA1 mice hippocampal slices to study the differences between mEPSC and evoked EPSC variance. The synaptic current but not the coefficient of variation is maximal when the active zone where vesicles are released is apposed to the PSD. Moreover, we find that for certain type of synapses, receptor trafficking can affect the magnitude of synaptic depression. Finally, we demonstrate that perisynaptic microdomains located outside the PSD impacts synaptic transmission by regulating the number of desensitized receptors and their trafficking to the PSD. We conclude that geometrical modifications, reorganization of the PSD or perisynaptic microdomains modulate synaptic strength, as the mechanisms underlying long-term plasticity.

On failure of the pruning technique in "error repair in shift-reduce parsers"

NARCIS (Netherlands)

Bertsch, E; Nederhof, MJ

A previous article presented a technique to compute the least-cost error repair by incrementally generating configurations that result from inserting and deleting tokens in a syntactically incorrect input. An additional mechanism to improve the run-time efficiency of this algorithm by pruning some

Synaptic vesicle distribution by conveyor belt.

Science.gov (United States)

Moughamian, Armen J; Holzbaur, Erika L F

2012-03-02

The equal distribution of synaptic vesicles among synapses along the axon is critical for robust neurotransmission. Wong et al. show that the continuous circulation of synaptic vesicles throughout the axon driven by molecular motors ultimately yields this even distribution. Copyright © 2012 Elsevier Inc. All rights reserved.

EVALUATION OF THE WORK CONDITIONS OF ACTIVITIES OF URBAN TREE PRUNING

Directory of Open Access Journals (Sweden)

Nilton César Fiedler

2007-03-01

Full Text Available this work analyzed the work environment in the trees pruning activities in the urban arborization, comparison with the values of the legislation and the practical application of results to provide a better comfort, security, health, welfare to workers, and also a better efficiency and quality of the work. The weather conditions, the noise levels, the light conditions and vibration were analyzed using suitable ergonomic methods. The weather conditions in the work environment were according the permissible values in the legislation (NR15 for index of humid bulb and globe thermometer (IBUTG of 25°C for the activities of pruning, with exception of the schedule to twelve hours (26,2°C, the hours of working should be of 30 minutes of work and 30 minutes of rest. The noise levels found in the activities of cut were 105,7 dB (A and bucking were 103.9 dB (A, above the level permited by legislation (NR15. The minimum light conditions values were acceptable for legislation (NBR 5413/92, but the global indices were too high being able to cause problems to the worker health. The vibration conditions were acceptable.

Canopy and leaf composition drive patterns of nutrient release from pruning residues in a coffee agroforest.

Science.gov (United States)

Tully, Katherine L; Lawrence, Deborah

2012-06-01

In a coffee agroforest, the crop is cultivated under the shade of fruit-bearing and nitrogen (N)-fixing trees. These trees are periodically pruned to promote flowering and fruiting as well as to make nutrients stored in tree biomass available to plants. We investigated the effect of canopy composition and substrate quality on decomposition rates and patterns of nutrient release from pruning residues in a coffee agroforest located in Costa Rica's Central Valley. Initial phosphorus (P) release was enhanced under a canopy composed solely of N-fixing, Erythrina poeppigiana compared to a mixed canopy of Erythrina and Musa acuminata (banana). Both initial and final N release were similar under the two canopy types. However, after five months of decomposition, a higher proportion of initial N had been released under the single canopy. Although patterns of decomposition and nutrient release were not predicted by initial substrate quality, mass loss in leaf mixtures rates were well predicted by mean mass loss of their component species. This study identifies specific pruning regimes that may regulate N and P release during crucial growth periods, and it suggests that strategic pruning can enhance nutrient availability. For example, during the onset of rapid fruit growth, a two-species mixture may release more P than a three-species mixture. However, by the time of the harvest, the two- and three-species mixtures have released roughly the same amount of N and P. These nutrients do not always follow the same pattern, as N release can be maximized in single-species substrates, while P release is often facilitated in species mixtures. Our study indicates the importance of management practices in mediating patterns of nutrient release. Future research should investigate how canopy composition and farm management can also mediate on-farm nutrient losses.

Elevated progranulin contributes to synaptic and learning deficit due to loss of fragile X mental retardation protein.

Science.gov (United States)

Zhang, Kun; Li, Yu-Jiao; Guo, Yanyan; Zheng, Kai-Yin; Yang, Qi; Yang, Le; Wang, Xin-Shang; Song, Qian; Chen, Tao; Zhuo, Min; Zhao, Ming-Gao

2017-12-01

Fragile X syndrome is an inheritable form of intellectual disability caused by loss of fragile X mental retardation protein (FMRP, encoded by the FMR1 gene). Absence of FMRP caused overexpression of progranulin (PGRN, encoded by GRN), a putative tumour necrosis factor receptor ligand. In the present study, we found that progranulin mRNA and protein were upregulated in the medial prefrontal cortex of Fmr1 knock-out mice. In Fmr1 knock-out mice, elevated progranulin caused insufficient dendritic spine pruning and late-phase long-term potentiation in the medial prefrontal cortex of Fmr1 knock-out mice. Partial progranulin knock-down restored spine morphology and reversed behavioural deficits, including impaired fear memory, hyperactivity, and motor inflexibility in Fmr1 knock-out mice. Progranulin increased levels of phosphorylated glutamate ionotropic receptor GluA1 and nuclear factor kappa B in cultured wild-type neurons. Tumour necrosis factor receptor 2 antibody perfusion blocked the effects of progranulin on GluA1 phosphorylation; this result indicates that tumour necrosis factor receptor 2 is required for progranulin-mediated GluA1 phosphorylation and late-phase long-term potentiation expression. However, high basal level of progranulin in Fmr1 knock-out mice prevented further facilitation of synaptic plasticity by exogenous progranulin. Partial downregulation of progranulin or tumour necrosis factor receptor 2/nuclear factor kappa B signalling restored synaptic plasticity and memory deficits in Fmr1 knock-out mice. These findings suggest that elevated PGRN is linked to cognitive deficits of fragile X syndrome, and the progranulin/tumour necrosis factor receptor 2 signalling pathway may be a putative therapeutic target for improving cognitive deficits in fragile X syndrome. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Quadratus lumborum block for post-operative pain relief in patient with Prune belly syndrome

Directory of Open Access Journals (Sweden)

Chitra Garg

2017-01-01

Full Text Available Abdominal field blocks are commonly used as part of multimodal analgesia for post-operative pain relief in patients undergoing abdominal surgery. Conventionally, transversus abdominis plane block is used, but has the disadvantage of limited spread only to T10–T12 segments, providing only partial pain relief. The new quadratus lumborum (QL block has the advantage of providing wider sensory block from T6 to L1 and thus has an evolving role in opioid-free anaesthesia. Opioid-induced cough depression, urinary retention, and drowsiness can be problematic in patients with Prune belly syndrome, who have deficient abdominal muscles and myriad of genitourinary problems. We report a case of a young male with Prune belly syndrome, who had a pain-free post-operative period after high inguinal orchidectomy with unilateral QL block.

Effects of root pruning in sour cherry (Prunus cersus) "Stevnsbaer"

DEFF Research Database (Denmark)

Toldam-Andersen, Torben; Jensen, Nauja Lisa; Dencker, Ivar Blücher

2007-01-01

with trees of middle age on rootstock Colt were selected. Three trees with intact root systems were pulled up in each of the orchards. Based on the architecture of the root systems, a pruning distance of 30-35 cm from the trunk was used, removing approximately 30 percent of the roots. The one-sided root...

Effect of Staking and Pruning on the Growth and Yield of Cucumber ...

African Journals Online (AJOL)

A field trial was conducted to evaluate the effect of pruning and staking on the vegetative growth and yield of cucumber ( Cucumis sativus L.). The experiment was a 3 x 2 factorial laid out in Randomized Complete Block Design (RCBD) with five replications. The results showed that vine length, number of flowers, total ...

Selective pruning in pineapple plants as means to reduce heterogeneity in fruit quality

NARCIS (Netherlands)

Fassinou Hotegni, V.N.; Lommen, W.J.M.; Struik, P.C.; Agbossou, E.K.

2015-01-01

Heterogeneity in fruit quality (size and taste) is a major problem in pineapple production chains. The possibilities were investigated of reducing the heterogeneity in pineapple in the field by pruning slips on selected plants, in order to promote the fruit growth on these plants. Slips are side

Pruning dwarf mistletoe brooms reduces stress on Jeffrey pines, Cleveland National Forest, California

Science.gov (United States)

Robert F. Scharpf; Richard S. Smith; Detlev Vogler

1987-01-01

Western dwarf mistletoe (Arceuthobium campylopodum) is a damaging parasite of Jeffrey pines (Pinus jeffreyi) in southern California. Infected branches that develop into brooms are believed to reduce tlee vigor and increase mortality. Brooms were pruned from Jeffrey pines with varying levels of dwarf mistletoe infection and live...

Growth following pruning of young loblolly pine trees: some early results

Science.gov (United States)

Ralph L. Amateis; Harold E. Burkhart

2006-01-01

In the spring of 2000, a designed experiment was established to study the effects of pruning on juvenile loblolly pine (Pinus taeda L.) tree growth and the subsequent formation of mature wood. Trees were planted at a 3 m x 3 m square spacing in plots of 6 rows with 6 trees per row, with the inner 16 trees constituting the measurement plot. Among the...

Synaptic release and extracellular actions of Zn2+ limit propagation of spreading depression and related events in vitro and in vivo.

Science.gov (United States)

Aiba, Isamu; Carlson, Andrew P; Sheline, Christian T; Shuttleworth, C William

2012-02-01

Cortical spreading depression (CSD) is a consequence of a slowly propagating wave of neuronal and glial depolarization (spreading depolarization; SD). Massive release of glutamate contributes to SD propagation, and it was recently shown that Zn(2+) is also released from synaptic vesicles during SD. The present study examined consequences of extracellular Zn(2+) accumulation on the propagation of SD. SD mechanisms were studied first in murine brain slices, using focal KCl applications as stimuli and making electrical and optical recordings in hippocampal area CA1. Elevating extracellular Zn(2+) concentrations with exogenous ZnCl(2) reduced SD propagation rates. Selective chelation of endogenous Zn(2+) (using TPEN or CaEDTA) increased SD propagation rates, and these effects appeared due to chelation of Zn(2+) derived from synaptic vesicles. Thus, in tissues where synaptic Zn(2+) release was absent [knockout (KO) of vesicular Zn(2+) transporter ZnT-3], SD propagation rates were increased, and no additional increase was observed following chelation of endogenous Zn(2+) in these tissues. The role of synaptic Zn(2+) was then examined on CSD in vivo. ZnT-3 KO animals had higher susceptibility to CSD than wild-type controls as evidenced by significantly higher propagation rates and frequencies. Studies of candidate mechanisms excluded changes in neuronal excitability, presynaptic release, and GABA receptors but left open a possible contribution of N-methyl-d-aspartate (NMDA) receptor inhibition. These results suggest the extracellular accumulation of synaptically released Zn(2+) can serve as an intrinsic inhibitor to limit SD events. The inhibitory action of extracellular Zn(2+) on SD may counteract to some extent the neurotoxic effects of intracellular Zn(2+) accumulation in acute brain injury models.

Pregnancy outcome in a woman with prune belly syndrome.

Science.gov (United States)

Hillman, R Tyler; Garabedian, Matthew James; Wallerstein, Robert J

2012-11-30

Prune belly syndrome is a rare congenital syndrome that primarily affects male fetuses. Affected men are universally infertile; however, there is a paucity of information published on the reproductive potential of affected women. Pregnancy outcomes in affected women have not been described in the literature. We describe the case of pregnancy in an affected woman. Her pregnancy progressed without complication. Her fetus had no stigmata of the syndrome. Her labour and delivery were, however, complicated by a prolonged second stage of labour and need for vacuum-assisted vaginal delivery.

Prune belly syndrome with pouch colon and absent dermatome.

Science.gov (United States)

Baba, Aejaz A; Hussain, Syed A; Shera, Altaf H; Patnaik, Rekha

2010-01-01

Prune belly syndrome (PBS) is a rare congenital constellation of defects in pediatric surgical practice. Although anorectal anomalies have been reported in association with PBS, only few case of pouch colon with PBS has been reported. [1] In addition, our patient had deficient abdominal wall with absent dermatome in left upper quadrant, which has never been reported in the English literature. This association with abdominal wall deficiency and absent dermatome not only strengthens the theory of mesodermal arrest in the etiology of PBS but also points towards a defect in the ectodermal development.

7 CFR 944.350 - Safeguard procedures for avocados, grapefruit, kiwifruit, olives, oranges, prune variety plums...

Science.gov (United States)

2010-01-01

... plums (fresh prunes), and table grapes for processing; (3) Olives for processing into oil; (4) Grapefruit for animal feed; or (5) Avocados for seed shall obtain an “Importer's Exempt Commodity Form” (FV-6...

Experimental Implementation of a Biometric Laser Synaptic Sensor

Directory of Open Access Journals (Sweden)

Alexander N. Pisarchik

2013-12-01

Full Text Available We fabricate a biometric laser fiber synaptic sensor to transmit information from one neuron cell to the other by an optical way. The optical synapse is constructed on the base of an erbium-doped fiber laser, whose pumped diode current is driven by a pre-synaptic FitzHugh–Nagumo electronic neuron, and the laser output controls a post-synaptic FitzHugh–Nagumo electronic neuron. The implemented laser synapse displays very rich dynamics, including fixed points, periodic orbits with different frequency-locking ratios and chaos. These regimes can be beneficial for efficient biorobotics, where behavioral flexibility subserved by synaptic connectivity is a challenge.

Glutamatergic synaptic plasticity in the mesocorticolimbic system in addiction

Directory of Open Access Journals (Sweden)

Aile evan Huijstee

2015-01-01

Full Text Available Addictive drugs remodel the brain’s reward circuitry, the mesocorticolimbic dopamine system, by inducing widespread adaptations of glutamatergic synapses. This drug-induced synaptic plasticity is thought to contribute to both the development and the persistence of addiction. This review highlights the synaptic modifications that are induced by in vivo exposure to addictive drugs and describes how these drug-induced synaptic changes may contribute to the different components of addictive behaviour, such as compulsive drug use despite negative consequences and relapse. Initially, exposure to an addictive drug induces synaptic changes in the ventral tegmental area (VTA. This drug-induced synaptic potentiation in the VTA subsequently triggers synaptic changes in downstream areas of the mesocorticolimbic system, such as the nucleus accumbens (NAc and the prefrontal cortex (PFC, with further drug exposure. These glutamatergic synaptic alterations are then thought to mediate many of the behavioural symptoms that characterize addiction. The later stages of glutamatergic synaptic plasticity in the NAc and in particular in the PFC play a role in maintaining addiction and drive relapse to drug-taking induced by drug-associated cues. Remodelling of PFC glutamatergic circuits can persist into adulthood, causing a lasting vulnerability to relapse. We will discuss how these neurobiological changes produced by drugs of abuse may provide novel targets for potential treatment strategies for addiction.

Glutamatergic synaptic plasticity in the mesocorticolimbic system in addiction

Science.gov (United States)

van Huijstee, Aile N.; Mansvelder, Huibert D.

2015-01-01

Addictive drugs remodel the brain’s reward circuitry, the mesocorticolimbic dopamine (DA) system, by inducing widespread adaptations of glutamatergic synapses. This drug-induced synaptic plasticity is thought to contribute to both the development and the persistence of addiction. This review highlights the synaptic modifications that are induced by in vivo exposure to addictive drugs and describes how these drug-induced synaptic changes may contribute to the different components of addictive behavior, such as compulsive drug use despite negative consequences and relapse. Initially, exposure to an addictive drug induces synaptic changes in the ventral tegmental area (VTA). This drug-induced synaptic potentiation in the VTA subsequently triggers synaptic changes in downstream areas of the mesocorticolimbic system, such as the nucleus accumbens (NAc) and the prefrontal cortex (PFC), with further drug exposure. These glutamatergic synaptic alterations are then thought to mediate many of the behavioral symptoms that characterize addiction. The later stages of glutamatergic synaptic plasticity in the NAc and in particular in the PFC play a role in maintaining addiction and drive relapse to drug-taking induced by drug-associated cues. Remodeling of PFC glutamatergic circuits can persist into adulthood, causing a lasting vulnerability to relapse. We will discuss how these neurobiological changes produced by drugs of abuse may provide novel targets for potential treatment strategies for addiction. PMID:25653591

How young trees cope with removal of whole or parts of shoots: an analysis of local and distant responses to pruning in 1-year-old apple (Malus xdomestica; Rosaceae) trees.

Science.gov (United States)

Fumey, Damien; Lauri, Pierre-Éric; Guédon, Yann; Godin, Christophe; Costes, Evelyne

2011-11-01

Manipulation of tree architecture by pruning provides an experimental context to analyze architectural plasticity resulting from competition between developing organs. The objective of this study was to quantify the effects of the removal of all or part of shoots through pruning on the redistribution of growth and flowering at spatial and temporal levels. Two types of pruning cuts were applied: (1) heading cuts of either the main stem or laterals and (2) thinning cuts (i.e., complete removal) of laterals. These two types of cuts were applied in summer and winter on 1-yr-old cultivars of Fuji and Braeburn apple trees. Tree topology and geometry were described over 3 years, and responses were analyzed for both local and distant scales. Heading cuts induced quasi-deterministic local responses on pruned axes, whereas responses to thinning cuts were more variable. For the main stem and laterals, responses over greater spatial and temporal scales were highlighted with (1) stronger growth the year after summer pruning and (2) modification of branching and flowering along the unpruned parts after winter pruning. Pruning typically induced growth redistribution toward traumatic reiterations and enhanced growth of the remaining unpruned axes with a concomitant decrease of flowering and cambial growth. Although results could be interpreted in relation to the root-shoot balance, tree responses appeared highly cultivar-specific.

Agrin and synaptic laminin are required to maintain adult neuromuscular junctions.

Directory of Open Access Journals (Sweden)

Melanie A Samuel

Full Text Available As synapses form and mature the synaptic partners produce organizing molecules that regulate each other's differentiation and ensure precise apposition of pre- and post-synaptic specializations. At the skeletal neuromuscular junction (NMJ, these molecules include agrin, a nerve-derived organizer of postsynaptic differentiation, and synaptic laminins, muscle-derived organizers of presynaptic differentiation. Both become concentrated in the synaptic cleft as the NMJ develops and are retained in adulthood. Here, we used mutant mice to ask whether these organizers are also required for synaptic maintenance. Deletion of agrin from a subset of adult motor neurons resulted in the loss of acetylcholine receptors and other components of the postsynaptic apparatus and synaptic cleft. Nerve terminals also atrophied and eventually withdrew from muscle fibers. On the other hand, mice lacking the presynaptic organizer laminin-α4 retained most of the synaptic cleft components but exhibited synaptic alterations reminiscent of those observed in aged animals. Although we detected no marked decrease in laminin or agrin levels at aged NMJs, we observed alterations in the distribution and organization of these synaptic cleft components suggesting that such changes could contribute to age-related synaptic disassembly. Together, these results demonstrate that pre- and post-synaptic organizers actively function to maintain the structure and function of adult NMJs.

Molecular mechanisms of synaptic remodeling in alcoholism.

Science.gov (United States)

Kyzar, Evan J; Pandey, Subhash C

2015-08-05

Alcohol use and alcohol addiction represent dysfunctional brain circuits resulting from neuroadaptive changes during protracted alcohol exposure and its withdrawal. Alcohol exerts a potent effect on synaptic plasticity and dendritic spine formation in specific brain regions, providing a neuroanatomical substrate for the pathophysiology of alcoholism. Epigenetics has recently emerged as a critical regulator of gene expression and synaptic plasticity-related events in the brain. Alcohol exposure and withdrawal induce changes in crucial epigenetic processes in the emotional brain circuitry (amygdala) that may be relevant to the negative affective state defined as the "dark side" of addiction. Here, we review the literature concerning synaptic plasticity and epigenetics, with a particular focus on molecular events related to dendritic remodeling during alcohol abuse and alcoholism. Targeting epigenetic processes that modulate synaptic plasticity may yield novel treatments for alcoholism. Published by Elsevier Ireland Ltd.

Hepatoblastoma and prune belly syndrome: a potential association.

Science.gov (United States)

Becknell, Brian; Pais, Priya; Onimoe, Grace; Rangarajan, Hemalatha; Schwaderer, Andrew L; McHugh, Kirk; Ranalli, Mark A; Hains, David S

2011-08-01

Prune belly syndrome (PBS) is a congenital anomaly characterized by the clinical triad of lax abdominal musculature, bilateral cryptorchidism, and abnormalities of the kidney and urinary tract. Previous reports of malignancy in patients with PBS have been limited to germ cell tumors. Hepatoblastoma (HBL) is the most common hepatic malignancy of childhood, affecting approximately 100 children each year in the USA. We describe a set of 4 pediatric patients with PBS and HBL. All individuals were born after 2002. These subjects lacked genetic, natal, or environmental factors known to confer risk of HBL. The occurrence of PBS and HBL in these patients constitutes a novel potential association.

The Analysis of Alpha Beta Pruning and MTD(f) Algorithm to Determine the Best Algorithm to be Implemented at Connect Four Prototype

Science.gov (United States)

Tommy, Lukas; Hardjianto, Mardi; Agani, Nazori

2017-04-01

Connect Four is a two-player game which the players take turns dropping discs into a grid to connect 4 of one’s own discs next to each other vertically, horizontally, or diagonally. At Connect Four, Computer requires artificial intelligence (AI) in order to play properly like human. There are many AI algorithms that can be implemented to Connect Four, but the suitable algorithms are unknown. The suitable algorithm means optimal in choosing move and its execution time is not slow at search depth which is deep enough. In this research, analysis and comparison between standard alpha beta (AB) Pruning and MTD(f) will be carried out at the prototype of Connect Four in terms of optimality (win percentage) and speed (execution time and the number of leaf nodes). Experiments are carried out by running computer versus computer mode with 12 different conditions, i.e. varied search depth (5 through 10) and who moves first. The percentage achieved by MTD(f) based on experiments is win 45,83%, lose 37,5% and draw 16,67%. In the experiments with search depth 8, MTD(f) execution time is 35, 19% faster and evaluate 56,27% fewer leaf nodes than AB Pruning. The results of this research are MTD(f) is as optimal as AB Pruning at Connect Four prototype, but MTD(f) on average is faster and evaluates fewer leaf nodes than AB Pruning. The execution time of MTD(f) is not slow and much faster than AB Pruning at search depth which is deep enough.

Synaptic Contacts Enhance Cell-to-Cell Tau Pathology Propagation

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Sara Calafate

2015-05-01

Full Text Available Accumulation of insoluble Tau protein aggregates and stereotypical propagation of Tau pathology through the brain are common hallmarks of tauopathies, including Alzheimer’s disease (AD. Propagation of Tau pathology appears to occur along connected neurons, but whether synaptic contacts between neurons are facilitating propagation has not been demonstrated. Using quantitative in vitro models, we demonstrate that, in parallel to non-synaptic mechanisms, synapses, but not merely the close distance between the cells, enhance the propagation of Tau pathology between acceptor hippocampal neurons and Tau donor cells. Similarly, in an artificial neuronal network using microfluidic devices, synapses and synaptic activity are promoting neuronal Tau pathology propagation in parallel to the non-synaptic mechanisms. Our work indicates that the physical presence of synaptic contacts between neurons facilitate Tau pathology propagation. These findings can have implications for synaptic repair therapies, which may turn out to have adverse effects by promoting propagation of Tau pathology.

Synaptic Contacts Enhance Cell-to-Cell Tau Pathology Propagation.

Science.gov (United States)

Calafate, Sara; Buist, Arjan; Miskiewicz, Katarzyna; Vijayan, Vinoy; Daneels, Guy; de Strooper, Bart; de Wit, Joris; Verstreken, Patrik; Moechars, Diederik

2015-05-26

Accumulation of insoluble Tau protein aggregates and stereotypical propagation of Tau pathology through the brain are common hallmarks of tauopathies, including Alzheimer's disease (AD). Propagation of Tau pathology appears to occur along connected neurons, but whether synaptic contacts between neurons are facilitating propagation has not been demonstrated. Using quantitative in vitro models, we demonstrate that, in parallel to non-synaptic mechanisms, synapses, but not merely the close distance between the cells, enhance the propagation of Tau pathology between acceptor hippocampal neurons and Tau donor cells. Similarly, in an artificial neuronal network using microfluidic devices, synapses and synaptic activity are promoting neuronal Tau pathology propagation in parallel to the non-synaptic mechanisms. Our work indicates that the physical presence of synaptic contacts between neurons facilitate Tau pathology propagation. These findings can have implications for synaptic repair therapies, which may turn out to have adverse effects by promoting propagation of Tau pathology. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

SYNAPTIC DEPRESSION IN DEEP NEURAL NETWORKS FOR SPEECH PROCESSING.

Science.gov (United States)

Zhang, Wenhao; Li, Hanyu; Yang, Minda; Mesgarani, Nima

2016-03-01

A characteristic property of biological neurons is their ability to dynamically change the synaptic efficacy in response to variable input conditions. This mechanism, known as synaptic depression, significantly contributes to the formation of normalized representation of speech features. Synaptic depression also contributes to the robust performance of biological systems. In this paper, we describe how synaptic depression can be modeled and incorporated into deep neural network architectures to improve their generalization ability. We observed that when synaptic depression is added to the hidden layers of a neural network, it reduces the effect of changing background activity in the node activations. In addition, we show that when synaptic depression is included in a deep neural network trained for phoneme classification, the performance of the network improves under noisy conditions not included in the training phase. Our results suggest that more complete neuron models may further reduce the gap between the biological performance and artificial computing, resulting in networks that better generalize to novel signal conditions.

Prune belly syndrome in a set of twins, a family tragedy: Case report ...

African Journals Online (AJOL)

We report prune belly syndrome, a rare congenital malformation, in a set of twins delivered to a young couple with a history of three previous first trimester spontaneous abortions, discordant HIV seropositivity and antenatal ultrasound report that indicated renal abnormalities in only one of the twins. The challenges of ...

Scab severity in relation to hedge pruning pecan trees in the Southeastern USA

Science.gov (United States)

Scab is the most damaging disease of pecan in the Southeastern USA. Pecan trees are tall (up to 30+ m), and managing disease in the upper canopy is problematic. Hedge pruning trees to ~12 m is being explored to facilitate efficacy of ground-based fungicide sprays, but resulting vigorous shoot growth...

Nicotinic mechanisms influencing synaptic plasticity in the hippocampus

Institute of Scientific and Technical Information of China (English)

Andon Nicholas PLACZEK; Tao A ZHANG; John Anthony DANI

2009-01-01

Nicotinic acetylcholine receptors (nAChRs) are expressed throughout the hippocampus, and nicotinic signaling plays an important role in neuronal function. In the context of learning and memory related behaviors associated with hippocampal function, a potentially significant feature of nAChR activity is the impact it has on synaptic plasticity. Synaptic plasticity in hippocampal neurons has long been considered a contributing cellular mechanism of learning and memory. These same kinds of cellular mechanisms are a factor in the development of nicotine addiction. Nicotinic signaling has been demonstrated by in vitro studies to affect synaptic plasticity in hippocampal neurons via multiple steps, and the signaling has also been shown to evoke synaptic plasticity in vivo. This review focuses on the nAChRs subtypes that contribute to hippocampal synaptic plasticity at the cellular and circuit level. It also considers nicotinic influences over long-term changes in the hippocampus that may contribute to addiction.

Defective Glycinergic Synaptic Transmission in Zebrafish Motility Mutants

OpenAIRE

Hirata, Hiromi; Carta, Eloisa; Yamanaka, Iori; Harvey, Robert J.; Kuwada, John Y.

2010-01-01

Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using molecular genetics. An ENU mutagenesis screen identified two behavioral mutants that are defective in glycinergic synaptic transmission. Zebrafish bandoneon (beo) mutants have a defect in glrbb, one of the duplicated glycine receptor (GlyR) β subunit genes. These mutants exhibit a loss of glycinergic synaptic ...

Small-Scale Effect of Pine Stand Pruning on Snowpack Distribution in the Pyrenees Observed with a Terrestrial Laser Scanner

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Jesús Revuelto

2016-07-01

Full Text Available Forests in snow-dominated areas have substantial effects on the snowpack and its evolution over time. Such interactions have significant consequences for the hydrological response of mountain rivers. Thus, the impact of forest management actions on the snow distribution, and hence the storage of water in the form of snow during winter and spring, is a major concern. The results of this study provide the first detailed comparison of the small-scale effect of forest characteristics on the snowpack distribution, assessed prior to and following major modification of the structure of the canopy by pruning of the lower branches of the trees to 3 m above the ground. This is a common management practice aimed at reducing the spread of forest fires. The snowpack distribution was determined using terrestrial laser scanning (LiDAR technology at a high spatial resolution (0.25 m over a 1000 m2 study area during 23 survey dates over three snow seasons in a small study area in the central Pyrenees. The pruning was conducted during summer following the snow season in the second year of the study (i.e., the study duration encompassed two seasons prior to canopy pruning and one following. Principal component analysis (PCA was used to identify recurring spatial patterns of snow distribution. The results showed that pruning reduced the average radius of the canopy of trees by 1.2 m, and increased the clearance around the trunks, as all the branches that formerly contacted the ground were removed. However, the impact on the snowpack was moderate. The PCA revealed that the spatial configuration of the snowpack did not change significantly, as the principal components included survey days from different periods of the snow season, and did not discriminate days surveyed prior to and following pruning. Nevertheless, removal of the lower branches reduced the area beneath the canopy by 36%, and led to an average increase in total snow depth of approximately 14%.

Neuro-inspired computing using resistive synaptic devices

CERN Document Server

2017-01-01

This book summarizes the recent breakthroughs in hardware implementation of neuro-inspired computing using resistive synaptic devices. The authors describe how two-terminal solid-state resistive memories can emulate synaptic weights in a neural network. Readers will benefit from state-of-the-art summaries of resistive synaptic devices, from the individual cell characteristics to the large-scale array integration. This book also discusses peripheral neuron circuits design challenges and design strategies. Finally, the authors describe the impact of device non-ideal properties (e.g. noise, variation, yield) and their impact on the learning performance at the system-level, using a device-algorithm co-design methodology. • Provides single-source reference to recent breakthroughs in resistive synaptic devices, not only at individual cell-level, but also at integrated array-level; • Includes detailed discussion of the peripheral circuits and array architecture design of the neuro-crossbar system; • Focuses on...

Synaptic Correlates of Working Memory Capacity.

Science.gov (United States)

Mi, Yuanyuan; Katkov, Mikhail; Tsodyks, Misha

2017-01-18

Psychological studies indicate that human ability to keep information in readily accessible working memory is limited to four items for most people. This extremely low capacity severely limits execution of many cognitive tasks, but its neuronal underpinnings remain unclear. Here we show that in the framework of synaptic theory of working memory, capacity can be analytically estimated to scale with characteristic time of short-term synaptic depression relative to synaptic current time constant. The number of items in working memory can be regulated by external excitation, enabling the system to be tuned to the desired load and to clear the working memory of currently held items to make room for new ones. Copyright © 2017 Elsevier Inc. All rights reserved.

7 CFR 993.159 - Payments for services performed with respect to reserve tonnage prunes.

Science.gov (United States)

2010-01-01

..., incidental to acquisition or storage; (ii) Direct labor costs, which include those for weighing, receiving... overhead costs, which include those for supervision, indirect labor, fuel, power and water, taxes and... the costs for necessary services rendered by handlers in connection with reserve prunes. (2) Such...

Depression as a Glial-Based Synaptic Dysfunction

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Daniel eRial

2016-01-01

Full Text Available Recent studies combining pharmacological, behavioral, electrophysiological and molecular approaches indicate that depression results from maladaptive neuroplastic processing occurring in defined frontolimbic circuits responsible for emotional processing such as the prefrontal cortex, hippocampus, amygdala and ventral striatum. However, the exact mechanisms controlling synaptic plasticity that are disrupted to trigger depressive conditions have not been elucidated. Since glial cells (astrocytes and microglia tightly and dynamically interact with synapses, engaging a bi-directional communication critical for the processing of synaptic information, we now revisit the role of glial cells in the etiology of depression focusing on a dysfunction of the ‘quad-partite’ synapse. This interest is supported by the observations that depressive-like conditions are associated with a decreased density and hypofunction of astrocytes and with an increase microglia ‘activation’ in frontolimbic regions, which is expected to contribute for the synaptic dysfunction present in depression. Furthermore, the traditional culprits of depression (glucocorticoids, biogenic amines, BDNF affect glia functioning, whereas antidepressant treatments (SSRIs, electroshock, deep brain stimulation recover glia functioning. In this context of a quad-partite synapse, systems modulating glia-synapse bidirectional communication - such as the purinergic neuromodulation system operated by ATP and adenosine - emerge as promising candidates to re-normalize synaptic function by combining direct synaptic effects with an ability to also control astrocyte and microglia function. This proposed triple action of purines to control aberrant synaptic function illustrates the rationale to consider the interference with glia dysfunction as a mechanism of action driving the design of future pharmacological tools to manage depression.

Synaptic Vesicle Endocytosis in Different Model Systems

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Quan Gan

2018-06-01

Full Text Available Neurotransmission in complex animals depends on a choir of functionally distinct synapses releasing neurotransmitters in a highly coordinated manner. During synaptic signaling, vesicles fuse with the plasma membrane to release their contents. The rate of vesicle fusion is high and can exceed the rate at which synaptic vesicles can be re-supplied by distant sources. Thus, local compensatory endocytosis is needed to replenish the synaptic vesicle pools. Over the last four decades, various experimental methods and model systems have been used to study the cellular and molecular mechanisms underlying synaptic vesicle cycle. Clathrin-mediated endocytosis is thought to be the predominant mechanism for synaptic vesicle recycling. However, recent studies suggest significant contribution from other modes of endocytosis, including fast compensatory endocytosis, activity-dependent bulk endocytosis, ultrafast endocytosis, as well as kiss-and-run. Currently, it is not clear whether a universal model of vesicle recycling exist for all types of synapses. It is possible that each synapse type employs a particular mode of endocytosis. Alternatively, multiple modes of endocytosis operate at the same synapse, and the synapse toggles between different modes depending on its activity level. Here we compile review and research articles based on well-characterized model systems: frog neuromuscular junctions, C. elegans neuromuscular junctions, Drosophila neuromuscular junctions, lamprey reticulospinal giant axons, goldfish retinal ribbon synapses, the calyx of Held, and rodent hippocampal synapses. We will compare these systems in terms of their known modes and kinetics of synaptic vesicle endocytosis, as well as the underlying molecular machineries. We will also provide the future development of this field.

Using Multi-Spectral UAV Imagery to Extract Tree Crop Structural Properties and Assess Pruning Effects

KAUST Repository

Johansen, Kasper; Raharjo, Tri; McCabe, Matthew

2018-01-01

Unmanned aerial vehicles (UAV) provide an unprecedented capacity to monitor the development and dynamics of tree growth and structure through time. It is generally thought that the pruning of tree crops encourages new growth, has a positive effect

Role of the origin of glutamatergic synaptic inputs in controlling synaptic plasticity and its modulation by alcohol in mice nucleus accumbens

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Gilles Erwann Martin

2015-07-01

Full Text Available It is widely accepted that long-lasting changes of synaptic strength in the nucleus accumbens, a brain region involved in drug reward, mediate acute and chronic effects of alcohol. However, our understanding of the mechanisms underlying the effects of alcohol on synaptic plasticity is limited by the fact that the nucleus accumbens receives glutamatergic inputs from distinct brain regions (e.g. the prefrontal cortex, the amygdala and the hippocampus, each region providing different information (e.g. spatial, emotional and cognitive. Combining whole-cell patch-clamp recordings and the optogenetic technique, we examined synaptic plasticity, and its regulation by alcohol, at cortical, hippocampal and amygdala inputs in fresh slices of mouse tissue. We showed that the origin of synaptic inputs determines the basic properties of glutamatergic synaptic transmission, the expression of spike-timing dependent long-term depression (tLTD and long-term potentiation (tLTP and their regulation by alcohol. While we observed both tLTP and tLTD at amygadala and hippocampal synapses, we showed that cortical inputs only undergo tLTD. Functionally, we provide evidence that acute EtOH has little effects on higher order information coming from the prefrontal cortex (PFCx, while severely impacting the ability of emotional and contextual information to induce long-lasting changes of synaptic strength.

The effects of planting methods and head pruning on seed yield and yield components of medicinal pumpkin (Cucurbita pepo subsp. Pepo convar. Pepo var. styriaca) at low temperature areas.

Science.gov (United States)

Bahrami, R Nikkhah; Khodadadi, M; Pirivatlo, S Piry; Hassanpanah, D

2009-03-15

This experiment carried out to evaluate the effects of planting methods (seed sowing and transplanting) and head pruning (no pruning, pruning after 12th node and pruning after 16th node) on yield and yield components such as number of branches (sub-branches) per plant, fruits per plant, growth, fruit size, weight of fresh fruit, weight of seeds per fruit, number of seeds per fruit and seed yield of medicinal pumpkin. The experiment was carried out based of factorial experiment with Randomized Completely Blocks Design (RCBD) by three replications in Ardabil Agricultural and Natural Resources Researches Station at 2007. Seedlings were grown in heated greenhouse. When the climatic condition became suitable and seedlings were at the four leaves stage, both seeds and seedlings were planted at the same time in the farm. Maintenance operations were done during the growth season. Head pruning treatments were done the forecast time. The results showed that the planting methods had significant effect on the number of ripen fruits per plant, fruits diameter, weight of seeds per fruit, weight of 1000 seeds and seed yield and had no significant effect on the other traits. Also the results indicated that head pruning treatments had significant effects on the number of branches per plant, growth and seed yield and no significant on the other traits. In this experiment the most seed yield (997.8 kg ha(-1)) obtained from transplanting method with head pruning after 12th node and the least seed yield obtained from control.

Unique features of prune belly syndrome in laparoscopic surgery.

Science.gov (United States)

Saxena, Amulya K; Brinkmann, Olaf A

2007-08-01

The aim of this study was to evaluate the laparoscopic abdominal access modifications in children with prune belly syndrome undergoing a first stage Fowler-Stephens procedure. Eleven consecutive boys underwent a transperitoneal laparoscopic bilateral first stage Fowler-Stephens procedure. Patient age ranged from 1.5 to 3 years (mean age 2.2 years). In these patients, the floppy abdominal wall required a modified approach with regard to access technique, insufflation pressures, and work port stabilization methods. Duration of the procedures and intraoperative technical challenges encountered were prospectively documented. Mean operative time was 40 minutes (range 30 to 75 minutes), and all procedures were completed without any complications. Forceful insertion of ports was not possible, and all ports were introduced under complete open access. Larger volumes of carbon dioxide were used in the initial part of our series, when the ports were not sutured to the abdominal wall. An abdominal pressure of 8 mmHg was maintained in all patients and was considered optimal for the procedures. Short laparoscopy instruments (240 mm) were unsuitable for the procedures and had to be replaced by longer instruments (310 mm or 430 mm). Technical modifications are required to the approach in laparoscopic abdominal access to overcome the challenges posed by the floppy abdominal wall in prune belly patients. Open access, suture fixation of the optic and work ports, use of threaded sleeve ports, and use of proper length of laparoscopy instruments are valuable modifications to overcome the technical hurdles posed by these patients.

Growth of Gypsophila paniculata According to the Pruning Time and Ridge Position in Sub-alpine Area

International Nuclear Information System (INIS)

Cheong, D.C.; Lim, H.C.; Song, Y.J.; Park, H.B.

2008-01-01

This study was carried out to investigate the growth of Gypsophila paniculata affected by pruning time (July 10, July 18, and July 25) and ridge position (middle or window side) under south-north oriented plastic house in sub-alpine area. The average night temperature was similar between the two ridges, but the average day temperature and soil temperature were higher at the middle ridge; particularly, there was distinct difference after late October. Also the accumulative solar radiation was higher at the middle ridge than the window side ridge owing to the shading by neighboring plastic house and the structure of plastic house. The root activity, photosynthetic rate and transpiration rate of plants surveyed in late October were inclined to be more increased at the middle than the window side ridge. The flowering traits at the pruning time of July 10 and July 18 were similar between the two ridges, but the flower malformation rate was higher at the middle ridge. On the other hand, in case of the pruning time of July 25, the blooming was advanced by 13 days, and the flowering traits such as flower stalk length and branch number were better; also, the flower malformation and rosette formation rate decreased at the middle ridge, because of its higher air and soil temperature and the accumulative solar radiation

Two- and three-dimensional prenatal sonographic diagnosis of prune-belly syndrome.

Science.gov (United States)

Chen, Lizhu; Cai, Ailu; Wang, Xiaoguang; Wang, Bing; Li, Jingyu

2010-06-01

We report the prenatal diagnosis of 6 cases of Prune-belly syndrome in the 2(nd) trimester. The sonographic diagnosis was based on the findings of oligohydramnios, renal anomalies, and a lower abdominal cystic mass representing the abnormal dilatation of the bladder on conventional 2-dimensional sonographic examination. We discuss the role of Doppler imaging and 3-dimensional sonography as complementary methods to conventional sonography. Four of our 6 cases were confirmed with associated defects.

Massive branes

International Nuclear Information System (INIS)

Bergshoeff, E.; Ortin, T.

1998-01-01

We investigate the effective world-volume theories of branes in a background given by (the bosonic sector of) 10-dimensional massive IIA supergravity (''''massive branes'''') and their M-theoretic origin. In the case of the solitonic 5-brane of type IIA superstring theory the construction of the Wess-Zumino term in the world-volume action requires a dualization of the massive Neveu-Schwarz/Neveu-Schwarz target space 2-form field. We find that, in general, the effective world-volume theory of massive branes contains new world-volume fields that are absent in the massless case, i.e. when the mass parameter m of massive IIA supergravity is set to zero. We show how these new world-volume fields can be introduced in a systematic way. (orig.)

Prune belly syndrome in uniovular twin: a new finding or a case of ...

African Journals Online (AJOL)

A case of Prune Belly Syndrome associated with High Anorectal Anomaly and Unilateral Lung Cyst occurring in a uniovular twin is hereby presented. The twin brother has no clinical evidence of congenital anomaly in any system. We therefore ask; is this a new finding or a case of improper documentation of data. Keywords: ...

Synchronization of map-based neurons with memory and synaptic delay

Energy Technology Data Exchange (ETDEWEB)

Sausedo-Solorio, J.M. [Universidad Autónoma del Estado de Hidalgo, Carretera Pachuca-Tulancingo Km. 4.5, 42074 Pachuca, Hidalgo (Mexico); Pisarchik, A.N., E-mail: apisarch@cio.mx [Centro de Investigaciones en Optica, Loma del Bosque 115, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Centre for Biomedical Technology, Technical University of Madrid, Campus Montegancedo, 28223 Pozuelo de Alarcon, Madrid (Spain)

2014-06-13

Synchronization of two synaptically coupled neurons with memory and synaptic delay is studied using the Rulkov map, one of the simplest neuron models which displays specific features inherent to bursting dynamics. We demonstrate a transition from lag to anticipated synchronization as the relationship between the memory duration and the synaptic delay time changes. The neuron maps synchronize either with anticipation, if the memory is longer than the synaptic delay time, or with lag otherwise. The mean anticipation time is equal to the difference between the memory and synaptic delay independently of the coupling strength. Frequency entrainment and phase-locking phenomena as well as a transition from regular spikes to chaos are demonstrated with respect to the coupling strength. - Highlights: • We study synchronization of neurons with memory and synaptic delay in the map model. • Neurons synchronize either with anticipation or with lag depending on delay time. • Mean anticipation time is equal to the difference between memory and synaptic delay. • Frequency entrainment and phase locking are studied with respect to the coupling.

Prune belly syndrome with pouch colon and absent dermatome

Directory of Open Access Journals (Sweden)

Baba Aejaz

2010-01-01

Full Text Available Prune belly syndrome (PBS is a rare congenital constellation of defects in pediatric surgical practice. Although anorectal anomalies have been reported in association with PBS, only few case of pouch colon with PBS has been reported. [1] In addition, our patient had deficient abdominal wall with absent dermatome in left upper quadrant, which has never been reported in the English literature. This association with abdominal wall deficiency and absent dermatome not only strengthens the theory of mesodermal arrest in the etiology of PBS but also points towards a defect in the ectodermal development.

Synaptic Plasticity, Dementia and Alzheimer Disease.

Science.gov (United States)

Skaper, Stephen D; Facci, Laura; Zusso, Morena; Giusti, Pietro

2017-01-01

Neuroplasticity is not only shaped by learning and memory but is also a mediator of responses to neuron attrition and injury (compensatory plasticity). As an ongoing process it reacts to neuronal cell activity and injury, death, and genesis, which encompasses the modulation of structural and functional processes of axons, dendrites, and synapses. The range of structural elements that comprise plasticity includes long-term potentiation (a cellular correlate of learning and memory), synaptic efficacy and remodelling, synaptogenesis, axonal sprouting and dendritic remodelling, and neurogenesis and recruitment. Degenerative diseases of the human brain continue to pose one of biomedicine's most intractable problems. Research on human neurodegeneration is now moving from descriptive to mechanistic analyses. At the same time, it is increasing apparently that morphological lesions traditionally used by neuropathologists to confirm post-mortem clinical diagnosis might furnish us with an experimentally tractable handle to understand causative pathways. Consider the aging-dependent neurodegenerative disorder Alzheimer's disease (AD) which is characterised at the neuropathological level by deposits of insoluble amyloid β-peptide (Aβ) in extracellular plaques and aggregated tau protein, which is found largely in the intracellular neurofibrillary tangles. We now appreciate that mild cognitive impairment in early AD may be due to synaptic dysfunction caused by accumulation of non-fibrillar, oligomeric Aβ, occurring well in advance of evident widespread synaptic loss and neurodegeneration. Soluble Aβ oligomers can adversely affect synaptic structure and plasticity at extremely low concentrations, although the molecular substrates by which synaptic memory mechanisms are disrupted remain to be fully elucidated. The dendritic spine constitutes a primary locus of excitatory synaptic transmission in the mammalian central nervous system. These structures protruding from dendritic

Long-term follow-up of total abdominal wall reconstruction for prune belly syndrome.

Science.gov (United States)

Lesavoy, Malcolm A; Chang, Eric I; Suliman, Ahmed; Taylor, Jason; Taylor, James; Kim, Sara E; Ehrlich, Richard M

2012-01-01

Prune belly syndrome is a rare, congenital condition that consists of a major deficiency or hypoplasia of the abdominal wall musculature, bilateral cryptorchidism, and genitourinary tract malformations. Reconstruction of the abdominal wall in these patients has presented a challenge to plastic surgeons throughout the years. The authors previously described a technique for total abdominal wall reconstruction that permitted simultaneous urinary tract reconstruction and bilateral orchiopexy. This innovative procedure used medial advancement of the fascia in a "double-breasted" fashion with preservation of the umbilicus. The authors reviewed their experience with this particular technique in one of the largest series of patients in the literature and the series with the longest follow-up. Twenty patients underwent total abdominal wall reconstruction with simultaneous urinary tract reconstruction and orchiopexy with a mean follow-up of 20.4 years. There were no major complications noted during this period, and all patients were extremely satisfied with their postoperative result. Total abdominal wall reconstruction using the double-breasted technique in patients with prune belly syndrome is a safe and durable procedure that achieves excellent cosmetic results. Therapeutic, IV.

Concordant posterior urethral valves in male monochorionic twins with secondary prune belly syndrome.

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Nouaili, Emira Ben Hamida; Chaouachi, Sihem; Nouira, Faouzi; Benmassoud, Ines; Laabidi, Kamel; Chaouachi, Beji; Marrakchi, Zahra

2008-12-01

Posterior urethral valves (PUVs), the most common congenital cause of lower urinary tract obstruction, have been described to occur in identical and nonidentical twins. Until now, reports have been published on 15 cases of PUVs. We report a new case of concordant PUVs in one set of male monochorionic twins with secondary Prune Belly Syndrome. The twins were born by elective cesarean section at 38 weeks of gestation to a 36-year-old mother, gravida 6, para 6. On ultrasound perfomed at 18 weeks's gestation, both fetuses showed signs of PUVs. At birth, physical examination of both revealed a secondary Prune Belly Syndrome (PBS). Postnatal renal ultrasound confirmed the diagnosis of PUV. The two infants underwent transurethral resection of the valves after a cystoscopic evaluation of the urethra. Since this procedure, their voiding has been unremarkable with stable renal function and sterile urine until their discharge. We have documented a rare association between VUP and PBS in two monochiorionic twins. More studies are needed to throw light on the significance of the present associated anomalies.

Prune Belly syndrome: A rare case report.

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Samal, Sunil Kumar; Rathod, Setu

2015-01-01

Prune Belly syndrome (PBS) is a rare congenital anomaly of uncertain etiology almost exclusive to males. We report a case of term male baby born to a 39-year-old grand multipara with previous four normal vaginal births. There was no history of genetic or congenital anomaly in her family. Examination of the baby revealed hypotonia, deficient abdominal muscle, cryptorchidism, palpable kidney, and bladder. Ultrasound examination of the abdomen revealed bilateral gross hydronephrosis and megaureter. Provisional diagnosis of PBS was made and the baby was admitted in neonatal intensive care units for further management. Routine antenatal care with ultrasonography will help in detecting renal anomalies, which can be followed postnatally. Early diagnosis of this syndrome and determining its optimal treatment are very important in helping to avoid its fatal course.

A pivotal role of GSK-3 in synaptic plasticity

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Clarrisa A Bradley

2012-02-01

Full Text Available Glycogen synthase kinase-3 (GSK-3 has many cellular functions. Recent evidence suggests that it plays a key role in certain types of synaptic plasticity, in particular a form of long-term depression (LTD that is induced by the synaptic activation of N-methyl-D-aspartate (NMDA receptors. In the present article we summarise what is currently known concerning the roles of GSK-3 in synaptic plasticity at both glutamatergic and GABAergic synapses. We summarise its role in cognition and speculate on how alterations in the synaptic functioning of GSK-3 may be a major factor in certain neurodegenerative disorders.

BDNF-induced local protein synthesis and synaptic plasticity.

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Leal, Graciano; Comprido, Diogo; Duarte, Carlos B

2014-01-01

Brain-derived neurotrophic factor (BDNF) is an important regulator of synaptic transmission and long-term potentiation (LTP) in the hippocampus and in other brain regions, playing a role in the formation of certain forms of memory. The effects of BDNF in LTP are mediated by TrkB (tropomyosin-related kinase B) receptors, which are known to be coupled to the activation of the Ras/ERK, phosphatidylinositol 3-kinase/Akt and phospholipase C-γ (PLC-γ) pathways. The role of BDNF in LTP is best studied in the hippocampus, where the neurotrophin acts at pre- and post-synaptic levels. Recent studies have shown that BDNF regulates the transport of mRNAs along dendrites and their translation at the synapse, by modulating the initiation and elongation phases of protein synthesis, and by acting on specific miRNAs. Furthermore, the effect of BDNF on transcription regulation may further contribute to long-term changes in the synaptic proteome. In this review we discuss the recent progress in understanding the mechanisms contributing to the short- and long-term regulation of the synaptic proteome by BDNF, and the role in synaptic plasticity, which is likely to influence learning and memory formation. This article is part of the Special Issue entitled 'BDNF Regulation of Synaptic Structure, Function, and Plasticity'. Copyright © 2013 Elsevier Ltd. All rights reserved.

PET measures of pre- and post-synaptic cardiac beta adrenergic function

Energy Technology Data Exchange (ETDEWEB)

Link, Jeanne M.; Stratton, John R.; Levy, Wayne; Poole, Jeanne E.; Shoner, Steven C.; Stuetzle, Werner; Caldwell, James H. E-mail: jcald@u.washington.edu

2003-11-01

Positron Emission Tomography was used to measure global and regional cardiac {beta}-adrenergic function in 19 normal subjects and 9 congestive heart failure patients. [{sup 11}C]-meta-hydroxyephedrine was used to image norepinephrine transporter function as an indicator of pre-synaptic function and [{sup 11}C]-CGP12177 was used to measure cell surface {beta}-receptor density as an indicator of post-synaptic function. Pre-synaptic, but not post-synaptic, function was significantly different between normals and CHF patients. Pre-synaptic function was well matched to post-synaptic function in the normal hearts but significantly different and poorly matched in the CHF patients studied. This imaging technique can help us understand regional sympathetic function in cardiac disease.

Pseudo Prune Belly Syndrome: Diagnosis Revealed by Imaging - A Case Report and Brief Review.

Science.gov (United States)

Grover, Hemal; Sethi, Sanjay; Garg, Jatin; Ahluwalia, Amrit Pal

2017-01-01

Prune Belly Syndrome (PBS) is a rare entity, usually found in male neonates. It comprises complex urinary tract anomalies, bilateral undescended testis and absence of anterior abdominal wall muscles. Patients with unilateral abdominal wall deficiency, unilateral undescended testis and female neonates with abdominal wall laxity are classified as Pseudo Prune Belly syndrome (PPBS). Reports on PPBS do not highlight the radiological and imaging characteristics of this syndrome and the current literature on the role of newer imaging modalities, such as Magnetic Resonance Imaging (MRI), remains relatively sparse. We describe a new case of PPBS and emphasize the role of imaging, especially ultrasound and MRI in the process of diagnosis and briefly review the subject. A male infant of four months of age was referred for evaluation of left-sided cryptorchidism. Clinical examination revealed laxity of the left abdominal wall. Ultrasound examination of the abdomen, pelvis and scrotum was performed together with routine laboratory tests. Ultrasound examination was followed by intravenous urography, voiding cysto-urethrography and MRI of the abdomen. On ultrasound, the left testis was located in the inguinal canal, the right kidney was slightly enlarged and the left kidney could not be localized. Ultrasound appearances suggested chronic obstruction in the urinary bladder. Intravenous urography, voiding cysto-urethrography and MRI confirmed the ultrasound diagnosis and also revealed a left dysplastic kidney with a dilated, tortuous ureter. Clinical and imaging features were consistent with pseudo prune belly syndrome (PPBS). We report a new occurrence of PPBS, a rare entity. The imaging approach for a comprehensive evaluation of the renal system in PPBS, especially with MRI, is emphasized.

A presynaptic role for PKA in synaptic tagging and memory.

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Park, Alan Jung; Havekes, Robbert; Choi, Jennifer Hk; Luczak, Vince; Nie, Ting; Huang, Ted; Abel, Ted

2014-10-01

Protein kinase A (PKA) and other signaling molecules are spatially restricted within neurons by A-kinase anchoring proteins (AKAPs). Although studies on compartmentalized PKA signaling have focused on postsynaptic mechanisms, presynaptically anchored PKA may contribute to synaptic plasticity and memory because PKA also regulates presynaptic transmitter release. Here, we examine this issue using genetic and pharmacological application of Ht31, a PKA anchoring disrupting peptide. At the hippocampal Schaffer collateral CA3-CA1 synapse, Ht31 treatment elicits a rapid decay of synaptic responses to repetitive stimuli, indicating a fast depletion of the readily releasable pool of synaptic vesicles. The interaction between PKA and proteins involved in producing this pool of synaptic vesicles is supported by biochemical assays showing that synaptic vesicle protein 2 (SV2), Rim1, and SNAP25 are components of a complex that interacts with cAMP. Moreover, acute treatment with Ht31 reduces the levels of SV2. Finally, experiments with transgenic mouse lines, which express Ht31 in excitatory neurons at the Schaffer collateral CA3-CA1 synapse, highlight a requirement for presynaptically anchored PKA in pathway-specific synaptic tagging and long-term contextual fear memory. These results suggest that a presynaptically compartmentalized PKA is critical for synaptic plasticity and memory by regulating the readily releasable pool of synaptic vesicles. Copyright © 2014 Elsevier Inc. All rights reserved.

Produção da amoreira-preta 'Tupy' sob diferentes épocas de poda Productive of 'Tupy' blackberry under different pruning time

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Marcelo Angelo Campagnolo

2012-02-01

Full Text Available A amora-preta é uma opção importante para fruticultura paranaense, porém não há informações a respeito do cultivo dessa frutífera nas condições subtropicais do Estado. O objetivo deste trabalho foi avaliar a influência da época de poda na produção da amoreira-preta 'Tupy'. O trabalho foi realizado em um pomar comercial, conduzido em sistema agroecológico. O delineamento experimental foi em blocos ao acaso, com quatro blocos e seis tratamentos (podas quinzenais realizadas durante o inverno. Em cada parcela, constituída de três plantas úteis, foram coletados dados fenológicos, produtivos e físico-químicos no ciclo de produção 2008/09 e 2009/10. Podas efetuadas no início de julho são as mais indicadas e podas tardias podem prejudicar o desempenho produtivo das amoreiras-pretas 'Tupy' no oeste do Paraná.The blackberry is an important option to fruit growers in Paraná State. However, there aren't trials performed in subtropical area in that State. The objective of this research was to evaluate the pruning time effects at season production of 'Tupy' blackberry. The research was conducted in a commercial orchard, in an agroecological system. The experimental design was randomized blocks with four blocks and six treatments (pruning time by fifteen days during the winter pruning. In each plot, which was consisted of three plants, it was collected phenological, productive and physical-chemical production cycle in 2008/09 and 2009/10. Pruning made in early July are the most suitable and late pruning can harm the productive performance of blackberry 'Tupy' in western Paraná.

Two Classes of Secreted Synaptic Organizers in the Central Nervous System.

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Yuzaki, Michisuke

2018-02-10

Research in the last two decades has identified many synaptic organizers in the central nervous system that directly regulate the assembly of pre- and/or postsynaptic molecules, such as synaptic vesicles, active zone proteins, and neurotransmitter receptors. They are classified into secreted factors and cell adhesion molecules, such as neurexins and neuroligins. Certain secreted factors are termed extracellular scaffolding proteins (ESPs) because they are components of the synaptic extracellular matrix and serve as a scaffold at the synaptic cleft. These include Lgi1, Cbln1, neuronal pentraxins, Hevin, thrombospondins, and glypicans. Diffusible secreted factors, such as Wnts, fibroblast growth factors, and semaphorins, tend to act from a distance. In contrast, ESPs remain at the synaptic cleft and often help synaptic adhesion and/or accumulation of postsynaptic receptors. Many fundamental questions remain about when, how, and why various synaptic organizers establish and modify the vast numbers of connections during development and throughout life.

Electric Dipole Theory of Chemical Synaptic Transmission

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Wei, Ling Y.

1968-01-01

In this paper we propose that chemicals such as acetylcholine are electric dipoles which when oriented and arranged in a large array could produce an electric field strong enough to drive positive ions over the junction barrier of the post-synaptic membrane and thus initiate excitation or produce depolarization. This theory is able to explain a great number of facts such as cleft size, synaptic delay, nonregeneration, subthreshold integration, facilitation with repetition, and the calcium and magnesium effects. It also shows why and how acetylcholine could act as excitatory or inhibitory transmitters under different circumstances. Our conclusion is that the nature of synaptic transmission is essentially electrical, be it mediated by electrical or chemical transmitters. PMID:4296121

Astroglial Metabolic Networks Sustain Hippocampal Synaptic Transmission

Science.gov (United States)

Rouach, Nathalie; Koulakoff, Annette; Abudara, Veronica; Willecke, Klaus; Giaume, Christian

2008-12-01

Astrocytes provide metabolic substrates to neurons in an activity-dependent manner. However, the molecular mechanisms involved in this function, as well as its role in synaptic transmission, remain unclear. Here, we show that the gap-junction subunit proteins connexin 43 and 30 allow intercellular trafficking of glucose and its metabolites through astroglial networks. This trafficking is regulated by glutamatergic synaptic activity mediated by AMPA receptors. In the absence of extracellular glucose, the delivery of glucose or lactate to astrocytes sustains glutamatergic synaptic transmission and epileptiform activity only when they are connected by gap junctions. These results indicate that astroglial gap junctions provide an activity-dependent intercellular pathway for the delivery of energetic metabolites from blood vessels to distal neurons.

Astroglial metabolic networks sustain hippocampal synaptic transmission.

Science.gov (United States)

Rouach, Nathalie; Koulakoff, Annette; Abudara, Veronica; Willecke, Klaus; Giaume, Christian

2008-12-05

Astrocytes provide metabolic substrates to neurons in an activity-dependent manner. However, the molecular mechanisms involved in this function, as well as its role in synaptic transmission, remain unclear. Here, we show that the gap-junction subunit proteins connexin 43 and 30 allow intercellular trafficking of glucose and its metabolites through astroglial networks. This trafficking is regulated by glutamatergic synaptic activity mediated by AMPA receptors. In the absence of extracellular glucose, the delivery of glucose or lactate to astrocytes sustains glutamatergic synaptic transmission and epileptiform activity only when they are connected by gap junctions. These results indicate that astroglial gap junctions provide an activity-dependent intercellular pathway for the delivery of energetic metabolites from blood vessels to distal neurons.

Synaptic transmission block by presynaptic injection of oligomeric amyloid beta

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Moreno, Herman; Yu, Eunah; Pigino, Gustavo; Hernandez, Alejandro I.; Kim, Natalia; Moreira, Jorge E.; Sugimori, Mutsuyuki; Llinás, Rodolfo R.

2009-01-01

Early Alzheimer's disease (AD) pathophysiology is characterized by synaptic changes induced by degradation products of amyloid precursor protein (APP). The exact mechanisms of such modulation are unknown. Here, we report that nanomolar concentrations of intraaxonal oligomeric (o)Aβ42, but not oAβ40 or extracellular oAβ42, acutely inhibited synaptic transmission at the squid giant synapse. Further characterization of this phenotype demonstrated that presynaptic calcium currents were unaffected. However, electron microscopy experiments revealed diminished docked synaptic vesicles in oAβ42-microinjected terminals, without affecting clathrin-coated vesicles. The molecular events of this modulation involved casein kinase 2 and the synaptic vesicle rapid endocytosis pathway. These findings open the possibility of a new therapeutic target aimed at ameliorating synaptic dysfunction in AD. PMID:19304802

Spike Pattern Structure Influences Synaptic Efficacy Variability Under STDP and Synaptic Homeostasis. I: Spike Generating Models on Converging Motifs

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Zedong eBi

2016-02-01

Full Text Available In neural systems, synaptic plasticity is usually driven by spike trains. Due to the inherent noises of neurons and synapses as well as the randomness of connection details, spike trains typically exhibit variability such as spatial randomness and temporal stochasticity, resulting in variability of synaptic changes under plasticity, which we call efficacy variability. How the variability of spike trains influences the efficacy variability of synapses remains unclear. In this paper, we try to understand this influence under pair-wise additive spike-timing dependent plasticity (STDP when the mean strength of plastic synapses into a neuron is bounded (synaptic homeostasis. Specifically, we systematically study, analytically and numerically, how four aspects of statistical features, i.e. synchronous firing, burstiness/regularity, heterogeneity of rates and heterogeneity of cross-correlations, as well as their interactions influence the efficacy variability in converging motifs (simple networks in which one neuron receives from many other neurons. Neurons (including the post-synaptic neuron in a converging motif generate spikes according to statistical models with tunable parameters. In this way, we can explicitly control the statistics of the spike patterns, and investigate their influence onto the efficacy variability, without worrying about the feedback from synaptic changes onto the dynamics of the post-synaptic neuron. We separate efficacy variability into two parts: the drift part (DriftV induced by the heterogeneity of change rates of different synapses, and the diffusion part (DiffV induced by weight diffusion caused by stochasticity of spike trains. Our main findings are: (1 synchronous firing and burstiness tend to increase DiffV, (2 heterogeneity of rates induces DriftV when potentiation and depression in STDP are not balanced, and (3 heterogeneity of cross-correlations induces DriftV together with heterogeneity of rates. We anticipate our

Prune belly syndrome--report of 47 cases.

Science.gov (United States)

Woodhouse, C R; Ransley, P G; Innes-Williams, D

1982-01-01

Forty-seven cases of prune belly syndrome in children born between 1948 and 1977 are described. They have been classified into three groups according to the state of the urinary tract in the neonatal period. The results achieved in these cases form the basis of our present management. In group I, the most severely affected, early death is inevitable. In group 2 the children are ill as neonates; high diversion is often required and later reconstruction may be possible. Group 3 patients are healthy as neonates and little reconstructive surgery is required. The prognosis in groups 2 and 3 is good. Half the group 2 children and three-quarters of the group 3 children grew up normally with satisfactory renal function and health. It is important to establish free drainage of the urinary tract and avoid infection. Images Figure PMID:6128960

Phosphodiesterase Inhibition to Target the Synaptic Dysfunction in Alzheimer's Disease

Science.gov (United States)

Bales, Kelly R.; Plath, Niels; Svenstrup, Niels; Menniti, Frank S.

Alzheimer's Disease (AD) is a disease of synaptic dysfunction that ultimately proceeds to neuronal death. There is a wealth of evidence that indicates the final common mediator of this neurotoxic process is the formation and actions on synaptotoxic b-amyloid (Aβ). The premise in this review is that synaptic dysfunction may also be an initiating factor in for AD and promote synaptotoxic Aβ formation. This latter hypothesis is consistent with the fact that the most common risk factors for AD, apolipoprotein E (ApoE) allele status, age, education, and fitness, encompass suboptimal synaptic function. Thus, the synaptic dysfunction in AD may be both cause and effect, and remediating synaptic dysfunction in AD may have acute effects on the symptoms present at the initiation of therapy and also slow disease progression. The cyclic nucleotide (cAMP and cGMP) signaling systems are intimately involved in the regulation of synaptic homeostasis. The phosphodiesterases (PDEs) are a superfamily of enzymes that critically regulate spatial and temporal aspects of cyclic nucleotide signaling through metabolic inactivation of cAMP and cGMP. Thus, targeting the PDEs to promote improved synaptic function, or 'synaptic resilience', may be an effective and facile approach to new symptomatic and disease modifying therapies for AD. There continues to be a significant drug discovery effort aimed at discovering PDE inhibitors to treat a variety of neuropsychiatric disorders. Here we review the current status of those efforts as they relate to potential new therapies for AD.

The Destructive Birth of Massive Stars and Massive Star Clusters

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Rosen, Anna; Krumholz, Mark; McKee, Christopher F.; Klein, Richard I.; Ramirez-Ruiz, Enrico

2017-01-01

Massive stars play an essential role in the Universe. They are rare, yet the energy and momentum they inject into the interstellar medium with their intense radiation fields dwarfs the contribution by their vastly more numerous low-mass cousins. Previous theoretical and observational studies have concluded that the feedback associated with massive stars' radiation fields is the dominant mechanism regulating massive star and massive star cluster (MSC) formation. Therefore detailed simulation of the formation of massive stars and MSCs, which host hundreds to thousands of massive stars, requires an accurate treatment of radiation. For this purpose, we have developed a new, highly accurate hybrid radiation algorithm that properly treats the absorption of the direct radiation field from stars and the re-emission and processing by interstellar dust. We use our new tool to perform a suite of three-dimensional radiation-hydrodynamic simulations of the formation of massive stars and MSCs. For individual massive stellar systems, we simulate the collapse of massive pre-stellar cores with laminar and turbulent initial conditions and properly resolve regions where we expect instabilities to grow. We find that mass is channeled to the massive stellar system via gravitational and Rayleigh-Taylor (RT) instabilities. For laminar initial conditions, proper treatment of the direct radiation field produces later onset of RT instability, but does not suppress it entirely provided the edges of the radiation-dominated bubbles are adequately resolved. RT instabilities arise immediately for turbulent pre-stellar cores because the initial turbulence seeds the instabilities. To model MSC formation, we simulate the collapse of a dense, turbulent, magnetized Mcl = 106 M⊙ molecular cloud. We find that the influence of the magnetic pressure and radiative feedback slows down star formation. Furthermore, we find that star formation is suppressed along dense filaments where the magnetic field is

Impact of Early Pruning and Thinning on Lumber Grade Yield From Loblolly Pine

Science.gov (United States)

Alexander Clark; Mike Strub; Larry R. Anderson; H. Gwynne Lloyd; Richard F. Daniels; James H. Scarborough

2004-01-01

The Sudden Sawlog Study was established in 1954 near Crossett, AR, in a 9-year-old loblolly pine plantation to test the hypothesis that loblolly plantations can produce sawtimber in 30 years. To stimulate diameter and height growth and clear wood production, study plots were heavily thinned, trees pruned to 33 feet by age 24 years, under-story mowed, and growth of...

Thyroid hormone is required for the pruning of afferent type II spiral ganglion neurons in the mouse cochlea

Science.gov (United States)

Sundaresan, Srividya; Balasubbu, Suganthalakshmi; Mustapha, Mirna

2015-01-01

Afferent connections to the sensory inner and outer hair cells in the cochlea refine and functionally mature during the thyroid hormone (TH)- critical period of inner ear development that occurs perinatally in rodents. In this study, we investigated the effects of hypothyroidism on afferent type II innervation to outer hair cells (OHCs) using the Snell dwarf mouse (Pit1dw). Using a transgenic approach to specifically label type II spiral ganglion neurons, we found that a lack of TH causes persistence of excess type II SGN connections to the OHCs, as well as continued expression of the hair cell functional marker, otoferlin, in the OHCs beyond the maturation period. We also observed a concurrent delay in efferent attachment to the OHCs. Supplementing with TH during the early postnatal period from postnatal day (P) 3 to P4 reversed the defect in type II SGN pruning but did not alter otoferlin expression. Our results show that hypothyroidism causes a defect in the large-scale pruning of afferent type II spiral ganglion neurons in the cochlea, and a delay in efferent attachment and the maturation of otoferlin expression. Our data suggest that the state of maturation of hair cells, as determined by otoferlin expression, may not regulate the pruning of their afferent innervation. PMID:26592716

A lack of immune system genes causes loss in high frequency hearing but does not disrupt cochlear synapse maturation in mice.

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Calton, Melissa A; Lee, Dasom; Sundaresan, Srividya; Mendus, Diana; Leu, Rose; Wangsawihardja, Felix; Johnson, Kenneth R; Mustapha, Mirna

2014-01-01

Early cochlear development is marked by an exuberant outgrowth of neurites that innervate multiple targets. The establishment of mature cochlear neural circuits is, however, dependent on the pruning of inappropriate axons and synaptic connections. Such refinement also occurs in the central nervous system (CNS), and recently, genes ordinarily associated with immune and inflammatory processes have been shown to play roles in synaptic pruning in the brain. These molecules include the major histocompatibility complex class I (MHCI) genes, H2-K(b) and H2-D(b), and the complement cascade gene, C1qa. Since the mechanisms involved in synaptic refinement in the cochlea are not well understood, we investigated whether these immune system genes may be involved in this process and whether they are required for normal hearing function. Here we report that these genes are not necessary for normal synapse formation and refinement in the mouse cochlea. We further demonstrate that C1qa expression is not necessary for normal hearing in mice but the lack of expression of H2-K(b) and H2-D(b) causes hearing impairment. These data underscore the importance of the highly polymorphic family of MHCI genes in hearing in mice and also suggest that factors and mechanisms regulating synaptic refinement in the cochlea may be distinct from those in the CNS.

Massive Gravity

OpenAIRE

de Rham, Claudia

2014-01-01

We review recent progress in massive gravity. We start by showing how different theories of massive gravity emerge from a higher-dimensional theory of general relativity, leading to the Dvali–Gabadadze–Porrati model (DGP), cascading gravity, and ghost-free massive gravity. We then explore their theoretical and phenomenological consistency, proving the absence of Boulware–Deser ghosts and reviewing the Vainshtein mechanism and the cosmological solutions in these models. Finally, we present alt...

Statistical mechanics of attractor neural network models with synaptic depression

International Nuclear Information System (INIS)

Igarashi, Yasuhiko; Oizumi, Masafumi; Otsubo, Yosuke; Nagata, Kenji; Okada, Masato

2009-01-01

Synaptic depression is known to control gain for presynaptic inputs. Since cortical neurons receive thousands of presynaptic inputs, and their outputs are fed into thousands of other neurons, the synaptic depression should influence macroscopic properties of neural networks. We employ simple neural network models to explore the macroscopic effects of synaptic depression. Systems with the synaptic depression cannot be analyzed due to asymmetry of connections with the conventional equilibrium statistical-mechanical approach. Thus, we first propose a microscopic dynamical mean field theory. Next, we derive macroscopic steady state equations and discuss the stabilities of steady states for various types of neural network models.

Surgical tactic of high bilateral abdominal testicular retention in patient with a prune belly syndrome

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I. A. Panchenko

2014-11-01

Full Text Available Bilateral abdominal cryptorchism in combination with other defects of urogenital system and a prune belly syndrome keep within a syndrome of connective tissue dysplasia. In our medical center developed the method of surgical correction of a high bilateral abdominal testicular retention with preservation of vessels.

Surgical tactic of high bilateral abdominal testicular retention in patient with a prune belly syndrome

Directory of Open Access Journals (Sweden)

I. A. Panchenko

2013-01-01

Full Text Available Bilateral abdominal cryptorchism in combination with other defects of urogenital system and a prune belly syndrome keep within a syndrome of connective tissue dysplasia. In our medical center developed the method of surgical correction of a high bilateral abdominal testicular retention with preservation of vessels.

Synaptic membrane rafts: traffic lights for local neurotrophin signaling?

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Zonta, Barbara; Minichiello, Liliana

2013-10-18

Lipid rafts, cholesterol and lipid rich microdomains, are believed to play important roles as platforms for the partitioning of transmembrane and synaptic proteins involved in synaptic signaling, plasticity, and maintenance. There is increasing evidence of a physical interaction between post-synaptic densities and post-synaptic lipid rafts. Localization of proteins within lipid rafts is highly regulated, and therefore lipid rafts may function as traffic lights modulating and fine-tuning neuronal signaling. The tyrosine kinase neurotrophin receptors (Trk) and the low-affinity p75 neurotrophin receptor (p75(NTR)) are enriched in neuronal lipid rafts together with the intermediates of downstream signaling pathways, suggesting a possible role of rafts in neurotrophin signaling. Moreover, neurotrophins and their receptors are involved in the regulation of cholesterol metabolism. Cholesterol is an important component of lipid rafts and its depletion leads to gradual loss of synapses, underscoring the importance of lipid rafts for proper neuronal function. Here, we review and discuss the idea that translocation of neurotrophin receptors in synaptic rafts may account for the selectivity of their transduced signals.

Synaptic membrane rafts: traffic lights for local neurotrophin signalling?

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Barbara eZonta

2013-10-01

Full Text Available Lipid rafts, cholesterol and lipid rich microdomains, are believed to play important roles as platforms for the partitioning of transmembrane and synaptic proteins involved in synaptic signalling, plasticity and maintenance. There is increasing evidence of a physical interaction between post-synaptic densities and post-synaptic lipid rafts. Localization of proteins within lipid rafts is highly regulated, and therefore lipid rafts may function as traffic lights modulating and fine-tuning neuronal signalling. The tyrosine kinase neurotrophin receptors (Trk and the low-affinity p75 neurotrophin receptor (p75NTR are enriched in neuronal lipid rafts together with the intermediates of downstream signalling pathways, suggesting a possible role of rafts in neurotrophin signalling. Moreover, neurotrophins and their receptors are involved in the regulation of cholesterol metabolism. Cholesterol is an important component of lipid rafts and its depletion leads to gradual loss of synapses, underscoring the importance of lipid rafts for proper neuronal function. Here, we review and discuss the idea that translocation of neurotrophin receptors in synaptic rafts may account for the selectivity of their transduced signals.

Pseudo Prune Belly Syndrome: Diagnosis Revealed by Imaging – A Case Report and Brief Review

Science.gov (United States)

Grover, Hemal; Sethi, Sanjay; Garg, Jatin; Ahluwalia, Amrit Pal

2017-01-01

Summary Background Prune Belly Syndrome (PBS) is a rare entity, usually found in male neonates. It comprises complex urinary tract anomalies, bilateral undescended testis and absence of anterior abdominal wall muscles. Patients with unilateral abdominal wall deficiency, unilateral undescended testis and female neonates with abdominal wall laxity are classified as Pseudo Prune Belly syndrome (PPBS). Reports on PPBS do not highlight the radiological and imaging characteristics of this syndrome and the current literature on the role of newer imaging modalities, such as Magnetic Resonance Imaging (MRI), remains relatively sparse. We describe a new case of PPBS and emphasize the role of imaging, especially ultrasound and MRI in the process of diagnosis and briefly review the subject. Case Report A male infant of four months of age was referred for evaluation of left-sided cryptorchidism. Clinical examination revealed laxity of the left abdominal wall. Ultrasound examination of the abdomen, pelvis and scrotum was performed together with routine laboratory tests. Ultrasound examination was followed by intravenous urography, voiding cysto-urethrography and MRI of the abdomen. On ultrasound, the left testis was located in the inguinal canal, the right kidney was slightly enlarged and the left kidney could not be localized. Ultrasound appearances suggested chronic obstruction in the urinary bladder. Intravenous urography, voiding cysto-urethrography and MRI confirmed the ultrasound diagnosis and also revealed a left dysplastic kidney with a dilated, tortuous ureter. Clinical and imaging features were consistent with pseudo prune belly syndrome (PPBS). Conclusions We report a new occurrence of PPBS, a rare entity. The imaging approach for a comprehensive evaluation of the renal system in PPBS, especially with MRI, is emphasized. PMID:28580040

Teores de carboidratos em pessegueiros submetidos a diferentes intensidades de poda verde em clima tropical Levels of carbohydrates in peaches submitted to different intensity of green pruning in tropical climate

Directory of Open Access Journals (Sweden)

Marcelo Rehder da Cunha Borba

2005-04-01

Full Text Available Com o objetivo de verificar a partição de assimilados entre a copa e raízes de pessegueiro, duas intensidades de poda verde, após a colheita dos frutos, foram efetuadas em pessegueiros 'Ouromel-2', na região de Piracicaba-SP: poda leve e poda de renovação (poda drástica. Os teores de carboidratos nas raízes e parte aérea foram determinados em vários estágios fenológicos da planta ao longo do ciclo. Verificou-se que existe uma fase de consumo de carboidratos, que vai deste a poda de dormência (poda seca até a maturação dos frutos e uma fase de acúmulo, que vai desde a maturação dos frutos até a queda das folhas. Plantas que sofreram poda leve apresentaram, de maneira geral, maiores teores de carboidratos ao longo do ciclo do que plantas que sofreram poda de renovação, apresentando, assim, maior potencial de produção.With the objective to verify the photosynthate partitioning in roots and canopy of peache trees, two intensity of green pruning: light pruning and renovation pruning (heavy pruning. After fruit harvest were evaluated in 'Ouromel-2' peach in Piracicaba-SP. The carbohydrates levels of roots and canopy were evaluated in several phonological stages of the tree during the crop cycle. It was verified that there is a phase of consumption of carbohydrates, from dormant pruning to the ripening of fruits, and a phase of accumulation of carbohydrates, from the ripening of fruits to the falling of the leaves. In general, plants lightly pruned showed higher levels of carbohydrates during the crop cycle if compared to heavily pruned plants, showing then, higher potential of production.

Coordinated gene expression of neuroinflammatory and cell signaling markers in dorsolateral prefrontal cortex during human brain development and aging.

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Primiani, Christopher T; Ryan, Veronica H; Rao, Jagadeesh S; Cam, Margaret C; Ahn, Kwangmi; Modi, Hiren R; Rapoport, Stanley I

2014-01-01

Age changes in expression of inflammatory, synaptic, and neurotrophic genes are not well characterized during human brain development and senescence. Knowing these changes may elucidate structural, metabolic, and functional brain processes over the lifespan, as well vulnerability to neurodevelopmental or neurodegenerative diseases. Expression levels of inflammatory, synaptic, and neurotrophic genes in the human brain are coordinated over the lifespan and underlie changes in phenotypic networks or cascades. We used a large-scale microarray dataset from human prefrontal cortex, BrainCloud, to quantify age changes over the lifespan, divided into Development (0 to 21 years, 87 brains) and Aging (22 to 78 years, 144 brains) intervals, in transcription levels of 39 genes. Gene expression levels followed different trajectories over the lifespan. Many changes were intercorrelated within three similar groups or clusters of genes during both Development and Aging, despite different roles of the gene products in the two intervals. During Development, changes were related to reported neuronal loss, dendritic growth and pruning, and microglial events; TLR4, IL1R1, NFKB1, MOBP, PLA2G4A, and PTGS2 expression increased in the first years of life, while expression of synaptic genes GAP43 and DBN1 decreased, before reaching plateaus. During Aging, expression was upregulated for potentially pro-inflammatory genes such as NFKB1, TRAF6, TLR4, IL1R1, TSPO, and GFAP, but downregulated for neurotrophic and synaptic integrity genes such as BDNF, NGF, PDGFA, SYN, and DBN1. Coordinated changes in gene transcription cascades underlie changes in synaptic, neurotrophic, and inflammatory phenotypic networks during brain Development and Aging. Early postnatal expression changes relate to neuronal, glial, and myelin growth and synaptic pruning events, while late Aging is associated with pro-inflammatory and synaptic loss changes. Thus, comparable transcriptional regulatory networks that operate

Épocas e intensidades de poda de frutificação na goiabeira ' Paluma' , em Pinheiros-ES Effect of pruning time and intensity on ' Paluma' guava trees, in Pinheiros, ES, Brazil

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Luiz Augusto Lopes Serrano

2008-12-01

Full Text Available Este trabalho teve como objetivo avaliar os efeitos de diferentes intensidades de poda de frutificação realizadas em diferentes épocas do ano sobre a fenologia e a produção da goiabeira 'Paluma', em Pinheiros-ES. As plantas foram submetidas a três intensidades de poda de frutificação (curta, média e longa, em quatro diferentes épocas (25-11-2005, 21-12-2005, 27-01-2006 e 23-02-2006. O ciclo da goiabeira 'Paluma', entre a poda até o início da colheita dos frutos, variou de 189 dias (podas em novembro e dezembro a 203 dias (poda em fevereiro. Independentemente da época de poda, as plantas submetidas à poda longa apresentaram maior emissão de brotos novos e maior número de ramos estabelecidos. As plantas submetidas à poda curta apresentaram menores números de brotos emitidos e de ramos estabelecidos, bem como menor índice de pegamento de frutos, menor número de frutos por planta e, conseqüentemente, menor produção; entretanto produziram frutos de maior peso médio em relação às plantas submetidas à poda longa. A maior produção e o maior número de frutos colhidos por planta ocorreram nas plantas podadas em fevereiro. A época e a intensidade da poda de frutificação afetam a brotação e a produção da goiabeira 'Paluma'.The objective of this work was to evaluate the effects of different pruning times and intensities on the phenology and yield of 'Paluma' guava trees, in Pinheiros, Espírito Santo State, Brazil. The plants were submitted to three pruning intensities (heavy, medium and light, in four dates (November 25, 2005; December 21, 2005; January 27, 2006 and February 23, 2006. The period between pruning and the beginning of fruit ripening varied from 189 (pruning in November and December to 203 days (pruning in February. Regardless of pruning time, the larger numbers of buds and established branches occurred in plants submitted to light pruning. Plants submitted to heavy pruning produced the smallest numbers of

Defective glycinergic synaptic transmission in zebrafish motility mutants

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Hiromi Hirata

2010-01-01

Full Text Available Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using molecular genetics. An ENU mutagenesis screen identified two behavioral mutants that are defective in glycinergic synaptic transmission. Zebrafish bandoneon (beo mutants have a defect in glrbb, one of the duplicated glycine receptor (GlyR β subunit genes. These mutants exhibit a loss of glycinergic synaptic transmission due to a lack of synaptic aggregation of GlyRs. Due to the consequent loss of reciprocal inhibition of motor circuits between the two sides of the spinal cord, motor neurons activate simultaneously on both sides resulting in bilateral contraction of axial muscles of beo mutants, eliciting the so-called ‘accordion’ phenotype. Similar defects in GlyR subunit genes have been observed in several mammals and are the basis for human hyperekplexia/startle disease. By contrast, zebrafish shocked (sho mutants have a defect in slc6a9, encoding GlyT1, a glycine transporter that is expressed by astroglial cells surrounding the glycinergic synapse in the hindbrain and spinal cord. GlyT1 mediates rapid uptake of glycine from the synaptic cleft, terminating synaptic transmission. In zebrafish sho mutants, there appears to be elevated extracellular glycine resulting in persistent inhibition of postsynaptic neurons and subsequent reduced motility, causing the ‘twitch once’ phenotype. We review current knowledge regarding zebrafish ‘accordion’ and ‘twitch once’ mutants, including beo and sho, and report the identification of a new α2 subunit that revises the phylogeny of zebrafish GlyRs.

Defective Glycinergic Synaptic Transmission in Zebrafish Motility Mutants

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Hirata, Hiromi; Carta, Eloisa; Yamanaka, Iori; Harvey, Robert J.; Kuwada, John Y.

2009-01-01

Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using molecular genetics. An ENU mutagenesis screen identified two behavioral mutants that are defective in glycinergic synaptic transmission. Zebrafish bandoneon (beo) mutants have a defect in glrbb, one of the duplicated glycine receptor (GlyR) β subunit genes. These mutants exhibit a loss of glycinergic synaptic transmission due to a lack of synaptic aggregation of GlyRs. Due to the consequent loss of reciprocal inhibition of motor circuits between the two sides of the spinal cord, motor neurons activate simultaneously on both sides resulting in bilateral contraction of axial muscles of beo mutants, eliciting the so-called ‘accordion’ phenotype. Similar defects in GlyR subunit genes have been observed in several mammals and are the basis for human hyperekplexia/startle disease. By contrast, zebrafish shocked (sho) mutants have a defect in slc6a9, encoding GlyT1, a glycine transporter that is expressed by astroglial cells surrounding the glycinergic synapse in the hindbrain and spinal cord. GlyT1 mediates rapid uptake of glycine from the synaptic cleft, terminating synaptic transmission. In zebrafish sho mutants, there appears to be elevated extracellular glycine resulting in persistent inhibition of postsynaptic neurons and subsequent reduced motility, causing the ‘twitch-once’ phenotype. We review current knowledge regarding zebrafish ‘accordion’ and ‘twitch-once’ mutants, including beo and sho, and report the identification of a new α2 subunit that revises the phylogeny of zebrafish GlyRs. PMID:20161699

Eficiência da poda em cafeeiros no controle da Xylella fastidiosa Prune efficiency in the control of Xylella fastidiosa in coffee trees

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Rachel Benetti Queiroz-Voltan

2006-01-01

management procedures have attenuated the disease incidence, such as the use of bacteria-free seedlings and insect vector control. Pruning is an important practice for optimization of coffee orchard production. Coffee growers refer to pruning as training; coffee tree training depends on the coffee plant type and environment, using traditional or drastic trimming. This research aimed at evaluating the efficiency of different prune procedures in the control of X. fastidiosa incidence in coffee commercial cultivars Acaiá IAC 474-19 and Catuaí Vermelho IAC 81. Eight plants of each cultivar were submitted to three pruning types (traditional, "skeleton cut" and trunking; and eight plants were not pruned (controls. Prior to pruning, five plant branches were collected for anatomical studies. Thereafter, five other branches from all treatments were collected in October/2004 (rainy period and June/2005 (dry period for the anatomical studies. No significant differences were observed for `Acaiá IAC 474-19' that presented lower proportion of xylem vessel obstruction independent of the prune treatment. Prune treatments in `Catuaí Vermelho IAC 81' were also not significantly different; however, plants submitted to dramatic trimmings such as the "skeleton cut" and trunking showed a trend for lower proportion of xylem vessel obstruction by the bacteria, in both rainy and dry periods. It was suggested that the drastic pruning procedures ("skeleton cut" and trunking might be advantageous for the Xyllela control in situations of high disease incidence.

Frequência e intensidade de poda em pomar jovem de laranjeiras 'Valência' sob manejo orgânico Frequency and intensity of pruning young 'Valencia' orange trees in orchards under organic culture system

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Emiliano Santarosa

2010-10-01

Full Text Available Este trabalho teve por objetivo avaliar o efeito da frequência e intensidade de poda sobre a produção e qualidade dos frutos da laranjeira 'Valência', enxertada sobre Poncirus trifoliata, em pomar jovem, sob sistema de manejo orgânico. O plantio foi realizado em agosto de 2001, em espaçamento de 5,0x2,5m, em Montenegro, Rio Grande do Sul (RS. Os tratamentos testados foram: A - Testemunha (sem poda; B - Poda anual de 15%; C - Poda bienal de 15%; D - Poda bienal de 30%; e E - Poda trienal de 30% do volume da copa. O delineamento experimental foi de blocos ao acaso, sendo quatro repetições e quatro plantas por parcela. Nas safras de 2006, 2007 e 2008, foram avaliados: número, massa total de frutos e massa média dos frutos, teor de sólidos solúveis totais (SST, acidez total titulável (ATT e relação SST/AT do suco dos frutos. Em pomares jovens, com menos de sete anos de idade, durante três safras consecutivas, verificou-se que as podas de frutificação não alteram a produção acumulada, nem a qualidade físico-química dos frutos, mas reduzem a produção no ano subsequente à execução da poda.This study evaluated the influence of frequency and intensity of pruning on young orchards, with organic management system, on the yield and fruit quality of 'Valencia' oranges. The trees were budded on Poncirus trifoliata rootstock and implanted in August, 2001, in Montenegro-RS. The pruning tested was: A - control, without pruning; B - annual pruning of 15%; C - biennial pruning of 15%; D - biennial pruning of 30% and E - three-year 30% pruning of the canopy volume. The experiment had a randomized complete-block design, with four-trees plots and four replications. The total fruit mass production was registered and the average weight fruit in the crops 2006, 2007 and 2008 was determined. The fruit quality, total soluble solids (TSS, total acids concentration (TTA and ratio (TSS/TTA were assessed. In orchards with fewer than seven years old

Experience-Dependent Equilibration of AMPAR-Mediated Synaptic Transmission during the Critical Period

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Kyung-Seok Han

2017-01-01

Full Text Available Experience-dependent synapse refinement is essential for functional optimization of neural circuits. However, how sensory experience sculpts excitatory synaptic transmission is poorly understood. Here, we show that despite substantial remodeling of synaptic connectivity, AMPAR-mediated synaptic transmission remains at equilibrium during the critical period in the mouse primary visual cortex. The maintenance of this equilibrium requires neurogranin (Ng, a postsynaptic calmodulin-binding protein important for synaptic plasticity. With normal visual experience, loss of Ng decreased AMPAR-positive synapse numbers, prevented AMPAR-silent synapse maturation, and increased spine elimination. Importantly, visual deprivation halted synapse loss caused by loss of Ng, revealing that Ng coordinates experience-dependent AMPAR-silent synapse conversion to AMPAR-active synapses and synapse elimination. Loss of Ng also led to sensitized long-term synaptic depression (LTD and impaired visually guided behavior. Our synaptic interrogation reveals that experience-dependent coordination of AMPAR-silent synapse conversion and synapse elimination hinges upon Ng-dependent mechanisms for constructive synaptic refinement during the critical period.

Cell-specific gain modulation by synaptically released zinc in cortical circuits of audition.

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Anderson, Charles T; Kumar, Manoj; Xiong, Shanshan; Tzounopoulos, Thanos

2017-09-09

In many excitatory synapses, mobile zinc is found within glutamatergic vesicles and is coreleased with glutamate. Ex vivo studies established that synaptically released (synaptic) zinc inhibits excitatory neurotransmission at lower frequencies of synaptic activity but enhances steady state synaptic responses during higher frequencies of activity. However, it remains unknown how synaptic zinc affects neuronal processing in vivo. Here, we imaged the sound-evoked neuronal activity of the primary auditory cortex in awake mice. We discovered that synaptic zinc enhanced the gain of sound-evoked responses in CaMKII-expressing principal neurons, but it reduced the gain of parvalbumin- and somatostatin-expressing interneurons. This modulation was sound intensity-dependent and, in part, NMDA receptor-independent. By establishing a previously unknown link between synaptic zinc and gain control of auditory cortical processing, our findings advance understanding about cortical synaptic mechanisms and create a new framework for approaching and interpreting the role of the auditory cortex in sound processing.

Spatiotemporal discrimination in neural networks with short-term synaptic plasticity

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Shlaer, Benjamin; Miller, Paul

2015-03-01

Cells in recurrently connected neural networks exhibit bistability, which allows for stimulus information to persist in a circuit even after stimulus offset, i.e. short-term memory. However, such a system does not have enough hysteresis to encode temporal information about the stimuli. The biophysically described phenomenon of synaptic depression decreases synaptic transmission strengths due to increased presynaptic activity. This short-term reduction in synaptic strengths can destabilize attractor states in excitatory recurrent neural networks, causing the network to move along stimulus dependent dynamical trajectories. Such a network can successfully separate amplitudes and durations of stimuli from the number of successive stimuli. Stimulus number, duration and intensity encoding in randomly connected attractor networks with synaptic depression. Front. Comput. Neurosci. 7:59., and so provides a strong candidate network for the encoding of spatiotemporal information. Here we explicitly demonstrate the capability of a recurrent neural network with short-term synaptic depression to discriminate between the temporal sequences in which spatial stimuli are presented.

[Involvement of aquaporin-4 in synaptic plasticity, learning and memory].

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Wu, Xin; Gao, Jian-Feng

2017-06-25

Aquaporin-4 (AQP-4) is the predominant water channel in the central nervous system (CNS) and primarily expressed in astrocytes. Astrocytes have been generally believed to play important roles in regulating synaptic plasticity and information processing. However, the role of AQP-4 in regulating synaptic plasticity, learning and memory, cognitive function is only beginning to be investigated. It is well known that synaptic plasticity is the prime candidate for mediating of learning and memory. Long term potentiation (LTP) and long term depression (LTD) are two forms of synaptic plasticity, and they share some but not all the properties and mechanisms. Hippocampus is a part of limbic system that is particularly important in regulation of learning and memory. This article is to review some research progresses of the function of AQP-4 in synaptic plasticity, learning and memory, and propose the possible role of AQP-4 as a new target in the treatment of cognitive dysfunction.

Neuronal cytoskeleton in synaptic plasticity and regeneration.

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Gordon-Weeks, Phillip R; Fournier, Alyson E

2014-04-01

During development, dynamic changes in the axonal growth cone and dendrite are necessary for exploratory movements underlying initial axo-dendritic contact and ultimately the formation of a functional synapse. In the adult central nervous system, an impressive degree of plasticity is retained through morphological and molecular rearrangements in the pre- and post-synaptic compartments that underlie the strengthening or weakening of synaptic pathways. Plasticity is regulated by the interplay of permissive and inhibitory extracellular cues, which signal through receptors at the synapse to regulate the closure of critical periods of developmental plasticity as well as by acute changes in plasticity in response to experience and activity in the adult. The molecular underpinnings of synaptic plasticity are actively studied and it is clear that the cytoskeleton is a key substrate for many cues that affect plasticity. Many of the cues that restrict synaptic plasticity exhibit residual activity in the injured adult CNS and restrict regenerative growth by targeting the cytoskeleton. Here, we review some of the latest insights into how cytoskeletal remodeling affects neuronal plasticity and discuss how the cytoskeleton is being targeted in an effort to promote plasticity and repair following traumatic injury in the central nervous system. © 2013 International Society for Neurochemistry.

Distinct Subunit Domains Govern Synaptic Stability and Specificity of the Kainate Receptor

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Christoph Straub

2016-07-01

Full Text Available Synaptic communication between neurons requires the precise localization of neurotransmitter receptors to the correct synapse type. Kainate-type glutamate receptors restrict synaptic localization that is determined by the afferent presynaptic connection. The mechanisms that govern this input-specific synaptic localization remain unclear. Here, we examine how subunit composition and specific subunit domains contribute to synaptic localization of kainate receptors. The cytoplasmic domain of the GluK2 low-affinity subunit stabilizes kainate receptors at synapses. In contrast, the extracellular domain of the GluK4/5 high-affinity subunit synergistically controls the synaptic specificity of kainate receptors through interaction with C1q-like proteins. Thus, the input-specific synaptic localization of the native kainate receptor complex involves two mechanisms that underlie specificity and stabilization of the receptor at synapses.

Pruning high-value Douglas-fir can reduce dwarf mistletoe severity and increase longevity in Central Oregon

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Helen M. Maffei; Gregory M. Filip; Nancy E. Grulke; Brent W. Oblinger; Ellis Q. Margolis; Kristen L. Chadwick

2016-01-01

Mid- to very large-sized Douglas-fir (Pseudotsuga menzieseii var. menziesii) that were lightly- to moderately-infected by dwarf mistletoe (Arceuthobium douglasii) were analyzed over a 14-year period to evaluate whether mechanical pruning could eradicate mistletoe (or at least delay the onset of severe infection) without...

Synaptic excitation in spinal motoneurons alternates with synaptic inhibition and is balanced by outward rectification during rhythmic motor network activity

DEFF Research Database (Denmark)

Guzulaitis, Robertas; Hounsgaard, Jorn

2017-01-01

channels. Intrinsic outward rectification facilitates spiking by focusing synaptic depolarization near threshold for action potentials. By direct recording of synaptic currents, we also show that motoneurons are activated by out-of-phase peaks in excitation and inhibition during network activity, whereas......Regular firing in spinal motoneurons of red-eared turtles (Trachemys scripta elegans, either sex) evoked by steady depolarization at rest is replaced by irregular firing during functional network activity. The transition caused by increased input conductance and synaptic fluctuations in membrane...... potential was suggested to originate from intense concurrent inhibition and excitation. We show that the conductance increase in motoneurons during functional network activity is mainly caused by intrinsic outward rectification near threshold for action potentials by activation of voltage and Ca2+ gated K...

Synaptic heterogeneity and stimulus-induced modulation of depression in central synapses.

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Hunter, J D; Milton, J G

2001-08-01

Short-term plasticity is a pervasive feature of synapses. Synapses exhibit many forms of plasticity operating over a range of time scales. We develop an optimization method that allows rapid characterization of synapses with multiple time scales of facilitation and depression. Investigation of paired neurons that are postsynaptic to the same identified interneuron in the buccal ganglion of Aplysia reveals that the responses of the two neurons differ in the magnitude of synaptic depression. Also, for single neurons, prolonged stimulation of the presynaptic neuron causes stimulus-induced increases in the early phase of synaptic depression. These observations can be described by a model that incorporates two availability factors, e.g., depletable vesicle pools or desensitizing receptor populations, with different time courses of recovery, and a single facilitation component. This model accurately predicts the responses to novel stimuli. The source of synaptic heterogeneity is identified with variations in the relative sizes of the two availability factors, and the stimulus-induced decrement in the early synaptic response is explained by a slowing of the recovery rate of one of the availability factors. The synaptic heterogeneity and stimulus-induced modifications in synaptic depression observed here emphasize that synaptic efficacy depends on both the individual properties of synapses and their past history.

Synaptic theory of Replicator-like melioration

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Yonatan Loewenstein

2010-06-01

Full Text Available According to the theory of Melioration, organisms in repeated choice settings shift their choice preference in favor of the alternative that provides the highest return. The goal of this paper is to explain how this learning behavior can emerge from microscopic changes in the efficacies of synapses, in the context of two-alternative repeated-choice experiment. I consider a large family of synaptic plasticity rules in which changes in synaptic efficacies are driven by the covariance between reward and neural activity. I construct a general framework that predicts the learning dynamics of any decision-making neural network that implements this synaptic plasticity rule and show that melioration naturally emerges in such networks. Moreover, the resultant learning dynamics follows the Replicator equation which is commonly used to phenomenologically describe changes in behavior in operant conditioning experiments. Several examples demonstrate how the learning rate of the network is affected by its properties and by the specifics of the plasticity rule. These results help bridge the gap between cellular physiology and learning behavior.

Factors Influencing Short-term Synaptic Plasticity in the Avian Cochlear Nucleus Magnocellularis

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Jason Tait Sanchez Quinones

2015-01-01

Full Text Available Defined as reduced neural responses during high rates of activity, synaptic depression is a form of short-term plasticity important for the temporal filtering of sound. In the avian cochlear nucleus magnocellularis (NM, an auditory brainstem structure, mechanisms regulating short-term synaptic depression include pre-, post-, and extrasynaptic factors. Using varied paired-pulse stimulus intervals, we found that the time course of synaptic depression lasts up to four seconds at late-developing NM synapses. Synaptic depression was largely reliant on exogenous Ca 2+ -dependent probability of presynaptic neurotransmitter release, and to a lesser extent, on the desensitization of postsynaptic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-type glutamate receptor (AMPA-R. Interestingly, although extrasynaptic glutamate clearance did not play a significant role in regulating synaptic depression, blocking glutamate clearance at early-developing synapses altered synaptic dynamics, changing responses from depression to facilitation. These results suggest a developmental shift in the relative reliance on pre-, post-, and extrasynaptic factors in regulating short-term synaptic plasticity in NM.

Shank synaptic scaffold proteins: keys to understanding the pathogenesis of autism and other synaptic disorders.

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Sala, Carlo; Vicidomini, Cinzia; Bigi, Ilaria; Mossa, Adele; Verpelli, Chiara

2015-12-01

Shank/ProSAP proteins are essential to synaptic formation, development, and function. Mutations in the family of SHANK genes are strongly associated with autism spectrum disorders (ASD) and other neurodevelopmental and neuropsychiatric disorders, such as intellectual disability (ID), and schizophrenia. Thus, the term 'Shankopathies' identifies a number of neuronal diseases caused by alteration of Shank protein expression leading to abnormal synaptic development. With this review we want to summarize the major genetic, molecular, behavior and electrophysiological studies that provide new clues into the function of Shanks and pave the way for the discovery of new therapeutic drugs targeted to treat patients with SHANK mutations and also patients affected by other neurodevelopmental and neuropsychiatric disorders. Shank/ProSAP proteins are essential to synaptic formation, development, and function. Mutations in the family of SHANK genes are strongly associated with autism spectrum disorders (ASD) and other neurodevelopmental and neuropsychiatric disorders, such as intellectual disability (ID), and schizophrenia (SCZ). With this review we want to summarize the major genetic, molecular, behavior and electrophysiological studies that provide new clues into the function of Shanks and pave the way for the discovery of new therapeutic drugs targeted to treat patients with SHANK mutations. © 2015 International Society for Neurochemistry.

Classification Based on Pruning and Double Covered Rule Sets for the Internet of Things Applications

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Zhou, Zhongmei; Wang, Weiping

2014-01-01

The Internet of things (IOT) is a hot issue in recent years. It accumulates large amounts of data by IOT users, which is a great challenge to mining useful knowledge from IOT. Classification is an effective strategy which can predict the need of users in IOT. However, many traditional rule-based classifiers cannot guarantee that all instances can be covered by at least two classification rules. Thus, these algorithms cannot achieve high accuracy in some datasets. In this paper, we propose a new rule-based classification, CDCR-P (Classification based on the Pruning and Double Covered Rule sets). CDCR-P can induce two different rule sets A and B. Every instance in training set can be covered by at least one rule not only in rule set A, but also in rule set B. In order to improve the quality of rule set B, we take measure to prune the length of rules in rule set B. Our experimental results indicate that, CDCR-P not only is feasible, but also it can achieve high accuracy. PMID:24511304

Classification based on pruning and double covered rule sets for the internet of things applications.

Science.gov (United States)

Li, Shasha; Zhou, Zhongmei; Wang, Weiping

2014-01-01

The Internet of things (IOT) is a hot issue in recent years. It accumulates large amounts of data by IOT users, which is a great challenge to mining useful knowledge from IOT. Classification is an effective strategy which can predict the need of users in IOT. However, many traditional rule-based classifiers cannot guarantee that all instances can be covered by at least two classification rules. Thus, these algorithms cannot achieve high accuracy in some datasets. In this paper, we propose a new rule-based classification, CDCR-P (Classification based on the Pruning and Double Covered Rule sets). CDCR-P can induce two different rule sets A and B. Every instance in training set can be covered by at least one rule not only in rule set A, but also in rule set B. In order to improve the quality of rule set B, we take measure to prune the length of rules in rule set B. Our experimental results indicate that, CDCR-P not only is feasible, but also it can achieve high accuracy.

Synaptic vesicle dynamic changes in a model of fragile X.

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Broek, Jantine A C; Lin, Zhanmin; de Gruiter, H Martijn; van 't Spijker, Heleen; Haasdijk, Elize D; Cox, David; Ozcan, Sureyya; van Cappellen, Gert W A; Houtsmuller, Adriaan B; Willemsen, Rob; de Zeeuw, Chris I; Bahn, Sabine

2016-01-01

Fragile X syndrome (FXS) is a single-gene disorder that is the most common heritable cause of intellectual disability and the most frequent monogenic cause of autism spectrum disorders (ASD). FXS is caused by an expansion of trinucleotide repeats in the promoter region of the fragile X mental retardation gene (Fmr1). This leads to a lack of fragile X mental retardation protein (FMRP), which regulates translation of a wide range of messenger RNAs (mRNAs). The extent of expression level alterations of synaptic proteins affected by FMRP loss and their consequences on synaptic dynamics in FXS has not been fully investigated. Here, we used an Fmr1 knockout (KO) mouse model to investigate the molecular mechanisms underlying FXS by monitoring protein expression changes using shotgun label-free liquid-chromatography mass spectrometry (LC-MS(E)) in brain tissue and synaptosome fractions. FXS-associated candidate proteins were validated using selected reaction monitoring (SRM) in synaptosome fractions for targeted protein quantification. Furthermore, functional alterations in synaptic release and dynamics were evaluated using live-cell imaging, and interpretation of synaptic dynamics differences was investigated using electron microscopy. Key findings relate to altered levels of proteins involved in GABA-signalling, especially in the cerebellum. Further exploration using microscopy studies found reduced synaptic vesicle unloading of hippocampal neurons and increased vesicle unloading in cerebellar neurons, which suggests a general decrease of synaptic transmission. Our findings suggest that FMRP is a regulator of synaptic vesicle dynamics, which supports the role of FMRP in presynaptic functions. Taken together, these studies provide novel insights into the molecular changes associated with FXS.

Modulation of extrasynaptic NMDA receptors by synaptic and tonic zinc.

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Anderson, Charles T; Radford, Robert J; Zastrow, Melissa L; Zhang, Daniel Y; Apfel, Ulf-Peter; Lippard, Stephen J; Tzounopoulos, Thanos

2015-05-19

Many excitatory synapses contain high levels of mobile zinc within glutamatergic vesicles. Although synaptic zinc and glutamate are coreleased, it is controversial whether zinc diffuses away from the release site or whether it remains bound to presynaptic membranes or proteins after its release. To study zinc transmission and quantify zinc levels, we required a high-affinity rapid zinc chelator as well as an extracellular ratiometric fluorescent zinc sensor. We demonstrate that tricine, considered a preferred chelator for studying the role of synaptic zinc, is unable to efficiently prevent zinc from binding low-nanomolar zinc-binding sites, such as the high-affinity zinc-binding site found in NMDA receptors (NMDARs). Here, we used ZX1, which has a 1 nM zinc dissociation constant and second-order rate constant for binding zinc that is 200-fold higher than those for tricine and CaEDTA. We find that synaptic zinc is phasically released during action potentials. In response to short trains of presynaptic stimulation, synaptic zinc diffuses beyond the synaptic cleft where it inhibits extrasynaptic NMDARs. During higher rates of presynaptic stimulation, released glutamate activates additional extrasynaptic NMDARs that are not reached by synaptically released zinc, but which are inhibited by ambient, tonic levels of nonsynaptic zinc. By performing a ratiometric evaluation of extracellular zinc levels in the dorsal cochlear nucleus, we determined the tonic zinc levels to be low nanomolar. These results demonstrate a physiological role for endogenous synaptic as well as tonic zinc in inhibiting extrasynaptic NMDARs and thereby fine tuning neuronal excitability and signaling.

Modulation of extrasynaptic NMDA receptors by synaptic and tonic zinc

Science.gov (United States)

Anderson, Charles T.; Radford, Robert J.; Zastrow, Melissa L.; Zhang, Daniel Y.; Apfel, Ulf-Peter; Lippard, Stephen J.; Tzounopoulos, Thanos

2015-01-01

Many excitatory synapses contain high levels of mobile zinc within glutamatergic vesicles. Although synaptic zinc and glutamate are coreleased, it is controversial whether zinc diffuses away from the release site or whether it remains bound to presynaptic membranes or proteins after its release. To study zinc transmission and quantify zinc levels, we required a high-affinity rapid zinc chelator as well as an extracellular ratiometric fluorescent zinc sensor. We demonstrate that tricine, considered a preferred chelator for studying the role of synaptic zinc, is unable to efficiently prevent zinc from binding low-nanomolar zinc-binding sites, such as the high-affinity zinc-binding site found in NMDA receptors (NMDARs). Here, we used ZX1, which has a 1 nM zinc dissociation constant and second-order rate constant for binding zinc that is 200-fold higher than those for tricine and CaEDTA. We find that synaptic zinc is phasically released during action potentials. In response to short trains of presynaptic stimulation, synaptic zinc diffuses beyond the synaptic cleft where it inhibits extrasynaptic NMDARs. During higher rates of presynaptic stimulation, released glutamate activates additional extrasynaptic NMDARs that are not reached by synaptically released zinc, but which are inhibited by ambient, tonic levels of nonsynaptic zinc. By performing a ratiometric evaluation of extracellular zinc levels in the dorsal cochlear nucleus, we determined the tonic zinc levels to be low nanomolar. These results demonstrate a physiological role for endogenous synaptic as well as tonic zinc in inhibiting extrasynaptic NMDARs and thereby fine tuning neuronal excitability and signaling. PMID:25947151

Leucine-rich repeat-containing synaptic adhesion molecules as organizers of synaptic specificity and diversity.

Science.gov (United States)

Schroeder, Anna; de Wit, Joris

2018-04-09

The brain harbors billions of neurons that form distinct neural circuits with exquisite specificity. Specific patterns of connectivity between distinct neuronal cell types permit the transfer and computation of information. The molecular correlates that give rise to synaptic specificity are incompletely understood. Recent studies indicate that cell-surface molecules are important determinants of cell type identity and suggest that these are essential players in the specification of synaptic connectivity. Leucine-rich repeat (LRR)-containing adhesion molecules in particular have emerged as key organizers of excitatory and inhibitory synapses. Here, we discuss emerging evidence that LRR proteins regulate the assembly of specific connectivity patterns across neural circuits, and contribute to the diverse structural and functional properties of synapses, two key features that are critical for the proper formation and function of neural circuits.

Marjane Satrapi’s Poulet aux Prunes: fetish, desire, and illusions

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Stefania Rimini

2013-07-01

Full Text Available Il saggio si propone di individuare e descrivere le sfumature erotiche e sentimentali del film Poulet aux prunes di Marjane Satrapi, felice adattamento dell’omonima graphic novel. Il racconto procede per scarti, ellissi, anticipazioni e flasback, dando luogo a una narrazione labirintica dalla singolare trama arabescante. Le sottili dinamiche seduttive messe in campo dal complesso stile di regia di Satrapi-Paronnaud vengono analizzate alla luce delle categorie feticistiche individuate da Massimo Fusillo, che offrono interessanti modelli di interazione fra desiderio e creatività. L’esito di tale indagine consente di ampliare il dibattito relativo al rapporto di scambio e interferenza fra oggetti, pulsioni e sguardi nel cinema contemporaneo.

Long-term relationships between cholinergic tone, synchronous bursting and synaptic remodeling.

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Maya Kaufman

Full Text Available Cholinergic neuromodulation plays key roles in the regulation of neuronal excitability, network activity, arousal, and behavior. On longer time scales, cholinergic systems play essential roles in cortical development, maturation, and plasticity. Presumably, these processes are associated with substantial synaptic remodeling, yet to date, long-term relationships between cholinergic tone and synaptic remodeling remain largely unknown. Here we used automated microscopy combined with multielectrode array recordings to study long-term relationships between cholinergic tone, excitatory synapse remodeling, and network activity characteristics in networks of cortical neurons grown on multielectrode array substrates. Experimental elevations of cholinergic tone led to the abrupt suppression of episodic synchronous bursting activity (but not of general activity, followed by a gradual growth of excitatory synapses over hours. Subsequent blockage of cholinergic receptors led to an immediate restoration of synchronous bursting and the gradual reversal of synaptic growth. Neither synaptic growth nor downsizing was governed by multiplicative scaling rules. Instead, these occurred in a subset of synapses, irrespective of initial synaptic size. Synaptic growth seemed to depend on intrinsic network activity, but not on the degree to which bursting was suppressed. Intriguingly, sustained elevations of cholinergic tone were associated with a gradual recovery of synchronous bursting but not with a reversal of synaptic growth. These findings show that cholinergic tone can strongly affect synaptic remodeling and synchronous bursting activity, but do not support a strict coupling between the two. Finally, the reemergence of synchronous bursting in the presence of elevated cholinergic tone indicates that the capacity of cholinergic neuromodulation to indefinitely suppress synchronous bursting might be inherently limited.

Long-term Relationships between Cholinergic Tone, Synchronous Bursting and Synaptic Remodeling

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Kaufman, Maya; Corner, Michael A.; Ziv, Noam E.

2012-01-01

Cholinergic neuromodulation plays key roles in the regulation of neuronal excitability, network activity, arousal, and behavior. On longer time scales, cholinergic systems play essential roles in cortical development, maturation, and plasticity. Presumably, these processes are associated with substantial synaptic remodeling, yet to date, long-term relationships between cholinergic tone and synaptic remodeling remain largely unknown. Here we used automated microscopy combined with multielectrode array recordings to study long-term relationships between cholinergic tone, excitatory synapse remodeling, and network activity characteristics in networks of cortical neurons grown on multielectrode array substrates. Experimental elevations of cholinergic tone led to the abrupt suppression of episodic synchronous bursting activity (but not of general activity), followed by a gradual growth of excitatory synapses over hours. Subsequent blockage of cholinergic receptors led to an immediate restoration of synchronous bursting and the gradual reversal of synaptic growth. Neither synaptic growth nor downsizing was governed by multiplicative scaling rules. Instead, these occurred in a subset of synapses, irrespective of initial synaptic size. Synaptic growth seemed to depend on intrinsic network activity, but not on the degree to which bursting was suppressed. Intriguingly, sustained elevations of cholinergic tone were associated with a gradual recovery of synchronous bursting but not with a reversal of synaptic growth. These findings show that cholinergic tone can strongly affect synaptic remodeling and synchronous bursting activity, but do not support a strict coupling between the two. Finally, the reemergence of synchronous bursting in the presence of elevated cholinergic tone indicates that the capacity of cholinergic neuromodulation to indefinitely suppress synchronous bursting might be inherently limited. PMID:22911726

Long-term relationships between cholinergic tone, synchronous bursting and synaptic remodeling.

Science.gov (United States)

Kaufman, Maya; Corner, Michael A; Ziv, Noam E

2012-01-01

Cholinergic neuromodulation plays key roles in the regulation of neuronal excitability, network activity, arousal, and behavior. On longer time scales, cholinergic systems play essential roles in cortical development, maturation, and plasticity. Presumably, these processes are associated with substantial synaptic remodeling, yet to date, long-term relationships between cholinergic tone and synaptic remodeling remain largely unknown. Here we used automated microscopy combined with multielectrode array recordings to study long-term relationships between cholinergic tone, excitatory synapse remodeling, and network activity characteristics in networks of cortical neurons grown on multielectrode array substrates. Experimental elevations of cholinergic tone led to the abrupt suppression of episodic synchronous bursting activity (but not of general activity), followed by a gradual growth of excitatory synapses over hours. Subsequent blockage of cholinergic receptors led to an immediate restoration of synchronous bursting and the gradual reversal of synaptic growth. Neither synaptic growth nor downsizing was governed by multiplicative scaling rules. Instead, these occurred in a subset of synapses, irrespective of initial synaptic size. Synaptic growth seemed to depend on intrinsic network activity, but not on the degree to which bursting was suppressed. Intriguingly, sustained elevations of cholinergic tone were associated with a gradual recovery of synchronous bursting but not with a reversal of synaptic growth. These findings show that cholinergic tone can strongly affect synaptic remodeling and synchronous bursting activity, but do not support a strict coupling between the two. Finally, the reemergence of synchronous bursting in the presence of elevated cholinergic tone indicates that the capacity of cholinergic neuromodulation to indefinitely suppress synchronous bursting might be inherently limited.

Drosophila-Cdh1 (Rap/Fzr) a regulatory subunit of APC/C is required for synaptic morphology, synaptic transmission and locomotion.

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Wise, Alexandria; Schatoff, Emma; Flores, Julian; Hua, Shao-Ying; Ueda, Atsushi; Wu, Chun-Fang; Venkatesh, Tadmiri

2013-11-01

The assembly of functional synapses requires the orchestration of the synthesis and degradation of a multitude of proteins. Protein degradation and modification by the conserved ubiquitination pathway has emerged as a key cellular regulatory mechanism during nervous system development and function (Kwabe and Brose, 2011). The anaphase promoting complex/cyclosome (APC/C) is a multi-subunit ubiquitin ligase complex primarily characterized for its role in the regulation of mitosis (Peters, 2002). In recent years, a role for APC/C in nervous system development and function has been rapidly emerging (Stegmuller and Bonni, 2005; Li et al., 2008). In the mammalian central nervous system the activator subunit, APC/C-Cdh1, has been shown to be a regulator of axon growth and dendrite morphogenesis (Konishi et al., 2004). In the Drosophila peripheral nervous system (PNS), APC2, a ligase subunit of the APC/C complex has been shown to regulate synaptic bouton size and activity (van Roessel et al., 2004). To investigate the role of APC/C-Cdh1 at the synapse we examined loss-of-function mutants of Rap/Fzr (Retina aberrant in pattern/Fizzy related), a Drosophila homolog of the mammalian Cdh1 during the development of the larval neuromuscular junction in Drosophila. Our cell biological, ultrastructural, electrophysiological, and behavioral data showed that rap/fzr loss-of-function mutations lead to changes in synaptic structure and function as well as locomotion defects. Data presented here show changes in size and morphology of synaptic boutons, and, muscle tissue organization. Electrophysiological experiments show that loss-of-function mutants exhibit increased frequency of spontaneous miniature synaptic potentials, indicating a higher rate of spontaneous synaptic vesicle fusion events. In addition, larval locomotion and peristaltic movement were also impaired. These findings suggest a role for Drosophila APC/C-Cdh1 mediated ubiquitination in regulating synaptic morphology

Statistical theory of synaptic connectivity in the neocortex

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Escobar, Gina

Learning and long-term memory rely on plasticity of neural circuits. In adult cerebral cortex plasticity can be mediated by modulation of existing synapses and structural reorganization of circuits through growth and retraction of dendritic spines. In the first part of this thesis, we describe a theoretical framework for the analysis of spine remodeling plasticity. New synaptic contacts appear in the neuropil where gaps between axonal and dendritic branches can be bridged by dendritic spines. Such sites are termed potential synapses. We derive expressions for the densities of potential synapses in the neuropil. We calculate the ratio of actual to potential synapses, called the connectivity fraction, and use it to find the number of structurally different circuits attainable with spine remodeling. These parameters are calculated in four systems: mouse occipital cortex, rat hippocampal area CA1, monkey primary visual (V1), and human temporal cortex. The neurogeometric results indicate that a dendritic spine can choose among an average of 4-7 potential targets in rodents, while in primates it can choose from 10-20 potential targets. The potential of the neuropil to undergo circuit remodeling is found to be highest in rat CA1 (4.9-6.0 nats/mum 3) and lowest in monkey V1 (0.9-1.0 nats/mum3). We evaluate the lower bound of neuron selectivity in the choice of synaptic partners and find that post-synaptic excitatory neurons in rodents make synaptic contacts with more than 21-30% of pre-synaptic axons encountered with new spine growth. Primate neurons appear to be more selective, making synaptic connections with more than 7-15% of encountered axons. Another plasticity mechanism is included in the second part of this work: long-term potentiation and depression of excitatory synaptic connections. Because synaptic strength is correlated with the size of the synapse, the former can be inferred from the distribution of spine head volumes. To this end we analyze and compare 166

The Corticohippocampal Circuit, Synaptic Plasticity, and Memory

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Basu, Jayeeta; Siegelbaum, Steven A.

2015-01-01

Synaptic plasticity serves as a cellular substrate for information storage in the central nervous system. The entorhinal cortex (EC) and hippocampus are interconnected brain areas supporting basic cognitive functions important for the formation and retrieval of declarative memories. Here, we discuss how information flow in the EC–hippocampal loop is organized through circuit design. We highlight recently identified corticohippocampal and intrahippocampal connections and how these long-range and local microcircuits contribute to learning. This review also describes various forms of activity-dependent mechanisms that change the strength of corticohippocampal synaptic transmission. A key point to emerge from these studies is that patterned activity and interaction of coincident inputs gives rise to associational plasticity and long-term regulation of information flow. Finally, we offer insights about how learning-related synaptic plasticity within the corticohippocampal circuit during sensory experiences may enable adaptive behaviors for encoding spatial, episodic, social, and contextual memories. PMID:26525152

Synaptic control of motoneuronal excitability

DEFF Research Database (Denmark)

Rekling, J C; Funk, G D; Bayliss, D A

2000-01-01

important in understanding the transformation of neural activity to motor behavior. Here, we review recent studies on the control of motoneuronal excitability, focusing on synaptic and cellular properties. We first present a background description of motoneurons: their development, anatomical organization......, and membrane properties, both passive and active. We then describe the general anatomical organization of synaptic input to motoneurons, followed by a description of the major transmitter systems that affect motoneuronal excitability, including ligands, receptor distribution, pre- and postsynaptic actions...... and norepinephrine, and neuropeptides, as well as the glutamate and GABA acting at metabotropic receptors, modulate motoneuronal excitability through pre- and postsynaptic actions. Acting principally via second messenger systems, their actions converge on common effectors, e.g., leak K(+) current, cationic inward...

PRUNE BELLY SYNDROME: CASE REPORT OF A FAILED MANAGEMENT IN A LOWINCOME COUNTRY.

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Marcella Schiavone

2016-04-01

Full Text Available Prune Belly Syndrome (PBS is a rare congenital syndrome characterized by three main features: abdominal wall flaccidity, bilateral intra-abdominal cryptorchidism, and urologic abnormalities. In this study we describe the case of a 2,600 gr baby, born at the Central Hospital of Beira, Mozambique. Our study confirms that in a low-income country only conservative management can be delivered, and therefore prognosis is worse and less effective than high-income countries.

Época de poda da figueira cultivada no estado de São Paulo Pruning time for fig trees in the state of São Paulo

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Orlando Rigitano

1963-01-01

Full Text Available No Estado de São Paulo as figueiras (Ficus carica L. são anualmente submetidas a um tipo de poda hibernal que consiste na eliminação quase total da copa formada na estação anterior. Com a finalidade de estudar o comportamento de figueiras podadas em diferentes épocas durante o inverno, foi iniciado em 1960, em Campinas, um experimento com cinco épocas de poda no período de 1.° de maio a 1.° de setembro. São apresentados os dados de produção, por tratamento obtidos em 1962 e 1963, relativos ao número e ao pêso de figos, assim como os pesos médios de uma fruta. Os dados de 1963, revelaram diferenças significativas e permitiram várias conclusões. A poda feita em 1.° de agôsto ofereceu os melhores resultados, embora sem diferir significativamente daquela executada em 1.° de julho. Como era esperado, as podas levadas a efeito nas épocas extremas, isto é, em princípios de maio e de setembro, resultaram nas produções mais baixas. Observou-se tendência da obtenção de colheitas mais precoces e figos mais pesados nos tratamentos mais produtivos.With a view to compare the effects on fruit bearing, pruning of fig trees was carried out in Campinas, State of São Paulo, during the dormant season of the plant, at 5 different dates, namely on the 1st day of each of the months of May, June, July, August and September. Pruning was started as soon as the plants became more or less dormant in the fall and was continued until vegetation again appeared at the end of winter. The pruning operation took place for two following years and at the dates mentioned all the new branches were cut back to short stubs. The experimental plot consisted of 30 trees of the variety "Roxo de Valinhos" (San Piero spread apart 7 by 13 feet and was laid out in randomized blocks with 3 replications. The results of this trial can be summarized as follows: a Trees pruned on August 1st gave the highest yield followed by those pruned on July 1st. While the

Development of epicormic sprouts in Sitka spruce following thinning and pruning in south-east Alaska.

Science.gov (United States)

Robert L. Deal; R. James Barbour; Michael H. McClellan; Dean L. Parry

2003-01-01

The frequency and size of epicormic sprouts in Sitka spruce (Picea sitchensis (Bong.) Carr.) were assessed in five 23-29 year-old mixed Sitka spruce-western hemlock (Tsuga heterophylla (Raf.) Sarg.) stands that were uniformly thinned and pruned to 2.4, 3.7 and 5.2 m lift heights. Six to nine years after treatment sprouts were...

Synaptic vesicle exocytosis in hippocampal synaptosomes correlates directly with total mitochondrial volume

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Ivannikov, Maxim V.; Sugimori, Mutsuyuki; Llinás, Rodolfo R.

2012-01-01

Synaptic plasticity in many regions of the central nervous system leads to the continuous adjustment of synaptic strength, which is essential for learning and memory. In this study, we show by visualizing synaptic vesicle release in mouse hippocampal synaptosomes that presynaptic mitochondria and specifically, their capacities for ATP production are essential determinants of synaptic vesicle exocytosis and its magnitude. Total internal reflection microscopy of FM1-43 loaded hippocampal synaptosomes showed that inhibition of mitochondrial oxidative phosphorylation reduces evoked synaptic release. This reduction was accompanied by a substantial drop in synaptosomal ATP levels. However, cytosolic calcium influx was not affected. Structural characterization of stimulated hippocampal synaptosomes revealed that higher total presynaptic mitochondrial volumes were consistently associated with higher levels of exocytosis. Thus, synaptic vesicle release is linked to the presynaptic ability to regenerate ATP, which itself is a utility of mitochondrial density and activity. PMID:22772899

Glial processes at the Drosophila larval neuromuscular junction match synaptic growth.

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Deidre L Brink

Full Text Available Glia are integral participants in synaptic physiology, remodeling and maturation from blowflies to humans, yet how glial structure is coordinated with synaptic growth is unknown. To investigate the dynamics of glial development at the Drosophila larval neuromuscular junction (NMJ, we developed a live imaging system to establish the relationship between glia, neuronal boutons, and the muscle subsynaptic reticulum. Using this system we observed processes from two classes of peripheral glia present at the NMJ. Processes from the subperineurial glia formed a blood-nerve barrier around the axon proximal to the first bouton. Processes from the perineurial glial extended beyond the end of the blood-nerve barrier into the NMJ where they contacted synapses and extended across non-synaptic muscle. Growth of the glial processes was coordinated with NMJ growth and synaptic activity. Increasing synaptic size through elevated temperature or the highwire mutation increased the extent of glial processes at the NMJ and conversely blocking synaptic activity and size decreased the presence and size of glial processes. We found that elevated temperature was required during embryogenesis in order to increase glial expansion at the nmj. Therefore, in our live imaging system, glial processes at the NMJ are likely indirectly regulated by synaptic changes to ensure the coordinated growth of all components of the tripartite larval NMJ.

A light-stimulated synaptic transistor with synaptic plasticity and memory functions based on InGaZnO_x–Al_2O_3 thin film structure

International Nuclear Information System (INIS)

Li, H. K.; Chen, T. P.; Liu, P.; Zhang, Q.; Hu, S. G.; Liu, Y.; Lee, P. S.

2016-01-01

In this work, a synaptic transistor based on the indium gallium zinc oxide (IGZO)–aluminum oxide (Al_2O_3) thin film structure, which uses ultraviolet (UV) light pulses as the pre-synaptic stimulus, has been demonstrated. The synaptic transistor exhibits the behavior of synaptic plasticity like the paired-pulse facilitation. In addition, it also shows the brain's memory behaviors including the transition from short-term memory to long-term memory and the Ebbinghaus forgetting curve. The synapse-like behavior and memory behaviors of the transistor are due to the trapping and detrapping processes of the holes, which are generated by the UV pulses, at the IGZO/Al_2O_3 interface and/or in the Al_2O_3 layer.

Intense synaptic activity enhances temporal resolution in spinal motoneurons.

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Rune W Berg

Full Text Available In neurons, spike timing is determined by integration of synaptic potentials in delicate concert with intrinsic properties. Although the integration time is functionally crucial, it remains elusive during network activity. While mechanisms of rapid processing are well documented in sensory systems, agility in motor systems has received little attention. Here we analyze how intense synaptic activity affects integration time in spinal motoneurons during functional motor activity and report a 10-fold decrease. As a result, action potentials can only be predicted from the membrane potential within 10 ms of their occurrence and detected for less than 10 ms after their occurrence. Being shorter than the average inter-spike interval, the AHP has little effect on integration time and spike timing, which instead is entirely determined by fluctuations in membrane potential caused by the barrage of inhibitory and excitatory synaptic activity. By shortening the effective integration time, this intense synaptic input may serve to facilitate the generation of rapid changes in movements.

Prune belly anomaly on prenatal ultrasound as a presenting feature of ectrodactyly-ectodermal dysplasia-clefting syndrome (EEC).

NARCIS (Netherlands)

Janssens, S.; Defoort, P.; Vandenbroecke, C.; Scheffer, H.; Mortier, G.

2008-01-01

We report on a fetus with prune belly anomaly presenting at 16 weeks gestation. Clinical evaluation after birth revealed other malformations reminiscent of the EEC syndrome. This diagnosis was also suspected in the mother and finally confirmed in both relatives by identification of a heterozygous

Biofiltration of composting gases using different municipal solid waste-pruning residue composts: monitoring by using an electronic nose.

Science.gov (United States)

López, R; Cabeza, I O; Giráldez, I; Díaz, M J

2011-09-01

The concentration of volatile organic compounds (VOCs) during the composting of kitchen waste and pruning residues, and the abatement of VOCs by different compost biofilters was studied. VOCs removal efficiencies greater than 90% were obtained using composts of municipal solid waste (MSW) or MSW-pruning residue as biofilter material. An electronic nose identified qualitative differences among the biofilter output gases at very low concentrations of VOCs. These differences were related to compost constituents, compost particle size (2-7 or 7-20mm), and a combination of both factors. The total concentration of VOCs determined by a photoionization analyser and inferred from electronic nose data sets were correlated over an ample range of concentrations of VOCs, showing that these techniques could be specially adapted for the monitoring of these processes. Copyright © 2011 Elsevier Ltd. All rights reserved.

Irregular persistent activity induced by synaptic excitatory feedback

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Francesca Barbieri

2007-11-01

Full Text Available Neurophysiological experiments on monkeys have reported highly irregular persistent activity during the performance of an oculomotor delayed-response task. These experiments show that during the delay period the coefficient of variation (CV of interspike intervals (ISI of prefrontal neurons is above 1, on average, and larger than during the fixation period. In the present paper, we show that this feature can be reproduced in a network in which persistent activity is induced by excitatory feedback, provided that (i the post-spike reset is close enough to threshold , (ii synaptic efficacies are a non-linear function of the pre-synaptic firing rate. Non-linearity between presynaptic rate and effective synaptic strength is implemented by a standard short-term depression mechanism (STD. First, we consider the simplest possible network with excitatory feedback: a fully connected homogeneous network of excitatory leaky integrate-and-fire neurons, using both numerical simulations and analytical techniques. The results are then confirmed in a network with selective excitatory neurons and inhibition. In both the cases there is a large range of values of the synaptic efficacies for which the statistics of firing of single cells is similar to experimental data.

Survival of FUngi Associated with Grapevine Decline in Pruned Wood after Composting

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P. Lecomte

2006-04-01

Full Text Available Recycling vine wood pruned in winter in the vineyard, after grinding and composting, might pose a risk of recontamination with fungi associated with grapevine decline. The survival of four ascomycete fungi (Botryosphaeria obtusa, Phaeomoniella chlamydospora, Phaeoacremonium aleophilum and Eutypa lata in composted material was investigated in a 3-year study conducted in the Bordeaux area. Naturally and artificially infested material was examined before and after composting using classical isolation procedures. Results clearly showed that a composting process can eradicate the four target fungi efficiently.

Robust short-term memory without synaptic learning.

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Samuel Johnson

Full Text Available Short-term memory in the brain cannot in general be explained the way long-term memory can--as a gradual modification of synaptic weights--since it takes place too quickly. Theories based on some form of cellular bistability, however, do not seem able to account for the fact that noisy neurons can collectively store information in a robust manner. We show how a sufficiently clustered network of simple model neurons can be instantly induced into metastable states capable of retaining information for a short time (a few seconds. The mechanism is robust to different network topologies and kinds of neural model. This could constitute a viable means available to the brain for sensory and/or short-term memory with no need of synaptic learning. Relevant phenomena described by neurobiology and psychology, such as local synchronization of synaptic inputs and power-law statistics of forgetting avalanches, emerge naturally from this mechanism, and we suggest possible experiments to test its viability in more biological settings.

Robust short-term memory without synaptic learning.

Science.gov (United States)

Johnson, Samuel; Marro, J; Torres, Joaquín J

2013-01-01

Short-term memory in the brain cannot in general be explained the way long-term memory can--as a gradual modification of synaptic weights--since it takes place too quickly. Theories based on some form of cellular bistability, however, do not seem able to account for the fact that noisy neurons can collectively store information in a robust manner. We show how a sufficiently clustered network of simple model neurons can be instantly induced into metastable states capable of retaining information for a short time (a few seconds). The mechanism is robust to different network topologies and kinds of neural model. This could constitute a viable means available to the brain for sensory and/or short-term memory with no need of synaptic learning. Relevant phenomena described by neurobiology and psychology, such as local synchronization of synaptic inputs and power-law statistics of forgetting avalanches, emerge naturally from this mechanism, and we suggest possible experiments to test its viability in more biological settings.

Robust Short-Term Memory without Synaptic Learning

Science.gov (United States)

Johnson, Samuel; Marro, J.; Torres, Joaquín J.

2013-01-01

Short-term memory in the brain cannot in general be explained the way long-term memory can – as a gradual modification of synaptic weights – since it takes place too quickly. Theories based on some form of cellular bistability, however, do not seem able to account for the fact that noisy neurons can collectively store information in a robust manner. We show how a sufficiently clustered network of simple model neurons can be instantly induced into metastable states capable of retaining information for a short time (a few seconds). The mechanism is robust to different network topologies and kinds of neural model. This could constitute a viable means available to the brain for sensory and/or short-term memory with no need of synaptic learning. Relevant phenomena described by neurobiology and psychology, such as local synchronization of synaptic inputs and power-law statistics of forgetting avalanches, emerge naturally from this mechanism, and we suggest possible experiments to test its viability in more biological settings. PMID:23349664

Precise synaptic efficacy alignment suggests potentiation dominated learning

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Christoph eHartmann

2016-01-01

Full Text Available Recent evidence suggests that parallel synapses from the same axonal branch onto the same dendritic branch have almost identical strength. It has been proposed that this alignment is only possible through learning rules that integrate activity over long time spans. However, learning mechanisms such as spike-timing-dependent plasticity (STDP are commonly assumed to be temporally local. Here, we propose that the combination of temporally local STDP and a multiplicative synaptic normalization mechanism is sufficient to explain the alignment of parallel synapses.To address this issue, we introduce three increasingly complex models: First, we model the idealized interaction of STDP and synaptic normalization in a single neuron as a simple stochastic process and derive analytically that the alignment effect can be described by a so-called Kesten process. From this we can derive that synaptic efficacy alignment requires potentiation-dominated learning regimes. We verify these conditions in a single-neuron model with independent spiking activities but more realistic synapses. As expected, we only observe synaptic efficacy alignment for long-term potentiation-biased STDP. Finally, we explore how well the findings transfer to recurrent neural networks where the learning mechanisms interact with the correlated activity of the network. We find that due to the self-reinforcing correlations in recurrent circuits under STDP, alignment occurs for both long-term potentiation- and depression-biased STDP, because the learning will be potentiation dominated in both cases due to the potentiating events induced by correlated activity. This is in line with recent results demonstrating a dominance of potentiation over depression during waking and normalization during sleep. This leads us to predict that individual spine pairs will be more similar in the morning than they are after sleep depriviation.In conclusion, we show that synaptic normalization in conjunction with

Megacystis-microcolon-intestinal hypoperistalsis syndrome associated with prune belly syndrome: a case report.

Science.gov (United States)

Akhtar, Tanveer; Alladi, Anand; Siddappa, O S

2012-01-01

Megacystis Microcolon Intestinal Hypoperistalsis Syndrome is a quite rare congenital anomaly that presents with a functional obstruction of the gastrointestinal tract which is usually fatal. It is three to four times more prevalent in females. We present a case of a rare association of a male neonate with Megacystis Microcolon Intestinal Hypoperistalsis Syndrome who in addition had the classical triad of Prune Belly Syndrome and thus suggest a possibility of different spectrums with a common pathogenesis.

Preparation of synaptic plasma membrane and postsynaptic density proteins using a discontinuous sucrose gradient.

Science.gov (United States)

Bermejo, Marie Kristel; Milenkovic, Marija; Salahpour, Ali; Ramsey, Amy J

2014-09-03

Neuronal subcellular fractionation techniques allow the quantification of proteins that are trafficked to and from the synapse. As originally described in the late 1960's, proteins associated with the synaptic plasma membrane can be isolated by ultracentrifugation on a sucrose density gradient. Once synaptic membranes are isolated, the macromolecular complex known as the post-synaptic density can be subsequently isolated due to its detergent insolubility. The techniques used to isolate synaptic plasma membranes and post-synaptic density proteins remain essentially the same after 40 years, and are widely used in current neuroscience research. This article details the fractionation of proteins associated with the synaptic plasma membrane and post-synaptic density using a discontinuous sucrose gradient. Resulting protein preparations are suitable for western blotting or 2D DIGE analysis.

The prune belly syndrome in a female foetus with urorectal septum malformation sequence: a case report on a rare entity with an unusual association.

Science.gov (United States)

Goswami, Dibyajyoti; Kusre, Giriraj; Dutta, Hemonta Kumar; Sarma, Adity

2013-08-01

The prune belly syndrome is a rare congenital anomaly which is characterized by the triad of an absent or a deficient development of the abdominal muscle, bilateral cryptorchidism and an anomalous urinary tract. In its full form, this condition occurs only in males. However, a similar condition occurs in females in the absence of cryptorchidism. On the other hand, the urorectal septum malformation sequence is a lethal congenital malformation which is characterized by the development of a phallus like structure, a smooth perineum and the absence of urethral, vaginal and anal openings. We are reporting a case of a female foetus with the prune belly syndrome, which was associated with a urorectal septum malformation sequence. A dead foetus with a protruded abdomen and ambiguous genitalia, was born at 32 weeks of pregnancy. On autopsy, it was found to have female internal genital organs. The left kidney, the urinary bladder and the rectum were absent. The sigmoid colon, the ureters and the fallopian tubes opened into a common cloacal sac. The histopathological examination of the ovary showed the presence of Leydig's cells. The occurrence of the female counterpart of the prune belly syndrome is extremely rare and only few of such cases were found to be discussed in the details in the indexed English literature so far. Hence, we hope that this case report will contribute to the existing knowledge on the prune belly syndrome.

Fenologia da goiabeira 'Paluma' sob diferentes sistemas de cultivos, épocas e intensidades de poda de frutificação Phenology of 'Paluma' guava trees under different cultivation systems, times and intensities of fruit pruning

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Luiz Augusto Lopes Serrano

2008-01-01

Full Text Available O trabalho teve como objetivo avaliar os efeitos de diferentes épocas e intensidades de poda de frutificação sobre a fenologia da goiabeira 'Paluma', em dois sistemas de cultivo, em Pedro Canário (ES. O delineamento experimental foi o de blocos ao acaso, em esquema de parcelas sub-subdivididas. As parcelas foram os sistemas de cultivo irrigado e sequeiro; as subparcelas foram as épocas de poda (10/11/2005, 9/12/2005, 13/1/2006 e 10/2/2006; e as sub-subparcelas foram as intensidades de poda (curta, média e longa. O ciclo da goiabeira 'Paluma', entre a poda até o início da colheita dos frutos, variou de 182 (poda em novembro e dezembro a 203 dias (poda em fevereiro. A queda fisiológica dos frutos ocorreu até os 56 dias após o final do florescimento. A irrigação e a poda longa proporcionaram maior brotação e estabelecimento dos ramos. As plantas submetidas à poda longa em fevereiro produziram maior número de frutos por ramo. Independentemente da época de poda, as plantas submetidas à poda curta apresentaram menor número de frutos por ramo e menor índice de pegamento de frutos. A irrigação e as podas realizadas em dezembro e janeiro favoreceram a produção de frutos maiores.The objective of this work was to evaluate the effects of different fruit pruning times and intensities on the phenology of 'Paluma' guava trees in two cultivation systems, in Pedro Canário, Espírito Santo State, Brazil. The experimental design was a randomized complete block in a split split plots scheme. The main plots were the cultivation systems (with and without irrigation, the split plots were the pruning times (November 10, 2005; December 9, 2005; January 13, 2006 and February 10, 2006, and the split split plots were the pruning intensities (heavy, medium and light. The period between pruning and the beginning of fruit ripening was between 182 (pruning in November and December to 203 days (pruning in February. Fruit physiologic fall continued for

Spike Train Auto-Structure Impacts Post-Synaptic Firing and Timing-Based Plasticity

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Scheller, Bertram; Castellano, Marta; Vicente, Raul; Pipa, Gordon

2011-01-01

Cortical neurons are typically driven by several thousand synapses. The precise spatiotemporal pattern formed by these inputs can modulate the response of a post-synaptic cell. In this work, we explore how the temporal structure of pre-synaptic inhibitory and excitatory inputs impact the post-synaptic firing of a conductance-based integrate and fire neuron. Both the excitatory and inhibitory input was modeled by renewal gamma processes with varying shape factors for modeling regular and temporally random Poisson activity. We demonstrate that the temporal structure of mutually independent inputs affects the post-synaptic firing, while the strength of the effect depends on the firing rates of both the excitatory and inhibitory inputs. In a second step, we explore the effect of temporal structure of mutually independent inputs on a simple version of Hebbian learning, i.e., hard bound spike-timing-dependent plasticity. We explore both the equilibrium weight distribution and the speed of the transient weight dynamics for different mutually independent gamma processes. We find that both the equilibrium distribution of the synaptic weights and the speed of synaptic changes are modulated by the temporal structure of the input. Finally, we highlight that the sensitivity of both the post-synaptic firing as well as the spike-timing-dependent plasticity on the auto-structure of the input of a neuron could be used to modulate the learning rate of synaptic modification. PMID:22203800

Abdominoplasty in Prune Belly Syndrome.

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Dénes, F T; Park, R; Lopes, R I; Moscardi, P R M; Srougi, M

2015-10-01

Many patients with Prune Belly Syndrome (PBS) require abdominoplasty alone or in combination with correction of any urogenital abnormalities. This video presents a simplified technique with which to treat the abdominal flaccidity in PBS. A longitudinal xypho-pubic fusiform figure is drawn on the abdomen, based on the area of skin and subcutaneous tissue to be removed. This is performed with preservation of the musculo-fascial layer and the umbilicus. A lateral elliptical single xypho-pubic line is drawn in the most lax side of the fascia, which is incised along this line. After urinary tract reconstruction and orchidopexy, closure is initiated by suturing the medial edge of the wider fascial flap laterally to the peritoneal side of the contralateral flap. Next, the now outer fascial flap is laid over the inner flap, and a buttonhole is made to expose the umbilicus. The subcutaneous tissue of the inner flap is laterally undermined to gain extra distance for the suture of the outer flap over the inner flap. The subcutaneous tissue and skin are sutured in the midline, incorporating the umbilicus. In a 30-year period, 43 PBS patients underwent this procedure with good cosmetic and long-term functional results. This abdominoplasty technique is simple and presents good functional and cosmetic results in PBS patients. Copyright © 2015 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Regulation of synaptic structure by ubiquitin C-terminal hydrolase L1.

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Cartier, Anna E; Djakovic, Stevan N; Salehi, Afshin; Wilson, Scott M; Masliah, Eliezer; Patrick, Gentry N

2009-06-17

Ubiquitin C-terminal hydrolase L1 (UCH-L1) is a deubiquitinating enzyme that is selectively and abundantly expressed in the brain, and its activity is required for normal synaptic function. Here, we show that UCH-L1 functions in maintaining normal synaptic structure in hippocampal neurons. We found that UCH-L1 activity is rapidly upregulated by NMDA receptor activation, which leads to an increase in the levels of free monomeric ubiquitin. Conversely, pharmacological inhibition of UCH-L1 significantly reduces monomeric ubiquitin levels and causes dramatic alterations in synaptic protein distribution and spine morphology. Inhibition of UCH-L1 activity increases spine size while decreasing spine density. Furthermore, there is a concomitant increase in the size of presynaptic and postsynaptic protein clusters. Interestingly, however, ectopic expression of ubiquitin restores normal synaptic structure in UCH-L1-inhibited neurons. These findings point to a significant role of UCH-L1 in synaptic remodeling, most likely by modulating free monomeric ubiquitin levels in an activity-dependent manner.

Synaptic integration of transplanted interneuron progenitor cells into native cortical networks.

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Howard, MacKenzie A; Baraban, Scott C

2016-08-01

Interneuron-based cell transplantation is a powerful method to modify network function in a variety of neurological disorders, including epilepsy. Whether new interneurons integrate into native neural networks in a subtype-specific manner is not well understood, and the therapeutic mechanisms underlying interneuron-based cell therapy, including the role of synaptic inhibition, are debated. In this study, we tested subtype-specific integration of transplanted interneurons using acute cortical brain slices and visualized patch-clamp recordings to measure excitatory synaptic inputs, intrinsic properties, and inhibitory synaptic outputs. Fluorescently labeled progenitor cells from the embryonic medial ganglionic eminence (MGE) were used for transplantation. At 5 wk after transplantation, MGE-derived parvalbumin-positive (PV+) interneurons received excitatory synaptic inputs, exhibited mature interneuron firing properties, and made functional synaptic inhibitory connections to native pyramidal cells that were comparable to those of native PV+ interneurons. These findings demonstrate that MGE-derived PV+ interneurons functionally integrate into subtype-appropriate physiological niches within host networks following transplantation. Copyright © 2016 the American Physiological Society.

Two-Dimensional Bumps in Piecewise Smooth Neural Fields with Synaptic Depression

KAUST Repository

Bressloff, Paul C.

2011-01-01

We analyze radially symmetric bumps in a two-dimensional piecewise-smooth neural field model with synaptic depression. The continuum dynamics is described in terms of a nonlocal integrodifferential equation, in which the integral kernel represents the spatial distribution of synaptic weights between populations of neurons whose mean firing rate is taken to be a Heaviside function of local activity. Synaptic depression dynamically reduces the strength of synaptic weights in response to increases in activity. We show that in the case of a Mexican hat weight distribution, sufficiently strong synaptic depression can destabilize a stationary bump solution that would be stable in the absence of depression. Numerically it is found that the resulting instability leads to the formation of a traveling spot. The local stability of a bump is determined by solutions to a system of pseudolinear equations that take into account the sign of perturbations around the circular bump boundary. © 2011 Society for Industrial and Applied Mathematics.

Limited distal organelles and synaptic function in extensive monoaminergic innervation.

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Tao, Juan; Bulgari, Dinara; Deitcher, David L; Levitan, Edwin S

2017-08-01

Organelles such as neuropeptide-containing dense-core vesicles (DCVs) and mitochondria travel down axons to supply synaptic boutons. DCV distribution among en passant boutons in small axonal arbors is mediated by circulation with bidirectional capture. However, it is not known how organelles are distributed in extensive arbors associated with mammalian dopamine neuron vulnerability, and with volume transmission and neuromodulation by monoamines and neuropeptides. Therefore, we studied presynaptic organelle distribution in Drosophila octopamine neurons that innervate ∼20 muscles with ∼1500 boutons. Unlike in smaller arbors, distal boutons in these arbors contain fewer DCVs and mitochondria, although active zones are present. Absence of vesicle circulation is evident by proximal nascent DCV delivery, limited impact of retrograde transport and older distal DCVs. Traffic studies show that DCV axonal transport and synaptic capture are not scaled for extensive innervation, thus limiting distal delivery. Activity-induced synaptic endocytosis and synaptic neuropeptide release are also reduced distally. We propose that limits in organelle transport and synaptic capture compromise distal synapse maintenance and function in extensive axonal arbors, thereby affecting development, plasticity and vulnerability to neurodegenerative disease. © 2017. Published by The Company of Biologists Ltd.

Role of DHA in aging-related changes in mouse brain synaptic plasma membrane proteome.

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Sidhu, Vishaldeep K; Huang, Bill X; Desai, Abhishek; Kevala, Karl; Kim, Hee-Yong

2016-05-01

Aging has been related to diminished cognitive function, which could be a result of ineffective synaptic function. We have previously shown that synaptic plasma membrane proteins supporting synaptic integrity and neurotransmission were downregulated in docosahexaenoic acid (DHA)-deprived brains, suggesting an important role of DHA in synaptic function. In this study, we demonstrate aging-induced synaptic proteome changes and DHA-dependent mitigation of such changes using mass spectrometry-based protein quantitation combined with western blot or messenger RNA analysis. We found significant reduction of 15 synaptic plasma membrane proteins in aging brains including fodrin-α, synaptopodin, postsynaptic density protein 95, synaptic vesicle glycoprotein 2B, synaptosomal-associated protein 25, synaptosomal-associated protein-α, N-methyl-D-aspartate receptor subunit epsilon-2 precursor, AMPA2, AP2, VGluT1, munc18-1, dynamin-1, vesicle-associated membrane protein 2, rab3A, and EAAT1, most of which are involved in synaptic transmission. Notably, the first 9 proteins were further reduced when brain DHA was depleted by diet, indicating that DHA plays an important role in sustaining these synaptic proteins downregulated during aging. Reduction of 2 of these proteins was reversed by raising the brain DHA level by supplementing aged animals with an omega-3 fatty acid sufficient diet for 2 months. The recognition memory compromised in DHA-depleted animals was also improved. Our results suggest a potential role of DHA in alleviating aging-associated cognitive decline by offsetting the loss of neurotransmission-regulating synaptic proteins involved in synaptic function. Published by Elsevier Inc.

Outcomes of renal replacement therapy in boys with prune belly syndrome: findings from the ESPN/ERA-EDTA Registry

NARCIS (Netherlands)

Yalcinkaya, Fatos; Bonthuis, Marjolein; Erdogan, Beyza Doganay; van Stralen, Karlijn J.; Baiko, Sergey; Chehade, Hassib; Maxwell, Heather; Montini, Giovanni; Rönnholm, Kai; Sørensen, Søren Schwartz; Ulinski, Tim; Verrina, Enrico; Weber, Stefanie; Harambat, Jérôme; Schaefer, Franz; Jager, Kitty J.; Groothoff, Jaap W.

2018-01-01

As outcome data for prune belly syndrome (PBS) complicated by end-stage renal disease are scarce, we analyzed characteristics and outcomes of children with PBS using the European Society for Pediatric Nephrology/European Renal Association-European Dialysis and Transplant Association (ESPN/ERA-EDTA)

Synaptic pathology in the cerebellar dentate nucleus in chronic multiple sclerosis.

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Albert, Monika; Barrantes-Freer, Alonso; Lohrberg, Melanie; Antel, Jack P; Prineas, John W; Palkovits, Miklós; Wolff, Joachim R; Brück, Wolfgang; Stadelmann, Christine

2017-11-01

In multiple sclerosis, cerebellar symptoms are associated with clinical impairment and an increased likelihood of progressive course. Cortical atrophy and synaptic dysfunction play a prominent role in cerebellar pathology and although the dentate nucleus is a predilection site for lesion development, structural synaptic changes in this region remain largely unexplored. Moreover, the mechanisms leading to synaptic dysfunction have not yet been investigated at an ultrastructural level in multiple sclerosis. Here, we report on synaptic changes of dentate nuclei in post-mortem cerebella of 16 multiple sclerosis patients and eight controls at the histological level as well as an electron microscopy evaluation of afferent synapses of the cerebellar dentate and pontine nuclei of one multiple sclerosis patient and one control. We found a significant reduction of afferent dentate synapses in multiple sclerosis, irrespective of the presence of demyelination, and a close relationship between glial processes and dentate synapses. Ultrastructurally, we show autophagosomes containing degradation products of synaptic vesicles within dendrites, residual bodies within intact-appearing axons and free postsynaptic densities opposed to astrocytic appendages. Our study demonstrates loss of dentate afferent synapses and provides, for the first time, ultrastructural evidence pointing towards neuron-autonomous and neuroglia-mediated mechanisms of synaptic degradation in chronic multiple sclerosis. © 2016 International Society of Neuropathology.

Sleep and protein synthesis-dependent synaptic plasticity: impacts of sleep loss and stress

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Grønli, Janne; Soulé, Jonathan; Bramham, Clive R.

2014-01-01

Sleep has been ascribed a critical role in cognitive functioning. Several lines of evidence implicate sleep in the consolidation of synaptic plasticity and long-term memory. Stress disrupts sleep while impairing synaptic plasticity and cognitive performance. Here, we discuss evidence linking sleep to mechanisms of protein synthesis-dependent synaptic plasticity and synaptic scaling. We then consider how disruption of sleep by acute and chronic stress may impair these mechanisms and degrade sleep function. PMID:24478645

Presynaptic protein synthesis required for NT-3-induced long-term synaptic modulation

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Je H

2011-01-01

Full Text Available Abstract Background Neurotrophins elicit both acute and long-term modulation of synaptic transmission and plasticity. Previously, we demonstrated that the long-term synaptic modulation requires the endocytosis of neurotrophin-receptor complex, the activation of PI3K and Akt, and mTOR mediated protein synthesis. However, it is unclear whether the long-term synaptic modulation by neurotrophins depends on protein synthesis in pre- or post-synaptic cells. Results Here we have developed an inducible protein translation blocker, in which the kinase domain of protein kinase R (PKR is fused with bacterial gyrase B domain (GyrB-PKR, which could be dimerized upon treatment with a cell permeable drug, coumermycin. By genetically targeting GyrB-PKR to specific cell types, we show that NT-3 induced long-term synaptic modulation requires presynaptic, but not postsynaptic protein synthesis. Conclusions Our results provide mechanistic insights into the cell-specific requirement for protein synthesis in the long-term synaptic modulation by neurotrophins. The GyrB-PKR system may be useful tool to study protein synthesis in a cell-specific manner.

Polymer-electrolyte-gated nanowire synaptic transistors for neuromorphic applications

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Zou, Can; Sun, Jia; Gou, Guangyang; Kong, Ling-An; Qian, Chuan; Dai, Guozhang; Yang, Junliang; Guo, Guang-hua

2017-09-01

Polymer-electrolytes are formed by dissolving a salt in polymer instead of water, the conducting mechanism involves the segmental motion-assisted diffusion of ion in the polymer matrix. Here, we report on the fabrication of tin oxide (SnO2) nanowire synaptic transistors using polymer-electrolyte gating. A thin layer of poly(ethylene oxide) and lithium perchlorate (PEO/LiClO4) was deposited on top of the devices, which was used to boost device performances. A voltage spike applied on the in-plane gate attracts ions toward the polymer-electrolyte/SnO2 nanowire interface and the ions are gradually returned after the pulse is removed, which can induce a dynamic excitatory postsynaptic current in the nanowire channel. The SnO2 synaptic transistors exhibit the behavior of short-term plasticity like the paired-pulse facilitation and self-adaptation, which is related to the electric double-effect regulation. In addition, the synaptic logic functions and the logical function transformation are also discussed. Such single SnO2 nanowire-based synaptic transistors are of great importance for future neuromorphic devices.

Estrogen's Place in the Family of Synaptic Modulators.

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Kramár, Enikö A; Chen, Lulu Y; Rex, Christopher S; Gall, Christine M; Lynch, Gary

2009-01-01

Estrogen, in addition to its genomic effects, triggers rapid synaptic changes in hippocampus and cortex. Here we summarize evidence that the acute actions of the steroid arise from actin signaling cascades centrally involved in long-term potentiation (LTP). A 10-min infusion of E2 reversibly increased fast EPSPs and promoted theta burst-induced LTP within adult hippocampal slices. The latter effect reflected a lowered threshold and an elevated ceiling for the potentiation effect. E2's actions on transmission and plasticity were completely blocked by latrunculin, a toxin that prevents actin polymerization. E2 also caused a reversible increase in spine concentrations of filamentous (F-) actin and markedly enhanced polymerization caused by theta burst stimulation (TBS). Estrogen activated the small GTPase RhoA, but not the related GTPase Rac, and phosphorylated (inactivated) synaptic cofilin, an actin severing protein targeted by RhoA. An inhibitor of RhoA kinase (ROCK) thoroughly suppressed the synaptic effects of E2. Collectively, these results indicate that E2 engages a RhoA >ROCK> cofilin> actin pathway also used by brain-derived neurotrophic factor and adenosine, and therefore belongs to a family of 'synaptic modulators' that regulate plasticity. Finally, we describe evidence that the acute signaling cascade is critical to the depression of LTP produced by ovariectomy.

Prune Belly Syndrome Associated with Full Spectrum of VACTERL in a New Born.

Science.gov (United States)

Younous, Said; Zarrouki, Youssef; Boutbaoucht, Mustapha; Mouaffak, Youssef; El Idrissi, Kawtar Ennour; Aboussair, Nissrine; Saiad, Mohammed O

2012-01-01

Prune belly syndrome (PBS) is a rare congenital anomaly of uncertain etiology. Many associations of PBS with other malformations were previously reported, but only few cases of the association with VACTERL have been described. We report a rare case of a Moroccan new born with PBS and complete VACTERL association. The cause of this association is still unknown, but a common etiology is possible, especially when for the two syndromes, a defect in mesodermal differentiation, in early first trimester, has been suggested.

Prune-belly syndrome: an autopsy case report.

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Vasconcelos, Marcela Arruda Pereira Silva; de Lima, Patricia Picciarelli

2014-01-01

Prune-belly syndrome (PBS) is a rare congenital anomaly characterized by a spectrum of mild-to-severe presentations of urinary tract malformations, deficient abdominal wall musculature, and cryptorchidism in male newborns or genital abnormalities in the female newborns. Currently, antenatal diagnosis is feasible with ultrasound examination, and treatment is based on case report experience. More recently, intrauterine management has been undertaken with encouraging results. The authors report a case of PBS diagnosed at the seventeenth gestation week, when ultrasonographic examination revealed the presence of ascites, distended bladder, thickened bladder wall and posterior urethral valve. The fetus was submitted to an intrauterine intervention at the nineteenth gestational week. Delivery occurred at 34 weeks of gestation and the newborn examination was consistent with PBS. On the second day of life, the newborn was submitted to abdominoplasty, colostomy, and orchiopexy. However, the outcome was unfavorable with respiratory failure and death on the fifteenth day of life. The autopsy confirmed the diagnosis of PBS, but the immediate cause of death was attributed to aspiration pneumonia.

Prune-belly syndrome: an autopsy case report

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Marcela Arruda Pereira Silva Vasconcelos

2014-12-01

Full Text Available Prune-belly syndrome (PBS is a rare congenital anomaly characterized by a spectrum of mild-to-severe presentations of urinary tract malformations, deficient abdominal wall musculature, and cryptorchidism in male newborns or genital abnormalities in the female newborns. Currently, antenatal diagnosis is feasible with ultrasound examination, and treatment is based on case report experience. More recently, intrauterine management has been undertaken with encouraging results. The authors report a case of PBS diagnosed at the seventeenth gestation week, when ultrasonographic examination revealed the presence of ascites, distended bladder, thickened bladder wall and posterior urethral valve. The fetus was submitted to an intrauterine intervention at the nineteenth gestational week. Delivery occurred at 34 weeks of gestation and the newborn examination was consistent with PBS. On the second day of life, the newborn was submitted to abdominoplasty, colostomy, and orchiopexy. However, the outcome was unfavorable with respiratory failure and death on the fifteenth day of life. The autopsy confirmed the diagnosis of PBS, but the immediate cause of death was attributed to aspiration pneumonia.

Massive Submucosal Ganglia in Colonic Inertia.

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Naemi, Kaveh; Stamos, Michael J; Wu, Mark Li-Cheng

2018-02-01

- Colonic inertia is a debilitating form of primary chronic constipation with unknown etiology and diagnostic criteria, often requiring pancolectomy. We have occasionally observed massively enlarged submucosal ganglia containing at least 20 perikarya, in addition to previously described giant ganglia with greater than 8 perikarya, in cases of colonic inertia. These massively enlarged ganglia have yet to be formally recognized. - To determine whether such "massive submucosal ganglia," defined as ganglia harboring at least 20 perikarya, characterize colonic inertia. - We retrospectively reviewed specimens from colectomies of patients with colonic inertia and compared the prevalence of massive submucosal ganglia occurring in this setting to the prevalence of massive submucosal ganglia occurring in a set of control specimens from patients lacking chronic constipation. - Seven of 8 specimens affected by colonic inertia harbored 1 to 4 massive ganglia, for a total of 11 massive ganglia. One specimen lacked massive ganglia but had limited sampling and nearly massive ganglia. Massive ganglia occupied both superficial and deep submucosal plexus. The patient with 4 massive ganglia also had 1 mitotically active giant ganglion. Only 1 massive ganglion occupied the entire set of 10 specimens from patients lacking chronic constipation. - We performed the first, albeit distinctly small, study of massive submucosal ganglia and showed that massive ganglia may be linked to colonic inertia. Further, larger studies are necessary to determine whether massive ganglia are pathogenetic or secondary phenomena, and whether massive ganglia or mitotically active ganglia distinguish colonic inertia from other types of chronic constipation.

Aβ-Induced Synaptic Alterations Require the E3 Ubiquitin Ligase Nedd4-1.

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Rodrigues, Elizabeth M; Scudder, Samantha L; Goo, Marisa S; Patrick, Gentry N

2016-02-03

Alzheimer's disease (AD) is a neurodegenerative disease in which patients experience progressive cognitive decline. A wealth of evidence suggests that this cognitive impairment results from synaptic dysfunction in affected brain regions caused by cleavage of amyloid precursor protein into the pathogenic peptide amyloid-β (Aβ). Specifically, it has been shown that Aβ decreases surface AMPARs, dendritic spine density, and synaptic strength, and also alters synaptic plasticity. The precise molecular mechanisms by which this occurs remain unclear. Here we demonstrate a role for ubiquitination in Aβ-induced synaptic dysfunction in cultured rat neurons. We find that Aβ promotes the ubiquitination of AMPARs, as well as the redistribution and recruitment of Nedd4-1, a HECT E3 ubiquitin ligase we previously demonstrated to target AMPARs for ubiquitination and degradation. Strikingly, we show that Nedd4-1 is required for Aβ-induced reductions in surface AMPARs, synaptic strength, and dendritic spine density. Our findings, therefore, indicate an important role for Nedd4-1 and ubiquitin in the synaptic alterations induced by Aβ. Synaptic changes in Alzheimer's disease (AD) include surface AMPAR loss, which can weaken synapses. In a cell culture model of AD, we found that AMPAR loss correlates with increased AMPAR ubiquitination. In addition, the ubiquitin ligase Nedd4-1, known to ubiquitinate AMPARs, is recruited to synapses in response to Aβ. Strikingly, reducing Nedd4-1 levels in this model prevented surface AMPAR loss and synaptic weakening. These findings suggest that, in AD, Nedd4-1 may ubiquitinate AMPARs to promote their internalization and weaken synaptic strength, similar to what occurs in Nedd4-1's established role in homeostatic synaptic scaling. This is the first demonstration of Aβ-mediated control of a ubiquitin ligase to regulate surface AMPAR expression. Copyright © 2016 the authors 0270-6474/16/361590-06$15.00/0.

76 FR 21618 - Fresh Prunes Grown in Designated Counties in Washington and in Umatilla County, OR; Termination...

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2011-04-18

... marketing order is no longer an effective marketing tool for the fresh prune industry, and that termination... operation of the marketing order. DATES: Effective Date: April 19, 2011. FOR FURTHER INFORMATION CONTACT....64 of Marketing Agreement and Order No. 924, both as amended (7 CFR part 924), effective under the...

Synaptic contacts impaired by styrene-7,8-oxide toxicity

International Nuclear Information System (INIS)

Corsi, P.; D'Aprile, A.; Nico, B.; Costa, G.L.; Assennato, G.

2007-01-01

Styrene-7,8-oxide (SO), a chemical compound widely used in industrial applications, is a potential hazard for humans, particularly in occupational settings. Neurobehavioral changes are consistently observed in occupationally exposed individuals and alterations of neurotransmitters associated with neuronal loss have been reported in animal models. Although the toxic effects of styrene have been extensively documented, the molecular mechanisms responsible for SO-induced neurotoxicity are still unclear. A possible dopamine-mediated effect of styrene neurotoxicity has been previously demonstrated, since styrene oxide alters dopamine neurotransmission in the brain. Thus, the present study hypothesizes that styrene neurotoxicity may involve synaptic contacts. Primary striatal neurons were exposed to styrene oxide at different concentrations (0.1-1 mM) for different time periods (8, 16, and 24 h) to evaluate the dose able to induce synaptic impairments. The expression of proteins crucial for synaptic transmission such as Synapsin, Synaptophysin, and RAC-1 were considered. The levels of Synaptophysin and RAC-1 decreased in a dose-dependent manner. Accordingly, morphological alterations, observed at the ultrastructural level, primarily involved the pre-synaptic compartment. In SO-exposed cultures, the biochemical cascade of caspases was activated affecting the cytoskeleton components as their target. Thus the impairments in synaptic contacts observed in SO-exposed cultures might reflect a primarily morphological alteration of neuronal cytoskeleton. In addition, our data support the hypothesis developed by previous authors of reactive oxygen species (ROS) initiating events of SO cytotoxicity

New massive gravity

NARCIS (Netherlands)

Bergshoeff, Eric A.; Hohm, Olaf; Townsend, Paul K.

2012-01-01

We present a brief review of New Massive Gravity, which is a unitary theory of massive gravitons in three dimensions obtained by considering a particular combination of the Einstein-Hilbert and curvature squared terms.

Highly erodible terrain in agriculture land against chipped pruned branches. Or how to stop the soil erosion with low investment

Science.gov (United States)

Cerdà, A.

2009-04-01

The session on "Soil erosion and sediment control with vegetation and bioengineering on severely eroded terrain" pays special attention to the severe soil erosion suffered on steep slopes and erodible parent materials and soils. Within the last 20 years, in the Mediterranean lands, the citrus orchards were reallocated on steep slopes due to the urban development and better climatic and management conditions of the new plantations. The lack of vegetation cover on the new slope plantations of citrus resulted in high erosion rates. Those non-sustainable soil losses were measured by means of rainfall simulation experiments, Gerlach collectors, geomorphological transect and topographical measurements. The October 2007 and October 2008 rainy periods resulted in sheet, rill and gully erosion. Some recently planted orchards (2005) had the first pruning season in 2008. The pruned chipped branches reduced the soil losses to 50 % of the expected, although the litter (pruned branches) covered 4.67 % of the soil. This is why a research was developed by means of simulated rainfall experiments to determine the vegetation cover (litter, mainly leaves) to protect the soil to reach a sustainable erosion rate. Rainfall simulation experiments at 43 mm h-1 where performed on 1 m2 plots covered with 0, 3, 7, 15, 30, 45, 60, 80 and 100 % litter cover (pruned chipped branches) to determine the sustainable litter cover to avoid the soil losses. The results show that more that 45 % litter cover almost reduces the soil losses to negligible rates. The results confirm that 4 % of vegetation cover reduces the soil losses to 50 %. Key words: Agriculture land, erodible terrain, land management, citrus, erosion, Spain, Valencia, herbicides. Acknowledgements, We thanks the financial support of the Ministerio de Ciencia e Innovación by means of the project CGL2008-02879/BTE, "PERDIDA DE SUELO EN NUEVAS EXPLOTACIONES CITRICOLAS EN PENDIENTE. ESTRATEGIAS PARA EL CONTROL DE LA EROSION HIDRICA"

Levetiracetam reverses synaptic deficits produced by overexpression of SV2A.

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Amy Nowack

Full Text Available Levetiracetam is an FDA-approved drug used to treat epilepsy and other disorders of the nervous system. Although it is known that levetiracetam binds the synaptic vesicle protein SV2A, how drug binding affects synaptic functioning remains unknown. Here we report that levetiracetam reverses the effects of excess SV2A in autaptic hippocampal neurons. Expression of an SV2A-EGFP fusion protein produced a ∼1.5-fold increase in synaptic levels of SV2, and resulted in reduced synaptic release probability. The overexpression phenotype parallels that seen in neurons from SV2 knockout mice, which experience severe seizures. Overexpression of SV2A also increased synaptic levels of the calcium-sensor protein synaptotagmin, an SV2-binding protein whose stability and trafficking are regulated by SV2. Treatment with levetiracetam rescued normal neurotransmission and restored normal levels of SV2 and synaptotagmin at the synapse. These results indicate that changes in SV2 expression in either direction impact neurotransmission, and suggest that levetiracetam may modulate SV2 protein interactions.

STABLE ISOTOPE GEOCHEMISTRY OF MASSIVE ICE

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Yurij K. Vasil’chuk

2016-01-01

Full Text Available The paper summarises stable-isotope research on massive ice in the Russian and North American Arctic, and includes the latest understanding of massive-ice formation. A new classification of massive-ice complexes is proposed, encompassing the range and variabilityof massive ice. It distinguishes two new categories of massive-ice complexes: homogeneousmassive-ice complexes have a similar structure, properties and genesis throughout, whereasheterogeneous massive-ice complexes vary spatially (in their structure and properties andgenetically within a locality and consist of two or more homogeneous massive-ice bodies.Analysis of pollen and spores in massive ice from Subarctic regions and from ice and snow cover of Arctic ice caps assists with interpretation of the origin of massive ice. Radiocarbon ages of massive ice and host sediments are considered together with isotope values of heavy oxygen and deuterium from massive ice plotted at a uniform scale in order to assist interpretation and correlation of the ice.

Coordinated gene expression of neuroinflammatory and cell signaling markers in dorsolateral prefrontal cortex during human brain development and aging.

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Christopher T Primiani

Full Text Available Age changes in expression of inflammatory, synaptic, and neurotrophic genes are not well characterized during human brain development and senescence. Knowing these changes may elucidate structural, metabolic, and functional brain processes over the lifespan, as well vulnerability to neurodevelopmental or neurodegenerative diseases.Expression levels of inflammatory, synaptic, and neurotrophic genes in the human brain are coordinated over the lifespan and underlie changes in phenotypic networks or cascades.We used a large-scale microarray dataset from human prefrontal cortex, BrainCloud, to quantify age changes over the lifespan, divided into Development (0 to 21 years, 87 brains and Aging (22 to 78 years, 144 brains intervals, in transcription levels of 39 genes.Gene expression levels followed different trajectories over the lifespan. Many changes were intercorrelated within three similar groups or clusters of genes during both Development and Aging, despite different roles of the gene products in the two intervals. During Development, changes were related to reported neuronal loss, dendritic growth and pruning, and microglial events; TLR4, IL1R1, NFKB1, MOBP, PLA2G4A, and PTGS2 expression increased in the first years of life, while expression of synaptic genes GAP43 and DBN1 decreased, before reaching plateaus. During Aging, expression was upregulated for potentially pro-inflammatory genes such as NFKB1, TRAF6, TLR4, IL1R1, TSPO, and GFAP, but downregulated for neurotrophic and synaptic integrity genes such as BDNF, NGF, PDGFA, SYN, and DBN1.Coordinated changes in gene transcription cascades underlie changes in synaptic, neurotrophic, and inflammatory phenotypic networks during brain Development and Aging. Early postnatal expression changes relate to neuronal, glial, and myelin growth and synaptic pruning events, while late Aging is associated with pro-inflammatory and synaptic loss changes. Thus, comparable transcriptional regulatory networks

Coordinated Gene Expression of Neuroinflammatory and Cell Signaling Markers in Dorsolateral Prefrontal Cortex during Human Brain Development and Aging

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Primiani, Christopher T.; Ryan, Veronica H.; Rao, Jagadeesh S.; Cam, Margaret C.; Ahn, Kwangmi; Modi, Hiren R.; Rapoport, Stanley I.

2014-01-01

Background Age changes in expression of inflammatory, synaptic, and neurotrophic genes are not well characterized during human brain development and senescence. Knowing these changes may elucidate structural, metabolic, and functional brain processes over the lifespan, as well vulnerability to neurodevelopmental or neurodegenerative diseases. Hypothesis Expression levels of inflammatory, synaptic, and neurotrophic genes in the human brain are coordinated over the lifespan and underlie changes in phenotypic networks or cascades. Methods We used a large-scale microarray dataset from human prefrontal cortex, BrainCloud, to quantify age changes over the lifespan, divided into Development (0 to 21 years, 87 brains) and Aging (22 to 78 years, 144 brains) intervals, in transcription levels of 39 genes. Results Gene expression levels followed different trajectories over the lifespan. Many changes were intercorrelated within three similar groups or clusters of genes during both Development and Aging, despite different roles of the gene products in the two intervals. During Development, changes were related to reported neuronal loss, dendritic growth and pruning, and microglial events; TLR4, IL1R1, NFKB1, MOBP, PLA2G4A, and PTGS2 expression increased in the first years of life, while expression of synaptic genes GAP43 and DBN1 decreased, before reaching plateaus. During Aging, expression was upregulated for potentially pro-inflammatory genes such as NFKB1, TRAF6, TLR4, IL1R1, TSPO, and GFAP, but downregulated for neurotrophic and synaptic integrity genes such as BDNF, NGF, PDGFA, SYN, and DBN1. Conclusions Coordinated changes in gene transcription cascades underlie changes in synaptic, neurotrophic, and inflammatory phenotypic networks during brain Development and Aging. Early postnatal expression changes relate to neuronal, glial, and myelin growth and synaptic pruning events, while late Aging is associated with pro-inflammatory and synaptic loss changes. Thus, comparable

Synaptic dysfunction in amygdala in intellectual disorder models.

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Aincy, Marianne; Meziane, Hamid; Herault, Yann; Humeau, Yann

2018-06-08

The amygdala is a part of the limbic circuit that has been extensively studied in terms of synaptic connectivity, plasticity and cellular organization since decades (Ehrlich et al., 2009; Ledoux, 2000; Maren, 2001). Amygdala sub-nuclei, including lateral, basolateral and central amygdala appear now as "hubs" providing in parallel and in series neuronal processing enabling the animal to elicit freezing or escaping behavior in response to external threats. In rodents, these behaviors are easily observed and quantified following associative fear conditioning. Thus, studies on amygdala circuit in association with threat/fear behavior became very popular in laboratories and are often used among other behavioral tests to evaluate learning abilities of mouse models for various neuropsychiatric conditions including genetically encoded intellectual disabilities (ID). Yet, more than 100 human X-linked genes - and several hundreds of autosomal genes - have been associated with ID in humans. These mutations introduced in mice can generate social deficits, anxiety dysregulations and fear learning impairments (McNaughton et al., 2008; Houbaert et al., 2013; Jayachandran et al., 2014; Zhang et al., 2015). Noteworthy, a significant proportion of the coded ID gene products are synaptic proteins. It is postulated that the loss of function of these proteins could destabilize neuronal circuits by global changes of the balance between inhibitory and excitatory drives onto neurons. However, whereas amygdala related behavioral deficits are commonly observed in ID models, the role of most of these ID-genes in synaptic function and plasticity in the amygdala are only sparsely studied. We will here discuss some of the concepts that emerged from amygdala-targeted studies examining the role of syndromic and non-syndromic ID genes in fear-related behaviors and/or synaptic function. Along describing these cases, we will discuss how synaptic deficits observed in amygdala circuits could impact

Severity of scab and its effects on fruit weight in mechanically hedge-pruned and topped pecan trees

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Scab is the most damaging disease of pecan in the southeastern USA. Pecan trees can attain 44 m in height, so managing disease in the upper canopy is a problem. Fungicide is ordinarily applied using ground-based air-blast sprayers. Although mechanical hedge-pruning and topping of pecan is done for s...

75 FR 43039 - Fresh Prunes Grown in Designated Counties in Washington and in Umatilla County, OR; Suspension of...

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2010-07-23

... marketing of fresh prunes over the past four years. Based on its analysis, the Committee has determined that... DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 924 [Doc. No. AMS-FV-10-0054...; Suspension of Reporting and Assessment Requirements AGENCY: Agricultural Marketing Service, USDA. ACTION...

Massive graviton geons

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Aoki, Katsuki; Maeda, Kei-ichi; Misonoh, Yosuke; Okawa, Hirotada

2018-02-01

We find vacuum solutions such that massive gravitons are confined in a local spacetime region by their gravitational energy in asymptotically flat spacetimes in the context of the bigravity theory. We call such self-gravitating objects massive graviton geons. The basic equations can be reduced to the Schrödinger-Poisson equations with the tensor "wave function" in the Newtonian limit. We obtain a nonspherically symmetric solution with j =2 , ℓ=0 as well as a spherically symmetric solution with j =0 , ℓ=2 in this system where j is the total angular momentum quantum number and ℓ is the orbital angular momentum quantum number, respectively. The energy eigenvalue of the Schrödinger equation in the nonspherical solution is smaller than that in the spherical solution. We then study the perturbative stability of the spherical solution and find that there is an unstable mode in the quadrupole mode perturbations which may be interpreted as the transition mode to the nonspherical solution. The results suggest that the nonspherically symmetric solution is the ground state of the massive graviton geon. The massive graviton geons may decay in time due to emissions of gravitational waves but this timescale can be quite long when the massive gravitons are nonrelativistic and then the geons can be long-lived. We also argue possible prospects of the massive graviton geons: applications to the ultralight dark matter scenario, nonlinear (in)stability of the Minkowski spacetime, and a quantum transition of the spacetime.

Statistical Modelling of Synaptic Vesicles Distribution and Analysing their Physical Characteristics

DEFF Research Database (Denmark)

Khanmohammadi, Mahdieh

transmission electron microscopy is used to acquire images from two experimental groups of rats: 1) rats subjected to a behavioral model of stress and 2) rats subjected to sham stress as the control group. The synaptic vesicle distribution and interactions are modeled by employing a point process approach......This Ph.D. thesis deals with mathematical and statistical modeling of synaptic vesicle distribution, shape, orientation and interactions. The first major part of this thesis treats the problem of determining the effect of stress on synaptic vesicle distribution and interactions. Serial section...... on differences of statistical measures in section and the same measures in between sections. Three-dimensional (3D) datasets are reconstructed by using image registration techniques and estimated thicknesses. We distinguish the effect of stress by estimating the synaptic vesicle densities and modeling...

Associated rare anomalies in prune belly syndrome: A case report

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Andreas Fette

2015-02-01

Full Text Available The triad of deficient abdominal wall musculature, undescended testes and urinary tract anomalies characterizes the Prune Belly Syndrome (PBS. PBS can be associated with other comorbid urological and non urological conditions. But the full pathogenesis and best treatment is still a matter of debate. A term newborn with a classical PBS (Woodhouse Group 2, Smith and Woodard Group 2 plus lung hypoplasia and funnel chest deformity, a megapenis with a tight phimosis and an obturated anterior urethra is presented. Unfortunately, the baby died in urosepsis and renal failure in his 3rd week of life, despite urine drainage surgery and peritoneal dialysis undertaken. According to the best of our knowledge, this is an unique combination of rare anomalies in PBS patients.

Cavity size and copper root pruning affect production and establishment of container-grown longleaf pine seedlings

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Marry Anne Sword Sayer; James D. Haywood; Shi-Jean Susana Sung

2009-01-01

With six container types, we tested the effects of cavity size (i.e., 60, 93, and 170 ml) and copper root pruning on the root system development of longleaf pine (Pinus palustris Mill.) seedlings grown in a greenhouse. We then evaluated root egress during a root growth potential test and assessed seedling morphology and root system development 1 year after planting in...

Hardwiring of fine synaptic layers in the zebrafish visual pathway

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Taylor Michael R

2008-12-01

Full Text Available Abstract Background Neuronal connections are often arranged in layers, which are divided into sublaminae harboring synapses with similar response properties. It is still debated how fine-grained synaptic layering is established during development. Here we investigated two stratified areas of the zebrafish visual pathway, the inner plexiform layer (IPL of the retina and the neuropil of the optic tectum, and determined if activity is required for their organization. Results The IPL of 5-day-old zebrafish larvae is composed of at least nine sublaminae, comprising the connections between different types of amacrine, bipolar, and ganglion cells (ACs, BCs, GCs. These sublaminae were distinguished by their expression of cell type-specific transgenic fluorescent reporters and immunohistochemical markers, including protein kinase Cβ (PKC, parvalbumin (Parv, zrf3, and choline acetyltransferase (ChAT. In the tectum, four retinal input layers abut a laminated array of neurites of tectal cells, which differentially express PKC and Parv. We investigated whether these patterns were affected by experimental disruptions of retinal activity in developing fish. Neither elimination of light inputs by dark rearing, nor a D, L-amino-phosphono-butyrate-induced reduction in the retinal response to light onset (but not offset altered IPL or tectal lamination. Moreover, thorough elimination of chemical synaptic transmission with Botulinum toxin B left laminar synaptic arrays intact. Conclusion Our results call into question a role for activity-dependent mechanisms – instructive light signals, balanced on and off BC activity, Hebbian plasticity, or a permissive role for synaptic transmission – in the synaptic stratification we examined. We propose that genetically encoded cues are sufficient to target groups of neurites to synaptic layers in this vertebrate visual system.

Congenital mydriasis and prune belly syndrome in a child with an ACTA2 mutation.

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Brodsky, Michael C; Turan, Kadriye Erkan; Khanna, Cheryl L; Patton, Alice; Kirmani, Salman

2014-08-01

We report the association of congenital mydriasis with prune belly syndrome and cerebrovascular anomalies in a 9-year-old boy who was found to have an ACTA2 mutation. This case illustrates the spectrum of systemic malformations that are attributable to mutations in ACTA2 and expands the spectrum of cerebrovascular anomalies that are now known to accompany congenital mydriasis. Copyright © 2014 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

Pruning cycles and nitrogen fertilization of coffee fields conducted in the “safra zero” system

OpenAIRE

Japiassú, Leonardo Bíscaro; Fundação Procafé; Garcia, André Luiz Alvarenga; Fundação Procafé; Guimarães, Rubens José; Universidade Federal de Lavras - UFLA; Padilha, Lílian; Embrapa Café; Carvalho, Carlos Henrique Siqueira; Embrapa Café

2010-01-01

Modern, competitive and cost effective coffee production requires plants with high productivity that are more adapted to mechanical and manual harvesting. “Safra Zero” is a cultivation system designed to limit plant height and eliminate the need for expensive harvesting during years of low productivity, which usually follow years of high productivity. This system is based on pruning cycles, nitrogen fertilization and different management methods. To evaluate the “Safra Zero&...

A Voltage Mode Memristor Bridge Synaptic Circuit with Memristor Emulators

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Leon Chua

2012-03-01

Full Text Available A memristor bridge neural circuit which is able to perform signed synaptic weighting was proposed in our previous study, where the synaptic operation was verified via software simulation of the mathematical model of the HP memristor. This study is an extension of the previous work advancing toward the circuit implementation where the architecture of the memristor bridge synapse is built with memristor emulator circuits. In addition, a simple neural network which performs both synaptic weighting and summation is built by combining memristor emulators-based synapses and differential amplifier circuits. The feasibility of the memristor bridge neural circuit is verified via SPICE simulations.

Network-based characterization of the synaptic proteome reveals that removal of epigenetic regulator Prmt8 restricts proteins associated with synaptic maturation.

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Lee, Patrick Kia Ming; Goh, Wilson Wen Bin; Sng, Judy Chia Ghee

2017-02-01

The brain adapts to dynamic environmental conditions by altering its epigenetic state, thereby influencing neuronal transcriptional programs. An example of an epigenetic modification is protein methylation, catalyzed by protein arginine methyltransferases (PRMT). One member, Prmt8, is selectively expressed in the central nervous system during a crucial phase of early development, but little else is known regarding its function. We hypothesize Prmt8 plays a role in synaptic maturation during development. To evaluate this, we used a proteome-wide approach to characterize the synaptic proteome of Prmt8 knockout versus wild-type mice. Through comparative network-based analyses, proteins and functional clusters related to neurite development were identified to be differentially regulated between the two genotypes. One interesting protein that was differentially regulated was tenascin-R (TNR). Chromatin immunoprecipitation demonstrated binding of PRMT8 to the tenascin-r (Tnr) promoter. TNR, a component of perineuronal nets, preserves structural integrity of synaptic connections within neuronal networks during the development of visual-somatosensory cortices. On closer inspection, Prmt8 removal increased net formation and decreased inhibitory parvalbumin-positive (PV+) puncta on pyramidal neurons, thereby hindering the maturation of circuits. Consequently, visual acuity of the knockout mice was reduced. Our results demonstrated Prmt8's involvement in synaptic maturation and its prospect as an epigenetic modulator of developmental neuroplasticity by regulating structural elements such as the perineuronal nets. © 2016 International Society for Neurochemistry.

Vesicular GABA Uptake Can Be Rate Limiting for Recovery of IPSCs from Synaptic Depression

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Manami Yamashita

2018-03-01

Full Text Available Summary: Synaptic efficacy plays crucial roles in neuronal circuit operation and synaptic plasticity. Presynaptic determinants of synaptic efficacy are neurotransmitter content in synaptic vesicles and the number of vesicles undergoing exocytosis at a time. Bursts of presynaptic firings depress synaptic efficacy, mainly due to depletion of releasable vesicles, whereas recovery from strong depression is initiated by endocytic vesicle retrieval followed by refilling of vesicles with neurotransmitter. We washed out presynaptic cytosolic GABA to induce a rundown of IPSCs at cerebellar inhibitory cell pairs in slices from rats and then allowed fast recovery by elevating GABA concentration using photo-uncaging. The time course of this recovery coincided with that of IPSCs from activity-dependent depression induced by a train of high-frequency stimulation. We conclude that vesicular GABA uptake can be a limiting step for the recovery of inhibitory neurotransmission from synaptic depression. : Recovery of inhibitory synaptic transmission from activity-dependent depression requires refilling of vesicles with GABA. Yamashita et al. find that vesicular uptake rate of GABA is a slow process, limiting the recovery rate of IPSCs from depression.

Synaptic Tagging, Evaluation of Memories, and the Distal Reward Problem

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Papper, Marc; Kempter, Richard; Leibold, Christian

2011-01-01

Long-term synaptic plasticity exhibits distinct phases. The synaptic tagging hypothesis suggests an early phase in which synapses are prepared, or "tagged," for protein capture, and a late phase in which those proteins are integrated into the synapses to achieve memory consolidation. The synapse specificity of the tags is consistent with…

Brief environmental enrichment elicits metaplasticity of hippocampal synaptic potentiation in vivo

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Denise eManahan-Vaughan

2012-12-01

Full Text Available Long-term environmental enrichment (EE elicits enduring effects on the adult brain, including altered synaptic plasticity. Synaptic plasticity may underlie memory formation and includes robust (>24h and weak (<2h forms of long-term potentiation (LTP and long-term depression (LTD. Most studies of the effect of EE on synaptic efficacy have examined the consequences of very prolonged EE-exposure. It is unclear whether brief exposure to EE can alter synaptic plasticity. Clarifying this issue could help develop strategies to address cognitive deficits arising from neglect in children or adults.We assessed whether short-term EE elicits alterations in hippocampal synaptic plasticity and if social context may play a role. Adult mice were exposed to EE for 14 consecutive days. We found that robust late-LTP (>24h and short-term depression (<2h at Schaffer-collateral-CA1 synapses in freely behaving mice were unaltered, whereas early-LTP (E-LTP, <2h was significantly enhanced by EE. Effects were transient: E-LTP returned to control levels 1 week after cessation of EE. Six weeks later animals were re-exposed to EE for 14d. Under these conditions, E-LTP was facilitated into L-LTP (>24h, suggesting that metaplasticity was induced during the first EE experience and that EE-mediated modifications are cumulative. Effects were absent in mice that underwent solitary enrichment or were group-housed without EE. These data suggest that EE in naïve animals strengthens E-LTP, and also promotes L-LTP in animals that underwent EE in the past. This indicates that brief exposure to EE, particularly under social conditions can elicit lasting positive effects on synaptic strength that may have beneficial consequences for cognition that depends on synaptic plasticity.

Synaptic energy drives the information processing mechanisms in spiking neural networks.

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El Laithy, Karim; Bogdan, Martin

2014-04-01

Flow of energy and free energy minimization underpins almost every aspect of naturally occurring physical mechanisms. Inspired by this fact this work establishes an energy-based framework that spans the multi-scale range of biological neural systems and integrates synaptic dynamic, synchronous spiking activity and neural states into one consistent working paradigm. Following a bottom-up approach, a hypothetical energy function is proposed for dynamic synaptic models based on the theoretical thermodynamic principles and the Hopfield networks. We show that a synapse exposes stable operating points in terms of its excitatory postsynaptic potential as a function of its synaptic strength. We postulate that synapses in a network operating at these stable points can drive this network to an internal state of synchronous firing. The presented analysis is related to the widely investigated temporal coherent activities (cell assemblies) over a certain range of time scales (binding-by-synchrony). This introduces a novel explanation of the observed (poly)synchronous activities within networks regarding the synaptic (coupling) functionality. On a network level the transitions from one firing scheme to the other express discrete sets of neural states. The neural states exist as long as the network sustains the internal synaptic energy.

A neuromorphic implementation of multiple spike-timing synaptic plasticity rules for large-scale neural networks

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Runchun Mark Wang

2015-05-01

Full Text Available We present a neuromorphic implementation of multiple synaptic plasticity learning rules, which include both Spike Timing Dependent Plasticity (STDP and Spike Timing Dependent Delay Plasticity (STDDP. We present a fully digital implementation as well as a mixed-signal implementation, both of which use a novel dynamic-assignment time-multiplexing approach and support up to 2^26 (64M synaptic plasticity elements. Rather than implementing dedicated synapses for particular types of synaptic plasticity, we implemented a more generic synaptic plasticity adaptor array that is separate from the neurons in the neural network. Each adaptor performs synaptic plasticity according to the arrival times of the pre- and post-synaptic spikes assigned to it, and sends out a weighted and/or delayed pre-synaptic spike to the target synapse in the neural network. This strategy provides great flexibility for building complex large-scale neural networks, as a neural network can be configured for multiple synaptic plasticity rules without changing its structure. We validate the proposed neuromorphic implementations with measurement results and illustrate that the circuits are capable of performing both STDP and STDDP. We argue that it is practical to scale the work presented here up to 2^36 (64G synaptic adaptors on a current high-end FPGA platform.

Effects of tree species and wood particle size on the properties of cement-bonded particleboard manufacturing from tree prunings.

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Nasser, Ramadan A; Al-Mefarrej, H A; Abdel-Aal, M A; Alshahrani, T S

2014-09-01

This study investigated the possibility of using the prunings of six locally grown tree species in Saudi Arabia for cement-bonded particleboard (CBP) production. Panels were made using four different wood particle sizes and a constant wood/cement ratio (1/3 by weight) and target density (1200 kg/m3). The mechanical properties and dimensional stability of the produced panels were determined. The interfacial area and distribution of the wood particles in cement matrix were also investigated by scanning electron microscopy. The results revealed that the panels produced from these pruning materials at a target density of 1200 kg m(-3) meet the strength and dimensional stability requirements of the commercial CBP panels. The mean moduli of rupture and elasticity (MOR and MOE) ranged from 9.68 to 11.78 N mm2 and from 3952 to 5667 N mm2, respectively. The mean percent water absorption for twenty four hours (WA24) ranged from 12.93% to 23.39%. Thickness swelling values ranged from 0.62% to 1.53%. For CBP panels with high mechanical properties and good dimensional stability, mixed-size or coarse particles should be used. Using the tree prunings for CBPs production may help to solve the problem of getting rid of these residues by reducing their negative effects on environment, which are caused by poor disposal of such materials through direct combustion process and appearance of black cloud and then the impact on human health or the random accumulation and its indirect effects on the environment.

Love and death: microglia, NLRP3 and the Alzheimer's brain.

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Goldmann, Tobias; Tay, Tuan Leng; Prinz, Marco

2013-05-01

Microglia were previously attributed to be vital brain guardians for neuronal survival and synaptic pruning during development as well as for the brain's fight against environmental pathogens. A new report in Nature by the Heneka, Latz and Golenbock groups, however, sheds new light on these distinct myeloid cells by revealing their deadly nature for mature neurons during neurodegeneration.

Synaptic inputs compete during rapid formation of the calyx of Held: a new model system for neural development.

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Holcomb, Paul S; Hoffpauir, Brian K; Hoyson, Mitchell C; Jackson, Dakota R; Deerinck, Thomas J; Marrs, Glenn S; Dehoff, Marlin; Wu, Jonathan; Ellisman, Mark H; Spirou, George A

2013-08-07

Hallmark features of neural circuit development include early exuberant innervation followed by competition and pruning to mature innervation topography. Several neural systems, including the neuromuscular junction and climbing fiber innervation of Purkinje cells, are models to study neural development in part because they establish a recognizable endpoint of monoinnervation of their targets and because the presynaptic terminals are large and easily monitored. We demonstrate here that calyx of Held (CH) innervation of its target, which forms a key element of auditory brainstem binaural circuitry, exhibits all of these characteristics. To investigate CH development, we made the first application of serial block-face scanning electron microscopy to neural development with fine temporal resolution and thereby accomplished the first time series for 3D ultrastructural analysis of neural circuit formation. This approach revealed a growth spurt of added apposed surface area (ASA)>200 μm2/d centered on a single age at postnatal day 3 in mice and an initial rapid phase of growth and competition that resolved to monoinnervation in two-thirds of cells within 3 d. This rapid growth occurred in parallel with an increase in action potential threshold, which may mediate selection of the strongest input as the winning competitor. ASAs of competing inputs were segregated on the cell body surface. These data suggest mechanisms to select "winning" inputs by regional reinforcement of postsynaptic membrane to mediate size and strength of competing synaptic inputs.

Combustion behaviour of Olive pruning/animal manure blends in a fluidized bed combustor

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Despina Vamvuka

2017-09-01

Both fuels burned mostly within the bed. The maximum temperature of animal manure was 50 °C lower than that of olive pruning, however efficiency was nearly 99%. CO emissions were low, SO2 emissions were negligible, whereas NOx emissions of blends exceeded legislation limits, when excess air ratio was over 1.4. Decreasing excess air from 50 to 30%, or reducing reactor loading, resulted in improved burnout. The optimum performance for the blends was achieved when the feed rate was 0.6 kg/h and excess air was 30%.

A influência da poda mecânica na produção e na eficiência da colheita da azeitona por vibração The influence of mechanical pruning on olive production and shaker efficiency

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A. B. Dias

2007-01-01

Full Text Available Em Portugal tem-se verificado um incremento no custo de execução da poda da oliveira, pelo que os autores iniciaram em 1997 a avaliação da aplicação da poda mecânica como alternativa à poda manual efectuada com moto - serra. Estabeleceram-se ensaios de campo com os seguintes tratamentos: T1 – poda manual com moto-serra; T2 – poda mecânica, efectuada por uma máquina de podar de discos, montada no carregador frontal de um tractor agrícola; T3 – poda mecânica efectuada pela máquina de podar de discos, seguida de complemento manual com moto - serra. Em cada ensaio, efectuou-se a colheita da azeitona com vibradores de tronco multidireccionais, tendo-se avaliado a produção total por árvore e o desempenho do vibrador na colheita da azeitona, em termos de eficiência de colheita e tempo de vibração por árvore. Neste trabalho apresentam-se os resultados obtidos em dois ensaios, não se tendo verificado diferenças significativas (P>0,1 entre os tratamentos na produção de azeitona, nos quatro anos após a execução da poda. Relativamente ao desempenho do vibrador, os resultados obtidos mostram que há necessidade de adequar a forma de abordar a árvore e a duração da vibração, de modo a manter o mesmo grau de eficiência entre os tratamentos.In Portugal, olive farmers, particularly those with orchards of around 100 trees per hectare, are facing increasing pruning costs every year. As a result they tend to lengthen pruning intervals. With the purpose of studying a mechanised alternative to the labour intensive manual pruning practice, the authors established in 1997 field trials with the following three treatments: T1 -manual pruning cutting with a chain saw; T2 - mechanical pruning, performed by a tractor mounted cutting bar provided with 6 circular disc-saws; T3 -mechanical pruning, as in T2, followed by a manual pruning complement. In each test site, olives were harvested using a trunk shaker. Total production per tree

Emergence of Functional Specificity in Balanced Networks with Synaptic Plasticity.

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Sadra Sadeh

2015-06-01

Full Text Available In rodent visual cortex, synaptic connections between orientation-selective neurons are unspecific at the time of eye opening, and become to some degree functionally specific only later during development. An explanation for this two-stage process was proposed in terms of Hebbian plasticity based on visual experience that would eventually enhance connections between neurons with similar response features. For this to work, however, two conditions must be satisfied: First, orientation selective neuronal responses must exist before specific recurrent synaptic connections can be established. Second, Hebbian learning must be compatible with the recurrent network dynamics contributing to orientation selectivity, and the resulting specific connectivity must remain stable for unspecific background activity. Previous studies have mainly focused on very simple models, where the receptive fields of neurons were essentially determined by feedforward mechanisms, and where the recurrent network was small, lacking the complex recurrent dynamics of large-scale networks of excitatory and inhibitory neurons. Here we studied the emergence of functionally specific connectivity in large-scale recurrent networks with synaptic plasticity. Our results show that balanced random networks, which already exhibit highly selective responses at eye opening, can develop feature-specific connectivity if appropriate rules of synaptic plasticity are invoked within and between excitatory and inhibitory populations. If these conditions are met, the initial orientation selectivity guides the process of Hebbian learning and, as a result, functionally specific and a surplus of bidirectional connections emerge. Our results thus demonstrate the cooperation of synaptic plasticity and recurrent dynamics in large-scale functional networks with realistic receptive fields, highlight the role of inhibition as a critical element in this process, and paves the road for further computational

Fuzzy Pruning Based LS-SVM Modeling Development for a Fermentation Process

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Weili Xiong

2014-01-01

Full Text Available Due to the complexity and uncertainty of microbial fermentation processes, data coming from the plants often contain some outliers. However, these data may be treated as the normal support vectors, which always deteriorate the performance of soft sensor modeling. Since the outliers also contaminate the correlation structure of the least square support vector machine (LS-SVM, the fuzzy pruning method is provided to deal with the problem. Furthermore, by assigning different fuzzy membership scores to data samples, the sensitivity of the model to the outliers can be reduced greatly. The effectiveness and efficiency of the proposed approach are demonstrated through two numerical examples as well as a simulator case of penicillin fermentation process.

Synaptic activity regulates AMPA receptor trafficking through different recycling pathways

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Zheng, Ning; Jeyifous, Okunola; Munro, Charlotte; Montgomery, Johanna M; Green, William N

2015-01-01

Changes in glutamatergic synaptic strength in brain are dependent on AMPA-type glutamate receptor (AMPAR) recycling, which is assumed to occur through a single local pathway. In this study, we present evidence that AMPAR recycling occurs through different pathways regulated by synaptic activity. Without synaptic stimulation, most AMPARs recycled in dynamin-independent endosomes containing the GTPase, Arf6. Few AMPARs recycled in dynamin-dependent endosomes labeled by transferrin receptors (TfRs). AMPAR recycling was blocked by alterations in the GTPase, TC10, which co-localized with Arf6 endosomes. TC10 mutants that reduced AMPAR recycling had no effect on increased AMPAR levels with long-term potentiation (LTP) and little effect on decreased AMPAR levels with long-term depression. However, internalized AMPAR levels in TfR-containing recycling endosomes increased after LTP, indicating increased AMPAR recycling through the dynamin-dependent pathway with synaptic plasticity. LTP-induced AMPAR endocytosis is inconsistent with local recycling as a source of increased surface receptors, suggesting AMPARs are trafficked from other sites. DOI: http://dx.doi.org/10.7554/eLife.06878.001 PMID:25970033

The Role of Co-chaperones in Synaptic Proteostasis and Neurodegenerative Disease

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Erica L. Gorenberg

2017-05-01

Full Text Available Synapses must be preserved throughout an organism's lifespan to allow for normal brain function and behavior. Synapse maintenance is challenging given the long distances between the termini and the cell body, reliance on axonal transport for delivery of newly synthesized presynaptic proteins, and high rates of synaptic vesicle exo- and endocytosis. Hence, synapses rely on efficient proteostasis mechanisms to preserve their structure and function. To this end, the synaptic compartment has specific chaperones to support its functions. Without proper synaptic chaperone activity, local proteostasis imbalances lead to neurotransmission deficits, dismantling of synapses, and neurodegeneration. In this review, we address the roles of four synaptic chaperones in the maintenance of the nerve terminal, as well as their genetic links to neurodegenerative disease. Three of these are Hsp40 co-chaperones (DNAJs: Cysteine String Protein alpha (CSPα; DNAJC5, auxilin (DNAJC6, and Receptor-Mediated Endocytosis 8 (RME-8; DNAJC13. These co-chaperones contain a conserved J domain through which they form a complex with heat shock cognate 70 (Hsc70, enhancing the chaperone's ATPase activity. CSPα is a synaptic vesicle protein known to chaperone the t-SNARE SNAP-25 and the endocytic GTPase dynamin-1, thereby regulating synaptic vesicle exocytosis and endocytosis. Auxilin binds assembled clathrin cages, and through its interactions with Hsc70 leads to the uncoating of clathrin-coated vesicles, a process necessary for the regeneration of synaptic vesicles. RME-8 is a co-chaperone on endosomes and may have a role in clathrin-coated vesicle endocytosis on this organelle. These three co-chaperones maintain client function by preserving folding and assembly to prevent client aggregation, but they do not break down aggregates that have already formed. The fourth synaptic chaperone we will discuss is Heat shock protein 110 (Hsp110, which interacts with Hsc70, DNAJAs, and

Synaptic scaling enables dynamically distinct short- and long-term memory formation.

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Christian Tetzlaff

2013-10-01

Full Text Available Memory storage in the brain relies on mechanisms acting on time scales from minutes, for long-term synaptic potentiation, to days, for memory consolidation. During such processes, neural circuits distinguish synapses relevant for forming a long-term storage, which are consolidated, from synapses of short-term storage, which fade. How time scale integration and synaptic differentiation is simultaneously achieved remains unclear. Here we show that synaptic scaling - a slow process usually associated with the maintenance of activity homeostasis - combined with synaptic plasticity may simultaneously achieve both, thereby providing a natural separation of short- from long-term storage. The interaction between plasticity and scaling provides also an explanation for an established paradox where memory consolidation critically depends on the exact order of learning and recall. These results indicate that scaling may be fundamental for stabilizing memories, providing a dynamic link between early and late memory formation processes.

Synaptic scaling enables dynamically distinct short- and long-term memory formation.

Science.gov (United States)

Tetzlaff, Christian; Kolodziejski, Christoph; Timme, Marc; Tsodyks, Misha; Wörgötter, Florentin

2013-10-01

Memory storage in the brain relies on mechanisms acting on time scales from minutes, for long-term synaptic potentiation, to days, for memory consolidation. During such processes, neural circuits distinguish synapses relevant for forming a long-term storage, which are consolidated, from synapses of short-term storage, which fade. How time scale integration and synaptic differentiation is simultaneously achieved remains unclear. Here we show that synaptic scaling - a slow process usually associated with the maintenance of activity homeostasis - combined with synaptic plasticity may simultaneously achieve both, thereby providing a natural separation of short- from long-term storage. The interaction between plasticity and scaling provides also an explanation for an established paradox where memory consolidation critically depends on the exact order of learning and recall. These results indicate that scaling may be fundamental for stabilizing memories, providing a dynamic link between early and late memory formation processes.

Synaptic proteins and receptors defects in autism spectrum disorders

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Jianling eChen

2014-09-01

Full Text Available Recent studies have found that hundreds of genetic variants, including common and rare variants, rare and de novo mutations, and common polymorphisms have contributed to the occurrence of autism spectrum disorders (ASDs. The mutations in a number of genes such as neurexin, neuroligin, postsynaptic density protein 95 (PSD-95, SH3 and multiple ankyrin repeat domains 3 (SHANK3, synapsin, gephyrin, cadherin (CDH and protocadherin (PCDH, thousand-and-one-amino acid 2 kinase (TAOK2, and contactin (CNTN, have been shown to play important roles in the development and function of synapses. In addition, synaptic receptors, such as gamma-aminobutyric acid (GABA receptors and glutamate receptors, have also been associated with ASDs. This review will primarily focus on the defects of synaptic proteins and receptors associated with ASDs and their roles in the pathogenesis of ASDs via synaptic pathways.

Synaptic model for spontaneous activity in developing networks

DEFF Research Database (Denmark)

Lerchner, Alexander; Rinzel, J.

2005-01-01

Spontaneous rhythmic activity occurs in many developing neural networks. The activity in these hyperexcitable networks is comprised of recurring "episodes" consisting of "cycles" of high activity that alternate with "silent phases" with little or no activity. We introduce a new model of synaptic...... dynamics that takes into account that only a fraction of the vesicles stored in a synaptic terminal is readily available for release. We show that our model can reproduce spontaneous rhythmic activity with the same general features as observed in experiments, including a positive correlation between...

Learning Structure of Sensory Inputs with Synaptic Plasticity Leads to Interference

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Joseph eChrol-Cannon

2015-08-01

Full Text Available Synaptic plasticity is often explored as a form of unsupervised adaptationin cortical microcircuits to learn the structure of complex sensoryinputs and thereby improve performance of classification and prediction. The question of whether the specific structure of the input patterns is encoded in the structure of neural networks has been largely neglected. Existing studies that have analyzed input-specific structural adaptation have used simplified, synthetic inputs in contrast to complex and noisy patterns found in real-world sensory data.In this work, input-specific structural changes are analyzed forthree empirically derived models of plasticity applied to three temporal sensory classification tasks that include complex, real-world visual and auditory data. Two forms of spike-timing dependent plasticity (STDP and the Bienenstock-Cooper-Munro (BCM plasticity rule are used to adapt the recurrent network structure during the training process before performance is tested on the pattern recognition tasks.It is shown that synaptic adaptation is highly sensitive to specific classes of input pattern. However, plasticity does not improve the performance on sensory pattern recognition tasks, partly due to synaptic interference between consecutively presented input samples. The changes in synaptic strength produced by one stimulus are reversed by thepresentation of another, thus largely preventing input-specific synaptic changes from being retained in the structure of the network.To solve the problem of interference, we suggest that models of plasticitybe extended to restrict neural activity and synaptic modification to a subset of the neural circuit, which is increasingly found to be the casein experimental neuroscience.

Common mechanisms of synaptic plasticity in vertebrates and invertebrates

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Glanzman, David L.

2016-01-01

Until recently, the literature on learning-related synaptic plasticity in invertebrates has been dominated by models assuming plasticity is mediated by presynaptic changes, whereas the vertebrate literature has been dominated by models assuming it is mediated by postsynaptic changes. Here I will argue that this situation does not reflect a biological reality and that, in fact, invertebrate and vertebrate nervous systems share a common set of mechanisms of synaptic plasticity. PMID:20152143

Organic/inorganic hybrid synaptic transistors gated by proton conducting methylcellulose films

International Nuclear Information System (INIS)

Wan, Chang Jin; Wan, Qing; Zhu, Li Qiang; Wan, Xiang; Shi, Yi

2016-01-01

The idea of building a brain-inspired cognitive system has been around for several decades. Recently, electric-double-layer transistors gated by ion conducting electrolytes were reported as the promising candidates for synaptic electronics and neuromorphic system. In this letter, indium-zinc-oxide transistors gated by proton conducting methylcellulose electrolyte films were experimentally demonstrated with synaptic plasticity including paired-pulse facilitation and spatiotemporal-correlated dynamic logic. More importantly, a model based on proton-related electric-double-layer modulation and stretched-exponential decay function was proposed, and the theoretical results are in good agreement with the experimentally measured synaptic behaviors

Organic/inorganic hybrid synaptic transistors gated by proton conducting methylcellulose films

Energy Technology Data Exchange (ETDEWEB)

Wan, Chang Jin; Wan, Qing, E-mail: wanqing@nju.edu.cn, E-mail: yshi@nju.edu.cn [School of Electronic Science & Engineering, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Zhu, Li Qiang [Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Wan, Xiang; Shi, Yi, E-mail: wanqing@nju.edu.cn, E-mail: yshi@nju.edu.cn [School of Electronic Science & Engineering, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China)

2016-01-25

The idea of building a brain-inspired cognitive system has been around for several decades. Recently, electric-double-layer transistors gated by ion conducting electrolytes were reported as the promising candidates for synaptic electronics and neuromorphic system. In this letter, indium-zinc-oxide transistors gated by proton conducting methylcellulose electrolyte films were experimentally demonstrated with synaptic plasticity including paired-pulse facilitation and spatiotemporal-correlated dynamic logic. More importantly, a model based on proton-related electric-double-layer modulation and stretched-exponential decay function was proposed, and the theoretical results are in good agreement with the experimentally measured synaptic behaviors.

Synaptic damage underlies EEG abnormalities in postanoxic encephalopathy: A computational study.

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Ruijter, B J; Hofmeijer, J; Meijer, H G E; van Putten, M J A M

2017-09-01

In postanoxic coma, EEG patterns indicate the severity of encephalopathy and typically evolve in time. We aim to improve the understanding of pathophysiological mechanisms underlying these EEG abnormalities. We used a mean field model comprising excitatory and inhibitory neurons, local synaptic connections, and input from thalamic afferents. Anoxic damage is modeled as aggravated short-term synaptic depression, with gradual recovery over many hours. Additionally, excitatory neurotransmission is potentiated, scaling with the severity of anoxic encephalopathy. Simulations were compared with continuous EEG recordings of 155 comatose patients after cardiac arrest. The simulations agree well with six common categories of EEG rhythms in postanoxic encephalopathy, including typical transitions in time. Plausible results were only obtained if excitatory synapses were more severely affected by short-term synaptic depression than inhibitory synapses. In postanoxic encephalopathy, the evolution of EEG patterns presumably results from gradual improvement of complete synaptic failure, where excitatory synapses are more severely affected than inhibitory synapses. The range of EEG patterns depends on the excitation-inhibition imbalance, probably resulting from long-term potentiation of excitatory neurotransmission. Our study is the first to relate microscopic synaptic dynamics in anoxic brain injury to both typical EEG observations and their evolution in time. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Mapping synaptic pathology within cerebral cortical circuits in subjects with schizophrenia

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Robert Sweet

2010-06-01

Full Text Available Converging lines of evidence indicate that schizophrenia is characterized by impairments of synaptic machinery within cerebral cortical circuits. Efforts to localize these alterations in brain tissue from subjects with schizophrenia have frequently been limited to the quantification of structures that are non-selectively identified (e.g. dendritic spines labeled in Golgi preparations, axon boutons labeled with synaptophysin, or to quantification of proteins using methods unable to resolve relevant cellular compartments. Multiple label fluorescence confocal microscopy represents a means to circumvent many of these limitations, by concurrently extracting information regarding the number, morphology, and relative protein content of synaptic structures. An important adaptation required for studies of human disease is coupling this approach to stereologic methods for systematic random sampling of relevant brain regions. In this review article we consider the application of multiple label fluorescence confocal microscopy to the mapping of synaptic alterations in subjects with schizophrenia and describe the application of a novel, readily automated, iterative intensity/morphological segmentation algorithm for the extraction of information regarding synaptic structure number, size, and relative protein level from tissue sections obtained using unbiased stereological principles of sampling. In this context, we provide examples of the examination of pre- and post-synaptic structures within excitatory and inhibitory circuits of the cerebral cortex.

Massive Conformal Gravity

International Nuclear Information System (INIS)

Faria, F. F.

2014-01-01

We construct a massive theory of gravity that is invariant under conformal transformations. The massive action of the theory depends on the metric tensor and a scalar field, which are considered the only field variables. We find the vacuum field equations of the theory and analyze its weak-field approximation and Newtonian limit.

Activity Induces Fmr1-Sensitive Synaptic Capture of Anterograde Circulating Neuropeptide Vesicles.

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Cavolo, Samantha L; Bulgari, Dinara; Deitcher, David L; Levitan, Edwin S

2016-11-16

Synaptic neuropeptide and neurotrophin stores are maintained by constitutive bidirectional capture of dense-core vesicles (DCVs) as they circulate in and out of the nerve terminal. Activity increases DCV capture to rapidly replenish synaptic neuropeptide stores following release. However, it is not known whether this is due to enhanced bidirectional capture. Here experiments at the Drosophila neuromuscular junction, where DCVs contain neuropeptides and a bone morphogenic protein, show that activity-dependent replenishment of synaptic neuropeptides following release is evident after inhibiting the retrograde transport with the dynactin disruptor mycalolide B or photobleaching DCVs entering a synaptic bouton by retrograde transport. In contrast, photobleaching anterograde transport vesicles entering a bouton inhibits neuropeptide replenishment after activity. Furthermore, tracking of individual DCVs moving through boutons shows that activity selectively increases capture of DCVs undergoing anterograde transport. Finally, upregulating fragile X mental retardation 1 protein (Fmr1, also called FMRP) acts independently of futsch/MAP-1B to abolish activity-dependent, but not constitutive, capture. Fmr1 also reduces presynaptic neuropeptide stores without affecting activity-independent delivery and evoked release. Therefore, presynaptic motoneuron neuropeptide storage is increased by a vesicle capture mechanism that is distinguished from constitutive bidirectional capture by activity dependence, anterograde selectivity, and Fmr1 sensitivity. These results show that activity recruits a separate mechanism than used at rest to stimulate additional synaptic capture of DCVs for future release of neuropeptides and neurotrophins. Synaptic release of neuropeptides and neurotrophins depends on presynaptic accumulation of dense-core vesicles (DCVs). At rest, DCVs are captured bidirectionally as they circulate through Drosophila motoneuron terminals by anterograde and retrograde

Enzymatic hydrolyses of pretreated eucalyptus residues, wheat straw or olive tree pruning, and their mixtures towards flexible sugar-based biorefineries

DEFF Research Database (Denmark)

Silva-Fernandes, Talita; Marques, Susana; Rodrigues, Rita C. L. B.

2016-01-01

Eucalyptus residues, wheat straw, and olive tree pruning are lignocellulosic materials largely available in Southern Europe and have high potential to be used solely or in mixtures in sugar-based biorefineries for the production of biofuels and other bio-based products. Enzymatic hydrolysis...

Optimal autaptic and synaptic delays enhanced synchronization transitions induced by each other in Newman–Watts neuronal networks

International Nuclear Information System (INIS)

Wang, Baoying; Gong, Yubing; Xie, Huijuan; Wang, Qi

2016-01-01

Highlights: • Optimal autaptic delay enhanced synchronization transitions induced by synaptic delay in neuronal networks. • Optimal synaptic delay enhanced synchronization transitions induced by autaptic delay. • Optimal coupling strength enhanced synchronization transitions induced by autaptic or synaptic delay. - Abstract: In this paper, we numerically study the effect of electrical autaptic and synaptic delays on synchronization transitions induced by each other in Newman–Watts Hodgkin–Huxley neuronal networks. It is found that the synchronization transitions induced by synaptic delay vary with varying autaptic delay and become strongest when autaptic delay is optimal. Similarly, the synchronization transitions induced by autaptic delay vary with varying synaptic delay and become strongest at optimal synaptic delay. Also, there is optimal coupling strength by which the synchronization transitions induced by either synaptic or autaptic delay become strongest. These results show that electrical autaptic and synaptic delays can enhance synchronization transitions induced by each other in the neuronal networks. This implies that electrical autaptic and synaptic delays can cooperate with each other and more efficiently regulate the synchrony state of the neuronal networks. These findings could find potential implications for the information transmission in neural systems.

Biomass production and essential oil yield from leaves, fine stems and resprouts using pruning the crown of Aniba canelilla (H.B.K.) (Lauraceae) in the Central Amazon

OpenAIRE

Manhães,Adriana Pellegrini; Veiga-Júnior,Valdir Florêncio da; Wiedemann,Larissa Silveira Moreira; Fernandes,Karenn Silveira; Sampaio,Paulo de Tarso Barbosa

2012-01-01

Aniba canelilla (H.B.K.) Mez. is a tree species from Amazon that produces essential oil. The oil extraction from its leaves and stems can be an alternative way to avoid the tree cutting for production of essential oil. The aim of this study was to analyse factors that may influence the essential oil production and the biomass of resprouts after pruning the leaves and stems of A. canelilla trees. The tree crowns were pruned in the wet season and after nine months the leaves and stems of the re...

Structural Components of Synaptic Plasticity and Memory Consolidation

Science.gov (United States)

Bailey, Craig H.; Kandel, Eric R.; Harris, Kristen M.

2015-01-01

Consolidation of implicit memory in the invertebrate Aplysia and explicit memory in the mammalian hippocampus are associated with remodeling and growth of preexisting synapses and the formation of new synapses. Here, we compare and contrast structural components of the synaptic plasticity that underlies these two distinct forms of memory. In both cases, the structural changes involve time-dependent processes. Thus, some modifications are transient and may contribute to early formative stages of long-term memory, whereas others are more stable, longer lasting, and likely to confer persistence to memory storage. In addition, we explore the possibility that trans-synaptic signaling mechanisms governing de novo synapse formation during development can be reused in the adult for the purposes of structural synaptic plasticity and memory storage. Finally, we discuss how these mechanisms set in motion structural rearrangements that prepare a synapse to strengthen the same memory and, perhaps, to allow it to take part in other memories as a basis for understanding how their anatomical representation results in the enhanced expression and storage of memories in the brain. PMID:26134321

Synaptogenic proteins and synaptic organizers: "many hands make light work".

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Brose, Nils

2009-03-12

Synaptogenesis is thought to be mediated by cell adhesion proteins, which induce the initial contact between an axon and its target cell and subsequently recruit and organize the presynaptic and postsynaptic protein machinery required for synaptic transmission. A new study by Linhoff and colleagues in this issue of Neuron identifies adhesion proteins of the LRRTM family as novel synaptic organizers.

A case of ultrasound-guided prenatal diagnosis of prune belly syndrome in Papua New Guinea--implications for management.

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Ome, Maria; Wangnapi, Regina; Hamura, Nancy; Umbers, Alexandra J; Siba, Peter; Laman, Moses; Bolnga, John; Rogerson, Sheryle; Unger, Holger W

2013-05-07

Prune belly syndrome is a rare congenital malformation of unknown aetiology and is characterised by abnormalities of the urinary tract, a deficiency of abdominal musculature and bilateral cryptorchidism in males. We report a case of prune belly syndrome from Papua New Guinea, which was suspected on pregnancy ultrasound scan and confirmed upon delivery. A 26-year-old married woman, Gravida 3 Para 2, presented to antenatal clinic in Madang, Papua New Guinea, at 21(+5) weeks' gestation by dates. She was well with no past medical or family history of note. She gave consent to participate in a clinical trial on prevention of malaria in pregnancy and underwent repeated ultrasound examinations which revealed a live fetus with persistent megacystis and anhydramnios. Both mother and clinicians agreed on conservative management of the congenital abnormality. The mother spontaneously delivered a male fetus weighing 2010 grams at 34 weeks' gestation with grossly abnormal genitalia including cryptorchidism, penile aplasia and an absent urethral meatus, absent abdominal muscles and hypoplastic lungs. The infant passed away two hours after delivery. This report discusses the implications of prenatal detection of severe congenital abnormalities in PNG. This first, formally reported, case of prune belly syndrome from a resource-limited setting in the Oceania region highlights the importance of identifying and documenting congenital abnormalities. Women undergoing antenatal ultrasound examinations must be carefully counseled on the purpose and the limitations of the scan. The increasing use of obstetric ultrasound in PNG will inevitably result in a rise in prenatal detection of congenital abnormalities. This will need to be met with adequate training, referral mechanisms and better knowledge of women's attitudes and beliefs on birth defects and ultrasound. National medicolegal guidance regarding induced abortion and resuscitation of a fetus with severe congenital abnormalities may

Spike Pattern Structure Influences Synaptic Efficacy Variability Under STDP and Synaptic Homeostasis. II: Spike Shuffling Methods on LIF Networks

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Zedong Bi

2016-08-01

Full Text Available Synapses may undergo variable changes during plasticity because of the variability of spike patterns such as temporal stochasticity and spatial randomness. Here, we call the variability of synaptic weight changes during plasticity to be efficacy variability. In this paper, we investigate how four aspects of spike pattern statistics (i.e., synchronous firing, burstiness/regularity, heterogeneity of rates and heterogeneity of cross-correlations influence the efficacy variability under pair-wise additive spike-timing dependent plasticity (STDP and synaptic homeostasis (the mean strength of plastic synapses into a neuron is bounded, by implementing spike shuffling methods onto spike patterns self-organized by a network of excitatory and inhibitory leaky integrate-and-fire (LIF neurons. With the increase of the decay time scale of the inhibitory synaptic currents, the LIF network undergoes a transition from asynchronous state to weak synchronous state and then to synchronous bursting state. We first shuffle these spike patterns using a variety of methods, each designed to evidently change a specific pattern statistics; and then investigate the change of efficacy variability of the synapses under STDP and synaptic homeostasis, when the neurons in the network fire according to the spike patterns before and after being treated by a shuffling method. In this way, we can understand how the change of pattern statistics may cause the change of efficacy variability. Our results are consistent with those of our previous study which implements spike-generating models on converging motifs. We also find that burstiness/regularity is important to determine the efficacy variability under asynchronous states, while heterogeneity of cross-correlations is the main factor to cause efficacy variability when the network moves into synchronous bursting states (the states observed in epilepsy.

Massive gravity from bimetric gravity

International Nuclear Information System (INIS)

Baccetti, Valentina; Martín-Moruno, Prado; Visser, Matt

2013-01-01

We discuss the subtle relationship between massive gravity and bimetric gravity, focusing particularly on the manner in which massive gravity may be viewed as a suitable limit of bimetric gravity. The limiting procedure is more delicate than currently appreciated. Specifically, this limiting procedure should not unnecessarily constrain the background metric, which must be externally specified by the theory of massive gravity itself. The fact that in bimetric theories one always has two sets of metric equations of motion continues to have an effect even in the massive gravity limit, leading to additional constraints besides the one set of equations of motion naively expected. Thus, since solutions of bimetric gravity in the limit of vanishing kinetic term are also solutions of massive gravity, but the contrary statement is not necessarily true, there is no complete continuity in the parameter space of the theory. In particular, we study the massive cosmological solutions which are continuous in the parameter space, showing that many interesting cosmologies belong to this class. (paper)

The use of pruned chipped branches to increase the soil infiltration capacity and reduce the soil losses on citrus orchards in Eastern Spain

Science.gov (United States)

González-Pelayo, Óscar; Llovet, Joan; Giménez-Morera, Antonio; Jordán, Antonio; Pereira, Paulo; Novara, Agata; García-Orenes, Fuensanta; Cerdà, Artemi

2015-04-01

Soil water erosion is causing problems on the agriculture land of the world. The high erosion rates registered in the agriculture land are due to the lack of a vegetation cover that protects the soil. High erosion rates in agriculture lands are found in Africa, Europe, Asia, and any other continent. Soil erosion on citrus orchards has been researched recently and shown huge erosion rates in the Mediterranean and in China. All this research findings allow us to confirm that the soil erosion rates on citrus orchards are not sustainable and strategies to control the soil erosion should be applied. The increasing erosion rates are due to the bare soils, but also are due to the soil structure degradation and soil organic matter exhaustion. Some authors applied cover on crops to avoid the raindrop impact and the surfaces wash but there is a need to develop new strategies to reduce soil losses and keep sustainable the citrus productions. The agriculture production also results in a large amount of residues than can be a resource to improve the soil cover. This has been done in road embankments, in forest land affected by wildfires and on afforestation. As a consequence of the mechanization of the agriculture, and the reduction of the draft animals (mainly horses, mules, donkeys and oxen), the straw and the pruned branches are being a residue instead of a resource in many developed countries. Straw was used as a forage and the pruned branches as a source of heat and energy but both can be used as a mulch to control the soil erosion. The pruned branches can contribute with a valuable source of nutrients and a good soil protection. The leaves of the trees, and some parts of the plants, once harvest can contribute to reduce the soil losses. Our goal is to test if a residue such as the chipped pruned branches can be transformed as a resource that will help to control the soil erosion rates. Straw has been seen as a very efficient to reduce the water losses in agriculture land

A light-stimulated synaptic transistor with synaptic plasticity and memory functions based on InGaZnO{sub x}–Al{sub 2}O{sub 3} thin film structure

Energy Technology Data Exchange (ETDEWEB)

Li, H. K.; Chen, T. P., E-mail: echentp@ntu.edu.sg; Liu, P.; Zhang, Q. [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Hu, S. G. [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054 (China); Liu, Y. [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054 (China); Lee, P. S. [School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

2016-06-28

In this work, a synaptic transistor based on the indium gallium zinc oxide (IGZO)–aluminum oxide (Al{sub 2}O{sub 3}) thin film structure, which uses ultraviolet (UV) light pulses as the pre-synaptic stimulus, has been demonstrated. The synaptic transistor exhibits the behavior of synaptic plasticity like the paired-pulse facilitation. In addition, it also shows the brain's memory behaviors including the transition from short-term memory to long-term memory and the Ebbinghaus forgetting curve. The synapse-like behavior and memory behaviors of the transistor are due to the trapping and detrapping processes of the holes, which are generated by the UV pulses, at the IGZO/Al{sub 2}O{sub 3} interface and/or in the Al{sub 2}O{sub 3} layer.

Regulation of Synaptic Structure by the Ubiquitin C-terminal Hydrolase UCH-L1

Science.gov (United States)

Cartier, Anna E.; Djakovic, Stevan N.; Salehi, Afshin; Wilson, Scott M.; Masliah, Eliezer; Patrick, Gentry N.

2009-01-01

UCH-L1 is a de-ubiquitinating enzyme that is selectively and abundantly expressed in the brain, and its activity is required for normal synaptic function. Here, we show that UCH-L1 functions in maintaining normal synaptic structure in hippocampal neurons. We have found that UCH-L1 activity is rapidly up-regulated by NMDA receptor activation which leads to an increase in the levels of free monomeric ubiquitin. Conversely, pharmacological inhibition of UCH-L1 significantly reduces monomeric ubiquitin levels and causes dramatic alterations in synaptic protein distribution and spine morphology. Inhibition of UCH-L1 activity increases spine size while decreasing spine density. Furthermore, there is a concomitant increase in the size of pre and postsynaptic protein clusters. Interestingly, however, ectopic expression of ubiquitin restores normal synaptic structure in UCH-L1 inhibited neurons. These findings point to a significant role of UCH-L1 in synaptic remodeling most likely by modulating free monomeric ubiquitin levels in an activity-dependent manner. PMID:19535597

Exogenous Alpha-Synuclein Alters Pre- and Post-Synaptic Activity by Fragmenting Lipid Rafts

Directory of Open Access Journals (Sweden)

Marco Emanuele

2016-05-01

Full Text Available Alpha-synuclein (αSyn interferes with multiple steps of synaptic activity at pre-and post-synaptic terminals, however the mechanism/s by which αSyn alters neurotransmitter release and synaptic potentiation is unclear. By atomic force microscopy we show that human αSyn, when incubated with reconstituted membrane bilayer, induces lipid rafts' fragmentation. As a consequence, ion channels and receptors are displaced from lipid rafts with consequent changes in their activity. The enhanced calcium entry leads to acute mobilization of synaptic vesicles, and exhaustion of neurotransmission at later stages. At the post-synaptic terminal, an acute increase in glutamatergic transmission, with increased density of PSD-95 puncta, is followed by disruption of the interaction between N-methyl-d-aspartate receptor (NMDAR and PSD-95 with ensuing decrease of long term potentiation. While cholesterol loading prevents the acute effect of αSyn at the presynapse; inhibition of casein kinase 2, which appears activated by reduction of cholesterol, restores the correct localization and clustering of NMDARs.

Bigger is better and worse: on the intricate relationship between hippocampal size and memory.

Science.gov (United States)

Molnár, Katalin; Kéri, Szabolcs

2014-04-01

The structure-function relationship between the hippocampal region and memory is a debated topic in the literature. It has been suggested that larger hippocampi are associated with less effective memory performance in healthy young adults because of a partial synaptic pruning. Here, we tested this hypothesis in individuals with Fragile X Syndrome (FXS) with known abnormal pruning and IQ- and age-matched individuals with hypoxic brain injury, preterm birth, and obstetric complications. Results revealed larger normalized hippocampal volume in FXS compared with neurotypical controls, whereas individuals with hypoxic injury had smaller hippocampi. In neurotypical controls and individuals with hypoxic injury, better general memory, as indexed by the Wechsler Memory Scale-Revised, was associated with larger hippocampus. In contrast, in FXS we observed the opposite relationship: larger hippocampus was associated with worse general memory. Caudate volume did not correlate with memory in either group. These results suggest that incomplete pruning in young healthy adults may not contribute to less efficient memory capacity, and hippocampal size is positively associated with memory performance. However, abnormally large and poorly pruned hippocampus may indeed be less effective in FXS. Copyright © 2014 Elsevier Ltd. All rights reserved.

Inflammation subverts hippocampal synaptic plasticity in experimental multiple sclerosis.

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Robert Nisticò

Full Text Available Abnormal use-dependent synaptic plasticity is universally accepted as the main physiological correlate of memory deficits in neurodegenerative disorders. It is unclear whether synaptic plasticity deficits take place during neuroinflammatory diseases, such as multiple sclerosis (MS and its mouse model, experimental autoimmune encephalomyelitis (EAE. In EAE mice, we found significant alterations of synaptic plasticity rules in the hippocampus. When compared to control mice, in fact, hippocampal long-term potentiation (LTP induction was favored over long-term depression (LTD in EAE, as shown by a significant rightward shift in the frequency-synaptic response function. Notably, LTP induction was also enhanced in hippocampal slices from control mice following interleukin-1β (IL-1β perfusion, and both EAE and IL-1β inhibited GABAergic spontaneous inhibitory postsynaptic currents (sIPSC without affecting glutamatergic transmission and AMPA/NMDA ratio. EAE was also associated with selective loss of GABAergic interneurons and with reduced gamma-frequency oscillations in the CA1 region of the hippocampus. Finally, we provided evidence that microglial activation in the EAE hippocampus was associated with IL-1β expression, and hippocampal slices from control mice incubated with activated microglia displayed alterations of GABAergic transmission similar to those seen in EAE brains, through a mechanism dependent on enhanced IL-1β signaling. These data may yield novel insights into the basis of cognitive deficits in EAE and possibly of MS.

Inflammation Subverts Hippocampal Synaptic Plasticity in Experimental Multiple Sclerosis

Science.gov (United States)

Mandolesi, Georgia; Piccinin, Sonia; Berretta, Nicola; Pignatelli, Marco; Feligioni, Marco; Musella, Alessandra; Gentile, Antonietta; Mori, Francesco; Bernardi, Giorgio; Nicoletti, Ferdinando; Mercuri, Nicola B.; Centonze, Diego

2013-01-01

Abnormal use-dependent synaptic plasticity is universally accepted as the main physiological correlate of memory deficits in neurodegenerative disorders. It is unclear whether synaptic plasticity deficits take place during neuroinflammatory diseases, such as multiple sclerosis (MS) and its mouse model, experimental autoimmune encephalomyelitis (EAE). In EAE mice, we found significant alterations of synaptic plasticity rules in the hippocampus. When compared to control mice, in fact, hippocampal long-term potentiation (LTP) induction was favored over long-term depression (LTD) in EAE, as shown by a significant rightward shift in the frequency–synaptic response function. Notably, LTP induction was also enhanced in hippocampal slices from control mice following interleukin-1β (IL-1β) perfusion, and both EAE and IL-1β inhibited GABAergic spontaneous inhibitory postsynaptic currents (sIPSC) without affecting glutamatergic transmission and AMPA/NMDA ratio. EAE was also associated with selective loss of GABAergic interneurons and with reduced gamma-frequency oscillations in the CA1 region of the hippocampus. Finally, we provided evidence that microglial activation in the EAE hippocampus was associated with IL-1β expression, and hippocampal slices from control mice incubated with activated microglia displayed alterations of GABAergic transmission similar to those seen in EAE brains, through a mechanism dependent on enhanced IL-1β signaling. These data may yield novel insights into the basis of cognitive deficits in EAE and possibly of MS. PMID:23355887

Early-life seizures alter synaptic calcium-permeable AMPA receptor function and plasticity

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Lippman-Bell, Jocelyn J.; Zhou, Chengwen; Sun, Hongyu; Feske, Joel S.; Jensen, Frances E.

2016-01-01

Calcium (Ca2+)-mediated1 signaling pathways are critical to synaptic plasticity. In adults, the NMDA glutamate receptor (NMDAR) represents a major route for activity-dependent synaptic Ca2+ entry. However, during neonatal development, when synaptic plasticity is high, many AMPA glutamate receptors (AMPARs) are also permeable to Ca2+ (CP-AMPAR) due to low GluA2 subunit expression, providing an additional route for activity- and glutamate-dependent Ca2+ influx and subsequent signaling. Therefore, altered hippocampal Ca2+ signaling may represent an age-specific pathogenic mechanism. We thus aimed to assess Ca2+ responses 48 hours after hypoxia-induced neonatal seizures (HS) in postnatal day (P)10 rats, a post-seizure time point at which we previously reported LTP attenuation. We found that Ca2+ responses were higher in brain slices from post-HS rats than in controls and this increase was CP-AMPAR-dependent. To determine whether synaptic CP-AMPAR expression was also altered post-HS, we assessed the expression of GluA2 at hippocampal synapses and the expression of long-term depression (LTD), which has been linked to the presence of synaptic GluA2. Here we report a decrease 48 hours after HS in synaptic GluA2 expression at synapses and LTD in hippocampal CA1. Given the potentially critical role of AMPAR trafficking in disease progression, we aimed to establish whether post-seizure in vivo AMPAR antagonist treatment prevented the enhanced Ca2+ responses, changes in GluA2 synaptic expression, and diminished LTD. We found that NBQX treatment prevents all three of these post-seizure consequences, further supporting a critical role for AMPARs as an age-specific therapeutic target. PMID:27521497

Molecular Machines Determining the Fate of Endocytosed Synaptic Vesicles in Nerve Terminals.

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Fassio, Anna; Fadda, Manuela; Benfenati, Fabio

2016-01-01

The cycle of a synaptic vesicle (SV) within the nerve terminal is a step-by-step journey with the final goal of ensuring the proper synaptic strength under changing environmental conditions. The SV cycle is a precisely regulated membrane traffic event in cells and, because of this, a plethora of membrane-bound and cytosolic proteins are devoted to assist SVs in each step of the journey. The cycling fate of endocytosed SVs determines both the availability for subsequent rounds of release and the lifetime of SVs in the terminal and is therefore crucial for synaptic function and plasticity. Molecular players that determine the destiny of SVs in nerve terminals after a round of exo-endocytosis are largely unknown. Here we review the functional role in SV fate of phosphorylation/dephosphorylation of SV proteins and of small GTPases acting on membrane trafficking at the synapse, as they are emerging as key molecules in determining the recycling route of SVs within the nerve terminal. In particular, we focus on: (i) the cyclin-dependent kinase-5 (cdk5) and calcineurin (CN) control of the recycling pool of SVs; (ii) the role of small GTPases of the Rab and ADP-ribosylation factor (Arf) families in defining the route followed by SV in their nerve terminal cycle. These regulatory proteins together with their synaptic regulators and effectors, are molecular nanomachines mediating homeostatic responses in synaptic plasticity and potential targets of drugs modulating the efficiency of synaptic transmission.

MOLECULAR MACHINES DETERMINING THE FATE OF ENDOCYTOSED SYNAPTIC VESICLES IN NERVE TERMINALS

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Anna eFassio

2016-05-01

Full Text Available The cycle of a synaptic vesicle (SV within the nerve terminal is a step-by-step journey with the final goal of ensuring the proper synaptic strength under changing environmental conditions.The SV cycle is a precisely regulated membrane traffic event in cells and, because of this, a plethora of membrane-bound and cytosolic proteins are devoted to assist SVs in each step of the journey. The cycling fate of endocytosed SVs determines both the availability for subsequent rounds of release and the lifetime of SVs in the terminal and is therefore crucial for synaptic function and plasticity. Molecular players that determine the destiny of SVs in nerve terminals after a round of exo-endocytosis are largely unknown. Here we review the functional role in SV fate of phosphorylation/dephosphorylation of SV proteins and of small GTPases acting on membrane trafficking at the synapse, as they are emerging as key molecules in determining the recycling route of SVs within the nerve terminal. In particular, we focus on (i the cyclin-dependent kinase-5 and calcineurin control of the recycling pool of SVs; (ii the role of small GTPases of the Rab and ADP-ribosylation factor (Arf families in defining the route followed by SV in their nerve terminal cycle. These regulatory proteins together with their synaptic regulators and effectors, are molecular nanomachines mediating homeostatic responses in synaptic plasticity and potential targets of drugs modulating the efficiency of synaptic transmission.

The Prune Belly syndrome: urological aspects and long-term outcomes of a rare disease

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Vahudin Zugor

2012-06-01

Full Text Available Prune-Belly syndrome is a disorder characterized by the following triad of symptoms: deficiency of the abdominal muscles, malformations of the urinary tract and bilateral cryptorchidism. This study included a total of 16 patients. The findings included clinical characteristics, diagnostics, therapy and long-term clinical outcomes. All patients were asked to complete a questionnaire and, in some cases, were given further examination. All patients were diagnosed with congenital aplasia of the abdominal wall and a variety of urogenital malformations. Cryptorchidism was present in 11 patients (68.8%, malformations of the prostate in 3 (18.8%, urethral malformations in 8 (50% and mega-ureter in 14 patients (87.5%. A mega-bladder was observed in 13 patients (81.3%. Distinctive renal malformations, such as renal dysplasia, in 3 patients (18.8% and hydronephrosis in 9 patients (56.3%, respectively. Abdominoplasty was performed on 4 patients (25%. Urethral surgery was performed in 10 patients (62.5%. Seven patients (43.8% required ureter surgery, most of which involved re-implantation of the ureter and, in some cases, additional ureter modeling. Renal surgery was performed on 5 patients. Four patients with non-functioning kidneys with hydronephrosis underwent a nephrectomy and one patient pyeloplasty. We demonstrate that successful treatment is possible even in cases of serious and complex malformations, such as those of the Prune-Belly syndrome. Treatment must be tailored to the individual patient. The severity of the renal dysplasia is the main prognostic factor.

The Prune Belly syndrome: urological aspects and long-term outcomes of a rare disease.

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Zugor, Vahudin; Schott, Günter E; Labanaris, Apostolos P

2012-04-02

Prune-Belly syndrome is a disorder characterized by the following triad of symptoms: deficiency of the abdominal muscles, malformations of the urinary tract and bilateral cryptorchidism. This study included a total of 16 patients. The findings included clinical characteristics, diagnostics, therapy and long-term clinical outcomes. All patients were asked to complete a questionnaire and, in some cases, were given further examination. All patients were diagnosed with congenital aplasia of the abdominal wall and a variety of urogenital malformations. Cryptorchidism was present in 11 patients (68.8%), malformations of the prostate in 3 (18.8%), urethral malformations in 8 (50%) and mega-ureter in 14 patients (87.5%). A mega-bladder was observed in 13 patients (81.3%). Distinctive renal malformations, such as renal dysplasia, in 3 patients (18.8%) and hydronephrosis in 9 patients (56.3%), respectively. Abdominoplasty was performed on 4 patients (25%). Urethral surgery was performed in 10 patients (62.5%). Seven patients (43.8%) required ureter surgery, most of which involved re-implantation of the ureter and, in some cases, additional ureter modeling. Renal surgery was performed on 5 patients. Four patients with non-functioning kidneys with hydronephrosis underwent a nephrectomy and one patient pyeloplasty. We demonstrate that successful treatment is possible even in cases of serious and complex malformations, such as those of the Prune-Belly syndrome. Treatment must be tailored to the individual patient. The severity of the renal dysplasia is the main prognostic factor.

Synaptic plasticity, memory and the hippocampus: a neural network approach to causality.

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Neves, Guilherme; Cooke, Sam F; Bliss, Tim V P

2008-01-01

Two facts about the hippocampus have been common currency among neuroscientists for several decades. First, lesions of the hippocampus in humans prevent the acquisition of new episodic memories; second, activity-dependent synaptic plasticity is a prominent feature of hippocampal synapses. Given this background, the hypothesis that hippocampus-dependent memory is mediated, at least in part, by hippocampal synaptic plasticity has seemed as cogent in theory as it has been difficult to prove in practice. Here we argue that the recent development of transgenic molecular devices will encourage a shift from mechanistic investigations of synaptic plasticity in single neurons towards an analysis of how networks of neurons encode and represent memory, and we suggest ways in which this might be achieved. In the process, the hypothesis that synaptic plasticity is necessary and sufficient for information storage in the brain may finally be validated.

Caracterização fenológica da goiabeira 'Pedro Sato' sob diferentes épocas de poda 'Pedro Sato' guava tree phenological characterization in different pruning times

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Ronaldo Hissayuki Hojo

2007-04-01

Full Text Available O cultivo da goiabeira na região de Lavras-MG, vem tendo grande importância, porém não há uma oferta freqüente durante o ano, concentrando muitas vezes a produção em um único período. A prática de podas escalonadas é fundamental para auxiliar o produtor a colher frutos em praticamente todos os meses do ano. Visando a esse escalonamento, objetivou-se a caracterização fenológica da goiabeira 'Pedro Sato', em quatro épocas de poda (setembro, e dezembro de 2003, março e junho de 2004. Foram utilizadas dez plantas, com quatro anos de idade, para cada época de poda. O delineamento foi de blocos casualizados, onde em cada planta foram marcados doze ramos, avaliando-se semanalmente os dados sobre os estádios fenológicos. Com as mensurações, foi possível estabelecer a indicação das diferentes fenofases da cultura, sendo a duração entre a poda e o início da brotação de 30,8 a 39,2 dias; poda ao florescimento de 68,6 a 133 dias; da abertura da flor (floração plena à maturação do fruto de 118,3 a 148,4 dias; e o ciclo poda à colheita foi em média de 214,2, 211,4, 247,8 e 237,3 dias para as podas realizadas em setembro, dezembro, março e junho.Although the guava tree cultivation in the area of Lavras, MG, has had great importance, there is not a frequent offer during the year, concentrating the production in an only period. The practice of staggered prunings is fundamental to aid the producer to pick fruits in practically every month of the year. Seeking that stagger, it was aimed the 'Pedro Sato' guava tree phenological characterization in four pruning times (September and December of 2003, March and June of 2004. Ten four-year-old plants were used for each pruning time in randomized block design, where, in each plant, twelve branches were marked and the data were evaluated weekly on the phenological stages. It was possible to establish the indication of the different phenophases of the culture with the measuring, being

Synaptic clustering within dendrites: an emerging theory of memory formation

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Kastellakis, George; Cai, Denise J.; Mednick, Sara C.; Silva, Alcino J.; Poirazi, Panayiota

2015-01-01

It is generally accepted that complex memories are stored in distributed representations throughout the brain, however the mechanisms underlying these representations are not understood. Here, we review recent findings regarding the subcellular mechanisms implicated in memory formation, which provide evidence for a dendrite-centered theory of memory. Plasticity-related phenomena which affect synaptic properties, such as synaptic tagging and capture, synaptic clustering, branch strength potentiation and spinogenesis provide the foundation for a model of memory storage that relies heavily on processes operating at the dendrite level. The emerging picture suggests that clusters of functionally related synapses may serve as key computational and memory storage units in the brain. We discuss both experimental evidence and theoretical models that support this hypothesis and explore its advantages for neuronal function. PMID:25576663

Histone Deacetylase Inhibition Facilitates Massed Pattern-Induced Synaptic Plasticity and Memory

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Pandey, Kiran; Sharma, Kaushik P.; Sharma, Shiv K.

2015-01-01

Massed training is less effective for long-term memory formation than the spaced training. The role of acetylation in synaptic plasticity and memory is now well established. However, the role of this important protein modification in synaptic plasticity induced by massed pattern of stimulation or memory induced by massed training is not well…

Synaptic plasticity, neural circuits, and the emerging role of altered short-term information processing in schizophrenia

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Crabtree, Gregg W.; Gogos, Joseph A.

2014-01-01

Synaptic plasticity alters the strength of information flow between presynaptic and postsynaptic neurons and thus modifies the likelihood that action potentials in a presynaptic neuron will lead to an action potential in a postsynaptic neuron. As such, synaptic plasticity and pathological changes in synaptic plasticity impact the synaptic computation which controls the information flow through the neural microcircuits responsible for the complex information processing necessary to drive adaptive behaviors. As current theories of neuropsychiatric disease suggest that distinct dysfunctions in neural circuit performance may critically underlie the unique symptoms of these diseases, pathological alterations in synaptic plasticity mechanisms may be fundamental to the disease process. Here we consider mechanisms of both short-term and long-term plasticity of synaptic transmission and their possible roles in information processing by neural microcircuits in both health and disease. As paradigms of neuropsychiatric diseases with strongly implicated risk genes, we discuss the findings in schizophrenia and autism and consider the alterations in synaptic plasticity and network function observed in both human studies and genetic mouse models of these diseases. Together these studies have begun to point toward a likely dominant role of short-term synaptic plasticity alterations in schizophrenia while dysfunction in autism spectrum disorders (ASDs) may be due to a combination of both short-term and long-term synaptic plasticity alterations. PMID:25505409

Interregional synaptic maps among engram cells underlie memory formation.

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Choi, Jun-Hyeok; Sim, Su-Eon; Kim, Ji-Il; Choi, Dong Il; Oh, Jihae; Ye, Sanghyun; Lee, Jaehyun; Kim, TaeHyun; Ko, Hyoung-Gon; Lim, Chae-Seok; Kaang, Bong-Kiun

2018-04-27

Memory resides in engram cells distributed across the brain. However, the site-specific substrate within these engram cells remains theoretical, even though it is generally accepted that synaptic plasticity encodes memories. We developed the dual-eGRASP (green fluorescent protein reconstitution across synaptic partners) technique to examine synapses between engram cells to identify the specific neuronal site for memory storage. We found an increased number and size of spines on CA1 engram cells receiving input from CA3 engram cells. In contextual fear conditioning, this enhanced connectivity between engram cells encoded memory strength. CA3 engram to CA1 engram projections strongly occluded long-term potentiation. These results indicate that enhanced structural and functional connectivity between engram cells across two directly connected brain regions forms the synaptic correlate for memory formation. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Axonal accumulation of synaptic markers in APP transgenic Drosophila depends on the NPTY motif and is paralleled by defects in synaptic plasticity

DEFF Research Database (Denmark)

Rusu, Patricia; Jansen, Anna; Soba, Peter

2007-01-01

. Specifically, axonal transport defects have been reported in AD animal models, including mice and flies that overexpress APP and tau. Here we demonstrate that the APP-induced traffic jam of vesicles in peripheral nerves of Drosophila melanogaster larvae depends on the four residues NPTY motif in the APP...... neurotransmission at the neuromuscular junction in transgenic larvae that express human APP. Consistent with the observation that these larvae do not show any obvious movement deficits, we found no changes in basal synaptic transmission. However, short-term synaptic plasticity was affected by overexpression of APP...

Reduced synaptic vesicle protein degradation at lysosomes curbs TBC1D24/sky-induced neurodegeneration.

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Fernandes, Ana Clara; Uytterhoeven, Valerie; Kuenen, Sabine; Wang, Yu-Chun; Slabbaert, Jan R; Swerts, Jef; Kasprowicz, Jaroslaw; Aerts, Stein; Verstreken, Patrik

2014-11-24

Synaptic demise and accumulation of dysfunctional proteins are thought of as common features in neurodegeneration. However, the mechanisms by which synaptic proteins turn over remain elusive. In this paper, we study Drosophila melanogaster lacking active TBC1D24/Skywalker (Sky), a protein that in humans causes severe neurodegeneration, epilepsy, and DOOR (deafness, onychdystrophy, osteodystrophy, and mental retardation) syndrome, and identify endosome-to-lysosome trafficking as a mechanism for degradation of synaptic vesicle-associated proteins. In fly sky mutants, synaptic vesicles traveled excessively to endosomes. Using chimeric fluorescent timers, we show that synaptic vesicle-associated proteins were younger on average, suggesting that older proteins are more efficiently degraded. Using a genetic screen, we find that reducing endosomal-to-lysosomal trafficking, controlled by the homotypic fusion and vacuole protein sorting (HOPS) complex, rescued the neurotransmission and neurodegeneration defects in sky mutants. Consistently, synaptic vesicle proteins were older in HOPS complex mutants, and these mutants also showed reduced neurotransmission. Our findings define a mechanism in which synaptic transmission is facilitated by efficient protein turnover at lysosomes and identify a potential strategy to suppress defects arising from TBC1D24 mutations in humans. © 2014 Fernandes et al.

Prune belly syndrome with urethral hypoplasia and vesico-cutaneous fistula: A case report and review of literature.

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Sarhan, Osama M; Al-Ghanbar, Mustafa S; Nakshabandi, Ziad M

2013-10-01

Association between Prune belly syndrome (PBS) and urethral hypoplasia is an unusual condition. It is usually fatal unless there is a communication between the fetal bladder and the amniotic sac. We report a case of PBS with urethral hypoplasia and congenital vesico-cutaneous fistula in a male neonate. Patient underwent cutaneous vesicostomy and was discharged for close follow up of his renal function and for future reconstruction.

Megacystis-microlon-intestinal hypoperistalsis syndrome in a newborn girl whose brother had Prune Belly syndrome: Common Pathogenesis

Energy Technology Data Exchange (ETDEWEB)

Oliveira, G.; Boechat, M.I.; Fereira, M.A.

1983-07-01

A case of Megacystis-Microcolon-Intestinal Hypoperistalsis Syndrome (MMIHS) is presented. There were important findings: a urachal remnant and a brother with Prune Belly Syndrome (PBS). After a review of the literature, many common characteristics of MMIHS and PBS are described: flaccid abdomen, dilatation of the urinary tract, intestinal malrotation, cryptorchidism, urachal remnants and familial incidence. MMIHS and PBS may be manifestations of the same underlying process.

The temporoammonic input to the hippocampal CA1 region displays distinctly different synaptic plasticity compared to the Schaffer collateral input in vivo: significance for synaptic information processing

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Ayla eAksoy Aksel

2013-08-01

Full Text Available In terms of its sub-regional differentiation, the hippocampal CA1 region receives cortical information directly via the perforant (temporoammonic path (pp-CA1 synapse and indirectly via the tri-synaptic pathway where the last relay station is the Schaffer collateral-CA1 synapse (Sc-CA1 synapse. Research to date on pp-CA1 synapses has been conducted predominantly in vitro and never in awake animals, but these studies hint that information processing at this synapse might be distinct to processing at the Sc-CA1 synapse. Here, we characterized synaptic properties and synaptic plasticity at the pp-CA1 synapse of freely behaving adult rats. We established that field excitatory postsynaptic potentials at the pp-CA1 have longer onset latencies and a shorter time-to-peak compared to the Sc-CA1 synapse. LTP (> 24h was successfully evoked by tetanic afferent stimulation of pp-CA1 synapses. Low frequency stimulation evoked synaptic depression at Sc-CA1 synapses, but did not elicit LTD at pp-CA1 synapses unless the Schaffer collateral afferents to the CA1 region had been severed. Paired-pulse responses also showed significant differences. Our data suggest that synaptic plasticity at the pp-CA1 synapse is distinct from the Sc-CA1 synapse and that this may reflect its specific role in hippocampal information processing.

Modulation of Synaptic Plasticity by Exercise Training as a Basis for Ischemic Stroke Rehabilitation.

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Nie, Jingjing; Yang, Xiaosu

2017-01-01

In recent years, rehabilitation of ischemic stroke draws more and more attention in the world, and has been linked to changes of synaptic plasticity. Exercise training improves motor function of ischemia as well as cognition which is associated with formation of learning and memory. The molecular basis of learning and memory might be synaptic plasticity. Research has therefore been conducted in an attempt to relate effects of exercise training to neuroprotection and neurogenesis adjacent to the ischemic injury brain. The present paper reviews the current literature addressing this question and discusses the possible mechanisms involved in modulation of synaptic plasticity by exercise training. This review shows the pathological process of synaptic dysfunction in ischemic roughly and then discusses the effects of exercise training on scaffold proteins and regulatory protein expression. The expression of scaffold proteins generally increased after training, but the effects on regulatory proteins were mixed. Moreover, the compositions of postsynaptic receptors were changed and the strength of synaptic transmission was enhanced after training. Finally, the recovery of cognition is critically associated with synaptic remodeling in an injured brain, and the remodeling occurs through a number of local regulations including mRNA translation, remodeling of cytoskeleton, and receptor trafficking into and out of the synapse. We do provide a comprehensive knowledge of synaptic plasticity enhancement obtained by exercise training in this review.

Vaidya spacetime in massive gravity's rainbow

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Yaghoub Heydarzade

2017-11-01

Full Text Available In this paper, we will analyze the energy dependent deformation of massive gravity using the formalism of massive gravity's rainbow. So, we will use the Vainshtein mechanism and the dRGT mechanism for the energy dependent massive gravity, and thus analyze a ghost free theory of massive gravity's rainbow. We study the energy dependence of a time-dependent geometry, by analyzing the radiating Vaidya solution in this theory of massive gravity's rainbow. The energy dependent deformation of this Vaidya metric will be performed using suitable rainbow functions.

Fragile X mental retardation protein regulates trans-synaptic signaling in Drosophila

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Samuel H. Friedman

2013-11-01

Fragile X syndrome (FXS, the most common inherited determinant of intellectual disability and autism spectrum disorders, is caused by loss of the fragile X mental retardation 1 (FMR1 gene product (FMRP, an mRNA-binding translational repressor. A number of conserved FMRP targets have been identified in the well-characterized Drosophila FXS disease model, but FMRP is highly pleiotropic in function and the full spectrum of FMRP targets has yet to be revealed. In this study, screens for upregulated neural proteins in Drosophila fmr1 (dfmr1 null mutants reveal strong elevation of two synaptic heparan sulfate proteoglycans (HSPGs: GPI-anchored glypican Dally-like protein (Dlp and transmembrane Syndecan (Sdc. Our recent work has shown that Dlp and Sdc act as co-receptors regulating extracellular ligands upstream of intracellular signal transduction in multiple trans-synaptic pathways that drive synaptogenesis. Consistently, dfmr1 null synapses exhibit altered WNT signaling, with changes in both Wingless (Wg ligand abundance and downstream Frizzled-2 (Fz2 receptor C-terminal nuclear import. Similarly, a parallel anterograde signaling ligand, Jelly belly (Jeb, and downstream ERK phosphorylation (dpERK are depressed at dfmr1 null synapses. In contrast, the retrograde BMP ligand Glass bottom boat (Gbb and downstream signaling via phosphorylation of the transcription factor MAD (pMAD seem not to be affected. To determine whether HSPG upregulation is causative for synaptogenic defects, HSPGs were genetically reduced to control levels in the dfmr1 null background. HSPG correction restored both (1 Wg and Jeb trans-synaptic signaling, and (2 synaptic architecture and transmission strength back to wild-type levels. Taken together, these data suggest that FMRP negatively regulates HSPG co-receptors controlling trans-synaptic signaling during synaptogenesis, and that loss of this regulation causes synaptic structure and function defects characterizing the FXS disease state.

The C1q complement family of synaptic organizers: not just complementary.

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Yuzaki, Michisuke

2017-08-01

Molecules that regulate formation, differentiation, and maintenance of synapses are called synaptic organizers. Recently, various 'C1q family' proteins have been shown to be released from neurons, and serve as a new class of synaptic organizers. Cbln1 and C1ql1 proteins regulate the formation and maintenance of parallel fiber-Purkinje cell and climbing fiber-Purkinje cell synapses, respectively, in the cerebellum. Cbln1 also modulates the function of postsynaptic delta2 glutamate receptors to regulate synaptic plasticity. C1ql2 and C1ql3, released from mossy fibers, determine the synaptic localization of postsynaptic kainate receptors in the hippocampus. C1ql3 also regulates the formation of synapses between the basolateral amygdala and the prefrontal cortex. These findings indicate the diverse functions of C1q family proteins in various brain regions. Copyright © 2017 Elsevier Ltd. All rights reserved.

MassiveNuS: cosmological massive neutrino simulations

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Liu, Jia; Bird, Simeon; Zorrilla Matilla, José Manuel; Hill, J. Colin; Haiman, Zoltán; Madhavacheril, Mathew S.; Petri, Andrea; Spergel, David N.

2018-03-01

The non-zero mass of neutrinos suppresses the growth of cosmic structure on small scales. Since the level of suppression depends on the sum of the masses of the three active neutrino species, the evolution of large-scale structure is a promising tool to constrain the total mass of neutrinos and possibly shed light on the mass hierarchy. In this work, we investigate these effects via a large suite of N-body simulations that include massive neutrinos using an analytic linear-response approximation: the Cosmological Massive Neutrino Simulations (MassiveNuS). The simulations include the effects of radiation on the background expansion, as well as the clustering of neutrinos in response to the nonlinear dark matter evolution. We allow three cosmological parameters to vary: the neutrino mass sum Mν in the range of 0–0.6 eV, the total matter density Ωm, and the primordial power spectrum amplitude As. The rms density fluctuation in spheres of 8 comoving Mpc/h (σ8) is a derived parameter as a result. Our data products include N-body snapshots, halo catalogues, merger trees, ray-traced galaxy lensing convergence maps for four source redshift planes between zs=1–2.5, and ray-traced cosmic microwave background lensing convergence maps. We describe the simulation procedures and code validation in this paper. The data are publicly available at http://columbialensing.org.

A scalable neural chip with synaptic electronics using CMOS integrated memristors

International Nuclear Information System (INIS)

Cruz-Albrecht, Jose M; Derosier, Timothy; Srinivasa, Narayan

2013-01-01

The design and simulation of a scalable neural chip with synaptic electronics using nanoscale memristors fully integrated with complementary metal–oxide–semiconductor (CMOS) is presented. The circuit consists of integrate-and-fire neurons and synapses with spike-timing dependent plasticity (STDP). The synaptic conductance values can be stored in memristors with eight levels, and the topology of connections between neurons is reconfigurable. The circuit has been designed using a 90 nm CMOS process with via connections to on-chip post-processed memristor arrays. The design has about 16 million CMOS transistors and 73 728 integrated memristors. We provide circuit level simulations of the entire chip performing neuronal and synaptic computations that result in biologically realistic functional behavior. (paper)

Synaptic inhibition and excitation estimated via the time constant of membrane potential fluctuations

DEFF Research Database (Denmark)

Berg, Rune W.; Ditlevsen, Susanne

2013-01-01

When recording the membrane potential, V, of a neuron it is desirable to be able to extract the synaptic input. Critically, the synaptic input is stochastic and non-reproducible so one is therefore often restricted to single trial data. Here, we introduce means of estimating the inhibition and ex...... close to soma (recording site). Though our data is in current-clamp, the method also works in V-clamp recordings, with some minor adaptations. All custom made procedures are provided in Matlab....... and excitation and their confidence limits from single sweep trials. The estimates are based on the mean membrane potential, (V) , and the membrane time constant,τ. The time constant provides the total conductance (G = capacitance/τ) and is extracted from the autocorrelation of V. The synaptic conductances can....... The method gives best results if the synaptic input is large compared to other conductances, the intrinsic conductances have little or no time dependence or are comparably small, the ligand gated kinetics is faster than the membrane time constant, and the majority of synaptic contacts are electrotonically...

Synaptically released zinc triggers metabotropic signaling via a zinc-sensing receptor in the hippocampus.

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Besser, Limor; Chorin, Ehud; Sekler, Israel; Silverman, William F; Atkin, Stan; Russell, James T; Hershfinkel, Michal

2009-03-04

Zn(2+) is coreleased with glutamate from mossy fiber terminals and can influence synaptic function. Here, we demonstrate that synaptically released Zn(2+) activates a selective postsynaptic Zn(2+)-sensing receptor (ZnR) in the CA3 region of the hippocampus. ZnR activation induced intracellular release of Ca(2+), as well as phosphorylation of extracellular-regulated kinase and Ca(2+)/calmodulin kinase II. Blockade of synaptic transmission by tetrodotoxin or CdCl inhibited the ZnR-mediated Ca(2+) rises. The responses mediated by ZnR were largely attenuated by the extracellular Zn(2+) chelator, CaEDTA, and in slices from mice lacking vesicular Zn(2+), suggesting that synaptically released Zn(2+) triggers the metabotropic activity. Knockdown of the expression of the orphan G-protein-coupled receptor 39 (GPR39) attenuated ZnR activity in a neuronal cell line. Importantly, we observed widespread GPR39 labeling in CA3 neurons, suggesting a role for this receptor in mediating ZnR signaling in the hippocampus. Our results describe a unique role for synaptic Zn(2+) acting as the physiological ligand of a metabotropic receptor and provide a novel pathway by which synaptic Zn(2+) can regulate neuronal function.

Holographically viable extensions of topologically massive and minimal massive gravity?

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Altas, Emel; Tekin, Bayram

2016-01-01

Recently [E. Bergshoeff et al., Classical Quantum Gravity 31, 145008 (2014)], an extension of the topologically massive gravity (TMG) in 2 +1 dimensions, dubbed as minimal massive gravity (MMG), which is free of the bulk-boundary unitarity clash that inflicts the former theory and all the other known three-dimensional theories, was found. Field equations of MMG differ from those of TMG at quadratic terms in the curvature that do not come from the variation of an action depending on the metric alone. Here we show that MMG is a unique theory and there does not exist a deformation of TMG or MMG at the cubic and quartic order (and beyond) in the curvature that is consistent at the level of the field equations. The only extension of TMG with the desired bulk and boundary properties having a single massive degree of freedom is MMG.

A case of ultrasound-guided prenatal diagnosis of prune belly syndrome in Papua New Guinea – implications for management

Science.gov (United States)

2013-01-01

Background Prune belly syndrome is a rare congenital malformation of unknown aetiology and is characterised by abnormalities of the urinary tract, a deficiency of abdominal musculature and bilateral cryptorchidism in males. We report a case of prune belly syndrome from Papua New Guinea, which was suspected on pregnancy ultrasound scan and confirmed upon delivery. Case presentation A 26-year-old married woman, Gravida 3 Para 2, presented to antenatal clinic in Madang, Papua New Guinea, at 21+5 weeks’ gestation by dates. She was well with no past medical or family history of note. She gave consent to participate in a clinical trial on prevention of malaria in pregnancy and underwent repeated ultrasound examinations which revealed a live fetus with persistent megacystis and anhydramnios. Both mother and clinicians agreed on conservative management of the congenital abnormality. The mother spontaneously delivered a male fetus weighing 2010 grams at 34 weeks’ gestation with grossly abnormal genitalia including cryptorchidism, penile aplasia and an absent urethral meatus, absent abdominal muscles and hypoplastic lungs. The infant passed away two hours after delivery. This report discusses the implications of prenatal detection of severe congenital abnormalities in PNG. Conclusion This first, formally reported, case of prune belly syndrome from a resource-limited setting in the Oceania region highlights the importance of identifying and documenting congenital abnormalities. Women undergoing antenatal ultrasound examinations must be carefully counseled on the purpose and the limitations of the scan. The increasing use of obstetric ultrasound in PNG will inevitably result in a rise in prenatal detection of congenital abnormalities. This will need to be met with adequate training, referral mechanisms and better knowledge of women’s attitudes and beliefs on birth defects and ultrasound. National medicolegal guidance regarding induced abortion and resuscitation of a

Changed Synaptic Plasticity in Neural Circuits of Depressive-Like and Escitalopram-Treated Rats

Science.gov (United States)

Li, Xiao-Li; Yuan, Yong-Gui; Xu, Hua; Wu, Di; Gong, Wei-Gang; Geng, Lei-Yu; Wu, Fang-Fang; Tang, Hao; Xu, Lin

2015-01-01

Background: Although progress has been made in the detection and characterization of neural plasticity in depression, it has not been fully understood in individual synaptic changes in the neural circuits under chronic stress and antidepressant treatment. Methods: Using electron microscopy and Western-blot analyses, the present study quantitatively examined the changes in the Gray’s Type I synaptic ultrastructures and the expression of synapse-associated proteins in the key brain regions of rats’ depressive-related neural circuit after chronic unpredicted mild stress and/or escitalopram administration. Meanwhile, their depressive behaviors were also determined by several tests. Results: The Type I synapses underwent considerable remodeling after chronic unpredicted mild stress, which resulted in the changed width of the synaptic cleft, length of the active zone, postsynaptic density thickness, and/or synaptic curvature in the subregions of medial prefrontal cortex and hippocampus, as well as the basolateral amygdaloid nucleus of the amygdala, accompanied by changed expression of several synapse-associated proteins. Chronic escitalopram administration significantly changed the above alternations in the chronic unpredicted mild stress rats but had little effect on normal controls. Also, there was a positive correlation between the locomotor activity and the maximal synaptic postsynaptic density thickness in the stratum radiatum of the Cornu Ammonis 1 region and a negative correlation between the sucrose preference and the length of the active zone in the basolateral amygdaloid nucleus region in chronic unpredicted mild stress rats. Conclusion: These findings strongly indicate that chronic stress and escitalopram can alter synaptic plasticity in the neural circuits, and the remodeled synaptic ultrastructure was correlated with the rats’ depressive behaviors, suggesting a therapeutic target for further exploration. PMID:25899067

Prevention of Synaptic Alterations and Neurotoxic Effects of PAMAM Dendrimers by Surface Functionalization

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Felipe Vidal

2017-12-01

Full Text Available One of the most studied nanocarriers for drug delivery are polyamidoamine (PAMAM dendrimers. However, the alterations produced by PAMAM dendrimers in neuronal function have not been thoroughly investigated, and important aspects such as effects on synaptic transmission remain unexplored. We focused on the neuronal activity disruption induced by dendrimers and the possibility to prevent these effects by surface chemical modifications. Therefore, we studied the effects of fourth generation PAMAM with unmodified positively charged surface (G4 in hippocampal neurons, and compared the results with dendrimers functionalized in 25% of their surface groups with folate (PFO25 and polyethylene glycol (PPEG25. G4 dendrimers significantly reduced cell viability at 1 µM, which was attenuated by both chemical modifications, PPEG25 being the less cytotoxic. Patch clamp recordings demonstrated that G4 induced a 7.5-fold increment in capacitive currents as a measure of membrane permeability. Moreover, treatment with this dendrimer increased intracellular Ca2+ by 8-fold with a complete disruption of transients pattern, having as consequence that G4 treatment increased the synaptic vesicle release and frequency of synaptic events by 2.4- and 3-fold, respectively. PFO25 and PPEG25 treatments did not alter membrane permeability, total Ca2+ intake, synaptic vesicle release or synaptic activity frequency. These results demonstrate that cationic G4 dendrimers have neurotoxic effects and induce alterations in normal synaptic activity, which are generated by the augmentation of membrane permeability and a subsequent intracellular Ca2+ increase. Interestingly, these toxic effects and synaptic alterations are prevented by the modification of 25% of PAMAM surface with either folate or polyethylene glycol.

PRRT2: from Paroxysmal Disorders to Regulation of Synaptic Function.

Science.gov (United States)

Valtorta, Flavia; Benfenati, Fabio; Zara, Federico; Meldolesi, Jacopo

2016-10-01

In the past few years, proline-rich transmembrane protein (PRRT)2 has been identified as the causative gene for several paroxysmal neurological disorders. Recently, an important role of PRRT2 in synapse development and function has emerged. Knock down of the protein strongly impairs the formation of synaptic contacts and neurotransmitter release. At the nerve terminal, PRRT2 endows synaptic vesicle exocytosis with Ca 2+ sensitivity by interacting with proteins of the fusion complex and with the Ca 2+ sensors synaptotagmins (Syts). In the postsynaptic compartment, PRRT2 interacts with glutamate receptors. The study of PRRT2 and of its mutations may help in refining our knowledge of the process of synaptic transmission and elucidating the pathogenetic mechanisms leading to derangement of network function in paroxysmal disorders. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Roles of Cortical Slow Waves in Synaptic Plasticity and Memory Consolidation.

Science.gov (United States)

Miyamoto, Daisuke; Hirai, Daichi; Murayama, Masanori

2017-01-01

Sleep plays important roles in sensory and motor memory consolidation. Sleep oscillations, reflecting neural population activity, involve the reactivation of learning-related neurons and regulate synaptic strength and, thereby affect memory consolidation. Among sleep oscillations, slow waves (0.5-4 Hz) are closely associated with memory consolidation. For example, slow-wave power is regulated in an experience-dependent manner and correlates with acquired memory. Furthermore, manipulating slow waves can enhance or impair memory consolidation. During slow wave sleep, inter-areal interactions between the cortex and hippocampus (HC) have been proposed to consolidate declarative memory; however, interactions for non-declarative (HC-independent) memory remain largely uninvestigated. We recently showed that the directional influence in a slow-wave range through a top-down cortical long-range circuit is involved in the consolidation of non-declarative memory. At the synaptic level, the average cortical synaptic strength is known to be potentiated during wakefulness and depressed during sleep. Moreover, learning causes plasticity in a subset of synapses, allocating memory to them. Sleep may help to differentiate synaptic strength between allocated and non-allocated synapses (i.e., improving the signal-to-noise ratio, which may facilitate memory consolidation). Herein, we offer perspectives on inter-areal interactions and synaptic plasticity for memory consolidation during sleep.

The Roles of Cortical Slow Waves in Synaptic Plasticity and Memory Consolidation

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Daisuke Miyamoto

2017-11-01

Full Text Available Sleep plays important roles in sensory and motor memory consolidation. Sleep oscillations, reflecting neural population activity, involve the reactivation of learning-related neurons and regulate synaptic strength and, thereby affect memory consolidation. Among sleep oscillations, slow waves (0.5–4 Hz are closely associated with memory consolidation. For example, slow-wave power is regulated in an experience-dependent manner and correlates with acquired memory. Furthermore, manipulating slow waves can enhance or impair memory consolidation. During slow wave sleep, inter-areal interactions between the cortex and hippocampus (HC have been proposed to consolidate declarative memory; however, interactions for non-declarative (HC-independent memory remain largely uninvestigated. We recently showed that the directional influence in a slow-wave range through a top-down cortical long-range circuit is involved in the consolidation of non-declarative memory. At the synaptic level, the average cortical synaptic strength is known to be potentiated during wakefulness and depressed during sleep. Moreover, learning causes plasticity in a subset of synapses, allocating memory to them. Sleep may help to differentiate synaptic strength between allocated and non-allocated synapses (i.e., improving the signal-to-noise ratio, which may facilitate memory consolidation. Herein, we offer perspectives on inter-areal interactions and synaptic plasticity for memory consolidation during sleep.

Megacystis-microlon-intestinal hypoperistalsis syndrome in a newborn girl whose brother had Prune Belly syndrome: Common Pathogenesis

International Nuclear Information System (INIS)

Oliveira, G.; Boechat, M.I.; Fereira, M.A.

1983-01-01

A case of Megacystis-Microcolon-Intestinal Hypoperistalsis Syndrome (MMIHS) is presented. There were important findings: a urachal remnant and a brother with Prune Belly Syndrome (PBS). After a review of the literature, many common characteristics of MMIHS and PBS are described: flaccid abdomen, dilatation of the urinary tract, intestinal malrotation, cryptorchidism, urachal remnants and familial incidence. MMIHS and PBS may be manifestations of the same underlying process. (orig.)

Prune belly syndrome with urethral hypoplasia and vesico-cutaneous fistula: A case report and review of literature

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Osama M Sarhan

2013-01-01

Full Text Available Association between Prune belly syndrome (PBS and urethral hypoplasia is an unusual condition. It is usually fatal unless there is a communication between the fetal bladder and the amniotic sac. We report a case of PBS with urethral hypoplasia and congenital vesico-cutaneous fistula in a male neonate. Patient underwent cutaneous vesicostomy and was discharged for close follow up of his renal function and for future reconstruction.

An Attractive Reelin Gradient Establishes Synaptic Lamination in the Vertebrate Visual System.

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Di Donato, Vincenzo; De Santis, Flavia; Albadri, Shahad; Auer, Thomas Oliver; Duroure, Karine; Charpentier, Marine; Concordet, Jean-Paul; Gebhardt, Christoph; Del Bene, Filippo

2018-03-07

A conserved organizational and functional principle of neural networks is the segregation of axon-dendritic synaptic connections into laminae. Here we report that targeting of synaptic laminae by retinal ganglion cell (RGC) arbors in the vertebrate visual system is regulated by a signaling system relying on target-derived Reelin and VLDLR/Dab1a on the projecting neurons. Furthermore, we find that Reelin is distributed as a gradient on the target tissue and stabilized by heparan sulfate proteoglycans (HSPGs) in the extracellular matrix (ECM). Through genetic manipulations, we show that this Reelin gradient is important for laminar targeting and that it is attractive for RGC axons. Finally, we suggest a comprehensive model of synaptic lamina formation in which attractive Reelin counter-balances repulsive Slit1, thereby guiding RGC axons toward single synaptic laminae. We establish a mechanism that may represent a general principle for neural network assembly in vertebrate species and across different brain areas. Copyright © 2018 Elsevier Inc. All rights reserved.

Synaptic activity and bioenergy homeostasis: implications in brain trauma and neurodegenerative diseases

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Natasha eKhatri

2013-12-01

Full Text Available Powered by glucose metabolism, the brain is the most energy-demanding organ in our body, accounting for a quarter of total oxygen consumption. Adequate ATP production and regulation of the metabolic processes are essential for the maintenance of synaptic transmission and neuronal function. Glutamatergic synaptic activity utilizes the largest portion of bioenergy for synaptic events including neurotransmitter synthesis, vesicle recycling, and most importantly the postsynaptic activities leading to channel activation and rebalancing of ionic gradients. Bioenergy homeostasis is coupled with synaptic function via activities of the sodium pumps, glutamate transporters, glucose transport and mitochondria translocation. Energy insufficiency will be sensed by the AMP-activated dependent protein kinase (AMPK, a master metabolic regulator that stimulates the catalytic process to enhance energy production. A decline in energy supply and a disruption in bioenergy homeostasis play a critical role in multiple neuropathological conditions including ischemia, stroke and neurodegenerative diseases including Alzheimer’s disease and traumatic brain injuries.

Ensemble stacking mitigates biases in inference of synaptic connectivity

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Brendan Chambers

2018-03-01

Full Text Available A promising alternative to directly measuring the anatomical connections in a neuronal population is inferring the connections from the activity. We employ simulated spiking neuronal networks to compare and contrast commonly used inference methods that identify likely excitatory synaptic connections using statistical regularities in spike timing. We find that simple adjustments to standard algorithms improve inference accuracy: A signing procedure improves the power of unsigned mutual-information-based approaches and a correction that accounts for differences in mean and variance of background timing relationships, such as those expected to be induced by heterogeneous firing rates, increases the sensitivity of frequency-based methods. We also find that different inference methods reveal distinct subsets of the synaptic network and each method exhibits different biases in the accurate detection of reciprocity and local clustering. To correct for errors and biases specific to single inference algorithms, we combine methods into an ensemble. Ensemble predictions, generated as a linear combination of multiple inference algorithms, are more sensitive than the best individual measures alone, and are more faithful to ground-truth statistics of connectivity, mitigating biases specific to single inference methods. These weightings generalize across simulated datasets, emphasizing the potential for the broad utility of ensemble-based approaches. Mapping the routing of spikes through local circuitry is crucial for understanding neocortical computation. Under appropriate experimental conditions, these maps can be used to infer likely patterns of synaptic recruitment, linking activity to underlying anatomical connections. Such inferences help to reveal the synaptic implementation of population dynamics and computation. We compare a number of standard functional measures to infer underlying connectivity. We find that regularization impacts measures

On-line identification of hybrid systems using an adaptive growing and pruning RBF neural network

DEFF Research Database (Denmark)

Alizadeh, Tohid

2008-01-01

This paper introduces an adaptive growing and pruning radial basis function (GAP-RBF) neural network for on-line identification of hybrid systems. The main idea is to identify a global nonlinear model that can predict the continuous outputs of hybrid systems. In the proposed approach, GAP......-RBF neural network uses a modified unscented kalman filter (UKF) with forgetting factor scheme as the required on-line learning algorithm. The effectiveness of the resulting identification approach is tested and evaluated on a simulated benchmark hybrid system....

Poda e sistemas de condução na produção de figos verdes Pruning and conduction system in the yield of green fig

Directory of Open Access Journals (Sweden)

Carlos Antonio Alvarenga Gonçalves

2006-06-01

Full Text Available O objetivo deste trabalho foi verificar o efeito da época de poda e de sistemas de condução sobre crescimento, produção e qualidade de frutos da figueira cultivada na região norte mineira, sob irrigação. O delineamento utilizado foi em blocos ao acaso, com quatro repetições, e os tratamentos arranjados em esquema fatorial 4x2, tomando por fatores épocas de poda (junho, setembro, dezembro e março e sistemas de condução (com desponte e sem desponte. Em cada parcela, constituída de três plantas úteis, foram coletados dados nos ciclos de produção 2000/2001 e 2001/2002. Não houve interação entre os fatores época de poda e sistema de condução. Houve diferenças de produção entre épocas de poda; plantas podadas em março e junho apresentaram maiores produções. Não houve diferença de produção entre os dois sistemas de condução. Diferentes épocas de poda e sistemas de condução não influíram na qualidade dos frutos em relação a teores de sólidos solúveis totais, pH, acidez total titulável, açúcares totais, glucose, sacarose e amido. A poda da figueira em diferentes épocas do ano pode propiciar produção na entressafra da cultura no norte de Minas Gerais, sem alterar a qualidade dos frutos verdes com padrão para a indústria.The objective of the work was to verify the effect of pruning time and conduction system on growth, yield, and quality of the fig tree fruit grown in the northern Minas Gerais region, under irrigation. The design utilized was randomized blocks with four replicates, and the treatments arranged in a 4x2 factorial scheme, taking as factors pruning times (June, September, December and March and conduction system (with lopping and without lopping. In each plot, made up of three useful plants, data concerning the cropping cycles of 2000/2001 and 2001/2002 were collected. No interaction between the factors pruning time and conduction system was verified. There were yield differences between

A Flexible Computational Framework Using R and Map-Reduce for Permutation Tests of Massive Genetic Analysis of Complex Traits.

Science.gov (United States)

Mahjani, Behrang; Toor, Salman; Nettelblad, Carl; Holmgren, Sverker

2017-01-01

In quantitative trait locus (QTL) mapping significance of putative QTL is often determined using permutation testing. The computational needs to calculate the significance level are immense, 10 4 up to 10 8 or even more permutations can be needed. We have previously introduced the PruneDIRECT algorithm for multiple QTL scan with epistatic interactions. This algorithm has specific strengths for permutation testing. Here, we present a flexible, parallel computing framework for identifying multiple interacting QTL using the PruneDIRECT algorithm which uses the map-reduce model as implemented in Hadoop. The framework is implemented in R, a widely used software tool among geneticists. This enables users to rearrange algorithmic steps to adapt genetic models, search algorithms, and parallelization steps to their needs in a flexible way. Our work underlines the maturity of accessing distributed parallel computing for computationally demanding bioinformatics applications through building workflows within existing scientific environments. We investigate the PruneDIRECT algorithm, comparing its performance to exhaustive search and DIRECT algorithm using our framework on a public cloud resource. We find that PruneDIRECT is vastly superior for permutation testing, and perform 2 ×10 5 permutations for a 2D QTL problem in 15 hours, using 100 cloud processes. We show that our framework scales out almost linearly for a 3D QTL search.

Massive Supergravity and Deconstruction

CERN Document Server

Gregoire, T; Shadmi, Y; Gregoire, Thomas; Schwartz, Matthew D; Shadmi, Yael

2004-01-01

We present a simple superfield Lagrangian for massive supergravity. It comprises the minimal supergravity Lagrangian with interactions as well as mass terms for the metric superfield and the chiral compensator. This is the natural generalization of the Fierz-Pauli Lagrangian for massive gravity which comprises mass terms for the metric and its trace. We show that the on-shell bosonic and fermionic fields are degenerate and have the appropriate spins: 2, 3/2, 3/2 and 1. We then study this interacting Lagrangian using goldstone superfields. We find that a chiral multiplet of goldstones gets a kinetic term through mixing, just as the scalar goldstone does in the non-supersymmetric case. This produces Planck scale (Mpl) interactions with matter and all the discontinuities and unitarity bounds associated with massive gravity. In particular, the scale of strong coupling is (Mpl m^4)^1/5, where m is the multiplet's mass. Next, we consider applications of massive supergravity to deconstruction. We estimate various qu...

COLA with massive neutrinos

Energy Technology Data Exchange (ETDEWEB)

Wright, Bill S.; Winther, Hans A.; Koyama, Kazuya, E-mail: bill.wright@port.ac.uk, E-mail: hans.winther@port.ac.uk, E-mail: kazuya.koyama@port.ac.uk [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building, Burnaby Road, Portsmouth, Hampshire, PO1 3FX (United Kingdom)

2017-10-01

The effect of massive neutrinos on the growth of cold dark matter perturbations acts as a scale-dependent Newton's constant and leads to scale-dependent growth factors just as we often find in models of gravity beyond General Relativity. We show how to compute growth factors for ΛCDM and general modified gravity cosmologies combined with massive neutrinos in Lagrangian perturbation theory for use in COLA and extensions thereof. We implement this together with the grid-based massive neutrino method of Brandbyge and Hannestad in MG-PICOLA and compare COLA simulations to full N -body simulations of ΛCDM and f ( R ) gravity with massive neutrinos. Our implementation is computationally cheap if the underlying cosmology already has scale-dependent growth factors and it is shown to be able to produce results that match N -body to percent level accuracy for both the total and CDM matter power-spectra up to k ∼< 1 h /Mpc.

Methamphetamine reduces LTP and increases baseline synaptic transmission in the CA1 region of mouse hippocampus.

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Jarod Swant

2010-06-01

Full Text Available Methamphetamine (METH is an addictive psychostimulant whose societal impact is on the rise. Emerging evidence suggests that psychostimulants alter synaptic plasticity in the brain--which may partly account for their adverse effects. While it is known that METH increases the extracellular concentration of monoamines dopamine, serotonin, and norepinephrine, it is not clear how METH alters glutamatergic transmission. Within this context, the aim of the present study was to investigate the effects of acute and systemic METH on basal synaptic transmission and long-term potentiation (LTP; an activity-induced increase in synaptic efficacy in CA1 sub-field in the hippocampus. Both the acute ex vivo application of METH to hippocampal slices and systemic administration of METH decreased LTP. Interestingly, the acute ex vivo application of METH at a concentration of 30 or 60 microM increased baseline synaptic transmission as well as decreased LTP. Pretreatment with eticlopride (D2-like receptor antagonist did not alter the effects of METH on synaptic transmission or LTP. In contrast, pretreatment with D1/D5 dopamine receptor antagonist SCH23390 or 5-HT1A receptor antagonist NAN-190 abrogated the effect of METH on synaptic transmission. Furthermore, METH did not increase baseline synaptic transmission in D1 dopamine receptor haploinsufficient mice. Our findings suggest that METH affects excitatory synaptic transmission via activation of dopamine and serotonin receptor systems in the hippocampus. This modulation may contribute to synaptic maladaption induced by METH addiction and/or METH-mediated cognitive dysfunction.

Minimal massive 3D gravity

International Nuclear Information System (INIS)

Bergshoeff, Eric; Merbis, Wout; Hohm, Olaf; Routh, Alasdair J; Townsend, Paul K

2014-01-01

We present an alternative to topologically massive gravity (TMG) with the same ‘minimal’ bulk properties; i.e. a single local degree of freedom that is realized as a massive graviton in linearization about an anti-de Sitter (AdS) vacuum. However, in contrast to TMG, the new ‘minimal massive gravity’ has both a positive energy graviton and positive central charges for the asymptotic AdS-boundary conformal algebra. (paper)

Thalamic synaptic transmission of sensory information modulated by synergistic interaction of adenosine and serotonin.

Science.gov (United States)

Yang, Ya-Chin; Hu, Chun-Chang; Huang, Chen-Syuan; Chou, Pei-Yu

2014-03-01

The thalamic synapses relay peripheral sensory information to the cortex, and constitute an important part of the thalamocortical network that generates oscillatory activities responsible for different vigilance (sleep and wakefulness) states. However, the modulation of thalamic synaptic transmission by potential sleep regulators, especially by combination of regulators in physiological scenarios, is not fully characterized. We found that somnogen adenosine itself acts similar to wake-promoting serotonin, both decreasing synaptic strength as well as short-term depression, at the retinothalamic synapse. We then combined the two modulators considering the coexistence of them in the hypnagogic (sleep-onset) state. Adenosine plus serotonin results in robust synergistic inhibition of synaptic strength and dramatic transformation of short-term synaptic depression to facilitation. These synaptic effects are not achievable with a single modulator, and are consistent with a high signal-to-noise ratio but a low level of signal transmission through the thalamus appropriate for slow-wave sleep. This study for the first time demonstrates that the sleep-regulatory modulators may work differently when present in combination than present singly in terms of shaping information flow in the thalamocortical network. The major synaptic characters such as the strength and short-term plasticity can be profoundly altered by combination of modulators based on physiological considerations. © 2013 International Society for Neurochemistry.

Reduced Synaptic Vesicle Recycling during Hypoxia in Cultured Cortical Neurons

OpenAIRE

Fedorovich, Sergei; Hofmeijer, Jeannette; van Putten, Michel Johannes Antonius Maria; le Feber, Jakob

2017-01-01

Improvement of neuronal recovery in the ischemic penumbra, an area around the core of a brain infarct with some remaining perfusion, has a large potential for the development of therapy against acute ischemic stroke. However, mechanisms that lead to either recovery or secondary damage in the penumbra largely remain unclear. Recent studies in cultured networks of cortical neurons showed that failure of synaptic transmission (referred to as synaptic failure) is a critical factor in the penumbra...

Integrated neuron circuit for implementing neuromorphic system with synaptic device

Science.gov (United States)

Lee, Jeong-Jun; Park, Jungjin; Kwon, Min-Woo; Hwang, Sungmin; Kim, Hyungjin; Park, Byung-Gook

2018-02-01

In this paper, we propose and fabricate Integrate & Fire neuron circuit for implementing neuromorphic system. Overall operation of the circuit is verified by measuring discrete devices and the output characteristics of the circuit. Since the neuron circuit shows asymmetric output characteristic that can drive synaptic device with Spike-Timing-Dependent-Plasticity (STDP) characteristic, the autonomous weight update process is also verified by connecting the synaptic device and the neuron circuit. The timing difference of the pre-neuron and the post-neuron induce autonomous weight change of the synaptic device. Unlike 2-terminal devices, which is frequently used to implement neuromorphic system, proposed scheme of the system enables autonomous weight update and simple configuration by using 4-terminal synapse device and appropriate neuron circuit. Weight update process in the multi-layer neuron-synapse connection ensures implementation of the hardware-based artificial intelligence, based on Spiking-Neural- Network (SNN).

SynGAP regulates protein synthesis and homeostatic synaptic plasticity in developing cortical networks.

Directory of Open Access Journals (Sweden)

Chih-Chieh Wang

Full Text Available Disrupting the balance between excitatory and inhibitory neurotransmission in the developing brain has been causally linked with intellectual disability (ID and autism spectrum disorders (ASD. Excitatory synapse strength is regulated in the central nervous system by controlling the number of postsynaptic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs. De novo genetic mutations of the synaptic GTPase-activating protein (SynGAP are associated with ID and ASD. SynGAP is enriched at excitatory synapses and genetic suppression of SynGAP increases excitatory synaptic strength. However, exactly how SynGAP acts to maintain synaptic AMPAR content is unclear. We show here that SynGAP limits excitatory synaptic strength, in part, by suppressing protein synthesis in cortical neurons. The data presented here from in vitro, rat and mouse cortical networks, demonstrate that regulation of translation by SynGAP involves ERK, mTOR, and the small GTP-binding protein Rheb. Furthermore, these data show that GluN2B-containing NMDARs and the cognitive kinase CaMKII act upstream of SynGAP and that this signaling cascade is required for proper translation-dependent homeostatic synaptic plasticity of excitatory synapses in developing cortical networks.

The Roles of Protein Expression in Synaptic Plasticity and Memory Consolidation

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Tali eRosenberg

2014-11-01

Full Text Available The amount and availability of proteins are regulated by their synthesis, degradation, and transport. These processes can specifically, locally, and temporally regulate a protein or a population of proteins, thus affecting numerous biological processes in health and disease states. Accordingly, malfunction in the processes of protein turnover and localization underlies different neuronal diseases. However, as early as a century ago, it was recognized that there is a specific need for normal macromolecular synthesis in a specific fragment of the learning process, memory consolidation, which takes place minutes to hours following acquisition. Memory consolidation is the process by which fragile short-term memory is converted into stable long-term memory. It is accepted today that synaptic plasticity is a cellular mechanism of learning and memory processes. Interestingly, similar molecular mechanisms subserve both memory and synaptic plasticity consolidation. In this review, we survey the current view on the connection between memory consolidation processes and proteostasis, i.e., maintaining the protein contents at the neuron and the synapse. In addition, we describe the technical obstacles and possible new methods to determine neuronal proteostasis of synaptic function and better explain the process of memory and synaptic plasticity consolidation.

Feedforward inhibition and synaptic scaling--two sides of the same coin?

Science.gov (United States)

Keck, Christian; Savin, Cristina; Lücke, Jörg

2012-01-01

Feedforward inhibition and synaptic scaling are important adaptive processes that control the total input a neuron can receive from its afferents. While often studied in isolation, the two have been reported to co-occur in various brain regions. The functional implications of their interactions remain unclear, however. Based on a probabilistic modeling approach, we show here that fast feedforward inhibition and synaptic scaling interact synergistically during unsupervised learning. In technical terms, we model the input to a neural circuit using a normalized mixture model with Poisson noise. We demonstrate analytically and numerically that, in the presence of lateral inhibition introducing competition between different neurons, Hebbian plasticity and synaptic scaling approximate the optimal maximum likelihood solutions for this model. Our results suggest that, beyond its conventional use as a mechanism to remove undesired pattern variations, input normalization can make typical neural interaction and learning rules optimal on the stimulus subspace defined through feedforward inhibition. Furthermore, learning within this subspace is more efficient in practice, as it helps avoid locally optimal solutions. Our results suggest a close connection between feedforward inhibition and synaptic scaling which may have important functional implications for general cortical processing.

Feedforward inhibition and synaptic scaling--two sides of the same coin?

Directory of Open Access Journals (Sweden)

Christian Keck

Full Text Available Feedforward inhibition and synaptic scaling are important adaptive processes that control the total input a neuron can receive from its afferents. While often studied in isolation, the two have been reported to co-occur in various brain regions. The functional implications of their interactions remain unclear, however. Based on a probabilistic modeling approach, we show here that fast feedforward inhibition and synaptic scaling interact synergistically during unsupervised learning. In technical terms, we model the input to a neural circuit using a normalized mixture model with Poisson noise. We demonstrate analytically and numerically that, in the presence of lateral inhibition introducing competition between different neurons, Hebbian plasticity and synaptic scaling approximate the optimal maximum likelihood solutions for this model. Our results suggest that, beyond its conventional use as a mechanism to remove undesired pattern variations, input normalization can make typical neural interaction and learning rules optimal on the stimulus subspace defined through feedforward inhibition. Furthermore, learning within this subspace is more efficient in practice, as it helps avoid locally optimal solutions. Our results suggest a close connection between feedforward inhibition and synaptic scaling which may have important functional implications for general cortical processing.

Interplay of multiple synaptic plasticity features in filamentary memristive devices for neuromorphic computing

Science.gov (United States)

La Barbera, Selina; Vincent, Adrien F.; Vuillaume, Dominique; Querlioz, Damien; Alibart, Fabien

2016-12-01

Bio-inspired computing represents today a major challenge at different levels ranging from material science for the design of innovative devices and circuits to computer science for the understanding of the key features required for processing of natural data. In this paper, we propose a detail analysis of resistive switching dynamics in electrochemical metallization cells for synaptic plasticity implementation. We show how filament stability associated to joule effect during switching can be used to emulate key synaptic features such as short term to long term plasticity transition and spike timing dependent plasticity. Furthermore, an interplay between these different synaptic features is demonstrated for object motion detection in a spike-based neuromorphic circuit. System level simulation presents robust learning and promising synaptic operation paving the way to complex bio-inspired computing systems composed of innovative memory devices.

Emulating short-term synaptic dynamics with memristive devices

Science.gov (United States)

Berdan, Radu; Vasilaki, Eleni; Khiat, Ali; Indiveri, Giacomo; Serb, Alexandru; Prodromakis, Themistoklis

2016-01-01

Neuromorphic architectures offer great promise for achieving computation capacities beyond conventional Von Neumann machines. The essential elements for achieving this vision are highly scalable synaptic mimics that do not undermine biological fidelity. Here we demonstrate that single solid-state TiO2 memristors can exhibit non-associative plasticity phenomena observed in biological synapses, supported by their metastable memory state transition properties. We show that, contrary to conventional uses of solid-state memory, the existence of rate-limiting volatility is a key feature for capturing short-term synaptic dynamics. We also show how the temporal dynamics of our prototypes can be exploited to implement spatio-temporal computation, demonstrating the memristors full potential for building biophysically realistic neural processing systems.

Does autophagy work in synaptic plasticity and memory?

Science.gov (United States)