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Matthews, and James L. ... McClelland, is an intriguing and well-written book that provides a groundbreaking overview of diverse approaches to understanding memory that sets the agenda for an interdisciplinary approach to the topic ... Matthews, and James L. ...arXiv:1501.00197v1 fatcat:77y35mll4zcmrpqhubn2scx6oi
Many cell adhesion molecules are localized at synaptic sites in neuronal axons and dendrites. These molecules bridge pre-and postsynaptic specializations but do far more than simply provide a mechanical link between cells. In this review, we will discuss the roles these proteins have during development and at mature synapses. Synaptic adhesion proteins participate in the formation, maturation, function and plasticity of synaptic connections. Together with conventional synaptic transmissiondoi:10.1038/nrn2075 pmid:17299456 pmcid:PMC4756920 fatcat:lrk5wmk2uvh7zkhlkcb4xmprj4
more »... nisms, these molecules are an important element in the trans-cellular communication mediated by synapses. CNS synapses are specialized sites of cell-cell contact that mediate the transmission of information between neurons. Synapses are a key site of regulation within neural networks and are characterized by multi-protein complexes arranged at tightly apposed pre-and postsynaptic terminals. Communication between neurons at synapses is mediated primarily by neurotransmitter release and by the gating of postsynaptic receptor ion channels, but a growing body of evidence indicates that signalling is also mediated by adhesion molecules that interact in a homo-or heterophilic fashion across the synaptic cleft. As at other cell-cell junctions, such as epithelial tight junctions or the immune synapse, research in a variety of neuronal subtypes has shown that synaptically localized cell adhesion molecules (SAMs) are not merely static structural components but are often dynamic regulators of synapse function. When pairs of SAMs interact, they can induce the formation of new synapses or modulate the function of existing synapses through signalling cascades or secondary protein-protein interactions. Numerous studies indicate that interactions between specific SAMs can control synapse formation, regulate dendritic spine morphology, modify synaptic receptor function and modulate synaptic plasticity. So, SAMs can mediate physical interactions between cells and act at multiple steps in the life of a synapse (FIG. 1) . Here, we focus on well-studied classes of SAMs that have roles at both developing and mature synapses, namely neurexins and neuroligins, EphBs and ephrin-Bs, immunoglobulin Correspondence to: M.B.D. email@example.com. Competing interests statement The authors declare no competing financial interests. Note added in proof In a recently published manuscript, Futai et al. 144 demonstrate that trans-synaptic β-neurexin-neuroligin interactions can modulate presynaptic function. The authors show that overexpression or knockdown of PSD-95 in the postsynaptic cell modulates presynaptic release probability, and that these effects are blocked when trans-synaptic β-neurexin-neuroligin signalling is disrupted. This paper provides further evidence that SAMs act to regulate synaptic function. Glossary Synapse formation The initial contact of two neurons and organization of the earliest components of a young synapse, including presynaptic vesicles and release machinery, and postsynaptic NMDA receptors and PSD-95 Dalva et al.
International Encyclopedia of the Social & Behavioral Sciences
The ability to maintain information online beyond sensory stimulation is regarded as a key contribution of working memory to goaldirected behaviour. It is widely accepted that sustained neural activity is a key mechanism of stimulus maintenance, but it is unclear to what extent the neural generators of sustained activity change from stimulus-encoding to maintenance. Using eventrelated potentials in humans, we show that, in a delayed match-to-sample task, slow shifts over parieto-occipitaldoi:10.1016/b978-0-08-097086-8.56007-3 fatcat:vlpfqzkhjvdwvbswv4jfsxeuti
more »... ode sites had a different topography and polarity during encoding and delay maintenance of images depicting scenes. This clearly demonstrates that neural generators of sustained activity associated with stimulus-encoding and delay maintenance differed, and that the change between these generators occurred time-locked to the onset of the delay period. We also investigated how monetary reward incentives modulated the amplitude and topography of sustained delay activity and the ability to suppress irrelevant distracting information during the delay. Reward incentives improved maintenance performance and this was correlated with an expansion of the parieto-occipital electrode sites that were entrained into sustained delay activity (rather than improved distractor suppression), suggesting that under the influence of reward, the parieto-occipital regions that contributed to delay maintenance expanded in size.
We develop a new algorithm to compute a basis for M_k(Γ_0(N)), the space of weight k holomorphic modular forms on Γ_0(N), in the case when the graded algebra of modular forms over Γ_0(N) is generated at weight two. Our tests show that this algorithm significantly outperforms a commonly used algorithm which relies more heavily on modular symbols.arXiv:1709.07475v1 fatcat:qctj7wndw5gd7beczdn4lyhtte
Neuromorphic networks based on nanodevices, such as metal oxide memristors, phase change memories, and flash memory cells, have generated considerable interest for their increased energy efficiency and density in comparison to graphics processing units (GPUs) and central processing units (CPUs). Though immense acceleration of the training process can be achieved by leveraging the fact that the time complexity of training does not scale with the network size, it is limited by the spacearXiv:1903.01635v1 fatcat:mupsjv3nqne7lgtlpz33kwmqzm
more »... of stochastic gradient descent, which grows quadratically. The main objective of this work is to reduce this space complexity by using low-rank approximations of stochastic gradient descent. This low spatial complexity combined with streaming methods allows for significant reductions in memory and compute overhead, opening the doors for improvements in area, time and energy efficiency of training. We refer to this algorithm and architecture to implement it as the streaming batch eigenupdate (SBE) approach.
Journal of Trauma
Objective: The purpose of this study was to determine the incidence of missed and mismanaged injuries of the spinal cord, to identify factors contributing to a failure to recognize such injuries, and to assess the consequences of such failures. Methods: Missed and mismanaged injuries were defined using previously validated statements. All medical records and radiographs of patients with acute traumatic spinal cord injury admitted to the Regional Spinal Cord Injury Unit in Sheffield, Uniteddoi:10.1097/00005373-200208000-00021 pmid:12169940 fatcat:wqr5jbqb4rglppvihpxrkokoqa
more »... om, over a period of 10 years from 1989 were evaluated. Pa-tients with no neurologic deficits were excluded from the study. Results: Of the 569 patients, the diagnosis of spinal cord injury was missed in 52 instances (9.1%). The patients were mismanaged in 34 instances, and the treatment offered to 30 was considered negligent. In 26 of 52 (50%), mismanagement resulted in neurologic deterioration. The study identified several factors that contributed to a failure to recognize a spinal cord injury. These include ambience and circumstances surrounding the injury, inadequate neurologic assessment, associated injuries, and radiographic errors.
Virulence and persistence in the BALB/c mouse gut was tested for 32 strains of Salmonella enterica for which genome sequencing is complete or underway, including 17 serovars within subspecies I (enterica), and two representatives of each of the other five subspecies. Only serovar Paratyphi C strain BAA1715 and serovar Typhimurium strain 14028 were fully virulent in mice. Three divergent atypical Enteritidis strains were not virulent in BALB/c, but two efficiently persisted. Most of the otherdoi:10.1371/journal.pone.0036043 pmid:22558320 pmcid:PMC3338620 fatcat:32faqudvajfzvg5w263bi7fnbe
more »... ains in all six subspecies persisted in the mouse intestinal tract for several weeks in multiple repeat experiments although the frequency and level of persistence varied considerably. Strains with heavily degraded genomes persisted very poorly, if at all. None of the strains tested provided immunity to Typhimurium infection. These data greatly expand on the known significant strain-to-strain variation in mouse virulence and highlight the need for comparative genomic and phenotypic studies.
McClelland, Matthew J. Budoff and Michael H. Criqui Isac C. Thomas, Caroline A. Thompson, Mingan Yang, Matthew A. Allison, Nketi I. ...doi:10.1161/atvbaha.118.310850 pmid:29954753 pmcid:PMC6202121 fatcat:jycksknem5f3nafpwqclytiwam
doi:10.3389/fmicb.2016.00444 pmid:27065993 pmcid:PMC4815678 fatcat:dh5katp4xncsfd7bwzu3gcbhxq
Several recently-developed particle-tracking and imaging methods achieve three-dimensional sensitivity through the introduction of angled micromirrors into the observation volume of an optical microscope. Here, we model the imaging response of such devices, and show how the direct and reflected images of a fluorescent particle are affected. In particle-tracking applications, asymmetric image degradation manifests itself as systematic tracking errors. Based on our results, we identify strategiesdoi:10.1364/ol.35.001905 pmid:20517457 fatcat:x3tnpbhflvbt7hdwxt5jvzcvcy
more »... for reducing systematic errors to the 10 nm level in practical applications. PACS numbers:
Superparamagnetic tunnel junctions (SMTJs) are promising sources for the randomness required by some compact and energy-efficient computing schemes. Coupling SMTJs gives rise to collective behavior that could be useful for cognitive computing. We use a simple linear electrical circuit to mutually couple two SMTJs through their stochastic electrical transitions. When one SMTJ makes a thermally induced transition, the voltage across both SMTJs changes, modifying the transition rates of both. ThisarXiv:2106.03604v1 fatcat:pyns3tuumzh4lfqmdolci6oa2a
more »... coupling leads to significant correlation between the states of the two devices. Using fits to a generalized N\'eel-Brown model for the individual thermally bistable magnetic devices, we can accurately reproduce the behavior of the coupled devices with a Markov model.
Neural networks based on nanodevices, such as metal oxide memristors, phase change memories, and flash memory cells, have generated considerable interest for their increased energy efficiency and density in comparison to graphics processing units (GPUs) and central processing units (CPUs). Though immense acceleration of the training process can be achieved by leveraging the fact that the time complexity of training does not scale with the network size, it is limited by the space complexity ofdoi:10.3389/fnins.2019.00793 pmid:31447628 pmcid:PMC6691093 fatcat:zv3oh4habrbvtp6ese2ebeb4ym
more »... ochastic gradient descent, which grows quadratically. The main objective of this work is to reduce this space complexity by using low-rank approximations of stochastic gradient descent. This low spatial complexity combined with streaming methods allows for significant reductions in memory and compute overhead, opening the door for improvements in area, time and energy efficiency of training. We refer to this algorithm and architecture to implement it as the streaming batch eigenupdate (SBE) approach.
John & McClelland, 1990) , that allowed the model's hub to be influenced by its own previous state. ... , & Plaut, 2008; Patterson et al., 2007; Lambon Ralph et al., 2017; Schapiro, McClelland, Welbourne, Rogers, & Lambon Ralph, 2013) . ...doi:10.1037/rev0000094 pmid:29733663 pmcid:PMC5937916 fatcat:nbgfx4s5gvfvdkckcdyssdfn6m
and aims-The volume and density of coronary artery calcium (CAC) both independently predict cardiovascular disease (CVD) beyond standard risk factors, with CAC density inversely associated with incident CVD after accounting for CAC volume. We tested the hypothesis that ascending thoracic aorta calcium (ATAC) volume and density predict incident CVD events independently of CAC. Methods-The Multi-Ethnic Study of Atherosclerosis (MESA) is a prospective cohort study of participants without clinicaldoi:10.1016/j.atherosclerosis.2017.09.009 pmid:28917157 pmcid:PMC5646362 fatcat:vouu3pp5nfeltg5on6iwhv2mfa
more »... VD at baseline. ATAC and CAC were measured from baseline cardiac computed tomography (CT). Cox regression models were used to estimate the associations of ATAC volume and density with incident coronary heart disease (CHD) events and CVD events, after adjustment for standard CVD risk factors and CAC volume and density.
Objective-To describe the relationship between circulating resistin levels and cardiovascular diseases (CVD) and all-cause death in a multi-ethnic cohort. Methods and Results-We studied 1,913 participants from the Multi-Ethnic Study of Atherosclerosis with measurements of plasma resistin levels. Absolute proportions experiencing new-onset atrial fibrillation (AF), atherosclerotic CVD (myocardial infarction, angina, resuscitated cardiac arrest, stroke), heart failure (HF), and all-cause deathdoi:10.1016/j.atherosclerosis.2014.12.044 pmid:25585029 pmcid:PMC4331252 fatcat:klfpl4clsjh7dgzhbfnjrszq5a
more »... e calculated for each quartile of resistin. We used adjusted Cox proportional regression modeling resistin as a continuous variable per standard deviation of log-transformed resistin and secondarily as a categorical variable using resistin quartiles. Results were stratified by sex and race/ethnicity. The mean age of the population was 64.5 ± 10 years with half being female and a median resistin concentration of 15.1 ng/mL (11.9-19.1). Mean follow-up time was 7.2 ± 1.8 years. There was a graded increase in the occurrence of all outcomes across increasing quartiles of resistin. Modeled as a continuous variable, after adjustment for anthropomorphic measures, traditional risk factors, markers of
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