Jacopo eLamanna
2015-02-01
Full Text Available In neurons, power-law behavior with different scaling exponents has been reported at many different levels, including fluctuations in membrane potentials, synaptic transmission up to neuronal network dynamics. Unfortunately in most cases the source of this non-linear feature remains controversial. Here we have analyzed the dynamics of spontaneous quantal release at hippocampal synapses and characterized their power-law behavior. While in control conditions a fractal exponent greater than zero was rarely observed, its value was greatly increased by α-latrotoxin (α-LTX, a potent stimulator of spontaneous release, known to act at the very last step of vesicle fusion. Based on computer modeling, we confirmed that at an increase in fusion probability would unmask a pre-docking phenomenon with 1/f structure, where α estimated from the release series appears to sense the increase in release probability independently from the number of active sites. In the simplest scenario the pre-docking 1/f process could coincide with the Brownian diffusion of synaptic vesicles. Interestingly, when the effect of long-term potentiation (LTP was tested, a ~200% long-lasting increase in quantal frequency was accompanied by a significant increase in the scaling exponent. The similarity between the action of LTP and of α-LTX suggests an increased contribution of high release probability sites following the induction of LTP. In conclusion, our results indicate that the source of the synaptic power-law behavior arises before synaptic vesicles dock to the active zone and that the fractal exponent α is capable of sensing a change in release probability independently from the number of active sites or synapses.
Reid, Christopher A; Dixon, Don B; Takahashi, Michiko; Bliss, Tim V P; Fine, Alan
2004-04-01
It is generally believed that long-term potentiation (LTP) at hippocampal mossy fiber synapses between dentate granule and CA3 pyramidal cells is expressed through presynaptic mechanisms leading to an increase in quantal content. The source of this increase has remained undefined but could include enhanced probability of transmitter release at existing functional release sites or increases in the number of active release sites. We performed optical quantal analyses of transmission at individual mossy fiber synapses in cultured hippocampal slices, using confocal microscopy and intracellular fluorescent Ca(2+) indicators. Our results indicate that LTP is expressed at functional synapses by both increased probability of transmitter release and recruitment of new release sites, including the activation of previously silent synapses here visualized for the first time.
The roles of STP and LTP in synaptic encoding
Arturas Volianskis
2013-02-01
Full Text Available Long-term potentiation (LTP, a cellular model of learning and memory, is generally regarded as a unitary phenomenon that alters the strength of synaptic transmission by increasing the postsynaptic response to the release of a quantum of neurotransmitter. LTP, at CA3-CA1 synapses in the hippocampus, contains a stimulation-labile phase of short-term potentiation (STP, or transient LTP, t-LTP that decays into stable LTP. By studying the responses of populations of neurons to brief bursts of high-frequency afferent stimulation before and after the induction of LTP, we found that synaptic responses during bursts are potentiated equally during LTP but not during STP. We show that STP modulates the frequency response of synaptic transmission whereas LTP preserves the fidelity. Thus, STP and LTP have different functional consequences for the transfer of synaptic information.
High-Probability Neurotransmitter Release Sites Represent an Energy-Efficient Design.
Lu, Zhongmin; Chouhan, Amit K; Borycz, Jolanta A; Lu, Zhiyuan; Rossano, Adam J; Brain, Keith L; Zhou, You; Meinertzhagen, Ian A; Macleod, Gregory T
2016-10-10
Nerve terminals contain multiple sites specialized for the release of neurotransmitters. Release usually occurs with low probability, a design thought to confer many advantages. High-probability release sites are not uncommon, but their advantages are not well understood. Here, we test the hypothesis that high-probability release sites represent an energy-efficient design. We examined release site probabilities and energy efficiency at the terminals of two glutamatergic motor neurons synapsing on the same muscle fiber in Drosophila larvae. Through electrophysiological and ultrastructural measurements, we calculated release site probabilities to differ considerably between terminals (0.33 versus 0.11). We estimated the energy required to release and recycle glutamate from the same measurements. The energy required to remove calcium and sodium ions subsequent to nerve excitation was estimated through microfluorimetric and morphological measurements. We calculated energy efficiency as the number of glutamate molecules released per ATP molecule hydrolyzed, and high-probability release site terminals were found to be more efficient (0.13 versus 0.06). Our analytical model indicates that energy efficiency is optimal (∼0.15) at high release site probabilities (∼0.76). As limitations in energy supply constrain neural function, high-probability release sites might ameliorate such constraints by demanding less energy. Energy efficiency can be viewed as one aspect of nerve terminal function, in balance with others, because high-efficiency terminals depress significantly during episodic bursts of activity.
2012-01-01
Action potentials at the neurons and graded signals at the synapses are primary codes in the brain. In terms of their functional interaction, the studies were focused on the influence of presynaptic spike patterns on synaptic activities. How the synapse dynamics quantitatively regulates the encoding of postsynaptic digital spikes remains unclear. We investigated this question at unitary glutamatergic synapses on cortical GABAergic neurons, especially the quantitative influences of release probability on synapse dynamics and neuronal encoding. Glutamate release probability and synaptic strength are proportionally upregulated by presynaptic sequential spikes. The upregulation of release probability and the efficiency of probability-driven synaptic facilitation are strengthened by elevating presynaptic spike frequency and Ca2+. The upregulation of release probability improves spike capacity and timing precision at postsynaptic neuron. These results suggest that the upregulation of presynaptic glutamate release facilitates a conversion of synaptic analogue signals into digital spikes in postsynaptic neurons, i.e., a functional compatibility between presynaptic and postsynaptic partners. PMID:22852823
Jennrich, O.
The primary objective of the LISA (Laser Interferometer Space Antenna mission is the detection and observation of gravitational waves from massive black holes (MBH) and galactic binaries in the frequency range 10 -4 Hz … 10 -1 Hz. This low-frequency range is inaccessible to ground-based interferometers due to the background of local gravitational noise and because ground-based interferometers are limited in length to a few kilometres. LISA is envisaged as an ESA/NASA collaborative project, selected an ESA cornerstone mission and included in NASA's strategic plan and with a nominal launch date in 2011. SMART-2 is primarily intended to demonstrate the key technologies for the ESA/NASA collaborative LISA cornerstone mission. The synergy with the technology being used for Darwin motivates the utilization of SMART-2 for both missions. To this end, SMART-2 will accommodate a LISA technology package (LTP), provided by European institutes and industry and possibly also a Disturbance Reduction System (DRS) that is very similar to the LTP and has the same goals but is provided by US institutes and industry.
Elfn1 regulates target-specific release probability at CA1-interneuron synapses
Sylwestrak, Emily L.; Ghosh, Anirvan
2012-01-01
Although synaptic transmission may be unidirectional, the establishment of synaptic connections with specific properties can involve bidirectional signaling. Pyramidal neurons in the hippocampus form functionally distinct synapses onto two types of interneurons. Excitatory synapses onto oriens-lacunosum moleculare (O-LM) interneurons are facilitating and have a low release probability, whereas synapses onto parvalbumin interneurons are depressing and have a high release probability. Here, we ...
A probability model: Tritium release into the coolant of a light water tritium production reactor
Anderson, D N
1992-04-01
This report presents a probability model of the total amount of tritium that will be released from a core of tritium target rods into the coolant of a light water reactor during a tritium production cycle.The model relates the total tritium released from a core to the release characteristics of an individual target rod within the core. The model captures total tritium release from two sources-release via target rod breach and release via permeation through the target rod. Specifically, under conservative assumptions about the breach characteristics of a target rod, total tritium released from a core is modeled as a function of the probability of a target breach and the mean and standard deviation of the permeation reduction factor (PRF) of an individual target rod. Two dominant facts emerge from the analysis in this report. First, total tritium release cannot be controlled and minimized solely through the PRF characteristics of a target rod. Tritium release via breach must be abated if acceptable tritium production is to be achieved. Second, PRF values have a saturation point to their effectiveness. Specifically, in the presence of any realistic level of PRF variability, increasing PRF values above approximately 1000 wig contribute little to minimizing total tritium release.
Computational modeling of the effects of amyloid-beta on release probability at hippocampal synapses
Armando eRomani
2013-01-01
Full Text Available The role of amyloid-beta (Aβ in brain function and in the pathogenesis of Alzheimer’s disease remains elusive. Recent publications reported that an increase in Aβ concentration perturbs pre-synaptic release in hippocampal neurons. In particular, it was shown in vitro that Aβ is an endogenous regulator of synaptic transmission at the CA3-CA1 synapse, enhancing its release probability. How this synaptic modulator influences neuronal output during physiological stimulation patterns, such as those elicited in vivo, is still unknown. Using a realistic model of hippocampal CA1 pyramidal neurons, we first implemented this Aβ-induced enhancement of release probability and validated the model by reproducing the experimental findings. We then demonstrated that this synaptic modification can significantly alter synaptic integration properties in a wide range of physiologically relevant input frequencies (from 5 to 200 Hz. Finally, we used natural input patterns, obtained from CA3 pyramidal neurons in vivo during free exploration of rats in an open field, to investigate the effects of enhanced Aβ on synaptic release under physiological conditions. The model shows that the CA1 neuronal response to these natural patterns is altered in the increased-Aβ condition, especially for frequencies in the theta and gamma ranges. These results suggest that the perturbation of release probability induced by increased Aβ can significantly alter the spike probability of CA1 pyramidal neurons and thus contribute to abnormal hippocampal function during Alzheimer’s disease.
Emptage, Nigel J; Reid, Christopher A; Fine, Alan; Bliss, Timothy V P
2003-06-01
The mechanisms by which long-term potentiation (LTP) is expressed are controversial, with evidence for both presynaptic and postsynaptic involvement. We have used confocal microscopy and Ca(2+)-sensitive dyes to study LTP at individual visualized synapses. Synaptically evoked Ca(2+) transients were imaged in distal dendritic spines of pyramidal cells in cultured hippocampal slices, before and after the induction of LTP. At most synapses, from as early as 10 min to at least 60 min after induction, LTP was associated with an increase in the probability of a single stimulus evoking a postsynaptic Ca(2+) response. These observations provide compelling evidence of a presynaptic component to the expression of early LTP at Schaffer-associational synapses. In most cases, the store-dependent evoked Ca(2+) transient in the spine was also increased after induction, a novel postsynaptic aspect of LTP.
无
2009-01-01
【说词】1. He can probably tell us the truth.2. Will it rain this afternoong ？ Probably【解语】作副词，意为“大概、或许”，表示可能性很大，通常指根据目前情况作出积极推测或判断；
Release probability of hippocampal glutamatergic terminals scales with the size of the active zone.
Holderith, Noemi; Lorincz, Andrea; Katona, Gergely; Rózsa, Balázs; Kulik, Akos; Watanabe, Masahiko; Nusser, Zoltan
2012-06-10
Cortical synapses have structural, molecular and functional heterogeneity; our knowledge regarding the relationship between their ultrastructural and functional parameters is still fragmented. Here we asked how the neurotransmitter release probability and presynaptic [Ca(2+)] transients relate to the ultrastructure of rat hippocampal glutamatergic axon terminals. Two-photon Ca(2+) imaging-derived optical quantal analysis and correlated electron microscopic reconstructions revealed a tight correlation between the release probability and the active-zone area. Peak amplitude of [Ca(2+)] transients in single boutons also positively correlated with the active-zone area. Freeze-fracture immunogold labeling revealed that the voltage-gated calcium channel subunit Cav2.1 and the presynaptic protein Rim1/2 are confined to the active zone and their numbers scale linearly with the active-zone area. Gold particles labeling Cav2.1 were nonrandomly distributed in the active zones. Our results demonstrate that the numbers of several active-zone proteins, including presynaptic calcium channels, as well as the number of docked vesicles and the release probability, scale linearly with the active-zone area.
Molecular machines regulating the release probability of synaptic vesicles at the active zone.
Christoph eKoerber
2016-03-01
Full Text Available The fusion of synaptic vesicles (SVs with the plasma membrane of the active zone (AZ upon arrival of an action potential (AP at the presynaptic compartment is a tightly regulated probabil-istic process crucial for information transfer. The probability of a SV to release its transmitter content in response to an AP, termed release probability (Pr, is highly diverse both at the level of entire synapses and individual SVs at a given synapse. Differences in Pr exist between different types of synapses, between synapses of the same type, synapses originating from the same axon and even between different SV subpopulations within the same presynaptic terminal. The Pr of SVs at the AZ is set by a complex interplay of different presynaptic properties including the availability of release-ready SVs, the location of the SVs relative to the voltage-gated calcium channels (VGCCs at the AZ, the magnitude of calcium influx upon arrival of the AP, the buffer-ing of calcium ions as well as the identity and sensitivity of the calcium sensor. These properties are not only interconnected, but can also be regulated dynamically to match the requirements of activity patterns mediated by the synapse. Here, we review recent advances in identifying mole-cules and molecular machines taking part in the determination of vesicular Pr at the AZ.
Liu, Xiang; Saat, Mohd Rapik; Barkan, Christopher P L
2014-07-15
Railroads play a key role in the transportation of hazardous materials in North America. Rail transport differs from highway transport in several aspects, an important one being that rail transport involves trains in which many railcars carrying hazardous materials travel together. By contrast to truck accidents, it is possible that a train accident may involve multiple hazardous materials cars derailing and releasing contents with consequently greater potential impact on human health, property and the environment. In this paper, a probabilistic model is developed to estimate the probability distribution of the number of tank cars releasing contents in a train derailment. Principal operational characteristics considered include train length, derailment speed, accident cause, position of the first car derailed, number and placement of tank cars in a train and tank car safety design. The effect of train speed, tank car safety design and tank car positions in a train were evaluated regarding the number of cars that release their contents in a derailment. This research provides insights regarding the circumstances affecting multiple-tank-car release incidents and potential strategies to reduce their occurrences. The model can be incorporated into a larger risk management framework to enable better local, regional and national safety management of hazardous materials transportation by rail. Copyright © 2014 Elsevier B.V. All rights reserved.
Liu, Xiang, E-mail: liu94@illinois.edu; Saat, Mohd Rapik, E-mail: mohdsaat@illinois.edu; Barkan, Christopher P.L., E-mail: cbarkan@illinois.edu
2014-07-15
Railroads play a key role in the transportation of hazardous materials in North America. Rail transport differs from highway transport in several aspects, an important one being that rail transport involves trains in which many railcars carrying hazardous materials travel together. By contrast to truck accidents, it is possible that a train accident may involve multiple hazardous materials cars derailing and releasing contents with consequently greater potential impact on human health, property and the environment. In this paper, a probabilistic model is developed to estimate the probability distribution of the number of tank cars releasing contents in a train derailment. Principal operational characteristics considered include train length, derailment speed, accident cause, position of the first car derailed, number and placement of tank cars in a train and tank car safety design. The effect of train speed, tank car safety design and tank car positions in a train were evaluated regarding the number of cars that release their contents in a derailment. This research provides insights regarding the circumstances affecting multiple-tank-car release incidents and potential strategies to reduce their occurrences. The model can be incorporated into a larger risk management framework to enable better local, regional and national safety management of hazardous materials transportation by rail.
Hilla Fogel
2014-06-01
Full Text Available Accumulation of amyloid-β peptides (Aβ, the proteolytic products of the amyloid precursor protein (APP, induces a variety of synaptic dysfunctions ranging from hyperactivity to depression that are thought to cause cognitive decline in Alzheimer’s disease. While depression of synaptic transmission has been extensively studied, the mechanisms underlying synaptic hyperactivity remain unknown. Here, we show that Aβ40 monomers and dimers augment release probability through local fine-tuning of APP-APP interactions at excitatory hippocampal boutons. Aβ40 binds to the APP, increases the APP homodimer fraction at the plasma membrane, and promotes APP-APP interactions. The APP activation induces structural rearrangements in the APP/Gi/o-protein complex, boosting presynaptic calcium flux and vesicle release. The APP growth-factor-like domain (GFLD mediates APP-APP conformational changes and presynaptic enhancement. Thus, the APP homodimer constitutes a presynaptic receptor that transduces signal from Aβ40 to glutamate release. Excessive APP activation may initiate a positive feedback loop, contributing to hippocampal hyperactivity in Alzheimer’s disease.
Marian Joëls
2007-01-01
Full Text Available When an organism is exposed to a stressful situation, corticosteroid levels in the brain rise. This rise has consequences for behavioral performance, including memory formation. Over the past decades, it has become clear that a rise in corticosteroid level is also accompanied by a reduction in hippocampal long-term potentiation (LTP. Recent studies, however, indicate that stress does not lead to a universal suppression of LTP. Many factors, including the type of stress, the phase of the stress response, the area of investigation, type of LTP, and the life history of the organism determine in which direction LTP will be changed.
Lou, Xuelin; Fan, Fan; Messa, Mirko; Raimondi, Andrea; Wu, Yumei; Looger, Loren L; Ferguson, Shawn M; De Camilli, Pietro
2012-02-21
Endocytic recycling of synaptic vesicles after exocytosis is critical for nervous system function. At synapses of cultured neurons that lack the two "neuronal" dynamins, dynamin 1 and 3, smaller excitatory postsynaptic currents are observed due to an impairment of the fission reaction of endocytosis that results in an accumulation of arrested clathrin-coated pits and a greatly reduced synaptic vesicle number. Surprisingly, despite a smaller readily releasable vesicle pool and fewer docked vesicles, a strong facilitation, which correlated with lower vesicle release probability, was observed upon action potential stimulation at such synapses. Furthermore, although network activity in mutant cultures was lower, Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) activity was unexpectedly increased, consistent with the previous report of an enhanced state of synapsin 1 phosphorylation at CaMKII-dependent sites in such neurons. These changes were partially reversed by overnight silencing of synaptic activity with tetrodotoxin, a treatment that allows progression of arrested endocytic pits to synaptic vesicles. Facilitation was also counteracted by CaMKII inhibition. These findings reveal a mechanism aimed at preventing synaptic transmission failure due to vesicle depletion when recycling vesicle traffic is backed up by a defect in dynamin-dependent endocytosis and provide new insight into the coupling between endocytosis and exocytosis.
Malik, Ruchi; Chattarji, Sumantra
2012-03-01
Environmental enrichment (EE) is a well-established paradigm for studying naturally occurring changes in synaptic efficacy in the hippocampus that underlie experience-induced modulation of learning and memory in rodents. Earlier research on the effects of EE on hippocampal plasticity focused on long-term potentiation (LTP). Whereas many of these studies investigated changes in synaptic weight, little is known about potential contributions of neuronal excitability to EE-induced plasticity. Here, using whole-cell recordings in hippocampal slices, we address this gap by analyzing the impact of EE on both synaptic plasticity and intrinsic excitability of hippocampal CA1 pyramidal neurons. Consistent with earlier reports, EE increased contextual fear memory and dendritic spine density on CA1 cells. Furthermore, EE facilitated LTP at Schaffer collateral inputs to CA1 pyramidal neurons. Analysis of the underlying causes for enhanced LTP shows EE to increase the frequency but not amplitude of miniature excitatory postsynaptic currents. However, presynaptic release probability, assayed using paired-pulse ratios and use-dependent block of N-methyl-d-aspartate receptor currents, was not affected. Furthermore, CA1 neurons fired more action potentials (APs) in response to somatic depolarization, as well as during the induction of LTP. EE also reduced spiking threshold and after-hyperpolarization amplitude. Strikingly, this EE-induced increase in excitability caused the same-sized excitatory postsynaptic potential to fire more APs. Together, these findings suggest that EE may enhance the capacity for plasticity in CA1 neurons, not only by strengthening synapses but also by enhancing their efficacy to fire spikes-and the two combine to act as an effective substrate for amplifying LTP.
Reinforcement of Rat Hippocampal LTP by Holeboard Training
Frey, Julietta U.; Korz, Volker; Uzakov, Shukhrat
2005-01-01
Hippocampal long-term potentiation (LTP) can be dissociated in early-LTP lasting 4-5 h and late-LTP with a duration of more than 8 h, the latter of which requires protein synthesis and heterosynaptic activity during its induction. Previous studies in vivo have shown that early-LTP in the dentate gyrus can protein synthesis-dependently be…
Effects of antiepileptic drugs on associative LTP-like plasticity in human motor cortex.
Heidegger, Tonio; Krakow, Karsten; Ziemann, Ulf
2010-10-01
Antiepileptic drugs (AEDs) are used extensively in clinical practice but relatively little is known on their specific effects at the systems level of human cortex. Here we tested, using a double-blind randomized placebo-controlled crossover design in healthy subjects, the effects of a single therapeutic oral dose of seven AEDs with different modes of action (tiagabine, diazepam, gabapentin, lamotrigine, topiramate, levetiracetam and piracetam) on long-term potentiation (LTP)-like motor cortical plasticity induced by paired associative transcranial magnetic stimulation (PAS). PAS-induced LTP-like plasticity was assessed from the increase in motor evoked potential amplitude in a hand muscle contralateral to the stimulated motor cortex. Levetiracetam significantly reduced LTP-like plasticity when compared to the placebo condition. Tiagabine, diazepam, lamotrigine and piracetam resulted in nonsignificant trends towards reduction of LTP-like plasticity while gabapentin and topiramate had no effect. The particularly depressant effect of levetiracetam is probably explained by its unique mode of action through binding at the vesicle membrane protein SV2A. Enhancement of gamma-amino butyric acid-dependent cortical inhibition by tiagabine, diazepam and possibly levetiracetam, and blockage of voltage-gated sodium channels by lamotrigine, may also depress PAS-induced LTP-like plasticity but these mechanisms appear to be less relevant. Findings may inform about AED-related adverse effects on important LTP-dependent central nervous systems processes such as learning or memory formation. The particular depressant effect of levetiracetam on LTP-like plasticity may also relate to the unique properties of this drug to inhibit epileptogenesis, a potentially LTP-associated process.
Neubauer, Nicole; Wohlleben, Wendel; Tomović, Željko
2017-03-01
Nanocomposites can be considered safe during their life cycle as long as the nanofillers remain embedded in the matrix. Therefore, a possible release of nanofillers has to be assessed before commercialization. This report addresses possible life cycle release scenarios for carbon nanotubes (CNT), graphene, and carbon black (CB) from a thermoplastic polyurethane (TPU) matrix. The content of each nanofiller was adjusted to achieve the same conductivity level. The nanofillers reduced the rate of nanoscale releases during mechanical processing with decreasing release in the order neat TPU, TPU-CNT, TPU-graphene, and TPU-CB. Released fragments were dominated by the polymer matrix with embedded or surface-protruding nanofillers. During electron microscopy analysis, free CB was observed, however, there was no free CNT or graphene. Quantitatively, the presence of free nanofillers remained below the detection limit of drilled materials. Due to its optimal performance for further development, extruded TPU-CNT was investigated in a combined, stepwise worst case scenario (mechanical processing after weathering). After weathering by simulated sunlight and rain, CNT were visible at the surface of the nanocomposite; after additional sanding, fragments showed protruding CNT, but free CNT were not detected. In summary, this preliminary exposure assessment showed no indication that recommended occupational exposure limits for carbonaceous nanomaterials can be exceeded during the life cycle of the specific TPU nanocomposites and conditions investigated in this study.
Studies in Optimal Configuration of the LTP
McKinney, Wayne R.; Anders, Mark; Barber, Samuel K.; Domning, Edward E.; Lou, Yunian; Morrison, Gregory Y.; Salmassi, Farhad; Smith, Brian V.; Yashchuk, Valeriy V.
2010-08-10
Brightness preservation requirements for ever brighter synchrotron radiation and free electron laser beamlines require surface slope tolerances of x-ray optics on the order of 0.2 mu rad, or better. Hence, the accuracy of dedicated surface slope metrology must be 0.1 mu rad, or even less. Achieving this level of measurement accuracy with the flagship instrument at synchrotron radiation metrology laboratories, the Long Trace Profiler (LTP), requires all significant sources of systematic, random, and instrumental drift errors to be identified, and reduced or eliminated. In this respect, the performance of certain components of the Advanced Light Source LTP-II design [Kirschman, et al., Proc. SPIE, 7077, 70770A-12 (2008)] is analyzed, considering the principal justification for inclusion of each component, possible systematic error due to the quality of its optical material, and drift effects due to generated heat, etc. We investigate the effects of replacement of the existing diode laser with a fiber-coupled laser light source, and demonstrate that reducing the number of components by using a single beam on the surface under test (SUT), rather than an original double beam maintains, or even improves the accuracy of measurement with our LTP. Based on the performance of the upgraded LTP, we trace the further steps for improving of the LTP optical system.
LTP Induction Modifies Functional Relationship among Hippocampal Neurons
Yun, Sung H.; Lee, Deok S.; Lee, Hyunjung; Baeg, Eun H.; Kim, Yun B.; Jung, Min W.
2007-01-01
To obtain evidence linking long-term potentiation (LTP) and memory, we examined whether LTP induction modifies functional relationship among neurons in the rat hippocampus. In contrast to neurons in low-frequency stimulated or AP5-treated slices, LTP induction altered "functional connectivity," as defined by the degree of synchronous firing, among…
Éltes, Tímea; Kirizs, Tekla; Nusser, Zoltan; Holderith, Noemi
2017-02-15
Target cell type-dependent differences in presynaptic release probability (Pr ) and short-term plasticity are intriguing features of cortical microcircuits that increase the computational power of neuronal networks. Here, we tested the hypothesis that different voltage-gated Ca(2+) channel densities in presynaptic active zones (AZs) underlie different Pr values. Two-photon Ca(2+) imaging, triple immunofluorescent labeling, and 3D electron microscopic (EM) reconstruction of rat CA3 pyramidal cell axon terminals revealed ∼1.7-1.9 times higher Ca(2+) inflow per AZ area in high Pr boutons synapsing onto parvalbumin-positive interneurons (INs) than in low Pr boutons synapsing onto mGluR1α-positive INs. EM replica immunogold labeling, however, demonstrated only 1.15 times larger Cav2.1 and Cav2.2 subunit densities in high Pr AZs. Our results indicate target cell type-specific modulation of voltage-gated Ca(2+) channel function or different subunit composition as possible mechanisms underlying the functional differences. In addition, high Pr synapses are also characterized by a higher density of docked vesicles, suggesting that a concerted action of these mechanisms underlies the functional differences.SIGNIFICANCE STATEMENT Target cell type-dependent variability in presynaptic properties is an intriguing feature of cortical synapses. When a single cortical pyramidal cell establishes a synapse onto a somatostatin-expressing interneuron (IN), the synapse releases glutamate with low probability, whereas the next bouton of the same axon has high release probability when its postsynaptic target is a parvalbumin-expressing IN. Here, we used combined molecular, imaging, and anatomical approaches to investigate the mechanisms underlying these differences. Our functional experiments implied an approximately twofold larger Ca(2+) channel density in high release probability boutons, whereas freeze-fracture immunolocalization demonstrated only a 15% difference in Ca(2+) channel
Luo, Fei; Guo, Nan-Nan; Li, Si-Hai; Tang, Hua; Liu, Ying; Zhang, Yu
2014-08-01
The prefrontal cortex (PFC) plays a critical role in cognitive functions, including working memory, attention regulation and behavioral inhibition. Microinjection of β1-adrenoceptor (β1-AR) agonist into the PFC has been shown to impair PFC cognitive function. However, the underlying cellular and molecular mechanisms have not been determined yet. In the present study, we tested the hypothesis that β1-AR mediated modulation of excitatory synaptic transmission contributes to PFC dysfunction. We found that 1) the β1-AR agonist Dobutamine (Dobu) suppressed the amplitude evoked excitatory postsynaptic currents (eEPSCs). 2) Dobu induced a significant suppression of the frequency and amplitude of miniature EPSCs (mEPSCs). 3) Dobu-suppressed glutamate release was mediated via decreasing release probability and the number of releasable vesicles. 4) Dobu suppressed inward currents evoked by puff application of glutamate or NMDA via postsynaptic PKA-dependent pathway. The present study indicates that β1-AR activation suppresses excitatory synaptic transmission in medial PFC (mPFC) via both pre- and post-synaptic PKA-dependent mechanisms. Our results may provide a cellular and molecular mechanism that helps explain β1-AR-induced PFC dysfunction.
Müller, Martin; Genç, Özgür; Davis, Graeme W
2015-03-04
Here we define activities of RIM-binding protein (RBP) that are essential for baseline neurotransmission and presynaptic homeostatic plasticity. At baseline, rbp mutants have a ∼10-fold decrease in the apparent Ca(2+) sensitivity of release that we attribute to (1) impaired presynaptic Ca(2+) influx, (2) looser coupling of vesicles to Ca(2+) influx, and (3) limited access to the readily releasable vesicle pool (RRP). During homeostatic plasticity, RBP is necessary for the potentiation of Ca(2+) influx and the expansion of the RRP. Remarkably, rbp mutants also reveal a rate-limiting stage required for the replenishment of high release probability (p) vesicles following vesicle depletion. This rate slows ∼4-fold at baseline and nearly 7-fold during homeostatic signaling in rbp. These effects are independent of altered Ca(2+) influx and RRP size. We propose that RBP stabilizes synaptic efficacy and homeostatic plasticity through coordinated control of presynaptic Ca(2+) influx and the dynamics of a high-p vesicle pool.
LTP data analysis software and infrastructure
Nofrarias Serra, Miquel
The LTP (LISA Technology Package) is the core part of the LISA Pathfinder mission. The main goal of the mission is to study the sources of any disturbances that perturb the motion of the freely-falling test masses from their geodesic trajectories as well as to test various technologies needed for LISA. The LTP experiment is designed as a sequence of experimental runs in which the performance of the instrument is studied and characterised under different operating conditions. In order to best optimise subsequent experimental runs, each run must be promptly analysed to ensure that the following ones make best use of the available knowledge of the instrument. In order to do this, a robust and flexible data analysis software package is required. The software developed for the LTP Data Analysis is a comprehensive data analysis tool based on MATLAB. The environment provides an object-oriented approach to data analysis which allows the user to design and run data analysis pipelines, either graphically or via scripts. The output objects of the analyses contain a full history of the processing that took place; this history tree can be inspected and used to rebuild the objects. This poster introduces the analysis environment and the concepts that have gone in to its design.
Ghane, Alireza; Mazaheri, Mehdi; Mohammad Vali Samani, Jamal
2016-09-15
The pollution of rivers due to accidental spills is a major threat to environment and human health. To protect river systems from accidental spills, it is essential to introduce a reliable tool for identification process. Backward Probability Method (BPM) is one of the most recommended tools that is able to introduce information related to the prior location and the release time of the pollution. This method was originally developed and employed in groundwater pollution source identification problems. One of the objectives of this study is to apply this method in identifying the pollution source location and release time in surface waters, mainly in rivers. To accomplish this task, a numerical model is developed based on the adjoint analysis. Then the developed model is verified using analytical solution and some real data. The second objective of this study is to extend the method to pollution source identification in river networks. In this regard, a hypothetical test case is considered. In the later simulations, all of the suspected points are identified, using only one backward simulation. The results demonstrated that all suspected points, determined by the BPM could be a possible pollution source. The proposed approach is accurate and computationally efficient and does not need any simplification in river geometry and flow. Due to this simplicity, it is highly recommended for practical purposes. Copyright © 2016. Published by Elsevier Ltd.
Effects of calcineurin on LTP of rats in vivo
无
2002-01-01
Calcineurin (CN) is thought to play a role in the synaptic plastivity and long-term potentiation (LTP) in the hippocampus. Based on two LTP models in vivo, a specific inhibitor cyclosporin A (CsA) of CN was observed, which affected LTP in the hippocampal dentate gyrus of the rats. The results indicated that CsA blocked LTP induced by high frequency stimulation (HFS) partly, but it had no effect on the decrease of the onset and peak latency of population spikes (PS) except that it reduced the increase of the amplitude after HFS. On the other hand, CsA blocked LTP induced by ginsenosides (GSS) completely. It suppressed the GSS-enhanced amplitude of PS reversibly and blocked the decrease of the peak latency of PS induced by the GSS. These results suggest that the postsynaptic CN plays a role in the induction of LTP in the hippocampus of the rats.
Wang, Shouping; Kurada, Lalitha; Cilz, Nicholas I; Chen, Xiaotong; Xiao, Zhaoyang; Dong, Hailong; Lei, Saobo
2013-01-01
Adenosine is an inhibitory neuromodulator that exerts antiepileptic effects in the brain and the entorhinal cortex (EC) is an essential structure involved in temporal lobe epilepsy. Whereas microinjection of adenosine into the EC has been shown to exert powerful antiepileptic effects, the underlying cellular and molecular mechanisms in the EC have not been determined yet. We tested the hypothesis that adenosine-mediated modulation of synaptic transmission contributes to its antiepileptic effects in the EC. Our results demonstrate that adenosine reversibly inhibited glutamatergic transmission via activation of adenosine A1 receptors without effects on GABAergic transmission in layer III pyramidal neurons in the EC. Adenosine-induced depression of glutamatergic transmission was mediated by inhibiting presynaptic glutamate release probability and decreasing the number of readily releasable vesicles. Bath application of adenosine also reduced the frequency of the miniature EPSCs recorded in the presence of TTX suggesting that adenosine may interact with the exocytosis processes downstream of Ca(2+) influx. Both Gαi/o proteins and the protein kinase A pathway were required for adenosine-induced depression of glutamatergic transmission. We further showed that bath application of picrotoxin to the EC slices induced stable epileptiform activity and bath application of adenosine dose-dependently inhibited the epileptiform activity in this seizure model. Adenosine-mediated depression of epileptiform activity was mediated by activation of adenosine A1 receptors and required the functions of Gαi/o proteins and protein kinase A pathway. Our results suggest that the depression of glutamatergic transmission induced by adenosine contributes to its antiepileptic effects in the EC.
Shouping Wang
Full Text Available Adenosine is an inhibitory neuromodulator that exerts antiepileptic effects in the brain and the entorhinal cortex (EC is an essential structure involved in temporal lobe epilepsy. Whereas microinjection of adenosine into the EC has been shown to exert powerful antiepileptic effects, the underlying cellular and molecular mechanisms in the EC have not been determined yet. We tested the hypothesis that adenosine-mediated modulation of synaptic transmission contributes to its antiepileptic effects in the EC. Our results demonstrate that adenosine reversibly inhibited glutamatergic transmission via activation of adenosine A1 receptors without effects on GABAergic transmission in layer III pyramidal neurons in the EC. Adenosine-induced depression of glutamatergic transmission was mediated by inhibiting presynaptic glutamate release probability and decreasing the number of readily releasable vesicles. Bath application of adenosine also reduced the frequency of the miniature EPSCs recorded in the presence of TTX suggesting that adenosine may interact with the exocytosis processes downstream of Ca(2+ influx. Both Gαi/o proteins and the protein kinase A pathway were required for adenosine-induced depression of glutamatergic transmission. We further showed that bath application of picrotoxin to the EC slices induced stable epileptiform activity and bath application of adenosine dose-dependently inhibited the epileptiform activity in this seizure model. Adenosine-mediated depression of epileptiform activity was mediated by activation of adenosine A1 receptors and required the functions of Gαi/o proteins and protein kinase A pathway. Our results suggest that the depression of glutamatergic transmission induced by adenosine contributes to its antiepileptic effects in the EC.
Buhler, Sofie; Tedeschi, Tullia; Faccini, Andrea; Garino, Cristiano; Arlorio, Marco; Dossena, Arnaldo; Sforza, Stefano
2015-01-01
Non-specific lipid transfer proteins (nsLTP) were shown to be among the most significant allergens, in particular in several fruits belonging to the Rosaceae family. The molecular features of LTPs, such as the presence of eight cysteine residues forming four disulfide bridges, confer a compact structure, decreasing the probability of degradation due to cooking or digestion, thereby increasing the chance of systemic absorption and severe allergic reactions. Few studies on LTP-induced allergies regarding almond (Prunus dulcis L) are available in the literature. In the present work, we describe for the first time the extraction and purification of an almond LTP, achieving its full characterisation by using liquid chromatography and exact mass spectrometry; the full sequence was identified by means of LC-ESI-Orbitrap-MS applying a bottom-up approach. The characterised protein consists of 92 amino acids and has a calculated exact MW of 9579.0. The presence of four disulfide bridges was confirmed after reduction, as shown by a mass increment of 8 Da. Finally, its potential allergenicity was confirmed via an in silico approach. The results presented here demonstrate the enormous potential of advanced MS techniques for obtaining high-quality structural and functional data of allergenic proteins in a short time.
The Cdk5 Inhibitor Roscovitine Increases LTP Induction in Corticostriatal Synapses
Jorge Miranda-Barrientos
2014-02-01
Full Text Available In corticostriatal synapses, LTD (long-term depression and LTP (long-term potentiation are modulated by the activation of DA (dopamine receptors, with LTD being the most common type of long-term plasticity induced using the standard stimulation protocols. In particular, activation of the D1 signaling pathway increases cAMP/PKA (protein kinase A phosphorylation activity and promotes an increase in the amplitude of glutamatergic corticostriatal synapses. However, if the Cdk5 (cyclin-dependent kinase 5 phosphorylates the DARPP-32 (dopamine and cAMP-regulated phosphoprotein of 32 kDa at Thr75, DARPP-32 becomes a strong inhibitor of PKA activity. Roscovitine is a potent Cdk5 inhibitor; it has been previously shown that acute application of Roscovitine increases striatal transmission via Cdk5/DARPP-32. Since DARPP-32 controls long-term plasticity in the striatum, we wondered whether switching off CdK5 activity with Roscovitine contributes to the induction of LTP in corticostriatal synapses. For this purpose, excitatory population spikes and whole cell EPSC (excitatory postsynaptic currents were recorded in striatal slices from C57/BL6 mice. Experiments were carried out in the presence of Roscovitine (20 μM in the recording bath. Roscovitine increased the amplitude of excitatory population spikes and the percentage of population spikes that exhibited LTP after HFS (high-frequency stimulation; 100Hz. Results obtained showed that the mechanisms responsible for LTP induction after Cdk5 inhibition involved the PKA pathway, DA and NMDA (N-methyl-D-aspartate receptor activation, L-type calcium channels activation and the presynaptic modulation of neurotransmitter release.
The Cdk5 inhibitor Roscovitine increases LTP induction in corticostriatal synapses.
Miranda-Barrientos, Jorge; Nieto-Mendoza, Elizabeth; Hernández-Echeagaray, Elizabeth
2014-03-19
In corticostriatal synapses, LTD (long-term depression) and LTP (long-term potentiation) are modulated by the activation of DA (dopamine) receptors, with LTD being the most common type of long-term plasticity induced using the standard stimulation protocols. In particular, activation of the D1 signaling pathway increases cAMP/PKA (protein kinase A) phosphorylation activity and promotes an increase in the amplitude of glutamatergic corticostriatal synapses. However, if the Cdk5 (cyclin-dependent kinase 5) phosphorylates the DARPP-32 (dopamine and cAMP-regulated phosphoprotein of 32 kDa) at Thr75, DARPP-32 becomes a strong inhibitor of PKA activity. Roscovitine is a potent Cdk5 inhibitor; it has been previously shown that acute application of Roscovitine increases striatal transmission via Cdk5/DARPP-32. Since DARPP-32 controls long-term plasticity in the striatum, we wondered whether switching off CdK5 activity with Roscovitine contributes to the induction of LTP in corticostriatal synapses. For this purpose, excitatory population spikes and whole cell EPSC (excitatory postsynaptic currents) were recorded in striatal slices from C57/BL6 mice. Experiments were carried out in the presence of Roscovitine (20 μM) in the recording bath. Roscovitine increased the amplitude of excitatory population spikes and the percentage of population spikes that exhibited LTP after HFS (high-frequency stimulation; 100Hz). Results obtained showed that the mechanisms responsible for LTP induction after Cdk5 inhibition involved the PKA pathway, DA and NMDA (N-methyl-D-aspartate) receptor activation, L-type calcium channels activation and the presynaptic modulation of neurotransmitter release.
The Cdk5 inhibitor Roscovitine increases LTP induction in corticostriatal synapses
Jorge Miranda‑Barrientos
2014-03-01
Full Text Available In corticostriatal synapses, LTD (long-term depression and LTP (long-term potentiation are modulated by the activation of DA (dopamine receptors, with LTD being the most common type of long-term plasticity induced using the standard stimulation protocols. In particular, activation of the D1 signaling pathway increases cAMP/PKA (protein kinase A phosphorylation activity and promotes an increase in the amplitude of glutamatergic corticostriatal synapses. However, if the Cdk5 (cyclin-dependent kinase 5 phosphorylates the DARPP-32 (dopamine and cAMP-regulated phosphoprotein of 32 kDa at Thr75, DARPP-32 becomes a strong inhibitor of PKA activity. Roscovitine is a potent Cdk5 inhibitor; it has been previously shown that acute application of Roscovitine increases striatal transmission via Cdk5/DARPP-32. Since DARPP-32 controls long-term plasticity in the striatum, we wondered whether switching off CdK5 activity with Roscovitine contributes to the induction of LTP in corticostriatal synapses. For this purpose, excitatory population spikes and whole cell EPSC (excitatory postsynaptic currents were recorded in striatal slices from C57/BL6 mice. Experiments were carried out in the presence of Roscovitine (20 μM in the recording bath. Roscovitine increased the amplitude of excitatory population spikes and the percentage of population spikes that exhibited LTP after HFS (high-frequency stimulation; 100Hz. Results obtained showed that the mechanisms responsible for LTP induction after Cdk5 inhibition involved the PKA pathway, DA and NMDA (N-methyl-D-aspartate receptor activation, L-type calcium channels activation and the presynaptic modulation of neurotransmitter release.
Tierney, M.S.
1991-11-01
The Waste Isolation Pilot Plant (WIPP), in southeastern New Mexico, is a research and development facility to demonstrate safe disposal of defense-generated transuranic waste. The US Department of Energy will designate WIPP as a disposal facility if it meets the US Environmental Protection Agency's standard for disposal of such waste; the standard includes a requirement that estimates of cumulative releases of radioactivity to the accessible environment be incorporated in an overall probability distribution. The WIPP Project has chosen an approach to calculation of an overall probability distribution that employs the concept of scenarios for release and transport of radioactivity to the accessible environment. This report reviews the use of Monte Carlo methods in the calculation of an overall probability distribution and presents a logical and mathematical foundation for use of the scenario concept in such calculations. The report also draws preliminary conclusions regarding the shape of the probability distribution for the WIPP system; preliminary conclusions are based on the possible occurrence of three events and the presence of one feature: namely, the events attempted boreholes over rooms and drifts,'' mining alters ground-water regime,'' water-withdrawal wells provide alternate pathways,'' and the feature brine pocket below room or drift.'' Calculation of the WIPP systems's overall probability distributions for only five of sixteen possible scenario classes that can be obtained by combining the four postulated events or features.
CYLINDER LENS ALIGNMENT IN THE LTP
TAKACS, P.Z.
2005-07-26
The Long Trace Profiler (LTP), is well-suited for the measurement of the axial figure of cylindrical mirrors that usually have a long radius of curvature in the axial direction but have a short radius of curvature in the sagittal direction. The sagittal curvature causes the probe beam to diverge in the transverse direction without coming to a focus on the detector, resulting in a very weak signal. It is useful to place a cylinder lens into the optical system above the mirror under test to refocus the sagittal divergence and increase the signal level. A positive cylinder lens can be placed at two positions above the surface: the Cat's Eye reflection position and the Wavefront-Matching position. The Cat's Eye position, is very tolerant to mirror misalignment, which is not good if absolute axial radius of curvature is to be measured. Lateral positioning and rotational misalignments of lens and the mirror combine to produce unusual profile results. This paper looks at various alignment issues with measurements and by raytrace simulations to determine the best strategy to minimize radius of curvature errors in the measurement of cylindrical aspheres.
Song, Ming-Ke; Cui, Yong-Yao; Zhang, Wei-Wei; Zhu, Liang; Lu, Yang; Chen, Hong-Zhuan
2009-09-11
A large amount of in vitro studies demonstrate suppression of M-current in hippocampal neurons by Kv7/M channel blocker results in depolarization of membrane potential and release of neurotransmitters, such as acetylcholine and glutamate, suggesting that Kv7/M channel may play important roles in regulating synaptic plasticity. In the present study, we examined the in vivo effect of Kv7/M channel inhibition on the long-term potentiation (LTP) induction at basal dendrites in hippocampal CA1 area of urethane-anaesthetized rats. The Kv7/M channel was inhibited by intraperitoneal injection of XE991 (10mg/kg) and the LTP of field excitatory postsynaptic potential (fEPSP) was induced by supra-threshold high frequency stimulation (S1 HFS). A weak protocol which was just below the threshold for evoking LTP was used as sub-threshold high frequency stimulation (S2 HFS). XE991 did not significantly alter the slope of fEPSP and the magnitude of LTP induced by S1 HFS, suggesting that Kv7/M channel inhibition had little or no effect on glutamatergic transmission under basal conditions. However, XE991 could make S2 HFS evoke LTP even after the application of the muscarinic cholinergic (mACh) receptor antagonist scopolamine, suggesting that Kv7/M channel inhibition lowered the threshold for LTP induction and the effect was independent of muscarinic activation. Based on the above findings, we concluded that the facilitating effect of XE991 on LTP induction is not mediated by its ability to enhance the release of acetylcholine; therefore, Kv7/M channel blockers may provide a therapeutic benefit to cholinergic deficiency-related cognitive impairment, e.g., Alzheimer's disease.
Wang, Shouping; Chen, Xiaotong; Kurada, Lalitha; Huang, Zitong; Lei, Saobo
2012-03-01
Glutamate interacts with ionotropic and metabotropic glutamate receptors (mGluRs). Whereas the entorhinal cortex (EC) is a principal structure involved in learning and memory, the roles of mGluRs in synaptic transmission in the EC have not been completely determined. Here, we show that activation of group II mGluRs (mGluR II) induced robust depression of glutamatergic transmission in the EC. The mGluR II-induced depression was due to a selective reduction of presynaptic release probability without alterations of the quantal size and the number of release sites. The mechanisms underlying mGluR II-mediated suppression of glutamate release included the inhibition of presynaptic release machinery and the depression of presynaptic P/Q-type Ca(2+) channels. Whereas mGluR II-induced depression required the function of Gα(i/o) proteins, protein kinase A (PKA) pathway was only involved in mGluR II-mediated inhibition of release machinery and thereby partially required for mGluR II-induced inhibition of glutamate release. Presynaptic stimulation at 5 Hz for 10 min also induced depression of glutamatergic transmission via activation of presynaptic mGluR II suggesting an endogenous role for mGluR II in modulating glutamatergic transmission.
Nieuwoudt, Melanie; Lombard, Nicolaas; Rautenbach, Marina
2014-08-15
In beer brewing, brewers worldwide strive to obtain product consistency in terms of flavour, colour and foam. Important proteins contributing to beer foam are lipid transfer proteins (LTPs), in particular LTP1 and its lipid-bound isoform LTP1b, which are known to transport lipids in vivo and prevent lipids from destabilising the beer foam. LTP1 and LTP1b were successfully purified using only five purification steps with a high purified protein yield (160 mg LTP1 and LTP1b from 200 g barley). Circular dichroism of LTP1 and LTP1b confirmed that both proteins are highly tolerant to high temperatures (>90 °C) and are pH stable, particularly at a neutral to a more basic pH. Only LTP1 exhibited antiyeast and thermo-stable lytic activity, while LTP1b was inactive, indicating that the fatty acid moiety compromised the antimicrobial activity of LTP1. This lack in antiyeast activity and the positive foam properties of LTP1b would benefit beer fermentation and quality.
Ekinci, Ozalp; Gunes, Serkan; Ekinci, Nuran
2017-08-31
Galactorrhea, as an adverse effect of psychotropic medications, usually develops due to high dose of antipsychotics. Selective serotonin reuptake inhibitors (SSRIs) have also been reported to be related to galactorrhea. To the best of our knowledge, no previous study reported galactorrhea with methylphenidate (MPH) use. Hereby, we report a case of an adolescent girl who developed galactorrhea after increasing his modifed-release oral MPH to 50 mg/day while under treatment of sertraline and very low dose haloperidol.
Application of Electrostatic Probe in Wool Fabric LTP Finishing
Chen, Ying; Liu, Binghong
2009-12-01
By using a double electron probe the electron density and electron temperature were measured during the low temperature plasma (LTP) treatment of wool fabrics. The dependences of the electron density upon the power, pressure and the plasma-treating time was studied. The effects on the wool fabrics' shrinkage were studied. The results showed that the angle of the double electrostatic probe and the area of the treated fabrics had a strong impact on the density measurement. The felt-proof property of wool fabrics treated with an argon plasma was better than that with a nitrogen plasma. The gas, power and pressure of the LTP treatment all affected the electron density. The electron density increased with the increase in power and pressure. The electron density did not change significantly with treating time, in a certain range of both power and pressure of the LTP treatment.
Aguiar, Lais A.; Melo, P.F. Frutuoso e [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear]. E-mail: lais@con.ufrj.br; frutuoso@con.ufrj.br; Passos, Erivaldo; Alves, Antonio Sergio [ELETRONUCLEAR, Rio de Janeiro, RJ (Brazil). Div. de Seguranca Nuclear]. E-mail: epassos@eletronuclear.gov.br; asergi@eletronuclear.gov.br
2005-07-01
The safety analysis of a near surface repository for medium and low activity wastes leads to investigating accident scenarios related to water infiltration phenomena. The probability of radionuclide release through the infiltration water could be estimated with the aid of suitable probabilistic models. For the analysis, the repository system is divided into two subsystems: the first, due to the barriers against the water infiltration (backfill material and container), and the second one comprising the barriers against the leaching of radionuclide to the biosphere (solid matrix and geosphere). The repository system is supposed to have its components (barriers) working in an active parallel mode. The probability of the system failure is obtained from the logical structure of a failure tree. The study was based on the Probabilistic Safety Assessment (PSA) technique for the most significant radionuclides within the radioactive packages system of low and medium activity, and so the probability of failure of the system for each radionuclide during the time period of institutional control was obtained. (author)
Ryabchikova, T [Institute of Astronomy RAS, Moscow (Russian Federation); Kildiyarova, R [Institute of Spectroscopy RAS, Troitsk (Russian Federation); Piskunov, N; Heiter, U [Department of Astronomy and Space Physics, Uppsala University, Uppsala (Sweden); Fossati, L; Weiss, W W [Department of Astronomy, Vienna University, Vienna (Austria)], E-mail: ryabchik@inasan.ru
2008-10-15
We carried out a comparative analysis of the recent atomic data for iron-peak elements, mainly Ti, Cr and Fe, for a new release of the Vienna Atomic Line Database (VALD3). New data were compared with those available in VALD2 and were checked using high-resolution, high signal-to-noise spectra of sharp-lined chemically normal stars including the Sun, and the zero-rotation extremely Cr- and Fe-rich chemically peculiar star HD 133792. The observed spectrum of the latter star allowed for comparison with transition probability calculations based on the orthogonal operator technique with the Cowan code for Cr II and Fe II lines for lower level energies between 2 eV and 11 eV in the wavelength region 3100 to 9000 A. In general, the agreement between the new experimental transition probabilities and those currently available in VALD2 is fairly good, which helps to validate the stellar abundance data derived with the VALD2 atomic parameters. We also found that, for a few important Ti II and Fe II lines in the visible spectral region, new transition probabilities are not consistent within their quoted accuracy. In a series of recent works on experimental f-values for Fe II it was shown that calculations based on the orthogonal operator technique agree better with the experimental data than the Cowan code calculations and, hence, should have preference for stellar spectroscopy. Our analysis of the Ap star HD 133792 spectrum clearly demonstrates that there are quite a number of high-excitation Cr II and Fe II lines which are fitted reasonably well when using the transition probabilities calculated with the Cowan code. As a rule these lines have their upper energy levels classified differently in both methods of calculations.
Vignoli, Beatrice; Battistini, Giulia; Melani, Riccardo; Blum, Robert; Santi, Spartaco; Berardi, Nicoletta; Canossa, Marco
2016-11-23
Glial cells respond to neuronal activation and release neuroactive molecules (termed "gliotransmitters") that can affect synaptic activity and modulate plasticity. In this study, we used molecular genetic tools, ultra-structural microscopy, and electrophysiology to assess the role of brain-derived neurotrophic factor (BDNF) on cortical gliotransmission in vivo. We find that glial cells recycle BDNF that was previously secreted by neurons as pro-neurotrophin following long-term potentiation (LTP)-inducing electrical stimulation. Upon BDNF glial recycling, we observed tight, temporal, highly localized TrkB phosphorylation on adjacent neurons, a process required to sustain LTP. Engagement of BDNF recycling by astrocytes represents a novel mechanism by which cortical synapses can expand BDNF action and provide synaptic changes that are relevant for the acquisition of new memories. Accordingly, mice deficient in BDNF glial recycling fail to recognize familiar from novel objects, indicating a physiological requirement for this process in memory consolidation. Copyright © 2016 Elsevier Inc. All rights reserved.
Assessment of Lipid Transfer Protein (LTP1) Gene in Wheat Powdery Mildew Resistance
LI Ai-li; MENG Cheng-sheng; ZHOU Rong-hua; MA Zhi-ying; JIA Ji-zeng
2006-01-01
This study is to investigate the role of lipid transfer protein (LTP1) gene of wheat (Triticum aestivum L.) in powdery mildew (Blumeria graminis f. sp. tritici, Bgt) resistance. A pair of primers based on the full length cDNA of wheat LTP1was used for amplifying the coding regions of LTP in hexaploid (AABBDD) wheat and its diploid donors T. urartu (AA),Ae. speltoides ssp speltoide (SS) and Ae. tauchii ssp strangulate (DD). LTP1 and LTP2 of wheat were isolated from the tested two hexaploid (ABD) materials: powdery mildew resistance near isogenic line (NIL) Mardler/7 x B ainong 3217 and its susceptible parent Bainong 3217 at the same time, while only one kind of LTP gene was found in the tested three diploid materials respectively by using the above PCR primer pairs. Two peaks of the expression of LTP1 and LTP2 induced by powdery mildew were observed [one occurred at 3 h after inoculation (hai); the other occurred at 10 hai] in resistant NIL Mardler/7 x Bainong3217 in comparison with a steady transcript level of LTP1 and LTP2 in susceptible Bainong3217.Transient over-expression result showed that LTP1 reduced the penetration efficiency (PE) of powdery mildew in susceptible cultivar by about 28.3%. This result indicated an obvious effectiveness of LTP1 in powdery mildew resistance. Expression analysis also showed that LTP1 and LTP2 of wheat are generally involved in salt/drought, but not in low temperature stress early responses.
Navakkode, Sheeja; Sajikumar, Sreedharan; Korte, Martin; Soong, Tuck Wah
2012-01-01
The dopaminergic modulation of long-term potentiation (LTP) has been studied well, but the mechanism by which dopamine induces LTP (DA-LTP) in CA1 pyramidal neurons is unknown. Here, we report that DA-LTP in basal dendrites is dependent while in apical dendrites it is independent of activation of L-type voltage-gated calcium channels (VDCC).…
Navakkode, Sheeja; Sajikumar, Sreedharan; Korte, Martin; Soong, Tuck Wah
2012-01-01
The dopaminergic modulation of long-term potentiation (LTP) has been studied well, but the mechanism by which dopamine induces LTP (DA-LTP) in CA1 pyramidal neurons is unknown. Here, we report that DA-LTP in basal dendrites is dependent while in apical dendrites it is independent of activation of L-type voltage-gated calcium channels (VDCC).…
Sajikumar, Sreedharan; Navakkode, Sheeja; Frey, Julietta U.
2008-01-01
The protein synthesis-dependent form of hippocampal long-term potentiation (late-LTP) is thought to underlie memory. Its induction requires a distinct stimulation strength, and the common opinion is that only repeated tetani result in late-LTP whereas as single tetanus only reveals a transient early-LTP. Properties of LTP induction were compared…
Takeda, Atsushi; Tamano, Haruna; Murakami, Taku; Nakada, Hiroyuki; Minamino, Tatsuya; Koike, Yuta
2017-05-25
Memory is lost by the increased influx of extracellular Zn(2+) into neurons. It is possible that intracellular Zn(2+) dynamics is modified even at non-zincergic medial perforant pathway-dentate granule cell synapses along with aging and that vulnerability to the modification is linked to age-related cognitive decline. To examine these possibilities, vulnerability of long-term potentiation (LTP) maintenance, which underlies memory retention, to modification of synaptic Zn(2+) dynamics was compared between young and aged rats. The influx of extracellular Zn(2+) into dentate granule cells was increased in aged rats after injection of high K(+) into the dentate gyrus, but not in young rats. This increase impaired maintained LTP in aged rats. However, the impairment was rescued by co-injection of CaEDTA, an extracellular Zn(2+) chelator, or CNQX, an AMPA receptor antagonist, which suppressed the Zn(2+) influx. Maintained LTP was also impaired in aged rats after injection of ZnAF-2DA into the dentate gyrus that chelates intracellular Zn(2+), but not in young rats. Interestingly, the capacity of chelating intracellular Zn(2+) with intracellular ZnAF-2 was almost lost in the aged dentate gyrus 2 h after injection of ZnAF-2DA into the dentate gyrus, suggesting that intracellular Zn(2+)-buffering is weakened in the aged dentate gyrus, compared to the young dentate gyrus. In the dentate gyrus of aged rats, maintained LTP is more vulnerable to modification of intracellular Zn(2+) dynamics than in young rats, probably due to weakened intracellular Zn(2+)-buffering.
Heater induced thermal effects on the LTP dynamics
Gibert, Ferran; Lobo, Alberto; Díaz-Aguiló, Marc; Mateos, Ignacio; Karnesis, Nikolaos; Sanjuán, Josep; Gesa, Lluís; lloro, Ivan; Martín, Víctor
2013-01-01
The STOC (Science and Technology Operations Centre) simulator of the LPF (LISA PathFinder) mission is intended to provide a validation tool for the mission operations tele-commanding chain, as well as for a deeper understanding of the underlying physical processes happening in the LTP (LISA Technology Package). Amongst the different physical effects that will appear onboard, temperature fluctuations in the Electrode Housing (EH) could generate disturbances on the interferometer (IFO) readouts, therefore they must be known and controlled. In this article we report on the latest progress in the analysis at IEEC of the LTP response to thermal signals injected by means of heaters. More specifically, we determine the transfer functions relating heat input signals to forces on the Test Masses (TMs) in the LTP frequency band, from 1 mHz to 30 mHz. A complete thermal model of the entire LPF spacecraft plus payload, elaborated and maintained at European Space Technology Center (ESTEC), was used to obtain temperature d...
Vasopressin inhibits LTP in the CA2 mouse hippocampal area.
Magda Chafai
Full Text Available Growing evidence points to vasopressin (AVP as a social behavior regulator modulating various memory processes and involved in pathologies such as mood disorders, anxiety and depression. Accordingly, AVP antagonists are actually envisaged as putative treatments. However, the underlying mechanisms are poorly characterized, in particular the influence of AVP on cellular or synaptic activities in limbic brain areas involved in social behavior. In the present study, we investigated AVP action on the synapse between the entorhinal cortex and CA2 hippocampal pyramidal neurons, by using both field potential and whole-cell recordings in mice brain acute slices. Short application (1 min of AVP transiently reduced the synaptic response, only following induction of long-term potentiation (LTP by high frequency stimulation (HFS of afferent fibers. The basal synaptic response, measured in the absence of HFS, was not affected. The Schaffer collateral-CA1 synapse was not affected by AVP, even after LTP, while the Schaffer collateral-CA2 synapse was inhibited. Although investigated only recently, this CA2 hippocampal area appears to have a distinctive circuitry and a peculiar role in controlling episodic memory. Accordingly, AVP action on LTP-increased synaptic responses in this limbic structure may contribute to the role of this neuropeptide in controlling memory and social behavior.
State-dependent mechanisms of LTP expression revealed by optical quantal analysis.
Ward, Bonnie; McGuinness, Lindsay; Akerman, Colin J; Fine, Alan; Bliss, Tim V P; Emptage, Nigel J
2006-11-22
The expression mechanism of long-term potentiation (LTP) remains controversial. Here we combine electrophysiology and Ca(2+) imaging to examine the role of silent synapses in LTP expression. Induction of LTP fails to change p(r) at these synapses but instead mediates an unmasking process that is sensitive to the inhibition of postsynaptic membrane fusion. Once unmasked, however, further potentiation of formerly silent synapses leads to an increase in p(r). The state of the synapse thus determines how LTP is expressed.
Capocchi, Antonella; Fontanini, Debora; Muccilli, Vera; Cunsolo, Vincenzo; Saviozzi, Franco; Saletti, Rosaria; Lorenzi, Roberto; Foti, Salvatore; Galleschi, Luciano
2005-10-05
Isoforms of nonspecific lipid-transfer protein 1 (nsLTP1) and nonspecific lipid-transfer protein 2 (nsLTP2) were investigated in bran tissues isolated from caryopses of two cereal crops quite relevant for the Italian market, the cultivar Centauro of soft wheat (Triticum aestivum) and Italian emmer or farro (Triticum dicoccon Schrank). By sequential separation of the bran extracts on cation-exchange and gel filtration chromatographies, fractions containing only proteins belonging to the nsLTP1 and nsLTP2 classes were obtained. The proteins were roughly identified by SDS-PAGE and by immunoreactions in Western blotting experiments. By MALDI-MS and RP-HPLC/ESI-MS analyses we were able to show the presence of several LTP1 and LTP2 isoforms in the investigated species. Bioinformatic searches based on the determined Mr indicated that (i) two nsLTP1s already identified in T. aestivum have Mr and number of Cys residues identical to that of a 9.6 kDa protein present both in soft wheat cv. Centauro and in farro; (ii) two isoforms of nsLTP2 detected in T. aestivum have the same Mr and number of Cys residues of two 7 kDa proteins found in Centauro; and (iii) a nsLTP1 detected in Ambrosia artemisiifolia has Mr and number of Cys residues coincident to that of a 9.9 kDa protein found both in soft wheat cv. Centauro and in farro.
Learning, memory and hippocampal LTP in genetically obese rodents
无
2001-01-01
We have found that leptin, at physiological concentrations of 10-12 mol/L, facilitates learning and memory and LTP maintenance in Wistar rats. To explore the role of leptin recepors in learning, memory and synaptic plasticity, experiments were carried out using Zucker rats (Z), db/db mice (db), and ob/ob mice(ob). The former two have defects in leptin receptors and the latter cannot produce normal leptin. Unlike the effects observed in normal rats, high or low frequency stimulation of Schaffer collateral-CA1 synapses in hippocampal slices prepared from Z, db and ob animals failed to induce the learning and memory relevant long-term potentiation or depression in CA1 neurons. However, LTP in ob CA1 synapses was facilitated by leptin at 10-12 mol/L concentration. Moreover, the paired-pulse facilitation of CA1 synaptic potentials and intracellularly recorded postsynaptic responses to the neurotransmitters AMPA, NMDA and GABA, applied electrophoretically to the apical dendrites of CA1 neurons, were approximately the same compared to the control lean animals. In addition, unlike the second messenger responses observed in Wistar rats, calmodulin kinase Ⅱ activity in the CA1 area of Z and db animals was not activated after tetanic stimulation of the Schaffer collaterals. It has been shown that all three strains, Z, db and ob display impaired spatial learning and memory when tested in the Morris water maze. The results of these experiments indicate a close relationship between spatial learning and memory, facilitation of LTP, and calmodulin kinase Ⅱ activity.
Cutin monomer induces expression of the rice OsLTP5 lipid transfer protein gene.
Kim, Tae Hyun; Park, Jong Ho; Kim, Moon Chul; Cho, Sung Ho
2008-01-01
Treatment with the cutin monomer 16-hydroxypalmitic acid (HPA), a major component of cutin, elicited the synthesis of hydrogen peroxide (H2O2) in rice leaves and induced the expression of the lipid transfer protein gene OsLTP5. Treatment with HPA also induced expression of OsLTP1, OsLTP2, and the pathogen-related PR-10 genes to a lesser extent. The OsLTP5 transcript was expressed prominently in stems and flowers, but was barely detectable in leaves. Expression of OsLTP5 was induced in shoots in response to ABA and salicylic acid. It is proposed that HPA is perceived by rice as a signal, inducing defense reactions.
A mathematical model for astrocytes mediated LTP at single hippocampal synapses.
Tewari, Shivendra; Majumdar, Kaushik
2012-10-01
Many contemporary studies have shown that astrocytes play a significant role in modulating both short and long form of synaptic plasticity. There are very few experimental models which elucidate the role of astrocyte over Long-term Potentiation (LTP). Recently, Perea and Araque (Science 317:1083-1086, 2007) demonstrated a role of astrocytes in induction of LTP at single hippocampal synapses. They suggested a purely pre-synaptic basis for induction of this N-methyl-D-Aspartate (NMDA) Receptor-independent LTP. Also, the mechanisms underlying this pre-synaptic induction were not investigated. Here, in this article, we propose a mathematical model for astrocyte modulated LTP which successfully imitates the experimental findings of Perea and Araque (Science 317:1083-1086, 2007). Our study suggests the role of retrograde messengers, possibly Nitric Oxide (NO), for this pre-synaptically modulated LTP.
Reymann, Klaus G; Frey, Julietta U
2007-01-01
Our review focuses on the mechanisms which enable the late maintenance of hippocampal long-term potentiation (LTP; >3h), a phenomenon which is thought to underlie prolonged memory. About 20 years ago we showed for the first time that the maintenance of LTP - like memory storage--depends on intact protein synthesis and thus, consists of at least two temporal phases. Here we concentrate on mechanisms required for the induction of the transient early-LTP and of the protein synthesis-dependent late-LTP. Our group has shown that the induction of late-LTP requires the associative activation of heterosynaptic inputs, i.e. the synergistic activation of glutamatergic and modulatory, reinforcing inputs within specific, effective time windows. The induction of late-LTP is characterized by novel, late-associative properties such as 'synaptic tagging' and 'late-associative reinforcement'. Both phenomena require the associative setting of synaptic tags as well as the availability of plasticity-related proteins (PRPs) and they are restricted to functional dendritic compartments, in general. 'Synaptic tagging' guarantees input specificity and thus the specific processing of afferent signals for the establishment of late-LTP. 'Late-associative reinforcement' describes a process where early-LTP by the co-activation of modulatory inputs can be transformed into late-LTP in activated synapses where a tag is set. Recent evidence from behavioral experiments, which studied processes of emotional and cognitive reinforcement of LTP, point to the physiological relevance of the above mechanisms during cellular and system's memory formation.
Nakauchi, Sakura; Malvaez, Melissa; Su, Hailing; Kleeman, Elise; Dang, Richard; Wood, Marcelo A; Sumikawa, Katumi
2015-02-01
Fetal nicotine exposure from smoking during pregnancy causes long-lasting cognitive impairments in offspring, yet little is known about the mechanisms that underlie this effect. Here we demonstrate that early postnatal exposure of mouse pups to nicotine via maternal milk impairs long-term, but not short-term, hippocampus-dependent memory during adolescence. At the Schaffer collateral (SC) pathway, the most widely studied synapses for a cellular correlate of hippocampus-dependent memory, the induction of N-methyl-D-aspartate receptor-dependent transient long-term potentiation (LTP) and protein synthesis-dependent long-lasting LTP are not diminished by nicotine exposure, but rather unexpectedly the threshold for LTP induction becomes lower after nicotine treatment. Using voltage sensitive dye to visualize hippocampal activity, we found that early postnatal nicotine exposure also results in enhanced CA1 depolarization and hyperpolarization after SC stimulation. Furthermore, we show that postnatal nicotine exposure induces pervasive changes to the nicotinic modulation of CA1 activity: activation of nicotinic receptors no longer increases CA1 network depolarization, acute nicotine inhibits rather than facilitates the induction of LTP at the SC pathway by recruiting an additional nicotinic receptor subtype, and acute nicotine no longer blocks LTP induction at the temporoammonic pathway. These findings reflect the pervasive impact of nicotine exposure during hippocampal development, and demonstrate an association of hippocampal memory impairments with altered nicotinic cholinergic modulation of LTP, but not impaired LTP. The implication of our results is that nicotinic cholinergic-dependent plasticity is required for long-term memory formation and that postnatal nicotine exposure disrupts this form of plasticity.
Míriam Rodríguez-Vázquez
2015-06-01
Full Text Available Lipophorin, the main Drosophila lipoprotein, circulates in the hemolymph transporting lipids between organs following routes that must adapt to changing physiological requirements. Lipophorin receptors expressed in developmentally dynamic patterns in tissues such as imaginal discs, oenocytes and ovaries control the timing and tissular distribution of lipid uptake. Using an affinity purification strategy, we identified a novel ligand for the lipophorin receptors, the circulating lipoprotein Lipid Transfer Particle (LTP. We show that specific isoforms of the lipophorin receptors mediate the extracellular accumulation of LTP in imaginal discs and ovaries. The interaction requires the LA-1 module in the lipophorin receptors and is strengthened by a contiguous region of 16 conserved amino acids. Lipophorin receptor variants that do not interact with LTP cannot mediate lipid uptake, revealing an essential role of LTP in the process. In addition, we show that lipophorin associates with the lipophorin receptors and with the extracellular matrix through weak interactions. However, during lipophorin receptor-mediated lipid uptake, LTP is required for a transient stabilization of lipophorin in the basolateral plasma membrane of imaginal disc cells. Together, our data suggests a molecular mechanism by which the lipophorin receptors tether LTP to the plasma membrane in lipid acceptor tissues. LTP would interact with lipophorin particles adsorbed to the extracellular matrix and with the plasma membrane, catalyzing the exchange of lipids between them.
Duffy, S N; Craddock, K J; Abel, T; Nguyen, P V
2001-01-01
cAMP-dependent protein kinase (PKA) is critical for the expression of some forms of long-term potentiation (LTP) in area CA1 of the mouse hippocampus and for hippocampus-dependent memory. Exposure to spatially enriched environments can modify LTP and improve behavioral memory in rodents, but the molecular bases for the enhanced memory performance seen in enriched animals are undefined. We tested the hypothesis that exposure to a spatially enriched environment may alter the PKA dependence of hippocampal LTP. Hippocampal slices from enriched mice showed enhanced LTP following a single burst of 100-Hz stimulation in the Schaffer collateral pathway of area CA1. In slices from nonenriched mice, this single-burst form of LTP was less robust and was unaffected by Rp-cAMPS, an inhibitor of PKA. In contrast, the enhanced LTP in enriched mice was attenuated by Rp-cAMPS. Enriched slices expressed greater forskolin-induced, cAMP-dependent synaptic facilitation than did slices from nonenriched mice. Enriched mice showed improved memory for contextual fear conditioning, whereas memory for cued fear conditioning was unaffected following enrichment. Our data indicate that exposure of mice to spatial enrichment alters the PKA dependence of LTP and enhances one type of hippocampus-dependent memory. Environmental enrichment can transform the pharmacological profile of hippocampal LTP, possibly by altering the threshold for activity-dependent recruitment of the cAMP-PKA signaling pathway following electrical and chemical stimulation. We suggest that experience-dependent plasticity of the PKA dependence of hippocampal LTP may be important for regulating the efficacy of hippocampus-based memory.
Alkadhi, Karim A; Tran, Trinh T
2014-11-07
The CA1 and dentate gyrus regions of the hippocampus are physically and functionally closely related but they react differently to insults. This study examined the effect of chronic psychosocial stress on the dentate gyrus of an at-risk (preclinical) rat model of Alzheimer's disease (subAβ rats). Chronic psychosocial stress was produced using a rat intruder model. The at-risk rat model of Alzheimer's disease was created by osmotic pump infusion of sub-pathological dose of Aβ (160 pmol Aβ1-42/day i.c.v) for 14 days. Electrophysiological methods were used to evoke and record early and late phase LTP in the dentate gyrus of anesthetized rats, and immunoblotting was used to measure levels of memory-related signaling molecules in the same region. Electrophysiological and molecular tests in the dentate gyrus showed that subAβ rats or stressed rats were not different from control rats. However, when the subAβ rats were chronically stressed, the combined treatments severely suppressed early phase LTP without affecting the late phase LTP of dentate gyrus. Additionally, in the chronically stressed subAβ rats the expected elevation of levels of phosphorylated CaMKII did not materialize after expression of early phase LTP suggesting impaired phosphorylation, which may explain the severely blocked early phase LTP. Copyright © 2014 Elsevier B.V. All rights reserved.
Augmenting LTP-Like Plasticity in Human Motor Cortex by Spaced Paired Associative Stimulation.
Florian Müller-Dahlhaus
Full Text Available Paired associative stimulation (PASLTP of the human primary motor cortex (M1 can induce LTP-like plasticity by increasing corticospinal excitability beyond the stimulation period. Previous studies showed that two consecutive PASLTP protocols interact by homeostatic metaplasticity, but animal experiments provided evidence that LTP can be augmented by repeated stimulation protocols spaced by ~30 min. Here we tested in twelve healthy selected PASLTP responders the possibility that LTP-like plasticity can be augmented in the human M1 by systematically varying the interval between two consecutive PASLTP protocols. The first PASLTP protocol (PAS1 induced strong LTP-like plasticity lasting for 30-60 min. The effect of a second identical PASLTP protocol (PAS2 critically depended on the time between PAS1 and PAS2. At 10 min, PAS2 prolonged the PAS1-induced LTP-like plasticity. At 30 min, PAS2 augmented the LTP-like plasticity induced by PAS1, by increasing both magnitude and duration. At 60 min and 180 min, PAS2 had no effect on corticospinal excitability. The cumulative LTP-like plasticity after PAS1 and PAS2 at 30 min exceeded significantly the effect of PAS1 alone, and the cumulative PAS1 and PAS2 effects at 60 min and 180 min. In summary, consecutive PASLTP protocols interact in human M1 in a time-dependent manner. If spaced by 30 min, two consecutive PASLTP sessions can augment LTP-like plasticity in human M1. Findings may inspire further research on optimized therapeutic applications of non-invasive brain stimulation in neurological and psychiatric diseases.
Duffy, Steven N.; Craddock, Kenneth J.; Abel, Ted; Nguyen, Peter V.
2001-01-01
cAMP-dependent protein kinase (PKA) is critical for the expression of some forms of long-term potentiation (LTP) in area CA1 of the mouse hippocampus and for hippocampus-dependent memory. Exposure to spatially enriched environments can modify LTP and improve behavioral memory in rodents, but the molecular bases for the enhanced memory performance seen in enriched animals are undefined. We tested the hypothesis that exposure to a spatially enriched environment may alter the PKA dependence of h...
Synapse-specific compartmentalization of signaling cascades for LTP induction in CA3 interneurons
Galván, Emilio J; Pérez-Rosello, Tamara; Gómez-Lira, Gisela; Lara, Erika; Gutiérrez, Rafael; Barrionuevo, Germán
2015-01-01
Inhibitory interneurons with somata in strata radiatum and lacunosun-moleculare (SR/L-M) of hippocampal area CA3 receive excitatory input from pyramidal cells via the recurrent collaterals (RC), and the dentate gyrus granule cells via the mossy fibers (MFs). Here we demonstrate that Hebbian long-term potentiation (LTP) at RC synapses on SR/L-M interneurons requires the concomitant activation of calcium-impermeable AMPARs (CI- AMPARs) and NMDARs. RC LTP was prevented by voltage clamping the po...
Augmenting LTP-Like Plasticity in Human Motor Cortex by Spaced Paired Associative Stimulation.
Müller-Dahlhaus, Florian; Lücke, Caroline; Lu, Ming-Kuei; Arai, Noritoshi; Fuhl, Anna; Herrmann, Eva; Ziemann, Ulf
2015-01-01
Paired associative stimulation (PASLTP) of the human primary motor cortex (M1) can induce LTP-like plasticity by increasing corticospinal excitability beyond the stimulation period. Previous studies showed that two consecutive PASLTP protocols interact by homeostatic metaplasticity, but animal experiments provided evidence that LTP can be augmented by repeated stimulation protocols spaced by ~30 min. Here we tested in twelve healthy selected PASLTP responders the possibility that LTP-like plasticity can be augmented in the human M1 by systematically varying the interval between two consecutive PASLTP protocols. The first PASLTP protocol (PAS1) induced strong LTP-like plasticity lasting for 30-60 min. The effect of a second identical PASLTP protocol (PAS2) critically depended on the time between PAS1 and PAS2. At 10 min, PAS2 prolonged the PAS1-induced LTP-like plasticity. At 30 min, PAS2 augmented the LTP-like plasticity induced by PAS1, by increasing both magnitude and duration. At 60 min and 180 min, PAS2 had no effect on corticospinal excitability. The cumulative LTP-like plasticity after PAS1 and PAS2 at 30 min exceeded significantly the effect of PAS1 alone, and the cumulative PAS1 and PAS2 effects at 60 min and 180 min. In summary, consecutive PASLTP protocols interact in human M1 in a time-dependent manner. If spaced by 30 min, two consecutive PASLTP sessions can augment LTP-like plasticity in human M1. Findings may inspire further research on optimized therapeutic applications of non-invasive brain stimulation in neurological and psychiatric diseases.
REM sleep deprivation inhibits LTP in vivo in area CA1 of rat hippocampus.
Kim, Eun Young; Mahmoud, Ghada S; Grover, Lawrence M
2005-11-18
Rapid eye movement (REM) sleep deprivation has previously been shown to interfere with normal learning and memory and to inhibit long-term potentiation (LTP) in vitro. Previous studies on REM sleep deprivation and LTP have relied on in vitro analysis in isolated brain slices taken from animals following several days of sleep deprivation. LTP in the hippocampus in situ may differ from LTP in vitro due to modulatory inputs from other brain regions, which are altered after REM sleep deprivation. Here, we examined LTP in unanesthetized, behaving animals on the first and second recovery days following REM sleep deprivation to determine if similar effects are seen in vivo as previously reported in vitro. We found that LTP was significantly impaired in REM sleep-deprived animals on the second recovery day but not the first recovery day. Our results extend previous findings by showing that REM sleep deprivation continues to affect hippocampal function for more than 24h following the end of deprivation. Our results also suggest the presence of a modulatory process not present in vitro. Our findings are not explained by stress during REM sleep deprivation because equivalent circulating corticosterone levels (an index of stress) were found during both REM sleep deprivation and control treatment.
The Role of Monosialoganglioside GM1 in LTP-Induction in Rat Hippocampal Slices
李永新; 梅镇彤
1994-01-01
The effect of monosialoganglioside GM1 of different doses on the long-term potentiation (LTP) of synaptic transmission has been studied in the CA1 region of rat hippocampal slices, and the possible role that calcium ion and NMDA receptor play has also been investigated. The results reveal that larger magnitude of LTP is induced in hippocampal slices pre-incubated with GM1. The dose-response curve appears in diphase, and the largest magnitude of LTP has been obtained at the GM1 concentration of 50 mg/L in incubation ACSF. Moreover, the magnitude of LTP induced from the slices pre-incubated with GM1 at lower calcium ion concentration is similar to that obtained from the control slices at normal calcium ion concentration. Under higher calcium ion concentration, the enhancing effect of GM1 on LTP seems relatively feeble. After NMDA receptors were blocked, no enhancing effect of GM1 was observed. The mechanism of GM1 action on LTP is discussed.
LTP requires a reserve pool of glutamate receptors independent of subunit type.
Granger, Adam J; Shi, Yun; Lu, Wei; Cerpas, Manuel; Nicoll, Roger A
2013-01-24
Long-term potentiation (LTP) of synaptic transmission is thought to be an important cellular mechanism underlying memory formation. A widely accepted model posits that LTP requires the cytoplasmic carboxyl tail (C-tail) of the AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) receptor subunit GluA1. To find the minimum necessary requirement of the GluA1 C-tail for LTP in mouse CA1 hippocampal pyramidal neurons, we used a single-cell molecular replacement strategy to replace all endogenous AMPA receptors with transfected subunits. In contrast to the prevailing model, we found no requirement of the GluA1 C-tail for LTP. In fact, replacement with the GluA2 subunit showed normal LTP, as did an artificially expressed kainate receptor not normally found at these synapses. The only conditions under which LTP was impaired were those with markedly decreased AMPA receptor surface expression, indicating a requirement for a reserve pool of receptors. These results demonstrate the synapse's remarkable flexibility to potentiate with a variety of glutamate receptor subtypes, requiring a fundamental change in our thinking with regard to the core molecular events underlying synaptic plasticity.
Late-associativity, synaptic tagging, and the role of dopamine during LTP and LTD.
Sajikumar, Sreedharan; Frey, Julietta U
2004-07-01
Protein synthesis-dependent, synapse input-specific late phases of long-term potentiation (LTP) and depression (LTD) may underlie memory formation at the cellular level. Recently, it was described that the induction of LTP can mark a specifically activated synapse by a synaptic tag to capture synapse non-specific plasticity-related proteins (PRPs) and thus maintaining input-specific LTP for prolonged periods. Here we show in rat hippocampal slices in vitro, that the induction of protein synthesis-dependent late-LTD is also characterized by synaptic tagging and that heterosynaptic induction of either LTD or LTP on two sets of independent synaptic inputs S1 and S2 can lead to late-associative interactions: early-LTD in S2 was transformed into a late-LTD, if late-LTP was induced in S1. The synthesis of process-independent PRPs by late-LTP in S1 was sufficient to transform early- into late-LTD in S2 when process-specific synaptic tags were set. We name this new associative property of cellular information processing 'cross-tagging.'
Gudder, Stanley P
2014-01-01
Quantum probability is a subtle blend of quantum mechanics and classical probability theory. Its important ideas can be traced to the pioneering work of Richard Feynman in his path integral formalism.Only recently have the concept and ideas of quantum probability been presented in a rigorous axiomatic framework, and this book provides a coherent and comprehensive exposition of this approach. It gives a unified treatment of operational statistics, generalized measure theory and the path integral formalism that can only be found in scattered research articles.The first two chapters survey the ne
Asmussen, Søren; Albrecher, Hansjörg
The book gives a comprehensive treatment of the classical and modern ruin probability theory. Some of the topics are Lundberg's inequality, the Cramér-Lundberg approximation, exact solutions, other approximations (e.g., for heavy-tailed claim size distributions), finite horizon ruin probabilities......, extensions of the classical compound Poisson model to allow for reserve-dependent premiums, Markov-modulation, periodicity, change of measure techniques, phase-type distributions as a computational vehicle and the connection to other applied probability areas, like queueing theory. In this substantially...
Earth Data Analysis Center, University of New Mexico — USFS, State Forestry, BLM, and DOI fire occurrence point locations from 1987 to 2008 were combined and converted into a fire occurrence probability or density grid...
Shiryaev, Albert N
2016-01-01
This book contains a systematic treatment of probability from the ground up, starting with intuitive ideas and gradually developing more sophisticated subjects, such as random walks, martingales, Markov chains, the measure-theoretic foundations of probability theory, weak convergence of probability measures, and the central limit theorem. Many examples are discussed in detail, and there are a large number of exercises. The book is accessible to advanced undergraduates and can be used as a text for independent study. To accommodate the greatly expanded material in the third edition of Probability, the book is now divided into two volumes. This first volume contains updated references and substantial revisions of the first three chapters of the second edition. In particular, new material has been added on generating functions, the inclusion-exclusion principle, theorems on monotonic classes (relying on a detailed treatment of “π-λ” systems), and the fundamental theorems of mathematical statistics.
Collision Probability Analysis
Hansen, Peter Friis; Pedersen, Preben Terndrup
1998-01-01
probability, i.e. a study of the navigator's role in resolving critical situations, a causation factor is derived as a second step.The report documents the first step in a probabilistic collision damage analysis. Future work will inlcude calculation of energy released for crushing of structures giving...
Abreu, P.; Aglietta, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Alvarez Castillo, J.; Alvarez-Muniz, J.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Anticic, T.; Anzalone, A.; Aramo, C.; Arganda, E.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Baecker, T.; Balzer, M.; Barber, K. B.; Barbosa, A. F.; Bardenet, R.; Barroso, S. L. C.; Baughman, B.; Baeuml, J.; Beatty, J. J.; Becker, B. R.; Becker, K. H.; Belletoile, A.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Bluemer, H.; Bohacova, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brogueira, P.; Brown, W. C.; Bruijn, R.; Buchholz, P.; Bueno, A.; Burton, R. E.; Caballero-Mora, K. S.; Caramete, L.; Caruso, R.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chou, A.; Chudoba, J.; Clay, R. W.; Coluccia, M. R.; Conceicao, R.; Contreras, F.; Cook, H.; Cooper, M. J.; Coppens, J.; Cordier, A.; Cotti, U.; Coutu, S.; Covault, C. E.; Creusot, A.; Criss, A.; Cronin, J.; Curutiu, A.; Dagoret-Campagne, S.; Dallier, R.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; De Donato, C.; de Jong, S. J.; De La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; de Vries, K. D.; Decerprit, G.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Diaz, J. C.; Diaz Castro, M. L.; Diep, P. N.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; Ebr, T. J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Etchegoyen, A.; San Luis, P. Facal; Fajardo Tapia, I.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Ferrero, A.; Fick, B.; Filevich, A.; Filipcic, A.; Fliescher, S.; Fracchiolla, C. E.; Fraenkel, E. D.; Froehlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; Garcia, B.; Garcia Gamez, D.; Garcia-Pinto, D.; Gascon, A.; Gemmeke, H.; Gesterling, K.; Ghia, P. L.; Giaccari, U.; Giller, M.; Glass, H.; Cold, M. S.; Golup, G.; Gomez Albarracin, F.; Gomez Berisso, M.; Goncalves, P.; Gonzalez, D.; Gonzalez, J. G.; Gookin, B.; Gora, D.; Gorgi, A.; Gouffon, P.; Gozzini, S. R.; Grashorn, E.; Grebe, S.; Griffith, N.; Grigat, M.; Grillo, A. F.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Guzman, A.; Hague, J. D.; Hansen, P.; Harari, D.; Harmsma, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hojvat, C.; Hollon, N.; Holmes, V. C.; Homola, P.; Hoerandel, J. R.; Horneffer, A.; Hrabovsky, M.; Huege, T.; Insolia, A.; Ionita, F.; Italiano, A.; Jarne, C.; Jiraskova, S.; Kadija, K.; Kampert, K. H.; Karhan, P.; Kasper, P.; Kegl, B.; Keilhauer, B.; Keivani, A.; Kelley, J. L.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Koang, D. -H.; Kotera, K.; Krohm, N.; Kroemer, O.; Kruppke-Hansen, D.; Kuehn, F.; Kuempel, D.; Kulbartz, J. K.; Kunka, N.; La Rosa, G.; Lachaud, C.; Lautridou, P.; Leao, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Lemiere, A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lopez, R.; Lopez Agueera, A.; Louedec, K.; Lozano Bahilo, J.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Macolino, C.; Maldera, S.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marini, J.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martinez, H.; Martinez Bravo, O.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurizio, D.; Mazur, P. O.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Mertsch, P.; Meurer, C.; Mitanovic, S.; Micheletti, M. I.; Miller, W.; Miramonti, L.; Mollerach, S.; Monasor, M.; Ragaigne, D. Monnier; Montanet, F.; Morales, B.; Morello, C.; Moreno, E.; Moreno, J. C.; Morris, C.; Mostafa, M.; Moura, C. A.; Mueller, S.; Muller, M. A.; Mueller, G.; Muenchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Nhung, P. T.; Niemietz, L.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Nazka, L.; Nyklicek, M.; Oehischlaeger, J.; Olinto, A.; Oliva, P.; Olmos-Gilbaja, V. M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parizot, E.; Parra, A.; Parsons, R. D.; Pastor, S.; Paul, T.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrinca, P.; Petrolini, A.; Petrov, Y.; Petrovic, J.; Pfendner, C.; Phan, N.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Ponce, V. H.; Pontz, M.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rivera, H.; Rizi, V.; Roberts, J.; Robledo, C.; Rodrigues de Carvalho, W.; Rodriguez, G.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodriguez-Cabo, I.; Rodriguez-Frias, M. D.; Ros, G.; Rosado, J.; Rossier, T.; Roth, M.; Rouille-d'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Ruehle, C.; Salamida, F.; Salazar, H.; Salina, G.; Sanchez, F.; Santander, M.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarkar, S.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Schmidt, F.; Schmidt, T.; Scholten, O.; Schoorlemmer, H.; Schovancova, J.; Schovaneky, P.; Schroeder, F.; Schulte, S.; Schuster, D.; Scilltto, S. J.; Scuderi, M.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Silva Lopez, H. H.; Smialkowski, A.; Smida, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Stapleton, J.; Stasielak, J.; Stephan, M.; Strazzeri, E.; Stutz, A.; Suarez, F.; Suomijarvi, T.; Supanitsky, A. D.; Susa, T.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Tamashiro, A.; Tapia, A.; Tartare, M.; Tascau, O.; Tavera Ruiz, C. G.; Tcaciuc, R.; Tegolo, D.; Thao, N. T.; Thomas, D.; Tiffenberg, J.; Timmermans, C.; Tiwari, D. K.; Tkaczyk, W.; Todero Peixoto, C. J.; Tome, B.; Tonachini, A.; Travnicek, P.; Tridapalli, D. B.; Tristram, G.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdes Galicia, J. F.; Valino, I.; Valore, L.; van den Berg, A. M.; Varela, E.; Vargas Cardenas, B.; Vazquez, J. R.; Vazquez, R. A.; Veberic, D.; Verzi, V.; Vicha, J.; Videla, M.; Villasenor, L.; Wahlberg, H.; Wahrlich, P.; Wainberg, O.; Warner, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Westerhoff, S.; Whelan, B. J.; Wieczorek, G.; Wiencke, L.; Wilczynska, B.; Wilczynski, H.; Will, M.; Williams, C.; Winchen, T.; Winders, L.; Winnick, M. G.; Wommer, M.; Wundheiler, B.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Ziolkowski, M.; Martin, L.
2011-01-01
In this paper we introduce the concept of Lateral Trigger Probability (LTP) function, i.e., the probability for an Extensive Air Shower (EAS) to trigger an individual detector of a ground based array as a function of distance to the shower axis, taking into account energy, mass and direction of the
Lexicographic Probability, Conditional Probability, and Nonstandard Probability
2009-11-11
the following conditions: CP1. µ(U |U) = 1 if U ∈ F ′. CP2 . µ(V1 ∪ V2 |U) = µ(V1 |U) + µ(V2 |U) if V1 ∩ V2 = ∅, U ∈ F ′, and V1, V2 ∈ F . CP3. µ(V |U...µ(V |X)× µ(X |U) if V ⊆ X ⊆ U , U,X ∈ F ′, V ∈ F . Note that it follows from CP1 and CP2 that µ(· |U) is a probability measure on (W,F) (and, in... CP2 hold. This is easily seen to determine µ. Moreover, µ vaciously satisfies CP3, since there do not exist distinct sets U and X in F ′ such that U
Synapse-specific compartmentalization of signaling cascades for LTP induction in CA3 interneurons.
Galván, E J; Pérez-Rosello, T; Gómez-Lira, G; Lara, E; Gutiérrez, R; Barrionuevo, G
2015-04-02
Inhibitory interneurons with somata in strata radiatum and lacunosum-molecular (SR/L-M) of hippocampal area CA3 receive excitatory input from pyramidal cells via the recurrent collaterals (RCs), and the dentate gyrus granule cells via the mossy fibers (MFs). Here we demonstrate that Hebbian long-term potentiation (LTP) at RC synapses on SR/L-M interneurons requires the concomitant activation of calcium-impermeable AMPARs (CI-AMPARs) and N-methyl-d-aspartate receptors (NMDARs). RC LTP was prevented by voltage clamping the postsynaptic cell during high-frequency stimulation (HFS; 3 trains of 100 pulses delivered at 100 Hz every 10s), with intracellular injections of the Ca(2+) chelator BAPTA (20mM), and with the NMDAR antagonist D-AP5. In separate experiments, RC and MF inputs converging onto the same interneuron were sequentially activated. We found that RC LTP induction was blocked by inhibitors of the calcium/calmodulin-dependent protein kinase II (CaMKII; KN-62, 10 μM or KN-93, 10 μM) but MF LTP was CaMKII independent. Conversely, the application of the protein kinase A (PKA) activators forskolin/IBMX (50 μM/25 μM) potentiated MF EPSPs but not RC EPSPs. Together these data indicate that the aspiny dendrites of SR/L-M interneurons compartmentalize synapse-specific Ca(2+) signaling required for LTP induction at RC and MF synapses. We also show that the two signal transduction cascades converge to activate a common effector, protein kinase C (PKC). Specifically, LTP at RC and MF synapses on the same SR/LM interneuron was blocked by postsynaptic injections of chelerythrine (10 μM). These data indicate that both forms of LTP share a common mechanism involving PKC-dependent signaling modulation.
Giuseppe eTalani
2011-10-01
Full Text Available Ethanol (EtOH–induced impairment of long-term potentiation (LTP in the rat hippocampus is prevented by the 5α-reductase inhibitor finasteride, suggesting that this effect of EtOH is dependent on the increased local release of neurosteroids such as 3α,5α-THP that promote GABA–mediated transmission. Given that social isolation (SI in rodents is associated with altered plasma and brain levels of such neurosteroids as well as with an enhanced neurosteroidogenic action of EtOH, we examined whether the inhibitory effect of EtOH on LTP at CA3-CA1 hippocampal excitatory synapses is altered in C57BL/6J mice subjected to SI for 6 weeks in comparison with group-housed (GH animals. Extracellular recording of fEPSPs as well as patch-clamp analysis were performed in hippocampal slices prepared from both SI and GH mice. Consistent with previous observations, recording of fEPSPs revealed that the extent of LTP induced in the CA1 region of SI mice was significantly reduced compared with that in GH animals. EtOH (40 mM inhibited LTP in slices from SI mice but not in those from GH mice, and this effect of EtOH was abolished by co-application of 1 µM finasteride. Current-clamp analysis of CA1 pyramidal neurons revealed a decrease in action potential frequency and an increase in the intensity of injected current required to evoke the first action potential in SI mice compared with GH mice, indicative of a decrease in neuronal excitability associated with SI. Together, our data suggest that SI results in reduced levels of neuronal excitability and synaptic plasticity in the hippocampus. Furthermore, the increased sensitivity to the neurosteroidogenic effect of EtOH associated with SI likely accounts for the greater inhibitory effect of EtOH on LTP in SI mice. The increase in EtOH sensitivity induced by SI may be important for the changes in the effects of EtOH on anxiety and on learning and memory associated with the prolonged stress attributable to social
Rojas-Nandayapa, Leonardo
Tail probabilities of sums of heavy-tailed random variables are of a major importance in various branches of Applied Probability, such as Risk Theory, Queueing Theory, Financial Management, and are subject to intense research nowadays. To understand their relevance one just needs to think...... of insurance companies facing losses due to natural disasters, banks seeking protection against huge losses, failures in expensive and sophisticated systems or loss of valuable information in electronic systems. The main difficulty when dealing with this kind of problems is the unavailability of a closed...
S Varadhan, S R
2001-01-01
This volume presents topics in probability theory covered during a first-year graduate course given at the Courant Institute of Mathematical Sciences. The necessary background material in measure theory is developed, including the standard topics, such as extension theorem, construction of measures, integration, product spaces, Radon-Nikodym theorem, and conditional expectation. In the first part of the book, characteristic functions are introduced, followed by the study of weak convergence of probability distributions. Then both the weak and strong limit theorems for sums of independent rando
Filipy, R.E.; Borst, F.J.; Cross, F.T.; Park, J.F.; Moss, O.R.; Roswell, R.L.; Stevens, D.L.
1980-05-01
A mathematical model was constructed for the purpose of predicting the fraction of human population which would die within 1 year of an accidental exposure to airborne radionuclides. The model is based on data from laboratory experiments with rats, dogs and baboons, and from human epidemiological data. Doses from external, whole-body irradiation and from inhaled, alpha- and beta-emitting radionuclides are calculated for several organs. The probabilities of death from radiation pneumonitis and from bone marrow irradiation are predicted from doses accumulated within 30 days of exposure to the radioactive aerosol. The model is compared with existing similar models under hypothetical exposure conditions. Suggestions for further experiments with inhaled radionuclides are included. 25 refs., 16 figs., 13 tabs.
Galván, Emilio J; Cosgrove, Kathleen E.; Mauna, Jocelyn C.; Card, J. Patrick; Thiels, Edda; Meriney, Stephen D.; Barrionuevo, Germán
2010-01-01
Hippocampal mossy fiber (MF) synapses on area CA3 lacunosum-moleculare (L-M) interneurons are capable of undergoing a Hebbian form of NMDAR-independent LTP induced by the same type of high-frequency stimulation (HFS) that induces LTP at MF synapses on pyramidal cells. LTP of MF input to L-M interneurons occurs only at synapses containing mostly calcium impermeable (CI)-AMPARs. Here, we demonstrate that HFS-induced LTP at these MF-interneuron synapses requires postsynaptic activation of protei...
Manabu Yamanaka
2017-07-01
Full Text Available Long-term potentiation (LTP of synaptic transmission in the central nervous system is a key form of cortical plasticity. The insular cortex (IC is known to play important roles in pain perception, aversive memory and mood disorders. LTP has been recently reported in the IC, however, the signaling pathway for IC LTP remains unknown. Here, we investigated the synaptic mechanism of IC LTP. We found that IC LTP induced by the pairing protocol was N-methyl-D-aspartate receptors (NMDARs dependent, and expressed postsynaptically, since paired-pulse ratio (PPR was not affected. Postsynaptic calcium is important for the induction of post-LTP, since the postsynaptic application of BAPTA completely blocked the induction of LTP. Calcium-activated adenylyl cyclase subtype 1 (AC1 is required for potentiation. By contrast, AC8 is not required. Inhibition of Ca2+ permeable α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (CP-AMPARs or protein kinase M zeta (PKMζ reduced the expression of LTP. Our results suggest that calcium-stimulated AC1, but not AC8, can be a trigger of the induction and maintenance of LTP in the IC.
MGluR5 mediates the interaction between late-LTP, network activity, and learning.
Arthur Bikbaev
Full Text Available Hippocampal synaptic plasticity and learning are strongly regulated by metabotropic glutamate receptors (mGluRs and particularly by mGluR5. Here, we investigated the mechanisms underlying mGluR5-modulation of these phenomena. Prolonged pharmacological blockade of mGluR5 with MPEP produced a profound impairment of spatial memory. Effects were associated with 1 a reduction of mGluR1a-expression in the dentate gyrus; 2 impaired dentate gyrus LTP; 3 enhanced CA1-LTP and 4 suppressed theta (5-10 Hz and gamma (30-100 Hz oscillations in the dentate gyrus. Allosteric potentiation of mGluR1 after mGluR5 blockade significantly ameliorated dentate gyrus LTP, as well as suppression of gamma oscillatory activity. CA3-lesioning prevented MPEP effects on CA1-LTP, suggesting that plasticity levels in CA1 are driven by mGluR5-dependent synaptic and network activity in the dentate gyrus. These data support the hypothesis that prolonged mGluR5-inactivation causes altered hippocampal LTP levels and network activity, which is mediated in part by impaired mGluR1-expression in the dentate gyrus. The consequence is impairment of long-term learning.
Wiera, Grzegorz; Nowak, Daria; van Hove, Inge; Dziegiel, Piotr; Moons, Lieve; Mozrzymas, Jerzy W
2017-02-01
Long-term potentiation (LTP) is widely perceived as a memory substrate and in the hippocampal CA3-CA1 pathway, distinct forms of LTP depend on NMDA receptors (nmdaLTP) or L-type voltage-gated calcium channels (vdccLTP). LTP is also known to be effectively regulated by extracellular proteolysis that is mediated by various enzymes. Herein, we investigated whether in mice hippocampal slices these distinct forms of LTP are specifically regulated by different metalloproteinases (MMPs). We found that MMP-3 inhibition or knock-out impaired late-phase LTP in the CA3-CA1 pathway. Interestingly, late-phase LTP was also decreased by MMP-9 blockade. When both MMP-3 and MMP-9 were inhibited, both early- and late-phase LTP was impaired. Using immunoblotting, in situ zymography, and immunofluorescence, we found that LTP induction was associated with an increase in MMP-3 expression and activity in CA1 stratum radiatum. MMP-3 inhibition and knock-out prevented the induction of vdccLTP, with no effect on nmdaLTP. L-type channel-dependent LTP is known to be impaired by hyaluronic acid digestion. We found that slice treatment with hyaluronidase occluded the effect of MMP-3 blockade on LTP, further confirming a critical role for MMP-3 in this form of LTP. In contrast to the CA3-CA1 pathway, LTP in the mossy fiber-CA3 projection did not depend on MMP-3, indicating the pathway specificity of the actions of MMPs. Overall, our study indicates that the activation of perisynaptic MMP-3 supports L-type channel-dependent LTP in the CA1 region, whereas nmdaLTP depends solely on MMP-9. Various types of long-term potentiation (LTP) are correlated with distinct phases of memory formation and retrieval, but the underlying molecular signaling pathways remain poorly understood. Extracellular proteases have emerged as key players in neuroplasticity phenomena. The present study found that L-type calcium channel-dependent LTP in the CA3-CA1 hippocampal projection is critically regulated by the activity
李勇; 叶桂兰
2002-01-01
长时程增强(LTP)是学习和记忆过程的分子水平现象.参与LTP机制的因素很多,最近研究发现神经趋向因子,特别是其中的脑衍生的神经趋向因子(BDNF)对LTP起着重要的调节作用,而且对短时程及长时程突触可塑性均有影响.已经明确的神经趋向因子的功能包括调节神经分化,神经元轴突和树突的生长和修复,以及突触形成.本文综述了BDNF与LTP相关性的实验性根据.总结了BDNF通过突触前以及突触后机制影响LTP的引发和后期维持.BDNF的直接作用机制是作用于突触前后膜上的受体,导致突触前递质小泡增多从而增加递质释放.在突触后引起突触后膜去极化,从而打开电压依赖性钙通道、钙离子浓度增高,最终导致AMPA受体数目增多,功能强化,产生LTP.%Long-term potentiation (LTP) is believed underlined learning and memory. Recent research has attracted to brain-derived neurotrophic factor (BDNF) that may affect synaptic plasticity in both short- and long-term actions at the synapse. In vitro, neurotrophin regulate neuronal differentiation, axonal and dendritic growth and repair, synaptic formation, and synaptic plasticity. Here we summarized the experimental evidence linking BDNF to LTP. BDNF plays a role in LTP induction and late phase maintenance. The actions of BDNF are mediated by the TrkB receptor tyrosine kinase. BDNF potentiate LTP by modulating the number of docked vesicles and the level of vesicle protein on pre-synapse to increase neurotransmitter release, and by inducing postsynaptic depolarization to open voltage dependent Ca2+ channels. We also introduced the effects of LTP on the secretion of the neurotrophin. The experimental evidence strongly supports a role for BDNF in synaptic plasticity and should prompt further exploration of their functions at the synapse.
Allergy to beer in LTP-sensitized patients: beers are not all the same.
Quercia, O; Zoccatelli, G; Stefanini, G F; Mistrello, G; Amato, S; Bolla, M; Emiliani, F; Asero, R
2012-09-01
Most cases of beer allergy reported so far have been associated with hypersensitivity to the non-specific lipid transfer protein (LTP). In view of the marked differences in brewing processes we assessed IgE reactivity as well as tolerance to many different beers in an allergic patient. A 45 year-old man hypersensitive to grass pollen, cat dander and Alternaria tenuis with a history of urticaria and dyspnoea after drinking beer and a weak skin reactivity to commercial corn extract was studied. The patient underwent SPT with 36 different brands of beer and an open challenge with those scoring negative was performed. An immunoblot analysis was carried out using 2 SPT-positive beers, 2 SPT-negative beers, and barley, wheat, and maize extracts using both patient's serum and a maize LTP-specific in-house developed polyclonal antibody from rabbit. Further, the immune reactive LTP of one beer was separated by HPLC and the chromatogram was compared to that of purified maize LTP. Beer SPT scored positive in 30/36 cases. The immunoblot analysis showed IgE reactivity at about 10 kDa against the two SPT-positive beers and against maize with both patient's serum and the polyclonal anti-LTP rabbit serum, whereas the two SPT-negative beers, and barley extract scored negative. The immunodetected protein co-migrated with maize LTP. In beer-allergic patients the diagnostic workup may point to the detection of some tolerated products that can be consumed risk-free. © 2012 John Wiley & Sons A/S.
Luz M Suárez
Full Text Available Seizures have profound impact on synaptic function and plasticity. While kainic acid is a popular method to induce seizures and to potentially affect synaptic plasticity, it can also produce physiological-like oscillations and trigger some forms of long-term potentiation (LTP. Here, we examine whether induction of LTP is altered in hippocampal slices prepared from rats with different sensitivity to develop status epilepticus (SE by systemic injection of kainic acid. Rats were treated with multiple low doses of kainic acid (5 mg/kg; i.p. to develop SE in a majority of animals (72-85% rats. A group of rats were resistant to develop SE (15-28% after several accumulated doses. Animals were subsequently tested using chronic recordings and object recognition tasks before brain slices were prepared for histological studies and to examine basic features of hippocampal synaptic function and plasticity, including input/output curves, paired-pulse facilitation and theta-burst induced LTP. Consistent with previous reports in kindling and pilocapine models, LTP was reduced in rats that developed SE after kainic acid injection. These animals exhibited signs of hippocampal sclerosis and developed spontaneous seizures. In contrast, resistant rats did not become epileptic and had no signs of cell loss and mossy fiber sprouting. In slices from resistant rats, theta-burst stimulation induced LTP of higher magnitude when compared with control and epileptic rats. Variations on LTP magnitude correlate with animals' performance in a hippocampal-dependent spatial memory task. Our results suggest dissociable long-term effects of treatment with kainic acid on synaptic function and plasticity depending on its epileptogenic efficiency.
Strain-dependent differences in LTP and hippocampus-dependent memory in inbred mice.
Nguyen, P V; Abel, T; Kandel, E R; Bourtchouladze, R
2000-01-01
Many studies have used "reverse" genetics to produce "knock-out" and transgenic mice to explore the roles of various molecules in long-term potentiation (LTP) and spatial memory. The existence of a variety of inbred strains of mice provides an additional way of exploring the genetic bases of learning and memory. We examined behavioral memory and LTP expression in area CA1 of hippocampal slices prepared from four different inbred strains of mice: C57BL/6J, CBA/J, DBA/2J, and 129/SvEms-+(Ter?)/J. We found that LTP induced by four 100-Hz trains of stimulation was robust and long-lasting in C57BL/6J and DBA/2J mice but decayed in CBA/J and 129/SvEms-+(Ter?)/J mice. LTP induced by one 100-Hz train was significantly smaller after 1 hr in the 129/SvEms-+(Ter?)/J mice than in the other three strains. Theta-burst LTP was shorter lasting in CBA/J, DBA/2J, and 129/SvEms-+(Ter?)/J mice than in C57BL/6J mice. We also observed specific memory deficits, among particular mouse strains, in spatial and nonspatial tests of hippocampus-dependent memory. CBA/J mice showed defective learning in the Morris water maze, and both DBA/2J and CBA/J strains displayed deficient long-term memory in contextual and cued fear conditioning tests. Our findings provide strong support for a genetic basis for some forms of synaptic plasticity that are linked to behavioral long-term memory and suggest that genetic background can influence the electrophysiological and behavioral phenotypes observed in genetically modified mice generated for elucidating the molecular bases of learning, memory, and LTP.
Wiley, Joshua S; García-Reyes, Juan F; Harper, Jason D; Charipar, Nicholas A; Ouyang, Zheng; Cooks, R Graham
2010-05-01
Low-temperature plasma (LTP) permits direct ambient ionization and mass analysis of samples in their native environment with minimal or no prior preparation. LTP utilizes dielectric barrier discharges (DBDs) to create a low power plasma which is guided by gas flow onto the sample from which analytes are desorbed and ionized. In this study, the potential of LTP-MS for the detection of pesticide residues in food is demonstrated. Thirteen multi-class agricultural chemicals were studied (ametryn, amitraz, atrazine, buprofezin, DEET, diphenylamine, ethoxyquin, imazalil, isofenphos-methyl, isoproturon, malathion, parathion-ethyl and terbuthylazine). To evaluate the potential of the proposed approach, LTP-MS experiments were performed directly on fruit peels as well as on fruit/vegetable extracts. Most of the agrochemicals examined displayed remarkable sensitivity in the positive ion mode, giving limits of detection (LOD) for the direct measurement in the low picogram range. Tandem mass spectrometry (MS/MS) was used to confirm identification of selected pesticides by using for these experiments spiked fruit/vegetable extracts (QuEChERS, a standard sample treatment protocol) at levels as low as 1 pg, absolute, for some of the analytes. Comparisons of the data obtained by direct LTP-MS were made with the slower but more accurate conventional LC-MS/MS procedure. Herbicides spiked in aqueous solutions were detectable at LODs as low as 0.5 microg L(-1) without the need for any sample preparation. The results demonstrate that ambient LTP-MS can be applied for the detection and confirmation of traces of agrochemicals in actual market-purchased produce and in natural water samples. Quantitative analysis was also performed in a few selected cases and displayed a relatively high degree of linearity over four orders of magnitude.
Lindorff-Larsen, Kresten; Winther, J R
2001-01-01
Barley LTP1 belongs to a large family of plant proteins termed non-specific lipid transfer proteins. The in vivo function of these proteins is unknown, but it has been suggested that they are involved in responses towards stresses such as pathogens, drought, heat, cold and salt. Also, the proteins...... have been suggested as transporters of monomers for cutin synthesis. We have analysed the stability of LTP1 towards denaturant, heat and proteases and found it to be a highly stable protein, which apparently does not denature at temperatures up to 100 degrees C. This high stability may be important...
Strain-dependent Differences in LTP and Hippocampus-dependent Memory in Inbred Mice
Nguyen, Peter V.; Abel, Ted; Eric R Kandel; Bourtchouladze, Roussoudan
2000-01-01
Many studies have used “reverse” genetics to produce “knock-out” and transgenic mice to explore the roles of various molecules in long-term potentiation (LTP) and spatial memory. The existence of a variety of inbred strains of mice provides an additional way of exploring the genetic bases of learning and memory. We examined behavioral memory and LTP expression in area CA1 of hippocampal slices prepared from four different inbred strains of mice: C57BL/6J, CBA/J, DBA/2J, and 129/SvEms-+Ter?/J....
Crystallization of DIR1, a LTP2-like resistance signalling protein from Arabidopsis thaliana
Lascombe, Marie-Bernard, E-mail: marie-bernard.lascombe@univ-paris5.fr [UMR 8015 CNRS, Faculté de Pharmacie, 4 Avenue de l’Observatoire, 75006 Paris (France); Buhot, Nathalie [John Innes Centre, Norwich NR4 7UH (United Kingdom); Bakan, Bénédicte; Marion, Didier [Unité de Recherches Biopolymères, Interactions, Assemblages, INRA, La Géraudière, BP 71627 (France); Blein, Jean Pierre [Phytopharmacie et Biochimie des Interactions Cellulaires, UMR 692 CNRS, INRA, BP 86510, Dijon CEDEX (France); Lamb, Chris J. [John Innes Centre, Norwich NR4 7UH (United Kingdom); Prangé, Thierry [UMR 8015 CNRS, Faculté de Pharmacie, 4 Avenue de l’Observatoire, 75006 Paris (France)
2006-07-01
DIR1, a putative LTP2 protein from Arabidopsis thaliana implicated in systemic acquired resistance in planta, has been crystallized in space group P2{sub 1}2{sub 1}2{sub 1} with one molecule per asymmetric unit. DIR1, a putative LTP2 protein from Arabidopsis thaliana implicated in systemic acquired resistance in planta, has been crystallized in space group P2{sub 1}2{sub 1}2{sub 1} with one molecule per asymmetric unit. The crystals diffract to a resolution of 1.6 Å.
Ballesteros, Jesús J.; Buschler, Arne; Köhr, Georg; Manahan-Vaughan, Denise
2016-01-01
The glutamatergic N-methyl-D-aspartate receptor (NMDAR) is critically involved in many forms of hippocampus-dependent memory that may be enabled by synaptic plasticity. Behavioral studies with NMDAR antagonists and NMDAR subunit (GluN2) mutants revealed distinct contributions from GluN2A- and GluN2B-containing NMDARs to rapidly and slowly acquired memory performance. Furthermore, studies of synaptic plasticity, in genetically modified mice in vitro, suggest that GluN2A and GluN2B may contribute in different ways to the induction and longevity of synaptic plasticity. In contrast to the hippocampal slice preparation, in behaving mice, the afferent frequencies that induce synaptic plasticity are very restricted and specific. In fact, it is the stimulus pattern and not variations in afferent frequency that determine the longevity of long-term potentiation (LTP) in vivo. Here, we explored the contribution of GluN2A and GluN2B to LTP of differing magnitudes and persistence in freely behaving mice. We applied differing high-frequency stimulation (HFS) patterns at 100 Hz to the hippocampal CA1 region, to induce NMDAR-dependent LTP in wild-type (WT) mice, that endured for 24 h (late (L)-LTP). In GluN2A-knockout (KO) mice, E-LTP (HFS, 50 pulses) was significantly reduced in magnitude and duration, whereas LTP (HFS, 2 × 50 pulses) and L-LTP (HFS, 4 × 50 pulses) were unaffected compared to responses in WT animals. By contrast, pharmacological antagonism of GluN2B in WT had no effect on E-LTP but significantly prevented LTP. E-LTP and LTP were significantly impaired by GluN2B antagonism in GluN2A-KO mice. These data indicate that the pattern of afferent stimulation is decisive for the recruitment of distinct GluN2A and GluN2B signaling pathways that in turn determine the persistency of hippocampal LTP. Whereas brief bursts of patterned stimulation preferentially recruit GluN2A and lead to weak and short-lived forms of LTP, prolonged, more intense, afferent activation recruits
Jesús Javier Ballesteros
2016-10-01
Full Text Available The glutamatergic N-methyl-D-aspartate receptor (NMDAR is critically involved in many forms of hippocampus-dependent memory that may be enabled by synaptic plasticity. Behavioral studies with NMDAR antagonists and NMDAR subunit (GluN2 mutants revealed distinct contributions from GluN2A- and GluN2B-containing NMDARs to rapidly and slowly acquired memory performance. Furthermore, studies of synaptic plasticity, in genetically modified mice in vitro, suggest that GluN2A and GluN2B may contribute in different ways to the induction and longevity of synaptic plasticity. In contrast to the hippocampal slice preparation, in behaving mice, the afferent frequencies that induce synaptic plasticity are very restricted and specific. In fact, it is the stimulus pattern, and not variations in afferent frequency that determine the longevity of long-term potentiation (LTP. Here, we explored the contribution of GluN2A and GluN2B to LTP of differing magnitudes and persistencies in freely behaving mice. We applied differing high-frequency stimulation (HFS patterns at 100 Hz to the hippocampal CA1 region, to induce NMDAR-dependent LTP in wild-type (WT mice, that endured for 24h (late (L-LTP. In GluN2A-KO mice, E-LTP (HFS, 50 pulses was significantly reduced in magnitude and duration, whereas LTP (HFS, 2 x 50 pulses and L-LTP (HFS, 4 x 50 pulses were unaffected compared to responses in WT animals. By contrast, pharmacological antagonism of GluN2B in WT had no effect on E-LTP but significantly prevented LTP. E- LTP and LTP were significantly impaired by GluN2B antagonism in GluN2A-KO mice. These data indicate that the pattern of afferent stimulation is decisive for the recruitment of distinct GluN2A and GluN2B signaling pathways that in turn determine the persistency of hippocampal LTP. Whereas brief bursts of patterned stimulation preferentially recruit GluN2A and lead to weak and short-lived forms of LTP, prolonged, more intense, afferent activation recruits GluN2B
Collision Probability Analysis
Hansen, Peter Friis; Pedersen, Preben Terndrup
1998-01-01
It is the purpose of this report to apply a rational model for prediction of ship-ship collision probabilities as function of the ship and the crew characteristics and the navigational environment for MS Dextra sailing on a route between Cadiz and the Canary Islands.The most important ship and crew...... characteristics are: ship speed, ship manoeuvrability, the layout of the navigational bridge, the radar system, the number and the training of navigators, the presence of a look out etc. The main parameters affecting the navigational environment are ship traffic density, probability distributions of wind speeds...... probability, i.e. a study of the navigator's role in resolving critical situations, a causation factor is derived as a second step.The report documents the first step in a probabilistic collision damage analysis. Future work will inlcude calculation of energy released for crushing of structures giving...
Le Duigou, C.; Savary, E.; Kullmann, D M.; Miles, R.
2015-01-01
An anti-Hebbian form of LTP is observed at excitatory synapses made with some hippocampal interneurons. LTP induction is facilitated when postsynaptic interneurons are hyperpolarized, presumably because Ca(2+) entry through Ca(2+)-permeable glutamate receptors is enhanced. The contribution of modulatory transmitters to anti-Hebbian LTP induction remains to be established. Activation of group I metabotropic receptors (mGluRs) is required for anti-Hebbian LTP induction in interneurons with cell...
Huang, Yan-You; Kandel, Eric R.
2006-01-01
Protein synthesis-dependent late phase of LTP (L-LTP) is typically induced by repeated high-frequency stimulation (HFS). This form of L-LTP is reduced in the aged animal and is positively correlated with age-related memory loss. Here we report a novel form of protein synthesis-dependent late phase of LTP in the CA1 region of hippocampus induced by…
Jarod Swant
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.
REM Sleep-Dependent Bidirectional Regulation of Hippocampal-Based Emotional Memory and LTP.
Ravassard, Pascal; Hamieh, Al Mahdy; Joseph, Mickaël Antoine; Fraize, Nicolas; Libourel, Paul-Antoine; Lebarillier, Léa; Arthaud, Sébastien; Meissirel, Claire; Touret, Monique; Malleret, Gaël; Salin, Paul-Antoine
2016-04-01
Prolonged rapid-eye-movement (REM) sleep deprivation has long been used to study the role of REM sleep in learning and memory processes. However, this method potentially induces stress and fatigue that may directly affect cognitive functions. Here, by using a short-term and nonstressful REM sleep deprivation (RSD) method we assessed in rats the bidirectional influence of reduced and increased REM sleep amount on hippocampal-dependent emotional memory and plasticity. Our results indicate that 4 h RSD impaired consolidation of contextual fear conditioning (CFC) and induction of long-term potentiation (LTP), while decreasing density of Egr1/Zif268-expressing neurons in the CA1 region of the dorsal hippocampus. LTP and Egr1 expression were not affected in ventral CA1. Conversely, an increase in REM sleep restores and further facilitates CFC consolidation and LTP induction, and also increases Egr1 expression in dorsal CA1. Moreover, CFC consolidation, Egr1 neuron density, and LTP amplitude in dorsal CA1 show a positive correlation with REM sleep amount. Altogether, these results indicate that mild changes in REM sleep amount bidirectionally affect memory and synaptic plasticity mechanisms occurring in the CA1 area of the dorsal hippocampus.
Occlusion of LTP-like plasticity in human primary motor cortex by action observation.
Jean-François Lepage
Full Text Available Passive observation of motor actions induces cortical activity in the primary motor cortex (M1 of the onlooker, which could potentially contribute to motor learning. While recent studies report modulation of motor performance following action observation, the neurophysiological mechanism supporting these behavioral changes remains to be specifically defined. Here, we assessed whether the observation of a repetitive thumb movement--similarly to active motor practice--would inhibit subsequent long-term potentiation-like (LTP plasticity induced by paired-associative stimulation (PAS. Before undergoing PAS, participants were asked to either 1 perform abductions of the right thumb as fast as possible; 2 passively observe someone else perform thumb abductions; or 3 passively observe a moving dot mimicking thumb movements. Motor evoked potentials (MEP were used to assess cortical excitability before and after motor practice (or observation and at two time points following PAS. Results show that, similarly to participants in the motor practice group, individuals observing repeated motor actions showed marked inhibition of PAS-induced LTP, while the "moving dot" group displayed the expected increase in MEP amplitude, despite differences in baseline excitability. Interestingly, LTP occlusion in the action-observation group was present even if no increase in cortical excitability or movement speed was observed following observation. These results suggest that mere observation of repeated hand actions is sufficient to induce LTP, despite the absence of motor learning.
LTP and memory impairment caused by extracellular Aβ and Tau oligomers is APP-dependent
Puzzo, Daniela; Piacentini, Roberto; Fá, Mauro; Gulisano, Walter; Li Puma, Domenica D; Staniszewski, Agnes; Zhang, Hong; Tropea, Maria Rosaria; Cocco, Sara; Palmeri, Agostino; Fraser, Paul; D'Adamio, Luciano; Grassi, Claudio; Arancio, Ottavio
2017-01-01
The concurrent application of subtoxic doses of soluble oligomeric forms of human amyloid-beta (oAβ) and Tau (oTau) proteins impairs memory and its electrophysiological surrogate long-term potentiation (LTP), effects that may be mediated by intra-neuronal oligomers uptake. Intrigued by these findings, we investigated whether oAβ and oTau share a common mechanism when they impair memory and LTP in mice. We found that as already shown for oAβ, also oTau can bind to amyloid precursor protein (APP). Moreover, efficient intra-neuronal uptake of oAβ and oTau requires expression of APP. Finally, the toxic effect of both extracellular oAβ and oTau on memory and LTP is dependent upon APP since APP-KO mice were resistant to oAβ- and oTau-induced defects in spatial/associative memory and LTP. Thus, APP might serve as a common therapeutic target against Alzheimer's Disease (AD) and a host of other neurodegenerative diseases characterized by abnormal levels of Aβ and/or Tau. DOI: http://dx.doi.org/10.7554/eLife.26991.001 PMID:28696204
Neurofibromin Regulation of ERK Signaling Modulates GABA Release and Learning
Y. Cui (Yijun); R.M. Costa (Rui); G.G. Murphy (Geoffrey); Y. Elgersma (Ype); Y. Zhu (Yuan); D.H. Gutmann (David); L.F. Parada (Luis); I. Mody (Istvan); A.J. Silva (Alcino)
2008-01-01
textabstractWe uncovered a role for ERK signaling in GABA release, long-term potentiation (LTP), and learning, and show that disruption of this mechanism accounts for the learning deficits in a mouse model for learning disabilities in neurofibromatosis type I (NF1). Our results demonstrate that neur
Capsaicin-induced changes in LTP in the lateral amygdala are mediated by TRPV1.
Carsten Zschenderlein
Full Text Available The transient receptor potential vanilloid type 1 (TRPV1 channel is a well recognized polymodal signal detector that is activated by painful stimuli such as capsaicin. Here, we show that TRPV1 is expressed in the lateral nucleus of the amygdala (LA. Despite the fact that the central amygdala displays the highest neuronal density, the highest density of TRPV1 labeled neurons was found within the nuclei of the basolateral complex of the amygdala. Capsaicin specifically changed the magnitude of long-term potentiation (LTP in the LA in brain slices of mice depending on the anesthetic (ether, isoflurane used before euthanasia. After ether anesthesia, capsaicin had a suppressive effect on LA-LTP both in patch clamp and in extracellular recordings. The capsaicin-induced reduction of LTP was completely blocked by the nitric oxide synthase (NOS inhibitor L-NAME and was absent in neuronal NOS as well as in TRPV1 deficient mice. The specific antagonist of cannabinoid receptor type 1 (CB1, AM 251, was also able to reduce the inhibitory effect of capsaicin on LA-LTP, suggesting that stimulation of TRPV1 provokes the generation of anandamide in the brain which seems to inhibit NO synthesis. After isoflurane anesthesia before euthanasia capsaicin caused a TRPV1-mediated increase in the magnitude of LA-LTP. Therefore, our results also indicate that the appropriate choice of the anesthetics used is an important consideration when brain plasticity and the action of endovanilloids will be evaluated. In summary, our results demonstrate that TRPV1 may be involved in the amygdala control of learning mechanisms.
Differing presynaptic contributions to LTP and associative learning in behaving mice
Noelia Madroñal
2009-05-01
Full Text Available The hippocampal CA3-CA1 synapse is an excellent experimental model for studying the interactions between short- and long-term plastic changes taking place following high-frequency stimulation (HFS of Schaffer collaterals and during the acquisition and extinction of a classical eyeblink conditioning in behaving mice. Input/output curves and a full-range paired-pulse study enabled determining the optimal intensities and inter-stimulus intervals for evoking paired-pulse facilitation (PPF or depression (PPD at the CA3-CA1 synapse. Long-term potentiation (LTP induced by HFS lasted ≈ 10 days. HFS-induced LTP evoked an initial depression of basal PPF. Recovery of PPF baseline values was a steady and progressive process lasting ≈ 20 days, i.e., longer than the total duration of the LTP. In a subsequent series of experiments, we checked whether PPF was affected similarly during activity-dependent synaptic changes. Animals were conditioned using a trace paradigm, with a tone as a conditioned stimulus (CS and an electrical shock to the trigeminal nerve as an unconditioned stimulus (US. A pair of pulses (40 ms interval was presented to the Schaffer collateral-commissural pathway to evoke field EPSPs (fEPSPs during the CS-US interval. Basal PPF decreased steadily across conditioning sessions (i.e., in the opposite direction to that during LTP, reaching a minimum value during the 10th conditioning session. Thus, LTP and classical eyeblink conditioning share some presynaptic mechanisms, but with an opposite evolution. Furthermore, PPF and PPD might play a homeostatic role during long-term plastic changes at the CA3-CA1 synapse.
Kalweit, Alexander Nikolai; Yang, Honghong; Colitti-Klausnitzer, Jens; Fülöp, Livia; Bozsó, Zsolt; Penke, Botond; Manahan-Vaughan, Denise
2015-01-01
Accumulation of amyloid plaques comprises one of the major hallmarks of Alzheimer’s disease (AD). In rodents, acute treatment with amyloid-beta (Aβ; 1–42) elicits immediate debilitating effects on hippocampal long-term potentiation (LTP). Whereas LTP contributes to synaptic information storage, information is transferred across neurons by means of neuronal oscillations. Furthermore, changes in theta-gamma oscillations, that appear during high-frequency stimulation (HFS) to induce LTP, predict whether successful LTP will occur. Here, we explored if intra-cerebral treatment with Aβ(1–42), that prevents LTP, also results in alterations of hippocampal oscillations that occur during HFS of the perforant path-dentate gyrus synapse in 6-month-old behaving rats. HFS resulted in LTP that lasted for over 24 h. In Aβ-treated animals, LTP was significantly prevented. During HFS, spectral power for oscillations below 100 Hz (δ, θ, α, β and γ) was significantly higher in Aβ-treated animals compared to controls. In addition, the trough-to-peak amplitudes of theta and gamma cycles were higher during HFS in Aβ-treated animals. We also observed a lower amount of envelope-to-signal correlations during HFS in Aβ-treated animals. Overall, the characteristic profile of theta-gamma oscillations that accompany successful LTP induction was disrupted. These data indicate that alterations in network oscillations accompany Aβ-effects on hippocampal LTP. This may comprise an underlying mechanism through which disturbances in synaptic information storage and hippocampus-dependent memory occurs in AD. PMID:25999827
Debabrata Panja
2014-11-01
Full Text Available BDNF signaling contributes to protein-synthesis-dependent synaptic plasticity, but the dynamics of TrkB signaling and mechanisms of translation have not been defined. Here, we show that long-term potentiation (LTP consolidation in the dentate gyrus of live rodents requires sustained (hours BDNF-TrkB signaling. Surprisingly, this sustained activation maintains an otherwise labile signaling pathway from TrkB to MAP-kinase-interacting kinase (MNK. MNK activity promotes eIF4F translation initiation complex formation and protein synthesis in mechanistically distinct early and late stages. In early-stage translation, MNK triggers release of the CYFIP1/FMRP repressor complex from the 5′-mRNA cap. In late-stage translation, MNK regulates the canonical translational repressor 4E-BP2 in a synapse-compartment-specific manner. This late stage is coupled to MNK-dependent enhanced dendritic mRNA translation. We conclude that LTP consolidation in the dentate gyrus is mediated by sustained BDNF signaling to MNK and MNK-dependent regulation of translation in two functionally and mechanistically distinct stages.
Centonze, Diego; Siracusano, Alberto; Calabresi, Paolo; Bernardi, Giorgio
2004-11-01
Long-term potentiation (LTP) of synaptic transmission is considered a reliable cellular model of several forms of learning and memory. Described for the first time in 1973, this synaptic phenomenon consists in the enduring facilitation of the communication between two neurons in response to the sustained activation of the synapses by which they are interconnected. In a book of 1895 entitled Project for a Scientific Psychology, Sigmund Freud theorized about the possibility of representing memory at the synaptic level as "a permanent alteration following an event", and anticipated several crucial physiological properties of LTP. In the present article we aim at presenting Freudian theory on the functional organization of the nervous system developed in the Project, with particular respect to his ideas of the cellular bases of memory.
Comparison of LTI and LTP Models for Stability Analysis of Grid Converters
Kwon, Jun Bum; Wang, Xiongfei; Blaabjerg, Frede;
2016-01-01
The stability analysis of grid-connected converters have attracted increasing attentions, due to the oscillations arising in wind power plants, micro-grids, and other emerging power electronics based power systems. The modeling tool of converters thus becomes essential to faithfully reveal...... oscillations without any hidden regions. This paper presents a detailed comparison of two linearized modeling methods, which are, respectively, developed in the Linear Time-Invariant (LTI) and the Linear Time-Periodic (LTP) frameworks. The LTP model can consider the effect of frequency-coupling dynamics, which...... are occurred by the time-varying behavior, while the conventional LTI model can not capture this behavior. The advantages and limits of two models are then illustrated with examples. The compared results are verified in the frequency domain and time domain as well....
Combined LTP and LTD of modulatory inputs controls neuronal processing of primary sensory inputs.
Doiron, Brent; Zhao, Yanjun; Tzounopoulos, Thanos
2011-07-20
A hallmark of brain organization is the integration of primary and modulatory pathways by principal neurons. However, the pathway interactions that shape primary input processing remain unknown. We investigated this problem in mouse dorsal cochlear nucleus (DCN) where principal cells integrate primary, auditory nerve input with modulatory, parallel fiber input. Using a combined experimental and computational approach, we show that combined LTP and LTD of parallel fiber inputs to DCN principal cells and interneurons, respectively, broaden the time window within which synaptic inputs summate. Enhanced summation depolarizes the resting membrane potential and thus lowers the response threshold to auditory nerve inputs. Combined LTP and LTD, by preserving the variance of membrane potential fluctuations and the membrane time constant, fixes response gain and spike latency as threshold is lowered. Our data reveal a novel mechanism mediating adaptive and concomitant homeostatic regulation of distinct features of neuronal processing of sensory inputs.
Sivakumaran, Sudhir; Mohajerani, Majid H; Cherubini, Enrico
2009-02-25
In the adult rat hippocampus, the axons of granule cells in the dentate gyrus, the mossy fibers (MF), form excitatory glutamatergic synapses with CA3 principal cells. In neonates, MF release into their targets mainly GABA, which at this developmental stage is depolarizing. Here we tested the hypothesis that, at immature MF-CA3 synapses, correlated presynaptic [single fiber-evoked GABA(A)-mediated postsynaptic potentials (GPSPs)] and postsynaptic activity (back propagating action potentials) may exert a critical control on synaptic efficacy. This form of plasticity, called spike-timing-dependent plasticity (STDP), is a Hebbian type form of learning extensively studied at the level of glutamatergic synapses. Depending on the relative timing, pairing postsynaptic spiking and single MF-GPSPs induced bidirectional changes in synaptic efficacy. In case of positive pairing, spike-timing-dependent-long-term potentiation (STD-LTP) was associated with a persistent increase in GPSP slope and in the probability of cell firing. The transduction pathway involved a rise of calcium in the postsynaptic cell and the combined activity of cAMP-dependent PKA (protein kinase A) and brain-derived neurotrophic factor (BDNF). Retrograde signaling via BDNF and presynaptic TrkB receptors led to a persistent increase in GABA release. In "presynaptically" silent neurons, the enhanced probability of GABA release induced by the pairing protocol, unsilenced these synapses. Shifting E(GABA) from the depolarizing to the hyperpolarizing direction with bumetanide failed to modify synaptic strength. Thus, STD-LTP of GPSPs provides a reliable way to convey information from granule cells to the CA3 associative network at a time when glutamatergic synapses are still poorly developed.
Isolated NMDA receptor-mediated synaptic responses express both LTP and LTD.
Xie, X; Berger, T W; Barrionuevo, G
1992-04-01
1. The possibility of use-dependent, long-lasting modifications of pharmacologically isolated N-methyl-D-aspartate (NMDA) receptor-mediated synaptic transmission was examined by intracellular recordings from granule cells of the hippocampal dentate gyrus in vitro. In the presence of the non-NMDA receptor antagonist 6-cyano-7-nitroquinaxaline-2,3-dione (CNQX, 10 microM) robust, long-term potentiation (LTP) of NMDA receptor-mediated synaptic potentials was induced by brief, high (50 Hz) and lower (10 Hz) frequency tetanic stimuli of glutamatergic afferents (60 +/- 6%, n = 8, P less than 0.001 and 43 +/- 12%, n = 3, P less than 0.05, respectively). 2. Hyperpolarization of granule cell membrane potential to -100 mV during 50-Hz tetanic stimuli reversibly blocked the induction of LTP (-6 +/- 2%, n = 6, P greater than 0.05) indicating that simultaneous activation of pre- and postsynaptic elements is a prerequisite for potentiation of NMDA receptor-mediated synaptic transmission. In contrast, hyperpolarization of the granule cell membrane potential to -100 mV during 10-Hz tetanic stimuli resulted in long-term depression (LTD) of NMDA receptor-mediated synaptic potentials (-34 +/- 8%, n = 8, P less than 0.01). 3. We also studied the role of [Ca2+]i in the induction of LTP and LTD of NMDA receptor-mediated synaptic responses. Before tetanization, [Ca2+]i was buffered by iontophoretic injections of bis-(o-aminophenoxy)-N,N,N',N'-tetraacetic acid (BAPTA). BAPTA completely blocked the induction of LTP (3 +/- 5%, n = 13) and partially blocked LTD (-14.8 +/- 6%, n = 10).(ABSTRACT TRUNCATED AT 250 WORDS)
Entorhinal theta-frequency input to the dentate gyrus trisynaptically evokes hippocampal CA1 LTP
Jens eStepan
2012-09-01
Full Text Available There exists substantial evidence that some forms of explicit learning in mammals require long-term potentiation (LTP at hippocampal CA3-CA1 synapses. While CA1 LTP has been well characterized at the monosynaptic level, it still remains unclear how the afferent systems to the hippocampus can initiate formation of this neuroplastic phenomenon. Using voltage-sensitive dye imaging in a mouse brain slice preparation, we show that evoked entorhinal cortical (EC theta-frequency input to the dentate gyrus highly effectively generates waves of neuronal activity which propagate through the entire trisynaptic circuit of the hippocampus (‘HTC-Waves’. This flow of activity, which we also demonstrate in vivo, critically depends on frequency facilitation of mossy fiber to CA3 synaptic transmission. The HTC-Waves are rapidly boosted by the cognitive enhancer caffeine (5 µM and the stress hormone corticosterone (100 nM. They precisely follow the rhythm of the EC input, involve high-frequency firing (>100 Hz of CA3 pyramidal neurons, and induce NMDA receptor-dependent CA1 LTP within a few seconds. Our study provides the first experimental evidence that synchronous theta-rhythmical spiking of EC stellate cells, as occurring during EC theta oscillations, has the capacity to drive induction of CA1 LTP via the hippocampal trisynaptic pathway. Moreover, we present data pointing to a basic filter mechanism of the hippocampus regarding EC inputs and describe a methodology to reveal alterations in the ‘input-output relationship’ of the hippocampal trisynaptic circuit.
Integrated statistical modelling of spatial landslide probability
Mergili, M.; Chu, H.-J.
2015-09-01
Statistical methods are commonly employed to estimate spatial probabilities of landslide release at the catchment or regional scale. Travel distances and impact areas are often computed by means of conceptual mass point models. The present work introduces a fully automated procedure extending and combining both concepts to compute an integrated spatial landslide probability: (i) the landslide inventory is subset into release and deposition zones. (ii) We employ a simple statistical approach to estimate the pixel-based landslide release probability. (iii) We use the cumulative probability density function of the angle of reach of the observed landslide pixels to assign an impact probability to each pixel. (iv) We introduce the zonal probability i.e. the spatial probability that at least one landslide pixel occurs within a zone of defined size. We quantify this relationship by a set of empirical curves. (v) The integrated spatial landslide probability is defined as the maximum of the release probability and the product of the impact probability and the zonal release probability relevant for each pixel. We demonstrate the approach with a 637 km2 study area in southern Taiwan, using an inventory of 1399 landslides triggered by the typhoon Morakot in 2009. We observe that (i) the average integrated spatial landslide probability over the entire study area corresponds reasonably well to the fraction of the observed landside area; (ii) the model performs moderately well in predicting the observed spatial landslide distribution; (iii) the size of the release zone (or any other zone of spatial aggregation) influences the integrated spatial landslide probability to a much higher degree than the pixel-based release probability; (iv) removing the largest landslides from the analysis leads to an enhanced model performance.
Ayala, Jennifer E; Chen, Yelin; Banko, Jessica L; Sheffler, Douglas J; Williams, Richard; Telk, Alexandra N; Watson, Noreen L; Xiang, Zixiu; Zhang, Yongqin; Jones, Paulianda J; Lindsley, Craig W; Olive, M Foster; Conn, P Jeffrey
2009-08-01
Highly selective positive allosteric modulators (PAMs) of metabotropic glutamate receptor subtype 5 (mGluR5) have emerged as a potential approach to treat positive symptoms associated with schizophrenia. mGluR5 plays an important role in both long-term potentiation (LTP) and long-term depression (LTD), suggesting that mGluR5 PAMs may also have utility in improving impaired cognitive function. However, if mGluR5 PAMs shift the balance of LTP and LTD or induce a state in which afferent activity induces lasting changes in synaptic function that are not appropriate for a given pattern of activity, this could disrupt rather than enhance cognitive function. We determined the effect of selective mGluR5 PAMs on the induction of LTP and LTD at the Schaffer collateral-CA1 synapse in the hippocampus. mGluR5-selective PAMs significantly enhanced threshold theta-burst stimulation (TBS)-induced LTP. In addition, mGluR5 PAMs enhanced both DHPG-induced LTD and LTD induced by the delivery of paired-pulse low-frequency stimulation. Selective potentiation of mGluR5 had no effect on LTP induced by suprathreshold TBS or saturated LTP. The finding that potentiation of mGluR5-mediated responses to stimulation of glutamatergic afferents enhances both LTP and LTD and supports the hypothesis that the activation of mGluR5 by endogenous glutamate contributes to both forms of plasticity. Furthermore, two systemically active mGluR5 PAMs enhanced performance in the Morris water maze, a measure of hippocampus-dependent spatial learning. Discovery of small molecules that enhance both LTP and LTD in an activity-appropriate manner shows a unique action on synaptic plasticity that may provide a novel approach for the treatment of impaired cognitive function.
Lessmann, Volkmar; Stroh-Kaffei, Sigrid; Steinbrecher, Violetta; Edelmann, Elke; Brigadski, Tanja; Kilb, Werner; Luhmann, Heiko J
2011-05-19
BDNF and nitric oxide signaling both contribute to long-term potentiation (LTP) at glutamatergic synapses, but to date, few studies analyzed the interaction of both signaling cascades in the same synaptic pathway. Here we addressed the question whether the residual LTP in the CA1 region of hippocampal slices from heterozygous BDNF knockout mice (BDNF⁺/⁻) is dependent on nitric oxide (NO) signaling. Extracellular recording of synaptic field potentials elicited by presynaptic Schaffer collateral stimulation was performed in the CA1 region of hippocampal slices of 4- to 6-week-old mice, and LTP was induced by a theta burst stimulation protocol. Application of the nitric oxide inhibitor L-NAME (200 μM) strongly inhibited LTP by 70% in wildtype animals. This inhibition of LTP was not a consequence of altered basal synaptic properties. In CA1 of BDNF⁺/⁻ mice, stimulated with the same theta burst protocol, LTP was reduced by 50% as compared to wildtype animals. This impairment in the expression of LTP in BDNF⁺/⁻ mice did not result from an increased synaptic fatigue. The residual LTP in BDNF⁺/⁻ was not further reduced by preincubation of slices with L-NAME. These results suggest that BDNF and NO share overlapping intracellular signaling cascades to mediate LTP in CA1, and part of their signaling cascades are most likely arranged consecutively in the signaling pathway mediating LTP.
Probability Aggregates in Probability Answer Set Programming
Saad, Emad
2013-01-01
Probability answer set programming is a declarative programming that has been shown effective for representing and reasoning about a variety of probability reasoning tasks. However, the lack of probability aggregates, e.g. {\\em expected values}, in the language of disjunctive hybrid probability logic programs (DHPP) disallows the natural and concise representation of many interesting problems. In this paper, we extend DHPP to allow arbitrary probability aggregates. We introduce two types of p...
Ali, Zulfiqar [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Yashchuk, Valeriy V. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2011-05-11
Systematic error and instrumental drift are the major limiting factors of sub-microradian slope metrology with state-of-the-art x-ray optics. Significant suppression of the errors can be achieved by using an optimal measurement strategy suggested in [Rev. Sci. Instrum. 80, 115101 (2009)]. With this series of LSBL Notes, we report on development of an automated, kinematic, rotational system that provides fully controlled flipping, tilting, and shifting of a surface under test. The system is integrated into the Advanced Light Source long trace profiler, LTP-II, allowing for complete realization of the advantages of the optimal measurement strategy method. We provide details of the system’s design, operational control and data acquisition. The high performance of the system is demonstrated via the results of high precision measurements with a spherical test mirror.
Abreu, P.; /Lisbon, IST /Lisbon, LIFEP; Aglietta, M.; /INFN, Turin /Turin Observ. /Turin U.; Ahn, E.J.; /Fermilab; Albuquerque, I.F.M.; /Sao Paulo U.; Allard, D.; /APC, Paris; Allekotte, I.; /Centro Atomico Bariloche /Balseiro Inst., San Carlos de Bariloche; Allen, J.; /New York U.; Allison, P.; /Ohio State U.; Alvarez Castillo, J.; /Mexico U.; Alvarez-Muniz, J.; /Santiago de Compostela U.; Ambrosio, M.; /INFN, Naples /Naples U. /Nijmegen U., IMAPP
2011-01-01
In this paper we introduce the concept of Lateral Trigger Probability (LTP) function, i.e., the probability for an Extensive Air Shower (EAS) to trigger an individual detector of a ground based array as a function of distance to the shower axis, taking into account energy, mass and direction of the primary cosmic ray. We apply this concept to the surface array of the Pierre Auger Observatory consisting of a 1.5 km spaced grid of about 1600 water Cherenkov stations. Using Monte Carlo simulations of ultra-high energy showers the LTP functions are derived for energies in the range between 10{sup 17} and 10{sup 19} eV and zenith angles up to 65{sup o}. A parametrization combining a step function with an exponential is found to reproduce them very well in the considered range of energies and zenith angles. The LTP functions can also be obtained from data using events simultaneously observed by the fluorescence and the surface detector of the Pierre Auger Observatory (hybrid events). We validate the Monte Carlo results showing how LTP functions from data are in good agreement with simulations.
Pierre Auger Collaboration; Abreu, P.; Aglietta, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Antičić, T.; Anzalone, A.; Aramo, C.; Arganda, E.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Bäcker, T.; Balzer, M.; Barber, K. B.; Barbosa, A. F.; Bardenet, R.; Barroso, S. L. C.; Baughman, B.; Bäuml, J.; Beatty, J. J.; Becker, B. R.; Becker, K. H.; Bellétoile, A.; Bellido, J. A.; Benzvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brogueira, P.; Brown, W. C.; Bruijn, R.; Buchholz, P.; Bueno, A.; Burton, R. E.; Caballero-Mora, K. S.; Caramete, L.; Caruso, R.; Castellina, A.; Catalano, O.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chou, A.; Chudoba, J.; Clay, R. W.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cook, H.; Cooper, M. J.; Coppens, J.; Cordier, A.; Cotti, U.; Coutu, S.; Covault, C. E.; Creusot, A.; Criss, A.; Cronin, J.; Curutiu, A.; Dagoret-Campagne, S.; Dallier, R.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; de Domenico, M.; de Donato, C.; de Jong, S. J.; de La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; de Mitri, I.; de Souza, V.; de Vries, K. D.; Decerprit, G.; Del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; di Giulio, C.; Diaz, J. C.; Díaz Castro, M. L.; Diep, P. N.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; Dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Etchegoyen, A.; Facal San Luis, P.; Fajardo Tapia, I.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Ferrero, A.; Fick, B.; Filevich, A.; Filipčič, A.; Fliescher, S.; Fracchiolla, C. E.; Fraenkel, E. D.; Fröhlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; García, B.; García Gámez, D.; Garcia-Pinto, D.; Gascon, A.; Gemmeke, H.; Gesterling, K.; Ghia, P. L.; Giaccari, U.; Giller, M.; Glass, H.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gómez Berisso, M.; Gonçalves, P.; Gonzalez, D.; Gonzalez, J. G.; Gookin, B.; Góra, D.; Gorgi, A.; Gouffon, P.; Gozzini, S. R.; Grashorn, E.; Grebe, S.; Griffith, N.; Grigat, M.; Grillo, A. F.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Guzman, A.; Hague, J. D.; Hansen, P.; Harari, D.; Harmsma, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hojvat, C.; Hollon, N.; Holmes, V. C.; Homola, P.; Hörandel, J. R.; Horneffer, A.; Hrabovský, M.; Huege, T.; Insolia, A.; Ionita, F.; Italiano, A.; Jarne, C.; Jiraskova, S.; Kadija, K.; Kampert, K. H.; Karhan, P.; Kasper, P.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kelley, J. L.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Koang, D.-H.; Kotera, K.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuehn, F.; Kuempel, D.; Kulbartz, J. K.; Kunka, N.; La Rosa, G.; Lachaud, C.; Lautridou, P.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Lemiere, A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Macolino, C.; Maldera, S.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, J.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurizio, D.; Mazur, P. O.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Mertsch, P.; Meurer, C.; Mićanović, S.; Micheletti, M. I.; Miller, W.; Miramonti, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, E.; Moreno, J. C.; Morris, C.; Mostafá, M.; Moura, C. A.; Mueller, S.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Nhung, P. T.; Niemietz, L.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Nožka, L.; Nyklicek, M.; Oehlschläger, J.; Olinto, A.; Oliva, P.; Olmos-Gilbaja, V. M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parizot, E.; Parra, A.; Parsons, R. D.; Pastor, S.; Paul, T.; Pech, M.; Pȩkala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrinca, P.; Petrolini, A.; Petrov, Y.; Petrovic, J.; Pfendner, C.; Phan, N.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Ponce, V. H.; Pontz, M.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rivera, H.; Rizi, V.; Roberts, J.; Robledo, C.; Rodrigues de Carvalho, W.; Rodriguez, G.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodriguez-Cabo, I.; Rodríguez-Frías, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Rouillé-D'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Rühle, C.; Salamida, F.; Salazar, H.; Salina, G.; Sánchez, F.; Santander, M.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarkar, S.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Schmidt, F.; Schmidt, T.; Scholten, O.; Schoorlemmer, H.; Schovancova, J.; Schovánek, P.; Schröder, F.; Schulte, S.; Schuster, D.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Silva Lopez, H. H.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Stapleton, J.; Stasielak, J.; Stephan, M.; Strazzeri, E.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Šuša, T.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Tamashiro, A.; Tapia, A.; Tartare, M.; Taşcău, O.; Tavera Ruiz, C. G.; Tcaciuc, R.; Tegolo, D.; Thao, N. T.; Thomas, D.; Tiffenberg, J.; Timmermans, C.; Tiwari, D. K.; Tkaczyk, W.; Todero Peixoto, C. J.; Tomé, B.; Tonachini, A.; Travnicek, P.; Tridapalli, D. B.; Tristram, G.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van den Berg, A. M.; Varela, E.; Vargas Cárdenas, B.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Wahlberg, H.; Wahrlich, P.; Wainberg, O.; Warner, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Westerhoff, S.; Whelan, B. J.; Wieczorek, G.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Winders, L.; Winnick, M. G.; Wommer, M.; Wundheiler, B.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Ziolkowski, M.
2011-12-01
In this paper we introduce the concept of Lateral Trigger Probability (LTP) function, i.e., the probability for an Extensive Air Shower (EAS) to trigger an individual detector of a ground based array as a function of distance to the shower axis, taking into account energy, mass and direction of the primary cosmic ray. We apply this concept to the surface array of the Pierre Auger Observatory consisting of a 1.5 km spaced grid of about 1600 water Cherenkov stations. Using Monte Carlo simulations of ultra-high energy showers the LTP functions are derived for energies in the range between 1017 and 1019 eV and zenith angles up to 65°. A parametrization combining a step function with an exponential is found to reproduce them very well in the considered range of energies and zenith angles. The LTP functions can also be obtained from data using events simultaneously observed by the fluorescence and the surface detector of the Pierre Auger Observatory (hybrid events). We validate the Monte Carlo results showing how LTP functions from data are in good agreement with simulations.
Scaling Qualitative Probability
Burgin, Mark
2017-01-01
There are different approaches to qualitative probability, which includes subjective probability. We developed a representation of qualitative probability based on relational systems, which allows modeling uncertainty by probability structures and is more coherent than existing approaches. This setting makes it possible proving that any comparative probability is induced by some probability structure (Theorem 2.1), that classical probability is a probability structure (Theorem 2.2) and that i...
Li, Da-Ke; Zhang, Chao; Gu, Yu; Zhang, She-Hong; Shi, Jian; Chen, Xian-Hua
2017-03-20
During the early developmental period, long-term potentiation (LTP) can be induced in both vertical and horizontal connections in the rat visual cortex. However, the temporal difference in LTP change between the two pathways during animal development remains unclear. In this study, LTP in vertical (from layer IV to layer II/III) and horizontal (from layer II/III to layer II/III) synaptic connections were recorded in brain slices from the same rats, and the developmental changes of LTP in both directions were compared within the animals' eye-opening period. The results showed that the LTP amplitudes declined to unobservable levels on P16 in the horizontal connections and on P20 in the vertical synaptic connections. Meanwhile, V-LTP (LTP induced in the vertical direction) was always stronger than H-LTP (LTP induced in the horizontal direction) under the same conditions of pairing stimulus (PS). Next, H-LTP and V-LTP were induced from the same neuron in layer II/III to determine the spatiotemporal interactions between layer II/III horizontal inputs and ascending synaptic inputs during the maturation of rat visual cortex. The data show that the weak PS, which failed to induce H-LTP alone, was able to induce H-LTP effectively while V-LTP was performed on P10. Our results suggest that V-LTP can strengthen H-LTP induction in the visual cortex during the early developmental period. In contrast, the regulatory effect of H-LTP on V-LTP was much weaker.
Basavarajappa, Balapal S; Nagre, Nagaraja N; Xie, Shan; Subbanna, Shivakumar
2014-07-01
In rodents, many exogenous and endogenous cannabinoids, such as anandamide (AEA) and 2-arachidonyl glycerol (2-AG), have been shown to play an important role in certain hippocampal memory processes. However, the mechanisms by which endogenous AEA regulate this processes are not well understood. Here the effects of AEA on long-term potentiation (LTP), hippocampal-dependent learning and memory tasks, pERK1/2, pCaMKIV, and pCREB signaling events in both cannabinoid receptor type 1 (CB1R) wild-type (WT) and knockout (KO) mice were assessed following administration of URB597, an inhibitor of the fatty acid amide hydrolase (FAAH). Acute administration of URB597 enhanced AEA levels without affecting the levels of 2-AG or CB1R in the hippocampus and neocortex as compared to vehicle. In hippocampal slices, URB597 impaired LTP in CB1R WT but not in KO littermates. URB597 impaired object recognition, spontaneous alternation and spatial memory in the Y-maze test in CB1R WT mice but not in KO mice. Furthermore, URB597 enhanced ERK phosphorylation in WT without affecting total ERK levels in WT or KO mice. URB597 impaired CaMKIV and CREB phosphorylation in WT but not in KO mice. CB1R KO mice have a lower pCaMKIV/CaMKIV ratio and higher pCREB/CREB ratio as compared to WT littermates. Our results indicate that pharmacologically elevated AEA impair LTP, learning and memory and inhibit CaMKIV and CREB phosphorylation, via the activation of CB1Rs. Collectively, these findings also suggest that pharmacological elevation of AEA beyond normal concentrations is also detrimental for the underlying physiological responses.
Stefan eKlöppel
2015-09-01
Full Text Available LTP-like plasticity measured by visual evoked potentials (VEP can be induced in the intact human brain by presenting checkerboard reversals. Also associated with LTP-like plasticity, around two third of participants respond to transcranial magnetic stimulation with a paired-associate stimulation (PAS protocol with a potentiation of their motor evoked potentials. LTP-like processes are also required for verbal and motor learning tasks. We compared effect sizes, responder rates and intercorrelations as well as the potential influence of attention between these four assessments in a group of 37 young and healthy volunteers. We observed a potentiation effect of the N75 and P100 VEP component which positively correlated with plasticity induced by PAS. Subjects with a better subjective alertness were more likely to show PAS and VEP potentiation. No correlation was found between the other assessments. Effect sizes and responder rates of VEP potentiation were higher compared to PAS. Our results indicate a high variability of LTP-like effects and no evidence for a system-specific nature. As a consequence, studies wishing to assess individual levels of LTP-like plasticity should employ a combination of multiple assessments.
Gβγ and the C terminus of SNAP-25 are necessary for long-term depression of transmitter release.
Xiao-lei Zhang
Full Text Available BACKGROUND: Short-term presynaptic inhibition mediated by G protein-coupled receptors involves a direct interaction between G proteins and the vesicle release machinery. Recent studies implicate the C terminus of the vesicle-associated protein SNAP-25 as a molecular binding target of Gβγ that transiently reduces vesicular release. However, it is not known whether SNAP-25 is a target for molecular modifications expressing long-term changes in transmitter release probability. METHODOLOGY/PRINCIPAL FINDINGS: This study utilized two-photon laser scanning microscopy for real-time imaging of action potential-evoked [Ca(2+] increases, in single Schaffer collateral presynaptic release sites in in vitro hippocampal slices, plus simultaneous recording of Schaffer collateral-evoked synaptic potentials. We used electroporation to infuse small peptides through CA3 cell bodies into presynaptic Schaffer collateral terminals to selectively study the presynaptic effect of scavenging the G-protein Gβγ. We demonstrate here that the C terminus of SNAP-25 is necessary for expression of LTD, but not long-term potentiation (LTP, of synaptic strength. Using type A botulinum toxin (BoNT/A to enzymatically cleave the 9 amino acid C-terminus of SNAP-25 eliminated the ability of low frequency synaptic stimulation to induce LTD, but not LTP, even if release probability was restored to pre-BoNT/A levels by elevating extracellular [Ca(2+]. Presynaptic electroporation infusion of the 14-amino acid C-terminus of SNAP-25 (Ct-SNAP-25, to scavenge Gβγ, reduced both the transient presynaptic inhibition produced by the group II metabotropic glutamate receptor stimulation, and LTD. Furthermore, presynaptic infusion of mSIRK, a second, structurally distinct Gβγ scavenging peptide, also blocked the induction of LTD. While Gβγ binds directly to and inhibit voltage-dependent Ca(2+ channels, imaging of presynaptic [Ca(2+] with Mg-Green revealed that low-frequency stimulation
Briggs, William M.
2012-01-01
The probability leakage of model M with respect to evidence E is defined. Probability leakage is a kind of model error. It occurs when M implies that events $y$, which are impossible given E, have positive probability. Leakage does not imply model falsification. Models with probability leakage cannot be calibrated empirically. Regression models, which are ubiquitous in statistical practice, often evince probability leakage.
LTP is accompanied by an enhanced local excitability of pyramidal neuron dendrites.
Frick, Andreas; Magee, Jeffrey; Johnston, Daniel
2004-02-01
The propagation and integration of signals in the dendrites of pyramidal neurons is regulated, in part, by the distribution and biophysical properties of voltage-gated ion channels. It is thus possible that any modification of these channels in a specific part of the dendritic tree might locally alter these signaling processes. Using dendritic and somatic whole-cell recordings, combined with calcium imaging in rat hippocampal slices, we found that the induction of long-term potentiation (LTP) was accompanied by a local increase in dendritic excitability that was dependent on the activation of NMDA receptors. These changes favored the back-propagation of action potentials into this dendritic region with a subsequent boost in the Ca(2+) influx. Dendritic cell-attached patch recordings revealed a hyperpolarized shift in the inactivation curve of transient, A-type K(+) currents that can account for the enhanced excitability. These results suggest an important mechanism associated with LTP for shaping signal processing and controlling dendritic function.
Performance of the upgraded LTP-II at the ALS Optical Metrology Laboratory
Advanced Light Source; Yashchuk, Valeriy V; Kirschman, Jonathan L.; Domning, Edward E.; McKinney, Wayne R.; Morrison, Gregory Y.; Smith, Brian V.; Yashchuk, Valeriy V.
2008-07-14
The next generation of synchrotrons and free electron laser facilities requires x-ray optical systems with extremely high performance, generally of diffraction limited quality. Fabrication and use of such optics requires adequate, highly accurate metrology and dedicated instrumentation. Previously, we suggested ways to improve the performance of the Long Trace Profiler (LTP), a slope measuring instrument widely used to characterize x-ray optics at long spatial wavelengths. The main way is use of a CCD detector and corresponding technique for calibration of photo-response non-uniformity [J. L. Kirschman, et al., Proceedings of SPIE 6704, 67040J (2007)]. The present work focuses on the performance and characteristics of the upgraded LTP-II at the ALS Optical Metrology Laboratory. This includes a review of the overall aspects of the design, control system, the movement and measurement regimes for the stage, and analysis of the performance by a slope measurement of a highly curved super-quality substrate with less than 0.3 microradian (rms)slope variation.
Non-linear parameter estimation for the LTP experiment: analysis of an operational exercise
Congedo, G; Ferraioli, L; Hueller, M; Vitale, S; Hewitson, M; Nofrarias, M; Monsky, A; Armano, M; Grynagier, A; Diaz-Aguilo, M; Plagnol, E; Rais, B
2011-01-01
The precursor ESA mission LISA-Pathfinder, to be flown in 2013, aims at demonstrating the feasibility of the free-fall, necessary for LISA, the upcoming space-born gravitational wave observatory. LISA Technology Package (LTP) is planned to carry out a number of experiments, whose main targets are to identify and measure the disturbances on each test-mass, in order to reach an unprecedented low-level residual force noise. To fulfill this plan, it is then necessary to correctly design, set-up and optimize the experiments to be performed on-flight and do a full system parameter estimation. Here we describe the progress on the non-linear analysis using the methods developed in the framework of the \\textit{LTPDA Toolbox}, an object-oriented MATLAB Data Analysis environment: the effort is to identify the critical parameters and remove the degeneracy by properly combining the results of different experiments coming from a closed-loop system like LTP.
The LTP Experiment on LISA Pathfinder: Operational Definition of TT Gauge in Space
Armano, Michele
2011-01-01
The European Space Agency (ESA) and the National Aeronautics and Space Administration (NASA) are planning the Laser Interferometer Space Antenna (LISA) mission in order to detect GW. The need of accurate testing of free-fall and knowledge of noise in a space environment similar to LISA's is considered mandatory a pre-phase for the project. Therefore the LISA Pathfinder mission has been designed by ESA to fly the LISA Technology Package (LTP), aiming at testing free-fall by measuring the residual acceleration between two test-bodies in the dynamical scheme we address as "drag-free". The spectral map of the residual acceleration as function of frequency will convey information on the local noise level, thus producing a picture of the environmental working conditions for LISA itself. The thesis contains abundant material on the problem of compensating static gravity, the development of a theory of orthogonalization of reference and cross-talk for the LTP experiment. The construction of the laser detection proced...
Nair, Rajeevkumar R.; Patil, Sudarshan; Tiron, Adrian; Kanhema, Tambudzai; Panja, Debabrata; Schiro, Lars; Parobczak, Kamil; Wilczynski, Grzegorz; Bramham, Clive R.
2017-01-01
Activity-regulatedcytoskeleton-associated protein (Arc) protein is implicated as a master regulator of long-term forms of synaptic plasticity and memory formation, but the mechanisms controlling Arc protein function are little known. Post-translation modification by small ubiquitin-like modifier (SUMO) proteins has emerged as a major mechanism for regulating protein-protein interactions and function. We first show in cell lines that ectopically expressed Arc undergoes mono-SUMOylation. The covalent addition of a single SUMO1 protein was confirmed by in vitro SUMOylation of immunoprecipitated Arc. To explore regulation of endogenous Arc during synaptic plasticity, we induced long-term potentiation (LTP) in the dentate gyrus of live anesthetized rats. Using coimmunoprecipitation of native proteins, we show that Arc synthesized during the maintenance phase of LTP undergoes dynamic mono-SUMO1-ylation. Levels of unmodified Arc increase in multiple subcellular fractions (cytosol, membrane, nuclear and cytoskeletal), whereas enhanced Arc SUMOylation was specific to the synaptoneurosomal and the cytoskeletal fractions. Dentate gyrus LTP consolidation requires a period of sustained Arc synthesis driven by brain-derived neurotrophic factor (BDNF) signaling. Local infusion of the BDNF scavenger, TrkB-Fc, during LTP maintenance resulted in rapid reversion of LTP, inhibition of Arc synthesis and loss of enhanced Arc SUMO1ylation. Furthermore, coimmunoprecipitation analysis showed that SUMO1-ylated Arc forms a complex with the F-actin-binding protein drebrin A, a major regulator of cytoskeletal dynamics in dendritic spines. Although Arc also interacted with dynamin 2, calcium/calmodulindependentprotein kinase II-beta (CaMKIIβ), and postsynaptic density protein-95 (PSD-95), these complexes lacked SUMOylated Arc. The results support a model in which newly synthesized Arc is SUMOylated and targeted for actin cytoskeletal regulation during in vivo LTP. PMID:28553222
张俊芳; 姚仁太; 徐向军
2013-01-01
This paper simulated the potential impact of radioactive material from the Fukushima accident to the surrounding areas with China as an area of special concern. Using the five-year meteorological data in Spring during 2004—2008 as input, the forward 3D trajectories started 8 times a day at 50 m high above four simulated releasing points, which were ± 0. 2° latitude and longitude centering around the Fukushima Daiichi Nuclear Power Plant was calculated with an interval of 3 h and a trajectory length of 5 d. By means of cluster analysis to results of trajectory calculation, the atmospheric transport pathways of all the 14 720 trajectories derived were obtained that enabled the following statistical analysis to the frequency of radioactive material in reaching interest region as well the probability field of atmospheric transport and rapid migration. The results showed a relatively low frequency in Spring with its peak appeared in May. For instance the frequency of radioactive material arriving in Harbin in May is 0. 9% , Shanghai 0.6% , Taiwan 0. 2% , and Beijing 0. 1% with an average migration time of 3. 2 d, 4. 2 d, 4. 5 d and 4. 6 d respectively. The lowest frequency showed in March, the frequency of radioactive material arriving in Taiwan in March is merely 0. 1% , for Harbin is 0. 1% and 0 for the rest of areas concerned in our country. The probability field of atmospheric transport and rapid migration from the Fukushima Daiichi Nuclear Power Plant are consistent with the impact analysis results of trajectories. Meanwhile, the impact of probability field to other regions can be observed from the results.%模拟了福岛核事故放射性物质释放对周边地区,尤其是对我国关心区域的影响,利用2004年至2008年3-5月五年间的气象数据,以日本福岛第一核电站为中心,考虑经纬度各±0.2°的区域设置4个释放点,计算福岛核电站每天8次的正向3D轨迹,轨迹的起始高度为50 m,轨迹时间间隔为3h
Koo, Reginald; Jones, Martin L.
2011-01-01
Quite a number of interesting problems in probability feature an event with probability equal to 1/e. This article discusses three such problems and attempts to explain why this probability occurs with such frequency.
Goldberg, Samuel
1960-01-01
Excellent basic text covers set theory, probability theory for finite sample spaces, binomial theorem, probability distributions, means, standard deviations, probability function of binomial distribution, more. Includes 360 problems with answers for half.
Koo, Reginald; Jones, Martin L.
2011-01-01
Quite a number of interesting problems in probability feature an event with probability equal to 1/e. This article discusses three such problems and attempts to explain why this probability occurs with such frequency.
Swant, Jarod; Wagner, John J.
2006-01-01
Dopamine has been demonstrated to be involved in the modulation of long-term potentiation (LTP) in the CA1 region of the hippocampus. As monoamine transporter blockade will increase the actions of endogenous monoamine neurotransmitters, the effect of a dopamine transporter (DAT) antagonist on LTP was assessed using field excitatory postsynaptic…
Fang Liu
Full Text Available Plant non-specific lipid transfer proteins (nsLTPs constitute large multigene families that possess complex physiological functions, many of which remain unclear. This study isolated and characterized the function of a lipid transfer protein gene, BraLTP1 from Brassica rapa, in the important oilseed crops Brassica napus. BraLTP1 encodes a predicted secretory protein, in the little known VI Class of nsLTP families. Overexpression of BnaLTP1 in B. napus caused abnormal green coloration and reduced wax deposition on leaves and detailed wax analysis revealed 17-80% reduction in various major wax components, which resulted in significant water-loss relative to wild type. BnaLTP1 overexpressing leaves exhibited morphological disfiguration and abaxially curled leaf edges, and leaf cross-sections revealed cell overproliferation that was correlated to increased cytokinin levels (tZ, tZR, iP, and iPR in leaves and high expression of the cytokinin biosynthsis gene IPT3. BnaLTP1-overexpressing plants also displayed morphological disfiguration of flowers, with early-onset and elongated carpel development and outwardly curled stamen. This was consistent with altered expression of a a number of ABC model genes related to flower development. Together, these results suggest that BraLTP1 is a new nsLTP gene involved in wax production or deposition, with additional direct or indirect effects on cell division and flower development.
Quantum probability measures and tomographic probability densities
Amosov, GG; Man'ko, [No Value
2004-01-01
Using a simple relation of the Dirac delta-function to generalized the theta-function, the relationship between the tomographic probability approach and the quantum probability measure approach with the description of quantum states is discussed. The quantum state tomogram expressed in terms of the
Agreeing Probability Measures for Comparative Probability Structures
P.P. Wakker (Peter)
1981-01-01
textabstractIt is proved that fine and tight comparative probability structures (where the set of events is assumed to be an algebra, not necessarily a σ-algebra) have agreeing probability measures. Although this was often claimed in the literature, all proofs the author encountered are not valid
Schildt, Sandra; Endres, Thomas; Lessmann, Volkmar; Edelmann, Elke
2013-08-01
Brain-derived neurotrophic factor (BDNF) signaling via TrkB crucially regulates synaptic plasticity in the brain. Although BDNF is abundant at hippocampal mossy fiber (MF) synapses, which critically contribute to hippocampus dependent memory, its role in MF synaptic plasticity (long-term potentiation, LTP) remained largely unclear. Using field potential recordings in CA3 of adult heterozygous BDNF knockout (ko, BDNF+/-) mice we observed impaired (∼50%) NMDAR-independent MF-LTP. In contrast to MF synapses, LTP at neighboring associative/commissural (A/C) fiber synapses remained unaffected. To exclude that impaired MF-LTP in BDNF+/- mice was due to developmental changes in response to chronically reduced BDNF levels, and to prove the importance of acute availability of BDNF in MF-LTP, we also tested effects of acute interference with BDNF/TrkB signaling. Inhibition of TrkB tyrosine kinase signaling with k252a, or with the selective BDNF scavenger TrkB-Fc, both inhibited MF-LTP to the same extent as observed in BDNF+/- mice. Basal synaptic transmission, short-term plasticity, and synaptic fatigue during LTP induction were not significantly altered by treatment with k252a or TrkB-Fc, or by chronic BDNF reduction in BDNF+/- mice. Since the acute interference with BDNF-signaling did not completely block MF-LTP, our results provide evidence that an additional mechanism besides BDNF induced TrkB signaling contributes to this type of LTP. Our results prove for the first time a mechanistic action of acute BDNF/TrkB signaling in presynaptic expression of MF-LTP in adult hippocampus.
Huang, Yan-You; Lavine, Amir; Kandel, Denise B.; Yin, Deqi; Colnaghi, Luca; Drisaldi, Bettina; Kandel, Eric R.
2014-01-01
The dentate gyrus (DG) of the hippocampus is critical for spatial memory and is also thought to be involved in the formation of drug-related associative memory. Here, we attempt to test an aspect of the Gateway Hypothesis, by studying the effect of consecutive exposure to nicotine and cocaine on long-term synaptic potentiation (LTP) in the DG. We…
Bonsi, Paola; De Persis, Cristiano; Calabresi, Paolo; Bernardi, Giorgio; Pisani, Antonio
2004-01-01
Current evidence appoints a central role to cholinergic interneurons in modulating striatal function. Recently, a long-term potentiation (LTP) of synaptic transmission has been reported to occur in these neurons. The relationship between the pattern of cortico/thalamostriatal fibers stimulation, the consequent changes in the intracellular calcium…
Pang, Petti T.; Nagappan, Guhan; Guo, Wei; Lu, Bai
2016-05-01
Although late-phase long-term potentiation (L-LTP) is implicated in long-term memory, its molecular mechanisms are largely unknown. Here we provide evidence that L-LTP can be divided into two stages: an induction stage (I) and a maintenance stage (II). Both stages require mature brain-derived neurotrophic factor (mBDNF), but involve distinct underlying mechanisms. Stage I requires secretion of existing proBDNF followed by extracellular cleavage by tPA/plasmin. Stage II depends on newly synthesized BDNF. Surprisingly, mBDNF at stage II is derived from intracellular cleavage of proBDNF by furin/PC1. Moreover, stage I involves BDNF-TrkB signaling mainly through MAP kinase, whereas all three signaling pathways (phospholipase C-γ, PI3 kinase, and MAP kinase) are required for the maintenance of L-LTP at stage II. These results reveal the molecular basis for two temporally distinct stages in L-LTP, and provide insights on how BDNF modulates this long-lasting synaptic alternation at two critical time windows.
Qi, Yingjie; Hu, Neng-Wei; Rowan, Michael J
2013-04-01
Both electrically induced synaptic long-term potentiation (LTP) and long-term depression have been extensively studied as models of the cellular basis of learning and memory mechanisms. Recently, considerable interest has been generated by the possibility that the activity-dependent persistent reversal of previously established synaptic LTP (depotentiation) may play a role in the time- and state-dependent erasure of memory. Here, we examined the requirement for glutamate receptor activation in experience-induced reversal of previously established LTP in the CA1 area of the hippocampus of freely behaving rats. Continuous exploration of non-aversive novelty for ~30 min, which was associated with hippocampal activation as measured by increased theta power in the electroencephalogram, triggered a rapid and persistent reversal of high frequency stimulation-induced LTP both at apical and basal synapses. Blockade of metabotropic glutamate (mGlu) receptors with mGlu5 subtype-selective antagonists, or N-methyl-D-aspartate (NMDA) receptors with GluN2B subunit-selective antagonists, prevented novelty-induced depotentiation. These findings strongly indicate that activation of both mGlu5 receptors and GluN2B-containing NMDA receptors is required for experience-triggered induction of depotentiation at CA3-CA1 synapses. The mechanistic concordance of the present and previous studies of experience-induced and electrically induced synaptic depotentiation helps to integrate our understanding of the neurophysiological underpinnings of learning and memory.
Huang, Yan-You; Lavine, Amir; Kandel, Denise B.; Yin, Deqi; Colnaghi, Luca; Drisaldi, Bettina; Kandel, Eric R.
2014-01-01
The dentate gyrus (DG) of the hippocampus is critical for spatial memory and is also thought to be involved in the formation of drug-related associative memory. Here, we attempt to test an aspect of the Gateway Hypothesis, by studying the effect of consecutive exposure to nicotine and cocaine on long-term synaptic potentiation (LTP) in the DG. We…
Arnold, Andrew J; Razavieh, Ali; Nasr, Joseph R; Schulman, Daniel S; Eichfeld, Chad M; Das, Saptarshi
2017-03-10
Neurotransmitter release in chemical synapses is fundamental to diverse brain functions such as motor action, learning, cognition, emotion, perception, and consciousness. Moreover, improper functioning or abnormal release of neurotransmitter is associated with numerous neurological disorders such as epilepsy, sclerosis, schizophrenia, Alzheimer's disease, and Parkinson's disease. We have utilized hysteresis engineering in a back-gated MoS2 field effect transistor (FET) in order to mimic such neurotransmitter release dynamics in chemical synapses. All three essential features, i.e., quantal, stochastic, and excitatory or inhibitory nature of neurotransmitter release, were accurately captured in our experimental demonstration. We also mimicked an important phenomenon called long-term potentiation (LTP), which forms the basis of human memory. Finally, we demonstrated how to engineer the LTP time by operating the MoS2 FET in different regimes. Our findings could provide a critical component toward the design of next-generation smart and intelligent human-like machines and human-machine interfaces.
Tamano, Haruna; Minamino, Tatsuya; Fujii, Hiroaki; Takada, Shunsuke; Nakamura, Masatoshi; Ando, Masaki; Takeda, Atsushi
2015-08-01
There is no evidence on the precise role of synaptic Zn2+ signaling on the retention and recall of recognition memory. On the basis of the findings that intracellular Zn2+ signaling in the dentate gyrus is required for object recognition, short-term memory, the present study deals with the effect of spatiotemporally blocking Zn2+ signaling in the dentate gyrus after LTP induction and learning. Three-day-maintained LTP was impaired 1 day after injection of clioquinol into the dentate gyrus, which transiently reduced intracellular Zn2+ signaling in the dentate gyrus. The irreversible impairment was rescued not only by co-injection of ZnCl2 , which ameliorated the loss of Zn2+ signaling, but also by pre-injection of Jasplakinolide, a stabilizer of F-actin, prior to clioquinol injection. Simultaneously, 3-day-old space recognition memory was impaired 1 day after injection of clioquinol into the dentate gyrus, but not by pre-injection of Jasplakinolide. Jasplakinolide also rescued both impairments of 3-day-maintained LTP and 3-day-old memory after injection of ZnAF-2DA into the dentate gyrus, which blocked intracellular Zn2+ signaling in the dentate gyrus. The present paper indicates that the blockade and/or loss of intracellular Zn2+ signaling in the dentate gyrus coincidently impair maintained LTP and recognition memory. The mechanism maintaining LTP via intracellular Zn2+ signaling in dentate granule cells, which may be involved in the formation of F-actin, may retain space recognition memory. © 2015 Wiley Periodicals, Inc.
Alzoubi, K H; Alkadhi, K A
2014-06-01
We have previously shown that adult onset hypothyroidism impairs late-phase long-term potentiation (L-LTP) and reduces basal protein levels of cyclic-AMP response element binding protein (CREB), mutagen-activated protein kinase (MAPKp42/44), and calcium calmodulin kinase IV (CaMKIV) in area Cornu Ammonis 1 (CA1) of the hippocampus. These changes were reversed by chronic nicotine treatment. In the present study, levels of signaling molecules important for L-LTP were determined in CA1 area of the hippocampus during the induction phase. Standard multiple high-frequency stimulation (MHFS) was used to evoke L-LTP in the CA1 area of the hippocampus of hypothyroid, nicotine-treated hypothyroid, nicotine, and sham control anaesthetized adult rats. Chronic nicotine treatment reversed hypothyroidism-induced impairment of L-LTP at the induction phase. Five minutes after MHFS, Western blotting showed an increase in the levels of P-CREB, and P-MAPKp42/44 in sham-operated control, nicotine, and nicotine-treated hypothyroid animals, but not in hypothyroid animals. The protein levels of total CREB, total MAPK p42/44, BDNF, and CaMKIV were not altered in all groups 5 min after MHFS. Therefore, normalized phosphorylation of essential kinases such as P-CREB and P-MAPK p42/44 in the CA1 area of nicotine-treated hypothyroid animals plays a crucial role in nicotine-induced rescue of L-LTP induction during hypothyroidism.
Probability and Relative Frequency
Drieschner, Michael
2016-01-01
The concept of probability seems to have been inexplicable since its invention in the seventeenth century. In its use in science, probability is closely related with relative frequency. So the task seems to be interpreting that relation. In this paper, we start with predicted relative frequency and show that its structure is the same as that of probability. I propose to call that the `prediction interpretation' of probability. The consequences of that definition are discussed. The "ladder"-structure of the probability calculus is analyzed. The expectation of the relative frequency is shown to be equal to the predicted relative frequency. Probability is shown to be the most general empirically testable prediction.
Elements of probability theory
Rumshiskii, L Z
1965-01-01
Elements of Probability Theory presents the methods of the theory of probability. This book is divided into seven chapters that discuss the general rule for the multiplication of probabilities, the fundamental properties of the subject matter, and the classical definition of probability. The introductory chapters deal with the functions of random variables; continuous random variables; numerical characteristics of probability distributions; center of the probability distribution of a random variable; definition of the law of large numbers; stability of the sample mean and the method of moments
Evaluating probability forecasts
Lai, Tze Leung; Shen, David Bo; 10.1214/11-AOS902
2012-01-01
Probability forecasts of events are routinely used in climate predictions, in forecasting default probabilities on bank loans or in estimating the probability of a patient's positive response to treatment. Scoring rules have long been used to assess the efficacy of the forecast probabilities after observing the occurrence, or nonoccurrence, of the predicted events. We develop herein a statistical theory for scoring rules and propose an alternative approach to the evaluation of probability forecasts. This approach uses loss functions relating the predicted to the actual probabilities of the events and applies martingale theory to exploit the temporal structure between the forecast and the subsequent occurrence or nonoccurrence of the event.
Jeremy T T Kennard
Full Text Available The persistence and input specificity of long-term potentiation (LTP make it attractive as a mechanism of information storage. In its initial phase, both in vivo and in vitro studies have shown that LTP is associated with increased membrane localization of AMPA receptor subunits, but the molecular basis of LTP maintenance over the long-term is still unclear. We have previously shown that expression of AMPA and NMDA receptor subunits is elevated in whole homogenates prepared from dentate gyrus 48 h after LTP induction in vivo. In the present study, we utilized laser microdissection (LMD techniques to determine whether AMPA and NMDA receptor upregulation occurs specifically in the stimulated regions of the dentate gyrus dendritic arbor. Receptor proteins GluN1, GluA1 and GluA2, as well as postsynaptic density protein of 95 kDa and tubulin were detected by Western blot analysis in microdissected samples. Gradients of expression were observed for GluN1 and GluA2, decreasing from the inner to the outer zones of the molecular layer, and were independent of LTP. When induced at medial perforant path synapses, LTP was associated with an apparent specific redistribution of GluA1 and GluN1 to the middle molecular layer that contains these synapses. These data indicate that glutamate receptor proteins are delivered specifically to dendritic regions possessing LTP-expressing synapses, and that these changes are preserved for at least 48 h.
Baniekal Hiremath Gangadhar
2016-08-01
Full Text Available Abiotic stresses such as heat, drought and salinity are major environmental constraints that limit potato (Solanum tuberosum L. production worldwide. Previously, we found a potential thermo-tolerance gene, named StnsLTP1 from potato using yeast functional screening. Here, we report the functional characterization of StnsLTP1 and its role in multiple abiotic stresses in potato plants. Computational analysis of StnsLTP1 with other plant LTPs showed eight conserved cysteine residues, and four α-helices stabilized by four disulfide bridges. Expression analysis of StnsLTP1 gene showed differential expression under heat, water-deficit and salt stresses. Transgenic potato lines over-expressing StnsLTP1 gene displayed enhanced cell membrane integrity under stress conditions, as indicated by reduced membrane lipid per-oxidation, and hydrogen peroxide content relative to untransformed (UT control plants. In addition, transgenic lines over-expressing StLTP1 also exhibited increased antioxidant enzyme activity with enhanced accumulation of ascorbates, and up-regulation of stress-related genes including StAPX, StCAT, StSOD, StHsfA3, StHSP70, and StsHSP20 compared with the UT plants. These results suggests that StnsLTP1 transgenic plants acquired improved tolerance to multiple abiotic stresses through enhanced activation of antioxidative defense mechanisms via cyclic scavenging of reactive oxygen species (ROS and regulated expression of stress-related genes.
Bowden, Jared B; Abraham, Wickliffe C; Harris, Kristen M
2012-06-01
Because long-term potentiation (LTP) and long-term depression (LTD) are thought to be involved in learning and memory, it is important to delineate factors that modulate their induction and persistence, especially as studied in freely moving animals. Here, we investigated the effects of rat strain, circadian cycle, and high-frequency stimulation (HFS) pattern on LTP and concurrently induced LTD in the dentate gyrus (DG). Comparison of two commonly used rat strains revealed that medial perforant path field EPSP-population spike (E-S) coupling and LTP were greater in Long-Evans than Sprague-Dawley rats. Circadian cycle experiments conducted in Long-Evans rats revealed greater E-S coupling and enhanced LTP during the dark phase. Interestingly, concurrent LTD in the lateral perforant path did not significantly differ across strains or circadian cycle. Testing HFS protocols during the dark phase revealed that theta burst stimulation (100 Hz bursts at 5 Hz intervals) was ineffective in eliciting either LTP or concurrent LTD in DG, whereas 400 Hz bursts delivered at theta (5 Hz) or delta (1 Hz) frequencies produced substantial LTP and concurrent LTD. Thus, these natural and experimental factors regulate granule cell excitability, and differentially affect LTP and concurrent LTD in the DG of freely moving rats. © 2011 Wiley Periodicals, Inc.
The National Aquatic Resource Surveys (NARS) use probability-survey designs to assess the condition of the nation’s waters. In probability surveys (also known as sample-surveys or statistical surveys), sampling sites are selected randomly.
杨姝; 石玉秀
2011-01-01
创伤后应激障碍(Post-traumatic stress disorder,PTSD)是由于异常威胁性或灾难性心理创伤导致延迟出现和长期持续的精神障碍.长时程增强(Long term potentiation,LTP)是目前公认的代表学习记忆功能的电生理指标.LTP受体主要分为NMDA型和非NMDA型,LTP相关酶类及营养物质在LTP的形成及维持过程中起重要作用.在恐惧条件反射的形成过程中,其神经网络内(如杏仁核等)发生LTP,表明LTP是反应PTSD发生机制的重要指标.因此,通过研究影响LTP发生及维持的因素,可能进而推测出治疗PTSD的方法.%Post-traumatic stress disorder(PTSD) is an anxiety disorder that can develop after exposure to one or more traumatic events threatened or caused grave physical harm. Long term potentiation (LTP) is widely recognized as the electrophysiological parameter which represents learning and memory function. The receptors of LTP are divided into NMDA receptor type and non-NMDA-type, LTP-related enzymes and nutrients may play an important role in the formation and maintenance of LTP in the process. In fear conditioning, the formation of LTP in the neural network (such as the amygdala,etc.) indicates that LTP is an important indicator for the occurrence of PTSD. Therefore, study of the impact of the occurrence and maintenance factors of LTP may thus speculate ways to treat PTSD.
Roussas, George G
2006-01-01
Roussas's Introduction to Probability features exceptionally clear explanations of the mathematics of probability theory and explores its diverse applications through numerous interesting and motivational examples. It provides a thorough introduction to the subject for professionals and advanced students taking their first course in probability. The content is based on the introductory chapters of Roussas's book, An Intoduction to Probability and Statistical Inference, with additional chapters and revisions. Written by a well-respected author known for great exposition an
Philosophical theories of probability
Gillies, Donald
2000-01-01
The Twentieth Century has seen a dramatic rise in the use of probability and statistics in almost all fields of research. This has stimulated many new philosophical ideas on probability. Philosophical Theories of Probability is the first book to present a clear, comprehensive and systematic account of these various theories and to explain how they relate to one another. Gillies also offers a distinctive version of the propensity theory of probability, and the intersubjective interpretation, which develops the subjective theory.
Edwards, William F.; Shiflett, Ray C.; Shultz, Harris
2008-01-01
The mathematical model used to describe independence between two events in probability has a non-intuitive consequence called dependent spaces. The paper begins with a very brief history of the development of probability, then defines dependent spaces, and reviews what is known about finite spaces with uniform probability. The study of finite…
Benci, Vieri; Horsten, Leon; Wenmackers, Sylvia
We propose an alternative approach to probability theory closely related to the framework of numerosity theory: non-Archimedean probability (NAP). In our approach, unlike in classical probability theory, all subsets of an infinite sample space are measurable and only the empty set gets assigned
Interpretations of probability
Khrennikov, Andrei
2009-01-01
This is the first fundamental book devoted to non-Kolmogorov probability models. It provides a mathematical theory of negative probabilities, with numerous applications to quantum physics, information theory, complexity, biology and psychology. The book also presents an interesting model of cognitive information reality with flows of information probabilities, describing the process of thinking, social, and psychological phenomena.
Benci, Vieri; Horsten, Leon; Wenmackers, Sylvia
2013-01-01
We propose an alternative approach to probability theory closely related to the framework of numerosity theory: non-Archimedean probability (NAP). In our approach, unlike in classical probability theory, all subsets of an infinite sample space are measurable and only the empty set gets assigned prob
Dynamical Simulation of Probabilities
Zak, Michail
1996-01-01
It has been demonstrated that classical probabilities, and in particular, probabilistic Turing machine, can be simulated by combining chaos and non-Lipschitz dynamics, without utilization of any man-made devices(such as random number generators). Self-orgainizing properties of systems coupling simulated and calculated probabilities and their link to quantum computations are discussed. Special attention was focused upon coupled stochastic processes, defined in terms of conditional probabilities, for which joint probability does not exist. Simulations of quantum probabilities are also discussed.
Childers, Timothy
2013-01-01
Probability is increasingly important for our understanding of the world. What is probability? How do we model it, and how do we use it? Timothy Childers presents a lively introduction to the foundations of probability and to philosophical issues it raises. He keeps technicalities to a minimum, and assumes no prior knowledge of the subject. He explains the main interpretations of probability-frequentist, propensity, classical, Bayesian, and objective Bayesian-and uses stimulatingexamples to bring the subject to life. All students of philosophy will benefit from an understanding of probability,
Gómez-Gonzalo, Marta; Navarrete, Marta; Perea, Gertrudis; Covelo, Ana; Martín-Fernández, Mario; Shigemoto, Ryuichi; Luján, Rafael; Araque, Alfonso
2015-10-01
Endocannabinoids (eCBs) play key roles in brain function, acting as modulatory signals in synaptic transmission and plasticity. They are recognized as retrograde messengers that mediate long-term synaptic depression (LTD), but their ability to induce long-term potentiation (LTP) is poorly known. We show that eCBs induce the long-term enhancement of transmitter release at single hippocampal synapses through stimulation of astrocytes when coincident with postsynaptic activity. This LTP requires the coordinated activity of the 3 elements of the tripartite synapse: 1) eCB-evoked astrocyte calcium signal that stimulates glutamate release; 2) postsynaptic nitric oxide production; and 3) activation of protein kinase C and presynaptic group I metabotropic glutamate receptors, whose location at presynaptic sites was confirmed by immunoelectron microscopy. Hence, while eCBs act as retrograde signals to depress homoneuronal synapses, they serve as lateral messengers to induce LTP in distant heteroneuronal synapses through stimulation of astrocytes. Therefore, eCBs can trigger LTP through stimulation of astrocyte-neuron signaling, revealing novel cellular mechanisms of eCB effects on synaptic plasticity.
Abreu, P; Ahn, E J; Albuquerque, I F M; Allard, D; Allekotte, I; Allen, J; Allison, P; Castillo, J Alvarez; Alvarez-Muñiz, J; Ambrosio, M; Aminaei, A; Anchordoqui, L; Andringa, S; Antičić, T; Anzalone, A; Aramo, C; Arganda, E; Arqueros, F; Asorey, H; Assis, P; Aublin, J; Ave, M; Avenier, M; Avila, G; Bäcker, T; Balzer, M; Barber, K B; Barbosa, A F; Bardenet, R; Barroso, S L C; Baughman, B; Bäuml, J; Beatty, J J; Becker, B R; Becker, K H; Bellétoile, A; Bellido, J A; BenZvi, S; Berat, C; Bertou, X; Biermann, P L; Billoir, P; Blanco, F; Blanco, M; Bleve, C; Blümer, H; Boháčová, M; Boncioli, D; Bonifazi, C; Bonino, R; Borodai, N; Brack, J; Brogueira, P; Brown, W C; Bruijn, R; Buchholz, P; Bueno, A; Burton, R E; Caballero-Mora, K S; Caramete, L; Caruso, R; Castellina, A; Catalano, O; Cataldi, G; Cazon, L; Cester, R; Chauvin, J; Cheng, S H; Chiavassa, A; Chinellato, J A; Chou, A; Chudoba, J; Clay, R W; Coluccia, M R; Conceição, R; Contreras, F; Cook, H; Cooper, M J; Coppens, J; Cordier, A; Coutu, S; Covault, C E; Creusot, A; Criss, A; Cronin, J; Curutiu, A; Dagoret-Campagne, S; Dallier, R; Dasso, S; Daumiller, K; Dawson, B R; de Almeida, R M; De Domenico, M; De Donato, C; de Jong, S J; De La Vega, G; Junior, W J M de Mello; Neto, J R T de Mello; De Mitri, I; de Souza, V; de Vries, K D; Decerprit, G; del Peral, L; del Río, M; Deligny, O; Dembinski, H; Dhital, N; Di Giulio, C; Diaz, J C; Castro, M L Díaz; Diep, P N; Dobrigkeit, C; Docters, W; D'Olivo, J C; Dong, P N; Dorofeev, A; Anjos, J C dos; Dova, M T; D'Urso, D; Dutan, I; Ebr, J; Engel, R; Erdmann, M; Escobar, C O; Espadanal, J; Etchegoyen, A; Luis, P Facal San; Tapia, I Fajardo; Falcke, H; Farrar, G; Fauth, A C; Fazzini, N; Ferguson, A P; Ferrero, A; Fick, B; Filevich, A; Filipčič, A; Fliescher, S; Fracchiolla, C E; Fraenkel, E D; Fröhlich, U; Fuchs, B; Gaior, R; Gamarra, R F; Gambetta, S; García, B; Gámez, D García; Garcia-Pinto, D; Gascon, A; Gemmeke, H; Gesterling, K; Ghia, P L; Giaccari, U; Giller, M; Glass, H; Gold, M S; Golup, G; Albarracin, F Gomez; Berisso, M Gómez; Gonçalves, P; Gonzalez, D; Gonzalez, J G; Gookin, B; Góra, D; Gorgi, A; Gouffon, P; Gozzini, S R; Grashorn, E; Grebe, S; Griffith, N; Grigat, M; Grillo, A F; Guardincerri, Y; Guarino, F; Guedes, G P; Guzman, A; Hague, J D; Hansen, P; Harari, D; Harmsma, S; Harton, J L; Haungs, A; Hebbeker, T; Heck, D; Herve, A E; Hojvat, C; Hollon, N; Holmes, V C; Homola, P; Hörandel, J R; Horneffer, A; Hrabovský, M; Huege, T; Insolia, A; Ionita, F; Italiano, A; Jarne, C; Jiraskova, S; Josebachuili, M; Kadija, K; Kampert, K H; Karhan, P; Kasper, P; Kégl, B; Keilhauer, B; Keivani, A; Kelley, J L; Kemp, E; Kieckhafer, R M; Klages, H O; Kleifges, M; Kleinfeller, J; Knapp, J; Koang, D -H; Kotera, K; Krohm, N; Krömer, O; Kruppke-Hansen, D; Kuehn, F; Kuempel, D; Kulbartz, J K; Kunka, N; La Rosa, G; Lachaud, C; Lautridou, P; Leão, M S A B; Lebrun, D; Lebrun, P; de Oliveira, M A Leigui; Lemiere, A; Letessier-Selvon, A; Lhenry-Yvon, I; Link, K; López, R; Agüera, A Lopez; Louedec, K; Bahilo, J Lozano; Lu, L; Lucero, A; Ludwig, M; Lyberis, H; Maccarone, M C; Macolino, C; Maldera, S; Mandat, D; Mantsch, P; Mariazzi, A G; Marin, J; Marin, V; Maris, I C; Falcon, H R Marquez; Marsella, G; Martello, D; Martin, L; Martinez, H; Bravo, O Martínez; Mathes, H J; Matthews, J; Matthews, J A J; Matthiae, G; Maurizio, D; Mazur, P O; Medina-Tanco, G; Melissas, M; Melo, D; Menichetti, E; Menshikov, A; Mertsch, P; Meurer, C; Mićanović, S; Micheletti, M I; Miller, W; Miramonti, L; Molina-Bueno, L; Mollerach, S; Monasor, M; Ragaigne, D Monnier; Montanet, F; Morales, B; Morello, C; Moreno, E; Moreno, J C; Morris, C; Mostafá, M; Moura, C A; Mueller, S; Muller, M A; Müller, G; Münchmeyer, M; Mussa, R; ‡, G Navarra; Navarro, J L; Navas, S; Necesal, P; Nellen, L; Nelles, A; Neuser, J; Nhung, P T; Niemietz, L; Nierstenhoefer, N; Nitz, D; Nosek, D; Nožka, L; Nyklicek, M; Oehlschläger, J; Olinto, A; Oliva, P; Olmos-Gilbaja, V M; Ortiz, M; Pacheco, N; Selmi-Dei, D Pakk; Palatka, M; Pallotta, J; Palmieri, N; Parente, G; Parizot, E; Parra, A; Parsons, R D; Pastor, S; Paul, T; Pech, M; Pękala, J; Pelayo, R; Pepe, I M; Perrone, L; Pesce, R; Petermann, E; Petrera, S; Petrinca, P; Petrolini, A; Petrov, Y; Petrovic, J; Pfendner, C; Phan, N; Piegaia, R; Pierog, T; Pieroni, P; Pimenta, M; Pirronello, V; Platino, M; Ponce, V H; Pontz, M; Privitera, P; Prouza, M; Quel, E J; Querchfeld, S; Rautenberg, J; Ravel, O; Ravignani, D; Revenu, B; Ridky, J; Riggi, S; Risse, M; Ristori, P; Rivera, H; Rizi, V; Roberts, J; Robledo, C; de Carvalho, W Rodrigues; Rodriguez, G; Martino, J Rodriguez; Rojo, J Rodriguez; Rodriguez-Cabo, I; Rodríguez-Frías, M D; Ros, G; Rosado, J; Rossler, T; Roth, M; Rouillé-d'Orfeuil, B; Roulet, E; Rovero, A C; Rühle, C; Salamida, F; Salazar, H; Salina, G; Sánchez, F; Santo, C E; Santos, E; Santos, E M; Sarazin, F; Sarkar, B; Sarkar, S; Sato, R; Scharf, N; Scherini, V; Schieler, H; Schiffer, P; Schmidt, A; Schmidt, F; Scholten, O; Schoorlemmer, H; Schovancova, J; 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Weindl, A; Westerhoff, S; Whelan, B J; Wieczorek, G; Wiencke, L; Wilczyńska, B; Wilczyński, H; Will, M; Williams, C; Winchen, T; Winnick, M G; Wommer, M; Wundheiler, B; Yamamoto, T; Yapici, T; Younk, P; Yuan, G; Yushkov, A; Zamorano, B; Zas, E; Zavrtanik, D; Zavrtanik, M; Zaw, I; Zepeda, A; Silva, M Zimbres; Ziolkowski, M
2011-01-01
In this paper we introduce the concept of Lateral Trigger Probability (LTP) function, i.e., the probability for an extensive air shower (EAS) to trigger an individual detector of a ground based array as a function of distance to the shower axis, taking into account energy, mass and direction of the primary cosmic ray. We apply this concept to the surface array of the Pierre Auger Observatory consisting of a 1.5 km spaced grid of about 1600 water Cherenkov stations. Using Monte Carlo simulations of ultra-high energy showers the LTP functions are derived for energies in the range between 10^{17} and 10^{19} eV and zenith angles up to 65 degs. A parametrization combining a step function with an exponential is found to reproduce them very well in the considered range of energies and zenith angles. The LTP functions can also be obtained from data using events simultaneously observed by the fluorescence and the surface detector of the Pierre Auger Observatory (hybrid events). We validate the Monte-Carlo results sho...
Borges, J-P; Jauneau, A; Brulé, C; Culerrier, R; Barre, A; Didier, A; Rougé, P
2006-10-01
The localization and distribution of non-specific lipid transfer proteins (nsLTP) allergens in the skin and pulp of Rosaceae fruits (apple, peach, apricot, plum) has been investigated. nsLTP essentially concentrate in the pericarp of the fruits whereas the pulp contains lower amounts of allergens. Immunolocalization showed they are primarily located in the cytosol but are subsequently excreted and finally accumulate at the plasmalemma-cell wall interface and in the cell wall. However, high discrepancies were observed in the content of allergens among, e.g. different cultivars of apple. As a consequence, the consumption of peeled-off fruits is recommended to reduce the risk of severe allergic reactions (anaphylactic shock) in individuals sensitized to Rosaceae fruits.
Lindorff-Larsen, Kresten; Lerche, Mathilde H.; Poulsen, Flemming Martin
2001-01-01
the formation of cutin and involvement in stress and pathogen responses, but there is yet no direct demonstration of an in vivo function. We have found and characterized a novel post-translational modification of the barley nonspecific lipid transfer protein, LTP1. The protein-modification bond is of a new type...... in which an aspartic acid in LTP1 is bound to the modification through what most likely is an ester bond. The chemical structure of the modification has been characterized by means of two-dimensional homo- and heteronuclear nuclear magnetic resonance spectroscopy as well as mass spectrometry and is found...... to be lipid-like in nature. The modification does not resemble any standard lipid post-translational modification but is similar to a compound with known antimicrobial activity....
Probability and radical behaviorism
Espinosa, James M.
1992-01-01
The concept of probability appears to be very important in the radical behaviorism of Skinner. Yet, it seems that this probability has not been accurately defined and is still ambiguous. I give a strict, relative frequency interpretation of probability and its applicability to the data from the science of behavior as supplied by cumulative records. Two examples of stochastic processes are given that may model the data from cumulative records that result under conditions of continuous reinforcement and extinction, respectively. PMID:22478114
Probability and radical behaviorism
Espinosa, James M.
1992-01-01
The concept of probability appears to be very important in the radical behaviorism of Skinner. Yet, it seems that this probability has not been accurately defined and is still ambiguous. I give a strict, relative frequency interpretation of probability and its applicability to the data from the science of behavior as supplied by cumulative records. Two examples of stochastic processes are given that may model the data from cumulative records that result under conditions of continuous reinforc...
STATISTICAL ANALYSIS, REPORTS), (*PROBABILITY, REPORTS), INFORMATION THEORY, DIFFERENTIAL EQUATIONS, STATISTICAL PROCESSES, STOCHASTIC PROCESSES, MULTIVARIATE ANALYSIS, DISTRIBUTION THEORY , DECISION THEORY, MEASURE THEORY, OPTIMIZATION
Ash, Robert B; Lukacs, E
1972-01-01
Real Analysis and Probability provides the background in real analysis needed for the study of probability. Topics covered range from measure and integration theory to functional analysis and basic concepts of probability. The interplay between measure theory and topology is also discussed, along with conditional probability and expectation, the central limit theorem, and strong laws of large numbers with respect to martingale theory.Comprised of eight chapters, this volume begins with an overview of the basic concepts of the theory of measure and integration, followed by a presentation of var
Florescu, Ionut
2013-01-01
THE COMPLETE COLLECTION NECESSARY FOR A CONCRETE UNDERSTANDING OF PROBABILITY Written in a clear, accessible, and comprehensive manner, the Handbook of Probability presents the fundamentals of probability with an emphasis on the balance of theory, application, and methodology. Utilizing basic examples throughout, the handbook expertly transitions between concepts and practice to allow readers an inclusive introduction to the field of probability. The book provides a useful format with self-contained chapters, allowing the reader easy and quick reference. Each chapter includes an introductio
Opsahl-Sorteberg, Hilde-Gunn; Divon, Hege Hvattum; Nielsen, Peter Stein; Kalla, Roger; Hammond-Kosack, Michael; Shimamoto, Ko; Kohli, Ajay
2004-10-27
Identification of regulatory elements directing definite and specific spatiotemporal expression patterns is a prerequisite to the next generation of transgenic plants with commercial and ethical feasibility for producing plantibodies or other pharmaceutically important compounds. Here we describe the functional dissection of the barley nonspecific lipid transfer protein gene promoter, HvLTP2. The gene is specifically expressed in aleurone cells of cereals and used as an aleurone marker in maize and rice. The transcript is uniformly localised in the barley aleurone cells from around 10 DAP. Patchy expression in aleurone cells of transgenic rice has been reported and explained by silencing of transgenes. We have performed deletion analyses of the 801-bp HvLTP2 promoter to gain insight into the molecular basis of its regulation and the presence of putative regulatory elements. From the deletion studies, a 49-bp promoter region directing aleurone-specific expression was identified. Simultaneously, in vivo footprinting was carried out to identify promoter elements bound by putative regulatory proteins. Within the 49-bp fragment, the most promising candidate for a minimal cis-acting regulatory region directing aleurone specificity is the ds-sequence. Based on our results, we hypothesise that the ds-sequence directs aleurone specificity, possibly through a concerted action with elements directing general expression in the seed. Moreover, we present an overview of LTP2 elements putatively involved in directing seed, endosperm, and aleurone expression. Additionally, we report HvLTP2 expression in the embryo, not previously detected. The regulatory element(s) directing expression in embryo is located downstream of the 49-bp fragment directing aleurone specificity, thus demonstrating independent control of aleurone and embryo-localised expression. Finally, we discuss the existence of several endosperm-specific boxes and whether alternative promoter elements and combinations
Andersen, Maj-Britt Schmidt; Hall, Sharon; Dragsted, Lars Ove
2011-08-01
High fruit intakes are associated with significant health benefits but fruit allergy sufferers may be discouraged from eating fruit due to the symptoms they experience. Knowledge about allergens involved in fruit allergy and the frequent cross-reactions to other allergens is essential to (a) design the best strategy for fruit allergy testing (b) prescribe optimal avoidance diets, and (c) design technological solutions for development of hypoallergenic fruits. The objective of this review was to investigate whether some characteristic disease entities could be identified in Europe for allergy to Rosaceae fruits. Five allergy patterns were found involving the allergen families PR-10, LTP, and profilin. In the Western Mediterranean area allergies to Rosaceae fruits are caused by monosensitization to LTP, monosensitization to profilin, or co-sensitization to both these allergens. On the contrary, monosensitization to PR-10 and, to a lesser degree, co-sensitization to profilin and PR-10 is dominant in Northern and Central Europe. LTP sensitization is present both in pollinosis and non-pollinosis patients and is associated with peach allergy in particular. The disease pattern for patients sensitized to profilin is characterized by several concomitant allergies including grass and other pollens, Rosaceae and non-Rosaceae fruits. Finally, PR-10 sensitization is primarily associated to concomitant birch pollen and apple allergy.
Hashimotodani, Yuki; Nasrallah, Kaoutsar; Jensen, Kyle R; Chávez, Andrés E; Carrera, Daniel; Castillo, Pablo E
2017-08-16
Excitatory hilar mossy cells (MCs) in the dentate gyrus receive inputs from dentate granule cells (GCs) and project back to GCs locally, contralaterally, and along the longitudinal axis of the hippocampus, thereby establishing an associative positive-feedback loop and connecting functionally diverse hippocampal areas. MCs also synapse with GABAergic interneurons that mediate feed-forward inhibition onto GCs. Surprisingly, although these circuits have been implicated in both memory formation (e.g., pattern separation) and temporal lobe epilepsy, little is known about activity-dependent plasticity of their synaptic connections. Here, we report that MC-GC synapses undergo a presynaptic, NMDA-receptor-independent form of long-term potentiation (LTP) that requires postsynaptic brain-derived neurotrophic factor (BDNF)/TrkB and presynaptic cyclic AMP (cAMP)/PKA signaling. This LTP is input specific and selectively expressed at MC-GC synapses, but not at the disynaptic inhibitory loop. By increasing the excitation/inhibition balance, MC-GC LTP enhances GC output at the associative MC-GC recurrent circuit and may contribute to dentate-dependent forms of learning and epilepsy. Copyright © 2017 Elsevier Inc. All rights reserved.
Steven J. Coultrap
2014-02-01
Full Text Available Traditionally, hippocampal long-term potentiation (LTP of synaptic strength requires Ca2+/calmodulin (CaM-dependent protein kinase II (CaMKII and other kinases, whereas long-term depression (LTD requires phosphatases. Here, we found that LTD also requires CaMKII and its phospho-T286-induced “autonomous” (Ca2+-independent activity. However, whereas LTP is known to induce phosphorylation of the AMPA-type glutamate receptor (AMPAR subunit GluA1 at S831, LTD instead induced CaMKII-mediated phosphorylation at S567, a site known to reduce synaptic GluA1 localization. GluA1 S831 phosphorylation by “autonomous” CaMKII was further stimulated by Ca2+/CaM, as expected for traditional substrates. By contrast, GluA1 S567 represents a distinct substrate class that is unaffected by such stimulation. This differential regulation caused GluA1 S831 to be favored by LTP-type stimuli (strong but brief, whereas GluA1 S567 was favored by LTD-type stimuli (weak but prolonged. Thus, requirement of autonomous CaMKII in opposing forms of plasticity involves distinct substrate classes that are differentially regulated to enable stimulus-dependent substrate-site preference.
Hoeffer, Charles A; Tang, Wei; Wong, Helen; Santillan, Arturo; Patterson, Richard J; Martinez, Luis A; Tejada-Simon, Maria V; Paylor, Richard; Hamilton, Susan L; Klann, Eric
2008-12-10
FK506-binding protein 12 (FKBP12) binds the immunosuppressant drugs FK506 and rapamycin and regulates several signaling pathways, including mammalian target of rapamycin (mTOR) signaling. We determined whether the brain-specific disruption of the FKBP12 gene in mice altered mTOR signaling, synaptic plasticity, and memory. Biochemically, the FKBP12-deficient mice displayed increases in basal mTOR phosphorylation, mTOR-Raptor interactions, and p70 S6 kinase (S6K) phosphorylation. Electrophysiological experiments revealed that FKBP12 deficiency was associated with an enhancement in long-lasting hippocampal long-term potentiation (LTP). The LTP enhancement was resistant to rapamycin, but not anisomycin, suggesting that altered translation control is involved in the enhanced synaptic plasticity. Behaviorally, FKBP12 conditional knockout (cKO) mice displayed enhanced contextual fear memory and autistic/obsessive-compulsive-like perseveration in several assays including the water maze, Y-maze reversal task, and the novel object recognition test. Our results indicate that FKBP12 plays a critical role in the regulation of mTOR-Raptor interactions, LTP, memory, and perseverative behaviors.
Wild-Type, but Not Mutant N296H, Human Tau Restores Aβ-Mediated Inhibition of LTP in Tau−/− mice
Mariana Vargas-Caballero
2017-04-01
Full Text Available Microtubule associated protein tau (MAPT is involved in the pathogenesis of Alzheimer's disease and many forms of frontotemporal dementia (FTD. We recently reported that Aβ-mediated inhibition of hippocampal long-term potentiation (LTP in mice requires tau. Here, we asked whether expression of human MAPT can restore Aβ-mediated inhibition on a mouse Tau−/− background and whether human tau with an FTD-causing mutation (N296H can interfere with Aβ-mediated inhibition of LTP. We used transgenic mouse lines each expressing the full human MAPT locus using bacterial artificial chromosome technology. These lines expressed all six human tau protein isoforms on a Tau−/− background. We found that the human wild-type MAPT H1 locus was able to restore Aβ42-mediated impairment of LTP. In contrast, Aβ42 did not reduce LTP in slices in two independently generated transgenic lines expressing tau protein with the mutation N296H associated with frontotemporal dementia (FTD. Basal phosphorylation of tau measured as the ratio of AT8/Tau5 immunoreactivity was significantly reduced in N296H mutant hippocampal slices. Our data show that human MAPT is able to restore Aβ42-mediated inhibition of LTP in Tau−/− mice. These results provide further evidence that tau protein is central to Aβ-induced LTP impairment and provide a valuable tool for further analysis of the links between Aβ, human tau and impairment of synaptic function.
On Quantum Conditional Probability
Isabel Guerra Bobo
2013-02-01
Full Text Available We argue that quantum theory does not allow for a generalization of the notion of classical conditional probability by showing that the probability defined by the Lüders rule, standardly interpreted in the literature as the quantum-mechanical conditionalization rule, cannot be interpreted as such.
Choice Probability Generating Functions
Fosgerau, Mogens; McFadden, Daniel L; Bierlaire, Michel
This paper considers discrete choice, with choice probabilities coming from maximization of preferences from a random utility field perturbed by additive location shifters (ARUM). Any ARUM can be characterized by a choice-probability generating function (CPGF) whose gradient gives the choice...
Freund, John E
1993-01-01
Thorough, lucid coverage of permutations and factorials, probabilities and odds, frequency interpretation, mathematical expectation, decision making, postulates of probability, rule of elimination, binomial distribution, geometric distribution, standard deviation, law of large numbers, and much more. Exercises with some solutions. Summary. Bibliography. Includes 42 black-and-white illustrations. 1973 edition.
Choice Probability Generating Functions
Fosgerau, Mogens; McFadden, Daniel L; Bierlaire, Michel
This paper considers discrete choice, with choice probabilities coming from maximization of preferences from a random utility field perturbed by additive location shifters (ARUM). Any ARUM can be characterized by a choice-probability generating function (CPGF) whose gradient gives the choice...
Choice probability generating functions
Fosgerau, Mogens; McFadden, Daniel; Bierlaire, Michel
2013-01-01
This paper considers discrete choice, with choice probabilities coming from maximization of preferences from a random utility field perturbed by additive location shifters (ARUM). Any ARUM can be characterized by a choice-probability generating function (CPGF) whose gradient gives the choice...
Probability, Nondeterminism and Concurrency
Varacca, Daniele
Nondeterminism is modelled in domain theory by the notion of a powerdomain, while probability is modelled by that of the probabilistic powerdomain. Some problems arise when we want to combine them in order to model computation in which both nondeterminism and probability are present. In particula...
Xu, Xiaxia; Zheng, Chenguang; Zhang, Tao
2013-01-01
The theta-gamma cross-frequency coupling (CFC) in hippocampus was reported to reflect memory process. In this study, we measured the CFC of hippocampal local field potentials (LFPs) in a two-vessel occlusion (2VO) rat model, combined with both amplitude and phase properties and associated with short and long-term plasticity indicating the memory function. Male Wistar rats were used and a 2VO model was established. STP and LTP were recorded in hippocampal CA3-CA1 pathway after LFPs were collected in both CA3 and CA1. Based on the data of relative power spectra and phase synchronization, it suggested that both the amplitude and phase coupling of either theta or gamma rhythm were involved in modulating the neural network in 2VO rats. In order to determine whether the CFC was also implicated in neural impairment in 2VO rats, the coupling of CA3 theta-CA1 gamma was measured by both phase-phase coupling (n:m phase synchronization) and phase-amplitude coupling. The attenuated CFC strength in 2VO rats implied the impaired neural communication in the coordination of theta-gamma entraining process. Moreover, compared with modulation index (MI) a novel algorithm named cross frequency conditional mutual information (CF-CMI), was developed to focus on the coupling between theta phase and the phase of gamma amplitude. The results suggest that the reduced CFC strength probably attributed to the disruption of the phase of CA1 gamma envelop. In conclusion, it implied that the phase coupling and CFC of hippocampal theta and gamma played an important role in supporting functions of neural network. Furthermore, synaptic plasticity on CA3-CA1 pathway was reduced in line with the decreased CFC strength from CA3 to CA1. It partly supported our hypothesis that directional CFC indicator might probably be used as a measure of synaptic plasticity.
Tao eZhang
2013-04-01
Full Text Available The theta-gamma cross-frequency coupling (CFC in hippocampus was reported to reflect memory process. In this study, we measured the CFC of hippocampal local field potentials (LFPs in a two-vessel occlusion (2VO rat model, combined with both amplitude and phase properties and associated with short and long-term plasticity indicating the memory function. Male Wistar rats were used and a 2VO model was established. STP and LTP were recorded in hippocampal CA3-CA1 pathway after LFPs were collected in both CA3 and CA1. Based on the data of relative power spectra and phase synchronization, it suggested that both the amplitude and phase coupling of either theta or gamma rhythm were involved in modulating the neural network in 2VO rats. In order to determine whether the CFC was also implicated in neural impairment in 2VO rats, the coupling of CA3 theta–CA1 gamma was measured by both phase-phase coupling (n:m phase synchronization and phase-amplitude coupling. The attenuated CFC strength in 2VO rats implied the impaired neural communication in the coordination of theta-gamma entraining process. Moreover, compared with modulation index (MI a novel algorithm named cross frequency conditional mutual information (CF-CMI, was developed to focus on the coupling between theta phase and the phase of gamma amplitude. The results suggest that the reduced CFC strength probably attributed to the disruption of the phase of CA1 gamma envelop. In conclusion, it implied that the phase coupling and CFC of hippocampal theta and gamma played an important role in supporting functions of neural network. Furthermore, synaptic plasticity on CA3-CA1 pathway was reduced in line with the decreased CFC strength from CA3 to CA1. It partly supported our hypothesis that directional CFC indicator might probably be used as a measure of synaptic plasticity.
Kalweit, Alexander N.; Amanpour-Gharaei, Bezhad; Colitti-Klausnitzer, Jens; Manahan-Vaughan, Denise
2017-01-01
The first-episode of psychosis is followed by a transient time-window of ca. 60 days during which therapeutic interventions have a higher likelihood of being effective than interventions that are started with a greater latency. This suggests that, in the immediate time-period after first-episode psychosis, functional changes occur in the brain that render it increasingly resistant to intervention. The precise mechanistic nature of these changes is unclear, but at the cognitive level, sensory and hippocampus-based dysfunctions become increasingly manifest. In an animal model of first-episode psychosis that comprises acute treatment of rats with the irreversible N-methyl-D-aspartate receptor (NMDAR)-antagonist, MK801, acute but also chronic deficits in long-term potentiation (LTP) and spatial memory occur. Neuronal oscillations, especially in the form of information transfer through θ and γ frequency oscillations are an intrinsic component of normal information processing in the hippocampus. Changes in θ-γ coupling and power are known to accompany deficits in hippocampal plasticity. Here, we examined whether changes in δ, θ, α, β and γ oscillations, or θ-γ coupling accompany the chronic loss of LTP that is observed in the MK801-animal model of psychosis. One and 4 weeks after acute systemic treatment of adult rats with MK801, a potent loss of hippocampal in vivo LTP was evident compared to vehicle-treated controls. Overall, the typical pattern of θ-γ oscillations that are characteristic for the successful induction of LTP was altered. In particular, θ-power was lower and an uncoupling of θ-γ oscillations was evident in MK801-treated rats. The alterations in network oscillations that accompany LTP deficits in this animal model may comprise a mechanism through which disturbances in sensory information processing and hippocampal function occur in psychosis. These data suggest that the hippocampus is likely to comprise a very early locus of functional
Billingsley, Patrick
2012-01-01
Praise for the Third Edition "It is, as far as I'm concerned, among the best books in math ever written....if you are a mathematician and want to have the top reference in probability, this is it." (Amazon.com, January 2006) A complete and comprehensive classic in probability and measure theory Probability and Measure, Anniversary Edition by Patrick Billingsley celebrates the achievements and advancements that have made this book a classic in its field for the past 35 years. Now re-issued in a new style and format, but with the reliable content that the third edition was revered for, this
Hartmann, Stephan
2011-01-01
Many results of modern physics--those of quantum mechanics, for instance--come in a probabilistic guise. But what do probabilistic statements in physics mean? Are probabilities matters of objective fact and part of the furniture of the world, as objectivists think? Or do they only express ignorance or belief, as Bayesians suggest? And how are probabilistic hypotheses justified and supported by empirical evidence? Finally, what does the probabilistic nature of physics imply for our understanding of the world? This volume is the first to provide a philosophical appraisal of probabilities in all of physics. Its main aim is to make sense of probabilistic statements as they occur in the various physical theories and models and to provide a plausible epistemology and metaphysics of probabilities. The essays collected here consider statistical physics, probabilistic modelling, and quantum mechanics, and critically assess the merits and disadvantages of objectivist and subjectivist views of probabilities in these fie...
Concepts of probability theory
Pfeiffer, Paul E
1979-01-01
Using the Kolmogorov model, this intermediate-level text discusses random variables, probability distributions, mathematical expectation, random processes, more. For advanced undergraduates students of science, engineering, or math. Includes problems with answers and six appendixes. 1965 edition.
Hemmo, Meir
2012-01-01
What is the role and meaning of probability in physical theory, in particular in two of the most successful theories of our age, quantum physics and statistical mechanics? Laws once conceived as universal and deterministic, such as Newton‘s laws of motion, or the second law of thermodynamics, are replaced in these theories by inherently probabilistic laws. This collection of essays by some of the world‘s foremost experts presents an in-depth analysis of the meaning of probability in contemporary physics. Among the questions addressed are: How are probabilities defined? Are they objective or subjective? What is their explanatory value? What are the differences between quantum and classical probabilities? The result is an informative and thought-provoking book for the scientifically inquisitive.
Probability and Bayesian statistics
1987-01-01
This book contains selected and refereed contributions to the "Inter national Symposium on Probability and Bayesian Statistics" which was orga nized to celebrate the 80th birthday of Professor Bruno de Finetti at his birthplace Innsbruck in Austria. Since Professor de Finetti died in 1985 the symposium was dedicated to the memory of Bruno de Finetti and took place at Igls near Innsbruck from 23 to 26 September 1986. Some of the pa pers are published especially by the relationship to Bruno de Finetti's scientific work. The evolution of stochastics shows growing importance of probability as coherent assessment of numerical values as degrees of believe in certain events. This is the basis for Bayesian inference in the sense of modern statistics. The contributions in this volume cover a broad spectrum ranging from foundations of probability across psychological aspects of formulating sub jective probability statements, abstract measure theoretical considerations, contributions to theoretical statistics an...
Grimmett, Geoffrey
2014-01-01
Probability is an area of mathematics of tremendous contemporary importance across all aspects of human endeavour. This book is a compact account of the basic features of probability and random processes at the level of first and second year mathematics undergraduates and Masters' students in cognate fields. It is suitable for a first course in probability, plus a follow-up course in random processes including Markov chains. A special feature is the authors' attention to rigorous mathematics: not everything is rigorous, but the need for rigour is explained at difficult junctures. The text is enriched by simple exercises, together with problems (with very brief hints) many of which are taken from final examinations at Cambridge and Oxford. The first eight chapters form a course in basic probability, being an account of events, random variables, and distributions - discrete and continuous random variables are treated separately - together with simple versions of the law of large numbers and the central limit th...
THE NUCLEAR ENCOUNTER PROBABILITY
SMULDERS, PJM
1994-01-01
This Letter dicusses the nuclear encounter probability as used in ion channeling analysis. A formulation is given, incorporating effects of large beam angles and beam divergence. A critical examination of previous definitions is made.
Shorack, Galen R
2017-01-01
This 2nd edition textbook offers a rigorous introduction to measure theoretic probability with particular attention to topics of interest to mathematical statisticians—a textbook for courses in probability for students in mathematical statistics. It is recommended to anyone interested in the probability underlying modern statistics, providing a solid grounding in the probabilistic tools and techniques necessary to do theoretical research in statistics. For the teaching of probability theory to post graduate statistics students, this is one of the most attractive books available. Of particular interest is a presentation of the major central limit theorems via Stein's method either prior to or alternative to a characteristic function presentation. Additionally, there is considerable emphasis placed on the quantile function as well as the distribution function. The bootstrap and trimming are both presented. Martingale coverage includes coverage of censored data martingales. The text includes measure theoretic...
Probability and Statistical Inference
Prosper, Harrison B.
2006-01-01
These lectures introduce key concepts in probability and statistical inference at a level suitable for graduate students in particle physics. Our goal is to paint as vivid a picture as possible of the concepts covered.
Probability in quantum mechanics
J. G. Gilson
1982-01-01
Full Text Available By using a fluid theory which is an alternative to quantum theory but from which the latter can be deduced exactly, the long-standing problem of how quantum mechanics is related to stochastic processes is studied. It can be seen how the Schrödinger probability density has a relationship to time spent on small sections of an orbit, just as the probability density has in some classical contexts.
Quantum computing and probability.
Ferry, David K
2009-11-25
Over the past two decades, quantum computing has become a popular and promising approach to trying to solve computationally difficult problems. Missing in many descriptions of quantum computing is just how probability enters into the process. Here, we discuss some simple examples of how uncertainty and probability enter, and how this and the ideas of quantum computing challenge our interpretations of quantum mechanics. It is found that this uncertainty can lead to intrinsic decoherence, and this raises challenges for error correction.
Monte Carlo transition probabilities
Lucy, L. B.
2001-01-01
Transition probabilities governing the interaction of energy packets and matter are derived that allow Monte Carlo NLTE transfer codes to be constructed without simplifying the treatment of line formation. These probabilities are such that the Monte Carlo calculation asymptotically recovers the local emissivity of a gas in statistical equilibrium. Numerical experiments with one-point statistical equilibrium problems for Fe II and Hydrogen confirm this asymptotic behaviour. In addition, the re...
荣玮; 王金凤; 李钊; 王爱云; 杜丽璞; 叶兴国; 魏学宁; 张增艳
2013-01-01
[Objective] Take-all is a destructive disease of wheat production worldwide. The aim of this study is to develop and select stable PvPGIP2 and TaLTP5 transgenic wheat lines with resistance to take-all pathogen Gaeumannomyces graminis.[Method]Gene recombination technology was used to prepare the transformation vector pA25-PvPGIP2-TaLTP5 expressing both PvPGIP2 and TaLTP5. Particle bombardment method was used to introduce both PvPGIP2 and TaLTP5 into wheat cultivar Yangmai 18. PCR, RT-PCR and qRT-PCR methods were used to detect the presence and transcript levels of PvPGIP2 and TaLTP5 in the transgenic wheat plants of T0-T4 generations. G. graminis mycelia plug inoculation and take-all severity and the disease index were used to score the resistance degrees of these transgenic wheat lines and non-transgenic wheat Yangmai 18 at young seedling-stage.[Result]The results indicated that the introduced PvPGIP2 and TaLTP5 genes were stably inherited, and could be highly expressed in six transgenic wheat lines. The transgenic wheat plants expressing PvPGIP2 and TaLTP5 showed significantly enhanced resistance to G. graminis compared with non-transgenic wheat Yangmai 18. [Conclusion] These results suggested that the introduced PvPGIP2 and TaLTP5 genes can be used for improving wheat resistance to take-all.%[目的]全蚀病是小麦的毁灭性病害。创制转PvPGIP2和TaLTP5双价基因小麦，分析外源PvPGIP2和TaLTP5在转基因小麦中的遗传与表达情况，选育抗全蚀病的转基因小麦新种质。[方法]采用基因重组技术构建了PvPGIP2和TaLTP5双价表达转基因载体pA25-PvPGIP2-TaLTP5，利用基因枪介导法将该载体转入小麦品种扬麦18，采用PCR、RT-PCR与qRT-PCR方法分析转基因小麦T 0-T 4植株中目的基因及其表达量，并对T 3和T 4逐株进行全蚀病接种与抗性鉴定。[结果]创制并选育出稳定的抗全蚀病转PvPGIP2和TaLTP5小麦株系6个。PvPGIP2和TaLTP5能够在这6个转基因小麦
The perception of probability.
Gallistel, C R; Krishan, Monika; Liu, Ye; Miller, Reilly; Latham, Peter E
2014-01-01
We present a computational model to explain the results from experiments in which subjects estimate the hidden probability parameter of a stepwise nonstationary Bernoulli process outcome by outcome. The model captures the following results qualitatively and quantitatively, with only 2 free parameters: (a) Subjects do not update their estimate after each outcome; they step from one estimate to another at irregular intervals. (b) The joint distribution of step widths and heights cannot be explained on the assumption that a threshold amount of change must be exceeded in order for them to indicate a change in their perception. (c) The mapping of observed probability to the median perceived probability is the identity function over the full range of probabilities. (d) Precision (how close estimates are to the best possible estimate) is good and constant over the full range. (e) Subjects quickly detect substantial changes in the hidden probability parameter. (f) The perceived probability sometimes changes dramatically from one observation to the next. (g) Subjects sometimes have second thoughts about a previous change perception, after observing further outcomes. (h) The frequency with which they perceive changes moves in the direction of the true frequency over sessions. (Explaining this finding requires 2 additional parametric assumptions.) The model treats the perception of the current probability as a by-product of the construction of a compact encoding of the experienced sequence in terms of its change points. It illustrates the why and the how of intermittent Bayesian belief updating and retrospective revision in simple perception. It suggests a reinterpretation of findings in the recent literature on the neurobiology of decision making.
Experimental Probability in Elementary School
Andrew, Lane
2009-01-01
Concepts in probability can be more readily understood if students are first exposed to probability via experiment. Performing probability experiments encourages students to develop understandings of probability grounded in real events, as opposed to merely computing answers based on formulae.
Experimental Probability in Elementary School
Andrew, Lane
2009-01-01
Concepts in probability can be more readily understood if students are first exposed to probability via experiment. Performing probability experiments encourages students to develop understandings of probability grounded in real events, as opposed to merely computing answers based on formulae.
Isaac, Richard
1995-01-01
The ideas of probability are all around us. Lotteries, casino gambling, the al most non-stop polling which seems to mold public policy more and more these are a few of the areas where principles of probability impinge in a direct way on the lives and fortunes of the general public. At a more re moved level there is modern science which uses probability and its offshoots like statistics and the theory of random processes to build mathematical descriptions of the real world. In fact, twentieth-century physics, in embrac ing quantum mechanics, has a world view that is at its core probabilistic in nature, contrary to the deterministic one of classical physics. In addition to all this muscular evidence of the importance of probability ideas it should also be said that probability can be lots of fun. It is a subject where you can start thinking about amusing, interesting, and often difficult problems with very little mathematical background. In this book, I wanted to introduce a reader with at least a fairl...
Tabassum, Heena; Frey, Julietta U
2013-12-01
Hippocampal long-term potentiation (LTP) is a cellular model of learning and memory. An early form of LTP (E-LTP) can be reinforced into its late form (L-LTP) by various behavioral interactions within a specific time window ("behavioral LTP-reinforcement"). Depending on the type and procedure used, various studies have shown that stress differentially affects synaptic plasticity. Under low stress, such as novelty detection or mild foot shocks, E-LTP can be transformed into L-LTP in the rat dentate gyrus (DG). A reinforcing effect of a 2-min swim, however, has only been shown in (Korz and Frey (2003) J Neurosci 23:7281-7287; Korz and Frey (2005) J Neurosci 25:7393-7400; Ahmed et al. (2006) J Neurosci 26:3951-3958; Sajikumar et al., (2007) J Physiol 584.2:389-400) so far. We have reinvestigated these studies using the same as well as an improved recording technique which allowed the recording of field excitatory postsynaptic potentials (fEPSP) and the population spike amplitude (PSA) at their places of generation in freely moving rats. We show that acute swim stress led to a long-term depression (LTD) in baseline values of PSA and partially fEPSP. In contrast to earlier studies a LTP-reinforcement by swimming could never be reproduced. Our results indicate that 2-min swim stress influenced synaptic potentials as well as E-LTP negatively.
Improving Ranking Using Quantum Probability
Melucci, Massimo
2011-01-01
The paper shows that ranking information units by quantum probability differs from ranking them by classical probability provided the same data used for parameter estimation. As probability of detection (also known as recall or power) and probability of false alarm (also known as fallout or size) measure the quality of ranking, we point out and show that ranking by quantum probability yields higher probability of detection than ranking by classical probability provided a given probability of ...
Zurek, W H
2004-01-01
I show how probabilities arise in quantum physics by exploring implications of {\\it environment - assisted invariance} or {\\it envariance}, a recently discovered symmetry exhibited by entangled quantum systems. Envariance of perfectly entangled states can be used to rigorously justify complete ignorance of the observer about the outcome of any measurement on either of the members of the entangled pair. Envariance leads to Born's rule, $p_k \\propto |\\psi_k|^2$. Probabilities derived in this manner are an objective reflection of the underlying state of the system -- they reflect experimentally verifiable symmetries, and not just a subjective ``state of knowledge'' of the observer. Envariance - based approach is compared with and found superior to the key pre-quantum definitions of probability including the {\\it standard definition} based on the `principle of indifference' due to Laplace, and the {\\it relative frequency approach} advocated by von Mises. Implications of envariance for the interpretation of quantu...
Choice probability generating functions
Fosgerau, Mogens; McFadden, Daniel; Bierlaire, Michel
2010-01-01
This paper establishes that every random utility discrete choice model (RUM) has a representation that can be characterized by a choice-probability generating function (CPGF) with specific properties, and that every function with these specific properties is consistent with a RUM. The choice...... probabilities from the RUM are obtained from the gradient of the CPGF. Mixtures of RUM are characterized by logarithmic mixtures of their associated CPGF. The paper relates CPGF to multivariate extreme value distributions, and reviews and extends methods for constructing generating functions for applications...
Negative Probabilities and Contextuality
de Barros, J Acacio; Oas, Gary
2015-01-01
There has been a growing interest, both in physics and psychology, in understanding contextuality in experimentally observed quantities. Different approaches have been proposed to deal with contextual systems, and a promising one is contextuality-by-default, put forth by Dzhafarov and Kujala. The goal of this paper is to present a tutorial on a different approach: negative probabilities. We do so by presenting the overall theory of negative probabilities in a way that is consistent with contextuality-by-default and by examining with this theory some simple examples where contextuality appears, both in physics and psychology.
Introduction to imprecise probabilities
Augustin, Thomas; de Cooman, Gert; Troffaes, Matthias C M
2014-01-01
In recent years, the theory has become widely accepted and has been further developed, but a detailed introduction is needed in order to make the material available and accessible to a wide audience. This will be the first book providing such an introduction, covering core theory and recent developments which can be applied to many application areas. All authors of individual chapters are leading researchers on the specific topics, assuring high quality and up-to-date contents. An Introduction to Imprecise Probabilities provides a comprehensive introduction to imprecise probabilities, includin
Carr, D.B.; Tolley, H.D.
1982-12-01
This paper investigates procedures for univariate nonparametric estimation of tail probabilities. Extrapolated values for tail probabilities beyond the data are also obtained based on the shape of the density in the tail. Several estimators which use exponential weighting are described. These are compared in a Monte Carlo study to nonweighted estimators, to the empirical cdf, to an integrated kernel, to a Fourier series estimate, to a penalized likelihood estimate and a maximum likelihood estimate. Selected weighted estimators are shown to compare favorably to many of these standard estimators for the sampling distributions investigated.
Classic Problems of Probability
Gorroochurn, Prakash
2012-01-01
"A great book, one that I will certainly add to my personal library."—Paul J. Nahin, Professor Emeritus of Electrical Engineering, University of New Hampshire Classic Problems of Probability presents a lively account of the most intriguing aspects of statistics. The book features a large collection of more than thirty classic probability problems which have been carefully selected for their interesting history, the way they have shaped the field, and their counterintuitive nature. From Cardano's 1564 Games of Chance to Jacob Bernoulli's 1713 Golden Theorem to Parrondo's 1996 Perplexin
Deficits in LTP induction by 5-HT2A receptor antagonist in a mouse model for fragile X syndrome.
Zhao-hui Xu
Full Text Available Fragile X syndrome is a common inherited form of mental retardation caused by the lack of fragile X mental retardation protein (FMRP because of Fmr1 gene silencing. Serotonin (5-HT is significantly increased in the null mutants of Drosophila Fmr1, and elevated 5-HT brain levels result in cognitive and behavioral deficits in human patients. The serotonin type 2A receptor (5-HT2AR is highly expressed in the cerebral cortex; it acts on pyramidal cells and GABAergic interneurons to modulate cortical functions. 5-HT2AR and FMRP both regulate synaptic plasticity. Therefore, the lack of FMRP may affect serotoninergic activity. In this study, we determined the involvement of FMRP in the 5-HT modulation of synaptic potentiation with the use of primary cortical neuron culture and brain slice recording. Pharmacological inhibition of 5-HT2AR by R-96544 or ketanserin facilitated long-term potentiation (LTP in the anterior cingulate cortex (ACC of WT mice. The prefrontal LTP induction was dependent on the activation of NMDARs and elevation of postsynaptic Ca(2+ concentrations. By contrast, inhibition of 5-HT2AR could not restore the induction of LTP in the ACC of Fmr1 knock-out mice. Furthermore, 5-HT2AR inhibition induced AMPA receptor GluR1 subtype surface insertion in the cultured ACC neurons of Fmr1 WT mice, however, GluR1 surface insertion by inhibition of 5-HT2AR was impaired in the neurons of Fmr1KO mice. These findings suggested that FMRP was involved in serotonin receptor signaling and contributed in GluR1 surface expression induced by 5-HT2AR inactivation.
NF-κB p50 subunit knockout impairs late LTP and alters long term memory in the mouse hippocampus
Oikawa Kensuke
2012-07-01
Full Text Available Abstract Background Nuclear factor kappa B (NF-κB is a transcription factor typically expressed with two specific subunits (p50, p65. Investigators have reported that NF-κB is activated during the induction of in vitro long term potentiation (LTP, a paradigm of synaptic plasticity and correlate of memory, suggesting that NF-κB may be necessary for some aspects of memory encoding. Furthermore, NF-κB has been implicated as a potential requirement in behavioral tests of memory. Unfortunately, very little work has been done to explore the effects of deleting specific NF-κB subunits on memory. Studies have shown that NF-κB p50 subunit deletion (p50−/− leads to memory deficits, however some recent studies suggest the contrary where p50−/− mice show enhanced memory in the Morris water maze (MWM. To more critically explore the role of the NF-κB p50 subunit in synaptic plasticity and memory, we assessed long term spatial memory in vivo using the MWM, and synaptic plasticity in vitro utilizing high frequency stimuli capable of eliciting LTP in slices from the hippocampus of NF-κB p50−/− versus their controls (p50+/+. Results We found that the lack of the NF-κB p50 subunit led to significant decreases in late LTP and in selective but significant alterations in MWM tests (i.e., some improvements during acquisition, but deficits during retention. Conclusions These results support the hypothesis that the NF-κ p50 subunit is required in long term spatial memory in the hippocampus.
Maximilian Lenz
2015-01-01
Full Text Available The precise role of neural plasticity under pathological conditions remains not well understood. It appears to be well accepted, however, that changes in the ability of neurons to express plasticity accompany neurological diseases. Here, we discuss recent experimental evidence, which suggests that synaptic plasticity induced by a pathological stimulus, i.e., ischemic long-term-potentiation (iLTP of excitatory synapses, could play an important role for post-stroke recovery by influencing the post-lesional reorganization of surviving neuronal networks.
Plotnitsky, Arkady
2010-01-01
Offers an exploration of the relationships between epistemology and probability in the work of Niels Bohr, Werner Heisenberg, and Erwin Schrodinger; in quantum mechanics; and in modern physics. This book considers the implications of these relationships and of quantum theory for our understanding of the nature of thinking and knowledge in general
Counterexamples in probability
Stoyanov, Jordan M
2013-01-01
While most mathematical examples illustrate the truth of a statement, counterexamples demonstrate a statement's falsity. Enjoyable topics of study, counterexamples are valuable tools for teaching and learning. The definitive book on the subject in regards to probability, this third edition features the author's revisions and corrections plus a substantial new appendix.
Varga, Tamas
This booklet resulted from a 1980 visit by the author, a Hungarian mathematics educator, to the Teachers' Center Project at Southern Illinois University at Edwardsville. Included are activities and problems that make probablility concepts accessible to young children. The topics considered are: two probability games; choosing two beads; matching…
Frič, Roman; Papčo, Martin
2010-12-01
Motivated by IF-probability theory (intuitionistic fuzzy), we study n-component probability domains in which each event represents a body of competing components and the range of a state represents a simplex S n of n-tuples of possible rewards-the sum of the rewards is a number from [0,1]. For n=1 we get fuzzy events, for example a bold algebra, and the corresponding fuzzy probability theory can be developed within the category ID of D-posets (equivalently effect algebras) of fuzzy sets and sequentially continuous D-homomorphisms. For n=2 we get IF-events, i.e., pairs ( μ, ν) of fuzzy sets μ, ν∈[0,1] X such that μ( x)+ ν( x)≤1 for all x∈ X, but we order our pairs (events) coordinatewise. Hence the structure of IF-events (where ( μ 1, ν 1)≤( μ 2, ν 2) whenever μ 1≤ μ 2 and ν 2≤ ν 1) is different and, consequently, the resulting IF-probability theory models a different principle. The category ID is cogenerated by I=[0,1] (objects of ID are subobjects of powers I X ), has nice properties and basic probabilistic notions and constructions are categorical. For example, states are morphisms. We introduce the category S n D cogenerated by Sn=\\{(x1,x2,ldots ,xn)in In;sum_{i=1}nxi≤ 1\\} carrying the coordinatewise partial order, difference, and sequential convergence and we show how basic probability notions can be defined within S n D.
Negative probability in the framework of combined probability
Burgin, Mark
2013-01-01
Negative probability has found diverse applications in theoretical physics. Thus, construction of sound and rigorous mathematical foundations for negative probability is important for physics. There are different axiomatizations of conventional probability. So, it is natural that negative probability also has different axiomatic frameworks. In the previous publications (Burgin, 2009; 2010), negative probability was mathematically formalized and rigorously interpreted in the context of extende...
Negative probability in the framework of combined probability
Burgin, Mark
2013-01-01
Negative probability has found diverse applications in theoretical physics. Thus, construction of sound and rigorous mathematical foundations for negative probability is important for physics. There are different axiomatizations of conventional probability. So, it is natural that negative probability also has different axiomatic frameworks. In the previous publications (Burgin, 2009; 2010), negative probability was mathematically formalized and rigorously interpreted in the context of extende...
Paradoxes in probability theory
Eckhardt, William
2013-01-01
Paradoxes provide a vehicle for exposing misinterpretations and misapplications of accepted principles. This book discusses seven paradoxes surrounding probability theory. Some remain the focus of controversy; others have allegedly been solved, however the accepted solutions are demonstrably incorrect. Each paradox is shown to rest on one or more fallacies. Instead of the esoteric, idiosyncratic, and untested methods that have been brought to bear on these problems, the book invokes uncontroversial probability principles, acceptable both to frequentists and subjectivists. The philosophical disputation inspired by these paradoxes is shown to be misguided and unnecessary; for instance, startling claims concerning human destiny and the nature of reality are directly related to fallacious reasoning in a betting paradox, and a problem analyzed in philosophy journals is resolved by means of a computer program.
Contributions to quantum probability
Fritz, Tobias
2010-06-25
Chapter 1: On the existence of quantum representations for two dichotomic measurements. Under which conditions do outcome probabilities of measurements possess a quantum-mechanical model? This kind of problem is solved here for the case of two dichotomic von Neumann measurements which can be applied repeatedly to a quantum system with trivial dynamics. The solution uses methods from the theory of operator algebras and the theory of moment problems. The ensuing conditions reveal surprisingly simple relations between certain quantum-mechanical probabilities. It also shown that generally, none of these relations holds in general probabilistic models. This result might facilitate further experimental discrimination between quantum mechanics and other general probabilistic theories. Chapter 2: Possibilistic Physics. I try to outline a framework for fundamental physics where the concept of probability gets replaced by the concept of possibility. Whereas a probabilistic theory assigns a state-dependent probability value to each outcome of each measurement, a possibilistic theory merely assigns one of the state-dependent labels ''possible to occur'' or ''impossible to occur'' to each outcome of each measurement. It is argued that Spekkens' combinatorial toy theory of quantum mechanics is inconsistent in a probabilistic framework, but can be regarded as possibilistic. Then, I introduce the concept of possibilistic local hidden variable models and derive a class of possibilistic Bell inequalities which are violated for the possibilistic Popescu-Rohrlich boxes. The chapter ends with a philosophical discussion on possibilistic vs. probabilistic. It can be argued that, due to better falsifiability properties, a possibilistic theory has higher predictive power than a probabilistic one. Chapter 3: The quantum region for von Neumann measurements with postselection. It is determined under which conditions a probability distribution on a
Superpositions of probability distributions
Jizba, Petr; Kleinert, Hagen
2008-09-01
Probability distributions which can be obtained from superpositions of Gaussian distributions of different variances v=σ2 play a favored role in quantum theory and financial markets. Such superpositions need not necessarily obey the Chapman-Kolmogorov semigroup relation for Markovian processes because they may introduce memory effects. We derive the general form of the smearing distributions in v which do not destroy the semigroup property. The smearing technique has two immediate applications. It permits simplifying the system of Kramers-Moyal equations for smeared and unsmeared conditional probabilities, and can be conveniently implemented in the path integral calculus. In many cases, the superposition of path integrals can be evaluated much easier than the initial path integral. Three simple examples are presented, and it is shown how the technique is extended to quantum mechanics.
Superpositions of probability distributions.
Jizba, Petr; Kleinert, Hagen
2008-09-01
Probability distributions which can be obtained from superpositions of Gaussian distributions of different variances v=sigma;{2} play a favored role in quantum theory and financial markets. Such superpositions need not necessarily obey the Chapman-Kolmogorov semigroup relation for Markovian processes because they may introduce memory effects. We derive the general form of the smearing distributions in v which do not destroy the semigroup property. The smearing technique has two immediate applications. It permits simplifying the system of Kramers-Moyal equations for smeared and unsmeared conditional probabilities, and can be conveniently implemented in the path integral calculus. In many cases, the superposition of path integrals can be evaluated much easier than the initial path integral. Three simple examples are presented, and it is shown how the technique is extended to quantum mechanics.
Probability theory and applications
Hsu, Elton P
1999-01-01
This volume, with contributions by leading experts in the field, is a collection of lecture notes of the six minicourses given at the IAS/Park City Summer Mathematics Institute. It introduces advanced graduates and researchers in probability theory to several of the currently active research areas in the field. Each course is self-contained with references and contains basic materials and recent results. Topics include interacting particle systems, percolation theory, analysis on path and loop spaces, and mathematical finance. The volume gives a balanced overview of the current status of probability theory. An extensive bibliography for further study and research is included. This unique collection presents several important areas of current research and a valuable survey reflecting the diversity of the field.
Eliazar, Iddo; Klafter, Joseph
2008-06-01
We explore six classes of fractal probability laws defined on the positive half-line: Weibull, Frechét, Lévy, hyper Pareto, hyper beta, and hyper shot noise. Each of these classes admits a unique statistical power-law structure, and is uniquely associated with a certain operation of renormalization. All six classes turn out to be one-dimensional projections of underlying Poisson processes which, in turn, are the unique fixed points of Poissonian renormalizations. The first three classes correspond to linear Poissonian renormalizations and are intimately related to extreme value theory (Weibull, Frechét) and to the central limit theorem (Lévy). The other three classes correspond to nonlinear Poissonian renormalizations. Pareto's law--commonly perceived as the "universal fractal probability distribution"--is merely a special case of the hyper Pareto class.
von der Linden, Wolfgang; Dose, Volker; von Toussaint, Udo
2014-06-01
Preface; Part I. Introduction: 1. The meaning of probability; 2. Basic definitions; 3. Bayesian inference; 4. Combinatrics; 5. Random walks; 6. Limit theorems; 7. Continuous distributions; 8. The central limit theorem; 9. Poisson processes and waiting times; Part II. Assigning Probabilities: 10. Transformation invariance; 11. Maximum entropy; 12. Qualified maximum entropy; 13. Global smoothness; Part III. Parameter Estimation: 14. Bayesian parameter estimation; 15. Frequentist parameter estimation; 16. The Cramer-Rao inequality; Part IV. Testing Hypotheses: 17. The Bayesian way; 18. The frequentist way; 19. Sampling distributions; 20. Bayesian vs frequentist hypothesis tests; Part V. Real World Applications: 21. Regression; 22. Inconsistent data; 23. Unrecognized signal contributions; 24. Change point problems; 25. Function estimation; 26. Integral equations; 27. Model selection; 28. Bayesian experimental design; Part VI. Probabilistic Numerical Techniques: 29. Numerical integration; 30. Monte Carlo methods; 31. Nested sampling; Appendixes; References; Index.
Measurement uncertainty and probability
Willink, Robin
2013-01-01
A measurement result is incomplete without a statement of its 'uncertainty' or 'margin of error'. But what does this statement actually tell us? By examining the practical meaning of probability, this book discusses what is meant by a '95 percent interval of measurement uncertainty', and how such an interval can be calculated. The book argues that the concept of an unknown 'target value' is essential if probability is to be used as a tool for evaluating measurement uncertainty. It uses statistical concepts, such as a conditional confidence interval, to present 'extended' classical methods for evaluating measurement uncertainty. The use of the Monte Carlo principle for the simulation of experiments is described. Useful for researchers and graduate students, the book also discusses other philosophies relating to the evaluation of measurement uncertainty. It employs clear notation and language to avoid the confusion that exists in this controversial field of science.
1983-07-26
DeGroot , Morris H. Probability and Statistic. Addison-Wesley Publishing Company, Reading, Massachusetts, 1975. [Gillogly 78] Gillogly, J.J. Performance...distribution [ DeGroot 751 has just begun. The beta distribution has several features that might make it a more reasonable choice. As with the normal-based...1982. [Cooley 65] Cooley, J.M. and Tukey, J.W. An algorithm for the machine calculation of complex Fourier series. Math. Comp. 19, 1965. [ DeGroot 75
Takeda, Atsushi; Koike, Yuta; Osaw, Misa; Tamano, Haruna
2017-03-13
An increased influx of extracellular Zn(2+) into neurons is a cause of cognitive decline. The influx of extracellular Zn(2+) into dentate granule cells was compared between young and middle-aged rats because of vulnerability of the dentate gyrus to aging. The influx of extracellular Zn(2+) into dentate granule cells was increased in middle-aged rats after injection of AMPA and high K(+) into the dentate gyrus, but not in young rats. Simultaneously, high K(+)-induced attenuation of LTP was observed in middle-aged rats, but not in young rats. The attenuation was rescued by co-injection of CaEDTA, an extracellular Zn(2+) chelator. Intracellular Zn(2+) in dentate granule cells was also increased in middle-aged slices with high K(+), in which the increase in extracellular Zn(2+) was the same as young slices with high K(+), suggesting that ability of extracellular Zn(2+) influx into dentate granule cells is greater in middle-aged rats. Furthermore, extracellular zinc concentration in the hippocampus was increased age-dependently. The present study suggests that the influx of extracellular Zn(2+) into dentate granule cells is more readily increased in middle-aged rats and that its increase is a cause of age-related attenuation of LTP in the dentate gyrus.
Whittle, Peter
1992-01-01
This book is a complete revision of the earlier work Probability which ap peared in 1970. While revised so radically and incorporating so much new material as to amount to a new text, it preserves both the aim and the approach of the original. That aim was stated as the provision of a 'first text in probability, de manding a reasonable but not extensive knowledge of mathematics, and taking the reader to what one might describe as a good intermediate level'. In doing so it attempted to break away from stereotyped applications, and consider applications of a more novel and significant character. The particular novelty of the approach was that expectation was taken as the prime concept, and the concept of expectation axiomatized rather than that of a probability measure. In the preface to the original text of 1970 (reproduced below, together with that to the Russian edition of 1982) I listed what I saw as the advantages of the approach in as unlaboured a fashion as I could. I also took the view that the text...
Improving Ranking Using Quantum Probability
Melucci, Massimo
2011-01-01
The paper shows that ranking information units by quantum probability differs from ranking them by classical probability provided the same data used for parameter estimation. As probability of detection (also known as recall or power) and probability of false alarm (also known as fallout or size) measure the quality of ranking, we point out and show that ranking by quantum probability yields higher probability of detection than ranking by classical probability provided a given probability of false alarm and the same parameter estimation data. As quantum probability provided more effective detectors than classical probability within other domains that data management, we conjecture that, the system that can implement subspace-based detectors shall be more effective than a system which implements a set-based detectors, the effectiveness being calculated as expected recall estimated over the probability of detection and expected fallout estimated over the probability of false alarm.
Whiting, Alan B
2014-01-01
Professor Sir Karl Popper (1902-1994) was one of the most influential philosophers of science of the twentieth century, best known for his doctrine of falsifiability. His axiomatic formulation of probability, however, is unknown to current scientists, though it is championed by several current philosophers of science as superior to the familiar version. Applying his system to problems identified by himself and his supporters, it is shown that it does not have some features he intended and does not solve the problems they have identified.
Probably Almost Bayes Decisions
Anoulova, S.; Fischer, Paul; Poelt, S.
1996-01-01
discriminant functions for this purpose. We analyze this approach for different classes of distribution functions of Boolean features:kth order Bahadur-Lazarsfeld expansions andkth order Chow expansions. In both cases, we obtain upper bounds for the required sample size which are small polynomials...... in the relevant parameters and which match the lower bounds known for these classes. Moreover, the learning algorithms are efficient.......In this paper, we investigate the problem of classifying objects which are given by feature vectors with Boolean entries. Our aim is to "(efficiently) learn probably almost optimal classifications" from examples. A classical approach in pattern recognition uses empirical estimations of the Bayesian...
Sirca, Simon
2016-01-01
This book is designed as a practical and intuitive introduction to probability, statistics and random quantities for physicists. The book aims at getting to the main points by a clear, hands-on exposition supported by well-illustrated and worked-out examples. A strong focus on applications in physics and other natural sciences is maintained throughout. In addition to basic concepts of random variables, distributions, expected values and statistics, the book discusses the notions of entropy, Markov processes, and fundamentals of random number generation and Monte-Carlo methods.
Generalized Probability Functions
Alexandre Souto Martinez
2009-01-01
Full Text Available From the integration of nonsymmetrical hyperboles, a one-parameter generalization of the logarithmic function is obtained. Inverting this function, one obtains the generalized exponential function. Motivated by the mathematical curiosity, we show that these generalized functions are suitable to generalize some probability density functions (pdfs. A very reliable rank distribution can be conveniently described by the generalized exponential function. Finally, we turn the attention to the generalization of one- and two-tail stretched exponential functions. We obtain, as particular cases, the generalized error function, the Zipf-Mandelbrot pdf, the generalized Gaussian and Laplace pdf. Their cumulative functions and moments were also obtained analytically.
Probable Unusual Transmission of Zika Virus
2011-05-23
This podcast discusses a study about the probable unusual transmission of Zika Virus Infection from a scientist to his wife, published in the May 2011 issue of Emerging Infectious Diseases. Dr. Brian Foy, Associate Professor at Colorado State University, shares details of this event. Created: 5/23/2011 by National Center for Emerging Zoonotic and Infectious Diseases (NCEZID). Date Released: 5/25/2011.
Tapia, G; Morales-Quintana, L; Parra, C; Berbel, A; Alcorta, M
2013-07-01
The cuticle is the first defense against pathogens and the second way water is lost in plants. Hydrophobic layers covering aerial plant organs from primary stages of development form cuticle, including major classes of aliphatic wax components and cutin. Extensive research has been conducted to understand cuticle formation mechanisms in plants. However, many questions remain unresolved in the transport of lipid components to form cuticle. Database studies of the Lotus japonicus genome have revealed the presence of 24 sequences classified as putative non-specific lipid transfer proteins (nsLTPs), which were classified in seven groups; four groups were selected because of their expression in aerial organs. LjLTP8 forms a cluster with DIR1 in Arabidopsis thaliana while LjLTP6, LjLTP9, and LjLTP10 were grouped as type I LTPs. In silico studies showed a high level of structural conservation, and substrate affinity studies revealed palmitoyl-CoA as the most likely ligand for these LTPs, although the Lyso-Myristoyl Phosphatidyl Choline, Lyso-myristoyl phosphatidyl glycerol, and Lyso-stearyl phosphatidyl choline ligands also showed a high affinity with the proteins. The LjLTP6 and LjLTP10 genes were expressed in both the stems and the leaves under normal conditions and were highly induced during drought stress. LjLTP10 was the most induced gene in shoots during drought. The gene was only expressed in the epidermal cells of stems, primordial leaves, and young leaflets. LjLTP10 was positively regulated by MeJA but repressed by abscisic acid (ABA), ethylene, and H2O2, while LjLTP6 was weakly induced by MeJA, repressed by H2O2, and not affected by ABA and ethylene. We suggest that LjLTP10 is involved in plant development of stem and leaf cuticle, but also in acclimation to tolerate drought stress in L. japonicus.
Arcangeli, Sara; Tozzi, Alessandro; Tantucci, Michela; Spaccatini, Cristiano; de Iure, Antonio; Costa, Cinzia; Di Filippo, Massimiliano; Picconi, Barbara; Giampà, Carmen; Fusco, Francesca Romana; Amoroso, Salvatore; Calabresi, Paolo
2013-02-01
Striatal medium-sized spiny neurons (MSNs) are highly vulnerable to ischemia. A brief ischemic insult, produced by oxygen and glucose deprivation (OGD), can induce ischemic long-term potentiation (i-LTP) of corticostriatal excitatory postsynaptic response. Since nitric oxide (NO) is involved in the pathophysiology of brain ischemia and the dopamine D1/D5-receptors (D1-like-R) are expressed in striatal NOS-positive interneurons, we hypothesized a relation between NOS-positive interneurons and striatal i-LTP, involving D1R activation and NO production. We investigated the mechanisms involved in i-LTP induced by OGD in corticostriatal slices and found that the D1-like-R antagonist SCH-23390 prevented i-LTP in all recorded MSNs. Immunofluorescence analysis confirmed the induction of i-LTP in both substance P-positive, (putative D1R-expressing) and adenosine A2A-receptor-positive (putative D2R-expressing) MSNs. Furthermore, i-LTP was dependent on a NOS/cGMP pathway since pharmacological blockade of NOS, guanylate-cyclase, or PKG prevented i-LTP. However, these compounds failed to prevent i-LTP in the presence of a NO donor or cGMP analog, respectively. Interestingly, the D1-like-R antagonism failed to prevent i-LTP when intracellular cGMP was pharmacologically increased. We propose that NO, produced by striatal NOS-positive interneurons via the stimulation of D1-like-R located on these cells, is critical for i-LTP induction in the entire population of MSNs involving a cGMP-dependent pathway.
Measure, integral and probability
Capiński, Marek
2004-01-01
Measure, Integral and Probability is a gentle introduction that makes measure and integration theory accessible to the average third-year undergraduate student. The ideas are developed at an easy pace in a form that is suitable for self-study, with an emphasis on clear explanations and concrete examples rather than abstract theory. For this second edition, the text has been thoroughly revised and expanded. New features include: · a substantial new chapter, featuring a constructive proof of the Radon-Nikodym theorem, an analysis of the structure of Lebesgue-Stieltjes measures, the Hahn-Jordan decomposition, and a brief introduction to martingales · key aspects of financial modelling, including the Black-Scholes formula, discussed briefly from a measure-theoretical perspective to help the reader understand the underlying mathematical framework. In addition, further exercises and examples are provided to encourage the reader to become directly involved with the material.
Probabilities for Solar Siblings
Valtonen, Mauri; Bajkova, A. T.; Bobylev, V. V.; Mylläri, A.
2015-02-01
We have shown previously (Bobylev et al. Astron Lett 37:550-562, 2011) that some of the stars in the solar neighborhood today may have originated in the same star cluster as the Sun, and could thus be called Solar Siblings. In this work we investigate the sensitivity of this result to galactic models and to parameters of these models, and also extend the sample of orbits. There are a number of good candidates for the sibling category, but due to the long period of orbit evolution since the break-up of the birth cluster of the Sun, one can only attach probabilities of membership. We find that up to 10 % (but more likely around 1 %) of the members of the Sun's birth cluster could be still found within 100 pc from the Sun today.
Probabilities for Solar Siblings
Valtonen, M; Bobylev, V V; Myllari, A
2015-01-01
We have shown previously (Bobylev et al 2011) that some of the stars in the Solar neighborhood today may have originated in the same star cluster as the Sun, and could thus be called Solar Siblings. In this work we investigate the sensitivity of this result to Galactic models and to parameters of these models, and also extend the sample of orbits. There are a number of good candidates for the Sibling category, but due to the long period of orbit evolution since the break-up of the birth cluster of the Sun, one can only attach probabilities of membership. We find that up to 10% (but more likely around 1 %) of the members of the Sun's birth cluster could be still found within 100 pc from the Sun today.
Emptiness Formation Probability
Crawford, Nicholas; Ng, Stephen; Starr, Shannon
2016-08-01
We present rigorous upper and lower bounds on the emptiness formation probability for the ground state of a spin-1/2 Heisenberg XXZ quantum spin system. For a d-dimensional system we find a rate of decay of the order {exp(-c L^{d+1})} where L is the sidelength of the box in which we ask for the emptiness formation event to occur. In the {d=1} case this confirms previous predictions made in the integrable systems community, though our bounds do not achieve the precision predicted by Bethe ansatz calculations. On the other hand, our bounds in the case {d ≥ 2} are new. The main tools we use are reflection positivity and a rigorous path integral expansion, which is a variation on those previously introduced by Toth, Aizenman-Nachtergaele and Ueltschi.
Learning unbelievable marginal probabilities
Pitkow, Xaq; Miller, Ken D
2011-01-01
Loopy belief propagation performs approximate inference on graphical models with loops. One might hope to compensate for the approximation by adjusting model parameters. Learning algorithms for this purpose have been explored previously, and the claim has been made that every set of locally consistent marginals can arise from belief propagation run on a graphical model. On the contrary, here we show that many probability distributions have marginals that cannot be reached by belief propagation using any set of model parameters or any learning algorithm. We call such marginals `unbelievable.' This problem occurs whenever the Hessian of the Bethe free energy is not positive-definite at the target marginals. All learning algorithms for belief propagation necessarily fail in these cases, producing beliefs or sets of beliefs that may even be worse than the pre-learning approximation. We then show that averaging inaccurate beliefs, each obtained from belief propagation using model parameters perturbed about some le...
Chronic developmental lead (Pb) exposure increases the threshold and enhances decay of long-term potentiation (LTP) in the dentate gyrus of the hippocampal formation. MK-801 and other antagonists of the N-methyl-D-aspartate (NMDA) glutamate receptor subtype impair induction of LT...
Barry, Andrew E
2011-05-18
Synthetic amyloid-β protein (Aβ) oligomers bind with high affinity to cellular prion protein (PrP(C)), but the role of this interaction in mediating the disruption of synaptic plasticity by such soluble Aβ in vitro is controversial. Here we report that intracerebroventricular injection of Aβ-containing aqueous extracts of Alzheimer\\'s disease (AD) brain robustly inhibits long-term potentiation (LTP) without significantly affecting baseline excitatory synaptic transmission in the rat hippocampus in vivo. Moreover, the disruption of LTP was abrogated by immunodepletion of Aβ. Importantly, intracerebroventricular administration of antigen-binding antibody fragment D13, directed to a putative Aβ-binding site on PrP(C), prevented the inhibition of LTP by AD brain-derived Aβ. In contrast, R1, a Fab directed to the C terminus of PrP(C), a region not implicated in binding of Aβ, did not significantly affect the Aβ-mediated inhibition of LTP. These data support the pathophysiological significance of SDS-stable Aβ dimer and the role of PrP(C) in mediating synaptic plasticity disruption by soluble Aβ.
Jiang, Man; Polepalli, Jai; Chen, Lulu Y.; Zhang, Bo; Südhof, Thomas C.; Malenka, Robert C.
2016-01-01
Neuroligins are postsynaptic cell-adhesion molecules implicated in autism and other neuropsychiatric disorders. Despite extensive work, the role of neuroligins in synapse function and plasticity, especially NMDA receptor (NMDAR)-dependent LTP, remains unclear. To establish which synaptic functions unequivocally require neuroligins, we analyzed single and triple conditional knockout (cKO) mice for all three major neuroligin isoforms (NL1-NL3). We inactivated neuroligins by stereotactic viral expression of Cre-recombinase in hippocampal CA1 region pyramidal neurons at postnatal day 0 (P0) or day 21 (P21), and measured synaptic function, synaptic plasticity, and spine numbers in acute hippocampal slices 2–3 weeks later. Surprisingly, we find that ablation of neuroligins in newborn or juvenile mice only modestly impaired basal synaptic function in hippocampus, and caused no alteration in postsynaptic spine numbers. However, triple cKO of NL1-NL3 or single cKO of NL1 impaired NMDAR-mediated excitatory postsynaptic currents (NMDAR EPSCs), and abolished NMDAR-dependent LTP. Strikingly, the NL1 cKO also abolished LTP elicited by activation of L-type Ca2+-channels during blockade of NMDARs. These findings demonstrate that neuroligins are generally not essential for synapse formation in CA1 pyramidal neurons but shape synaptic properties and that NL1 specifically is required for LTP induced by postsynaptic Ca2+-elevations, a function which may contribute to the pathophysiological role of neuroligins in brain disorders. PMID:27217145
People's conditional probability judgments follow probability theory (plus noise).
Costello, Fintan; Watts, Paul
2016-09-01
A common view in current psychology is that people estimate probabilities using various 'heuristics' or rules of thumb that do not follow the normative rules of probability theory. We present a model where people estimate conditional probabilities such as P(A|B) (the probability of A given that B has occurred) by a process that follows standard frequentist probability theory but is subject to random noise. This model accounts for various results from previous studies of conditional probability judgment. This model predicts that people's conditional probability judgments will agree with a series of fundamental identities in probability theory whose form cancels the effect of noise, while deviating from probability theory in other expressions whose form does not allow such cancellation. Two experiments strongly confirm these predictions, with people's estimates on average agreeing with probability theory for the noise-cancelling identities, but deviating from probability theory (in just the way predicted by the model) for other identities. This new model subsumes an earlier model of unconditional or 'direct' probability judgment which explains a number of systematic biases seen in direct probability judgment (Costello & Watts, 2014). This model may thus provide a fully general account of the mechanisms by which people estimate probabilities.
Savage s Concept of Probability
熊卫
2003-01-01
Starting with personal preference, Savage [3] constructs a foundation theory for probability from the qualitative probability to the quantitative probability and to utility. There are some profound logic connections between three steps in Savage's theory; that is, quantitative concepts properly represent qualitative concepts. Moreover, Savage's definition of subjective probability is in accordance with probability theory, and the theory gives us a rational decision model only if we assume that the weak ...
Probability Theory without Bayes' Rule
Rodriques, Samuel G.
2014-01-01
Within the Kolmogorov theory of probability, Bayes' rule allows one to perform statistical inference by relating conditional probabilities to unconditional probabilities. As we show here, however, there is a continuous set of alternative inference rules that yield the same results, and that may have computational or practical advantages for certain problems. We formulate generalized axioms for probability theory, according to which the reverse conditional probability distribution P(B|A) is no...
Kristensen, A K; Brunstedt, J; Madsen, M T
2000-01-01
A novel protein (IWF5) comprising 92 amino acids has been purified from the intercellular washing fluid of sugar beet leaves using cation exchange chromatography and reversed phase high performance liquid chromatography. Based on amino acid sequence homology, including the presence of eight...... cysteines at conserved positions, the protein can be classified as a member of the plant family of non-specific lipid transfer proteins (nsLTPs). The protein is 47% identical to IWF1, an antifungal nsLTP previously isolated from leaves of sugar beet. A potential site for N-linked glycosylation present...... sequence of 26 amino acid residues. The protein shows a strong in vitro antifungal activity against Cercospora beticola (causal agent of leaf spot disease in sugar beet) and inhibits fungal growth at concentrations below 10 µg ml(-1)....
Image matching using SIFT and rotation invariant uniform LTP%基于SIFT和LTP的图像匹配方法
刘金颂; 张庆阳; 原思聪
2014-01-01
针对SIFT算法计算复杂度高,提出了一种SIFT (Scale Invariant Feature Transform)和旋转不变LTP(Local Ternary Pattern)特征相结合的图像匹配方法,以提高SIFT算法的速度.首先利用SIFT算法在两幅需要匹配的图像上分别检测出关键点;然后计算每个关键点周围的旋转不变LTP特征,并作为该关键点的描述子;最后找出两个关键点对之间的匹配点对.实验结果表明,本方法对于图像的匹配性能与SIFT算法相当,运算速度比SIFT算法较快.
PENG Xiao-dong
2008-01-01
Objective The effect of the ephedra/ephedrine alkaloid methylephedrine (dl-methylephedrine hydrochloride for testing in this paper) on cognitive related synaptic plasticity was investigated by recording extracellular field evoked potentials and its LTP in hippocampal dentate granule cells in urethane-anaesthetized rats in vivo. Methods Single pathway recording of evoked field potentials was made from the dentate granule cells of hippocampal hemisphere in response to stimulation of the ipsilateral medial perforant path (MPP). Two parameters, the amplitude of population spike (PS amplitude) and the latency of the PS, were employed to evaluate the effects of drug on the overall changes in cellular responses. Results The present study show that methylephedrine 90 mg·kg-1 intraperitoneally, about 1/3 LD50, could increase the latency of the PS in hippocampal dentate granule cells by constant single stimulation of the MPP as the basal ransportation. However, the 30 mg·kg-1 and 10 mg·kg-1 dosage had no effect on the latency, and there are no influences of PS amplitude for all examinational groups. The methylephedrine 90 mg·kg-1 group significant enhanced the development of amplitude LTP in hippocampal dentate granule cells that induced by 60 Hz, 60 pulses conditional tetanus in medial perforant path area. Also, the 30 mg·kg-1 group can promoted the maintenance of LTP induced by this tetanus, but no promotion on PS amplitude LTP appeared in this dosage and no any changes been found in 10 mg·kg-1 dosage group. Conclusions The ephedra/ephedrine alkaloid methylephedrine can modulate the synaptic plasticity in the lateral perforant path. A possible mechanism of methylephedrine on hippocampal LTP is been discussed.
Probability state modeling theory.
Bagwell, C Bruce; Hunsberger, Benjamin C; Herbert, Donald J; Munson, Mark E; Hill, Beth L; Bray, Chris M; Preffer, Frederic I
2015-07-01
As the technology of cytometry matures, there is mounting pressure to address two major issues with data analyses. The first issue is to develop new analysis methods for high-dimensional data that can directly reveal and quantify important characteristics associated with complex cellular biology. The other issue is to replace subjective and inaccurate gating with automated methods that objectively define subpopulations and account for population overlap due to measurement uncertainty. Probability state modeling (PSM) is a technique that addresses both of these issues. The theory and important algorithms associated with PSM are presented along with simple examples and general strategies for autonomous analyses. PSM is leveraged to better understand B-cell ontogeny in bone marrow in a companion Cytometry Part B manuscript. Three short relevant videos are available in the online supporting information for both of these papers. PSM avoids the dimensionality barrier normally associated with high-dimensionality modeling by using broadened quantile functions instead of frequency functions to represent the modulation of cellular epitopes as cells differentiate. Since modeling programs ultimately minimize or maximize one or more objective functions, they are particularly amenable to automation and, therefore, represent a viable alternative to subjective and inaccurate gating approaches.
Probability distributions for magnetotellurics
Stodt, John A.
1982-11-01
Estimates of the magnetotelluric transfer functions can be viewed as ratios of two complex random variables. It is assumed that the numerator and denominator are governed approximately by a joint complex normal distribution. Under this assumption, probability distributions are obtained for the magnitude, squared magnitude, logarithm of the squared magnitude, and the phase of the estimates. Normal approximations to the distributions are obtained by calculating mean values and variances from error propagation, and the distributions are plotted with their normal approximations for different percentage errors in the numerator and denominator of the estimates, ranging from 10% to 75%. The distribution of the phase is approximated well by a normal distribution for the range of errors considered, while the distribution of the logarithm of the squared magnitude is approximated by a normal distribution for a much larger range of errors than is the distribution of the squared magnitude. The distribution of the squared magnitude is most sensitive to the presence of noise in the denominator of the estimate, in which case the true distribution deviates significantly from normal behavior as the percentage errors exceed 10%. In contrast, the normal approximation to the distribution of the logarithm of the magnitude is useful for errors as large as 75%.
RANDOM VARIABLE WITH FUZZY PROBABILITY
吕恩琳; 钟佑明
2003-01-01
Mathematic description about the second kind fuzzy random variable namely the random variable with crisp event-fuzzy probability was studied. Based on the interval probability and using the fuzzy resolution theorem, the feasible condition about a probability fuzzy number set was given, go a step further the definition arid characters of random variable with fuzzy probability ( RVFP ) and the fuzzy distribution function and fuzzy probability distribution sequence of the RVFP were put forward. The fuzzy probability resolution theorem with the closing operation of fuzzy probability was given and proved. The definition and characters of mathematical expectation and variance of the RVFP were studied also. All mathematic description about the RVFP has the closing operation for fuzzy probability, as a result, the foundation of perfecting fuzzy probability operation method is laid.
Establishment probability in newly founded populations
Gusset Markus
2012-06-01
Full Text Available Abstract Background Establishment success in newly founded populations relies on reaching the established phase, which is defined by characteristic fluctuations of the population’s state variables. Stochastic population models can be used to quantify the establishment probability of newly founded populations; however, so far no simple but robust method for doing so existed. To determine a critical initial number of individuals that need to be released to reach the established phase, we used a novel application of the “Wissel plot”, where –ln(1 – P0(t is plotted against time t. This plot is based on the equation P0t=1–c1e–ω1t, which relates the probability of extinction by time t, P0(t, to two constants: c1 describes the probability of a newly founded population to reach the established phase, whereas ω1 describes the population’s probability of extinction per short time interval once established. Results For illustration, we applied the method to a previously developed stochastic population model of the endangered African wild dog (Lycaon pictus. A newly founded population reaches the established phase if the intercept of the (extrapolated linear parts of the “Wissel plot” with the y-axis, which is –ln(c1, is negative. For wild dogs in our model, this is the case if a critical initial number of four packs, consisting of eight individuals each, are released. Conclusions The method we present to quantify the establishment probability of newly founded populations is generic and inferences thus are transferable to other systems across the field of conservation biology. In contrast to other methods, our approach disaggregates the components of a population’s viability by distinguishing establishment from persistence.
Tsunami probability in the Caribbean region
Parsons, T.; Geist, E. L.
2008-12-01
We calculated tsunami runup probability at coastal sites throughout the Caribbean region. We applied a Poissonian probability model because of the variety of uncorrelated tsunami sources in the region. Coastlines were discretized into 20km by 20km cells, and the mean tsunami runup rate was determined for each cell. A remarkable ~500-year empirical record was used to calculate an empirical tsunami probability map, the first of three constructed for this study. However, it's unclear whether the 500-year record is complete, so we conducted a seismic moment-balance exercise using a finite element model of the Caribbean-North American plate boundaries and the earthquake catalog, and found that moment could be balanced if the seismic coupling coefficient is c=0.32. Modeled moment release was therefore used to generate synthetic earthquake sequences to calculate 50 tsunami runup scenarios for 500-year periods. We made a second probability map from numerically-calculated runup rates in each cell. Differences between the first two probability maps based on empirical and numerical-modeled rates suggest that each captured different aspects of tsunami generation; the empirical model may be deficient in primary plate-boundary events, whereas numerical model rates lack back-arc fault and landslide sources. We thus prepared a third probability map using Bayesian likelihood functions derived from the empirical and numerical rate models and their attendant uncertainty to weight a range of rates at each 20km by 20km coastal cell. Our best-estimate map gives a range of 30-year runup probability from 0-30 percent regionally.
Falk, Ruma; Kendig, Keith
2013-01-01
Two contestants debate the notorious probability problem of the sex of the second child. The conclusions boil down to explication of the underlying scenarios and assumptions. Basic principles of probability theory are highlighted.
Introduction to probability with R
Baclawski, Kenneth
2008-01-01
FOREWORD PREFACE Sets, Events, and Probability The Algebra of Sets The Bernoulli Sample Space The Algebra of Multisets The Concept of Probability Properties of Probability Measures Independent Events The Bernoulli Process The R Language Finite Processes The Basic Models Counting Rules Computing Factorials The Second Rule of Counting Computing Probabilities Discrete Random Variables The Bernoulli Process: Tossing a Coin The Bernoulli Process: Random Walk Independence and Joint Distributions Expectations The Inclusion-Exclusion Principle General Random Variable
Ross, Sheldon
2014-01-01
A First Course in Probability, Ninth Edition, features clear and intuitive explanations of the mathematics of probability theory, outstanding problem sets, and a variety of diverse examples and applications. This book is ideal for an upper-level undergraduate or graduate level introduction to probability for math, science, engineering and business students. It assumes a background in elementary calculus.
Conditionals, probability, and belief revision
Voorbraak, F.
1989-01-01
A famous result obtained in the mid-seventies by David Lewis shows that a straightforward interpretation of probabilities of conditionals as conditional probabilities runs into serious trouble. In this paper we try to circumvent this trouble by defining extensions of probability functions, called
The Art of Probability Assignment
Dimitrov, Vesselin I
2012-01-01
The problem of assigning probabilities when little is known is analized in the case where the quanities of interest are physical observables, i.e. can be measured and their values expressed by numbers. It is pointed out that the assignment of probabilities based on observation is a process of inference, involving the use of Bayes' theorem and the choice of a probability prior. When a lot of data is available, the resulting probability are remarkable insensitive to the form of the prior. In the oposite case of scarse data, it is suggested that the probabilities are assigned such that they are the least sensitive to specific variations of the probability prior. In the continuous case this results in a probability assignment rule wich calls for minimizing the Fisher information subject to constraints reflecting all available information. In the discrete case, the corresponding quantity to be minimized turns out to be a Renyi distance between the original and the shifted distribution.
Probability workshop to be better in probability topic
Asmat, Aszila; Ujang, Suriyati; Wahid, Sharifah Norhuda Syed
2015-02-01
The purpose of the present study was to examine whether statistics anxiety and attitudes towards probability topic among students in higher education level have an effect on their performance. 62 fourth semester science students were given statistics anxiety questionnaires about their perception towards probability topic. Result indicated that students' performance in probability topic is not related to anxiety level, which means that the higher level in statistics anxiety will not cause lower score in probability topic performance. The study also revealed that motivated students gained from probability workshop ensure that their performance in probability topic shows a positive improvement compared before the workshop. In addition there exists a significance difference in students' performance between genders with better achievement among female students compared to male students. Thus, more initiatives in learning programs with different teaching approaches is needed to provide useful information in improving student learning outcome in higher learning institution.
Propensity, Probability, and Quantum Theory
Ballentine, Leslie E.
2016-08-01
Quantum mechanics and probability theory share one peculiarity. Both have well established mathematical formalisms, yet both are subject to controversy about the meaning and interpretation of their basic concepts. Since probability plays a fundamental role in QM, the conceptual problems of one theory can affect the other. We first classify the interpretations of probability into three major classes: (a) inferential probability, (b) ensemble probability, and (c) propensity. Class (a) is the basis of inductive logic; (b) deals with the frequencies of events in repeatable experiments; (c) describes a form of causality that is weaker than determinism. An important, but neglected, paper by P. Humphreys demonstrated that propensity must differ mathematically, as well as conceptually, from probability, but he did not develop a theory of propensity. Such a theory is developed in this paper. Propensity theory shares many, but not all, of the axioms of probability theory. As a consequence, propensity supports the Law of Large Numbers from probability theory, but does not support Bayes theorem. Although there are particular problems within QM to which any of the classes of probability may be applied, it is argued that the intrinsic quantum probabilities (calculated from a state vector or density matrix) are most naturally interpreted as quantum propensities. This does not alter the familiar statistical interpretation of QM. But the interpretation of quantum states as representing knowledge is untenable. Examples show that a density matrix fails to represent knowledge.
Anderson, William W.; Fitzjohn, Stephen M.; Collingridge, Graham L.
2012-01-01
WinLTP is a data acquisition program for studying long-term potentiation (LTP) and other aspects of synaptic function. Earlier versions of WinLTP (J. Neurosci. Methods, 162:346–356, 2007) provided automated electrical stimulation and data acquisition capable of running nearly an entire synaptic plasticity experiment, with the primary exception that perfusion solutions had to be changed manually. This automated stimulation and acquisition was done by using ‘Sweep’, ‘Loop’ and ‘Delay’ events to build scripts using the ‘Protocol Builder’. However, this did not allow automatic changing of many solutions while running multiple slice experiments, or solution changing when this had to be performed rapidly and with accurate timing during patch-clamp experiments. We report here the addition of automated perfusion control to WinLTP. First, perfusion change between sweeps is enabled by adding the ‘Perfuse’ event to Protocol Builder scripting and is used in slice experiments. Second, fast perfusion changes during as well as between sweeps is enabled by using the Perfuse event in the protocol scripts to control changes between sweeps, and also by changing digital or analog output during a sweep and is used for single cell single-line perfusion patch-clamp experiments. The addition of stepper control of tube placement allows dual- or triple-line perfusion patch-clamp experiments for up to 48 solutions. The ability to automate perfusion changes and fully integrate them with the already automated stimulation and data acquisition goes a long way toward complete automation of multi-slice extracellularly recorded and single cell patch-clamp experiments. PMID:22524994
Huang, L; Zhao, L B; Yu, Z Y; He, X J; Ma, L P; Li, N; Guo, L J; Feng, W Y
2014-09-26
We previously demonstrated that inactivation of Rho-kinase by hydroxyfasudil could impact N-methyl-d-aspartate (NMDA) excitatory interneurons in the hippocampus and attenuate the spatial learning and memory dysfunction of rats caused by chronic forebrain hypoperfusion ischemia. Complementary interactions between the excitatory neurotransmitter glutamate and the inhibitory neurotransmitter GABA form the molecular basis of synaptic plasticity and cognitive performance. However, whether the GABAergic inhibitory interneurons are involved in the mechanisms underlying these processes remains unclear. Here, we further examined the role of GABAergic interneurons in the neuroprotective effect of the Rho-kinase inhibitor. Chronic forebrain ischemia was induced in Wistar rats by bilateral common carotid artery occlusion (BCAO). The general synaptic transmission and long-term potentiation (LTP) of hippocampal CA3 neurons were evaluated at 30 days after sham surgery or BCAO. Real-time PCR and Western blot analyses were conducted to determine the effect of the Rho-kinase inhibitor hydroxyfasudil on GABAergic inhibitory interneuron expression and function after ischemia. Hydroxyfasudil showed no significant effect on general synaptic transmission, but it could abolish the inhibition of LTP induced by chronic forebrain ischemia. Moreover, the mRNA and protein levels of GABAA and GABAB in three brain regions after ischemia were markedly decreased, and hydroxyfasudil could up-regulate all mRNA and protein expression levels in these areas except for GABAA mRNA in the cerebral cortex and striatum. Using phosphorylation antibodies against specific sites on the GABAA and GABAB receptors, we further demonstrated that hydroxyfasudil could inhibit GABAergic interneuron phosphorylation triggered by the theta burst stimulation. In summary, our results indicated that the inactivation of Rho-kinase could enhance GABAA and GABAB expressions by different mechanisms to guarantee the induction of
Maria Veronica Baez
Full Text Available NMDA receptor subunits change during development and their synaptic expression is modified rapidly after synaptic plasticity induction in hippocampal slices. However, there is scarce information on subunits expression after synaptic plasticity induction or memory acquisition, particularly in adults. GluN1, GluN2A and GluN2B NMDA receptor subunits were assessed by western blot in 1 adult rats that had explored an open field (OF for 5 minutes, a time sufficient to induce habituation, 2 mature rat hippocampal neuron cultures depolarized by KCl and 3 hippocampal slices from adult rats where long term potentiation (LTP was induced by theta-burst stimulation (TBS. GluN1 and GluN2A, though not GluN2B, were significantly higher 70 minutes--but not 30 minutes--after a 5 minutes session in an OF. GluN1 and GluN2A total immunofluorescence and puncta in neurites increased in cultures, as evaluated 70 minutes after KCl stimulation. Similar changes were found in hippocampal slices 70 minutes after LTP induction. To start to explore underlying mechanisms, hippocampal slices were treated either with cycloheximide (a translation inhibitor or actinomycin D (a transcription inhibitor during electrophysiological assays. It was corroborated that translation was necessary for LTP induction and expression. The rise in GluN1 depends on transcription and translation, while the increase in GluN2A appears to mainly depend on translation, though a contribution of some remaining transcriptional activity during actinomycin D treatment could not be rouled out. LTP effective induction was required for the subunits to increase. Although in the three models same subunits suffered modifications in the same direction, within an apparently similar temporal course, further investigation is required to reveal if they are related processes and to find out whether they are causally related with synaptic plasticity, learning and memory.
Hidden Variables or Positive Probabilities?
Rothman, T; Rothman, Tony
2001-01-01
Despite claims that Bell's inequalities are based on the Einstein locality condition, or equivalent, all derivations make an identical mathematical assumption: that local hidden-variable theories produce a set of positive-definite probabilities for detecting a particle with a given spin orientation. The standard argument is that because quantum mechanics assumes that particles are emitted in a superposition of states the theory cannot produce such a set of probabilities. We examine a paper by Eberhard who claims to show that a generalized Bell inequality, the CHSH inequality, can be derived solely on the basis of the locality condition, without recourse to hidden variables. We point out that he nonetheless assumes a set of positive-definite probabilities, which supports the claim that hidden variables or "locality" is not at issue here, positive-definite probabilities are. We demonstrate that quantum mechanics does predict a set of probabilities that violate the CHSH inequality; however these probabilities ar...
Applied probability and stochastic processes
Sumita, Ushio
1999-01-01
Applied Probability and Stochastic Processes is an edited work written in honor of Julien Keilson. This volume has attracted a host of scholars in applied probability, who have made major contributions to the field, and have written survey and state-of-the-art papers on a variety of applied probability topics, including, but not limited to: perturbation method, time reversible Markov chains, Poisson processes, Brownian techniques, Bayesian probability, optimal quality control, Markov decision processes, random matrices, queueing theory and a variety of applications of stochastic processes. The book has a mixture of theoretical, algorithmic, and application chapters providing examples of the cutting-edge work that Professor Keilson has done or influenced over the course of his highly-productive and energetic career in applied probability and stochastic processes. The book will be of interest to academic researchers, students, and industrial practitioners who seek to use the mathematics of applied probability i...
PROBABILITY SURVEYS , CONDITIONAL PROBABILITIES AND ECOLOGICAL RISK ASSESSMENT
We show that probability-based environmental resource monitoring programs, such as the U.S. Environmental Protection Agency's (U.S. EPA) Environmental Monitoring and Assessment Program, and conditional probability analysis can serve as a basis for estimating ecological risk over ...
PROBABILITY SURVEYS , CONDITIONAL PROBABILITIES AND ECOLOGICAL RISK ASSESSMENT
We show that probability-based environmental resource monitoring programs, such as the U.S. Environmental Protection Agency's (U.S. EPA) Environmental Monitoring and Assessment Program, and conditional probability analysis can serve as a basis for estimating ecological risk over ...
Monti, Maria C; Gabach, Laura A; Perez, Mariela F; Ramírez, Oscar A
2012-10-01
Hippocampal synaptic plasticity has been related to learning and adaptive processes developed during chronic drug administration, suggesting the existence of a common neurobiological mechanism mediating drug addiction and memory. Moreover, protein kinase M zeta (PKMζ) is critical for the maintenance of hippocampal long-term potentiation (LTP) and spatial conditioned long-term memories. Also, a link between activity-regulated cytoskeleton-associated protein (Arc), PKMζ and LTP has been proposed. Our previous results demonstrated that re-exposure to the withdrawal environment was able to evoke the memory acquired when the anxiety measured as a diazepam (DZ) withdrawal sign was experienced. In the present work we evaluated if the memory associated with DZ withdrawal could be affected by changes in the contextual cues presented during withdrawal and by intrahippocampal administration of a PKMζ inhibitor. We found that the context was relevant for the expression of withdrawal signs as changes in contextual cues prevented the expression of the anxiety-like behavior observed during plus-maze (PM) re-exposure, the associated enhanced synaptic plasticity and the increase in Arc expression. Furthermore, intrahippocampal administration of PKMζ inhibitor previous to re-exposure to the PM test also impaired expression of anxiety-like behavior and the facilitated LTP. These results support the relevance of the hippocampal synaptic plasticity in the maintenance of the memory trace during benzodiazepines withdrawal, adding new evidences for common mechanisms between memory and drug addiction that can be intervened for treatment or prevention of this pathology.
Li, Shaomin; Jin, Ming; Zhang, Dainan; Yang, Ting; Koeglsperger, Thomas; Fu, Hongjun; Selkoe, Dennis J
2013-03-06
A central question about human brain aging is whether cognitive enrichment slows the development of Alzheimer changes. Here, we show that prolonged exposure to an enriched environment (EE) facilitated signaling in the hippocampus of wild-type mice that promoted long-term potentiation. A key feature of the EE effect was activation of β2-adrenergic receptors and downstream cAMP/PKA signaling. This EE pathway prevented LTP inhibition by soluble oligomers of amyloid β-protein (Aβ) isolated from AD cortex. Protection by EE occurred in both young and middle-aged wild-type mice. Exposure to novelty afforded greater protection than did aerobic exercise. Mice chronically fed a β-adrenergic agonist without EE were protected from hippocampal impairment by Aβ oligomers. Thus, EE enhances hippocampal synaptic plasticity by activating β-adrenoceptor signaling and mitigating synaptotoxicity of human Aβ oligomers. These mechanistic insights support using prolonged exposure to cognitive novelty and/or oral β-adrenergic agonists to lessen the effects of Aβ accumulation during aging.
Elisa Barbarese
Full Text Available In neurons, specific RNAs are assembled into granules, which are translated in dendrites, however the functional consequences of granule assembly are not known. Tumor overexpressed gene (TOG is a granule-associated protein containing multiple binding sites for heterogeneous nuclear ribonucleoprotein (hnRNP A2, another granule component that recognizes cis-acting sequences called hnRNP A2 response elements (A2REs present in several granule RNAs. Translation in granules is sporadic, which is believed to reflect monosomal translation, with occasional bursts, which are believed to reflect polysomal translation. In this study, TOG expression was conditionally knocked out (TOG cKO in mouse hippocampal neurons using cre/lox technology. In TOG cKO cultured neurons granule assembly and bursty translation of activity-regulated cytoskeletal associated (ARC mRNA, an A2RE RNA, are disrupted. In TOG cKO brain slices synaptic sensitivity and long term potentiation (LTP are reduced. TOG cKO mice exhibit hyperactivity, perseveration and impaired short term habituation. These results suggest that in hippocampal neurons TOG is required for granule assembly, granule translation and synaptic plasticity, and affects behavior.
Blau, Christoph W; Cowley, Thelma R; O'Sullivan, Joan; Grehan, Belinda; Browne, Tara C; Kelly, Laura; Birch, Amy; Murphy, Niamh; Kelly, Aine M; Kerskens, Christian M; Lynch, Marina A
2012-05-01
In view of the increase in the aging population and the unavoidable parallel increase in the incidence of age-related neurodegenerative diseases, a key challenge in neuroscience is the identification of clinical signatures which change with age and impact on neuronal and cognitive function. Early diagnosis offers the possibility of early therapeutic intervention, thus magnetic resonance imaging (MRI) is potentially a powerful diagnostic tool. We evaluated age-related changes in relaxometry, blood flow, and blood-brain barrier (BBB) permeability in the rat by magnetic resonance imaging and assessed these changes in the context of the age-related decrease in synaptic plasticity. We report that T2 relaxation time was decreased with age; this was coupled with a decrease in gray matter perfusion, suggesting that the observed microglial activation, as identified by increased expression of CD11b, MHCII, and CD68 by immunohistochemistry, flow cytometry, or polymerase chain reaction (PCR), might be a downstream consequence of these changes. Increased permeability of the blood-brain barrier was observed in the perivascular area and the hippocampus of aged, compared with young, rats. Similarly there was an age-related increase in CD45-positive cells by flow cytometry, which are most likely infiltrating macrophages, with a parallel increase in the messenger mRNA expression of chemokines IP-10 and MCP-1. These combined changes may contribute to the deficit in long-term potentiation (LTP) in perforant path-granule cell synapses of aged animals.
The estimation of yearly probability gain for seismic statistical model
无
2000-01-01
Based on the calculation method of information gain in the stochastic process presented by Vere-Jones, the relation between information gain and probability gain is studied, which is very common in earthquake prediction, and the yearly probability gain for seismic statistical model is proposed. The method is applied to the non-stationary Poisson model with whole-process exponential increase and stress release model. In addition, the prediction method of stress release model is obtained based on the inverse function simulation method of stochastic variable.
Understanding Students' Beliefs about Probability.
Konold, Clifford
The concept of probability is not an easy concept for high school and college students to understand. This paper identifies and analyzes the students' alternative frameworks from the viewpoint of constructivism. There are various interpretations of probability through mathematical history: classical, frequentist, and subjectivist interpretation.…
Expected utility with lower probabilities
Hendon, Ebbe; Jacobsen, Hans Jørgen; Sloth, Birgitte
1994-01-01
An uncertain and not just risky situation may be modeled using so-called belief functions assigning lower probabilities to subsets of outcomes. In this article we extend the von Neumann-Morgenstern expected utility theory from probability measures to belief functions. We use this theory...
Varieties of Belief and Probability
D.J.N. van Eijck (Jan); S. Ghosh; J. Szymanik
2015-01-01
htmlabstractFor reasoning about uncertain situations, we have probability theory, and we have logics of knowledge and belief. How does elementary probability theory relate to epistemic logic and the logic of belief? The paper focuses on the notion of betting belief, and interprets a language for
Landau-Zener Probability Reviewed
Valencia, C
2008-01-01
We examine the survival probability for neutrino propagation through matter with variable density. We present a new method to calculate the level-crossing probability that differs from Landau's method by constant factor, which is relevant in the interpretation of neutrino flux from supernova explosion.
Probability and Statistics: 5 Questions
Probability and Statistics: 5 Questions is a collection of short interviews based on 5 questions presented to some of the most influential and prominent scholars in probability and statistics. We hear their views on the fields, aims, scopes, the future direction of research and how their work fits...
A graduate course in probability
Tucker, Howard G
2014-01-01
Suitable for a graduate course in analytic probability, this text requires only a limited background in real analysis. Topics include probability spaces and distributions, stochastic independence, basic limiting options, strong limit theorems for independent random variables, central limit theorem, conditional expectation and Martingale theory, and an introduction to stochastic processes.
Invariant probabilities of transition functions
Zaharopol, Radu
2014-01-01
The structure of the set of all the invariant probabilities and the structure of various types of individual invariant probabilities of a transition function are two topics of significant interest in the theory of transition functions, and are studied in this book. The results obtained are useful in ergodic theory and the theory of dynamical systems, which, in turn, can be applied in various other areas (like number theory). They are illustrated using transition functions defined by flows, semiflows, and one-parameter convolution semigroups of probability measures. In this book, all results on transition probabilities that have been published by the author between 2004 and 2008 are extended to transition functions. The proofs of the results obtained are new. For transition functions that satisfy very general conditions the book describes an ergodic decomposition that provides relevant information on the structure of the corresponding set of invariant probabilities. Ergodic decomposition means a splitting of t...
Linear Positivity and Virtual Probability
Hartle, J B
2004-01-01
We investigate the quantum theory of closed systems based on the linear positivity decoherence condition of Goldstein and Page. A quantum theory of closed systems requires two elements; 1) a condition specifying which sets of histories may be assigned probabilities that are consistent with the rules of probability theory, and 2) a rule for those probabilities. The linear positivity condition of Goldstein and Page is the weakest of the general conditions proposed so far. Its general properties relating to exact probability sum rules, time-neutrality, and conservation laws are explored. Its inconsistency with the usual notion of independent subsystems in quantum mechanics is reviewed. Its relation to the stronger condition of medium decoherence necessary for classicality is discussed. The linear positivity of histories in a number of simple model systems is investigated with the aim of exhibiting linearly positive sets of histories that are not decoherent. The utility of extending the notion of probability to i...
Survival probability and ruin probability of a risk model
LUO Jian-hua
2008-01-01
In this paper, a new risk model is studied in which the rate of premium income is regarded as a random variable, the arrival of insurance policies is a Poisson process and the process of claim occurring is p-thinning process. The integral representations of the survival probability are gotten. The explicit formula of the survival probability on the infinite interval is obtained in the special casc--exponential distribution.The Lundberg inequality and the common formula of the ruin probability are gotten in terms of some techniques from martingale theory.
无
2005-01-01
People much given to gambling usually manage to work out rough-and-ready ways of measuring the likelihood of certain situations so as to know which way to bet their money, and how much. If they did not do this., they would quickly lose all their money to those who did.
李立赛; 应自炉
2015-01-01
In order to improve the facial expression recognition rate in practical application, an improved local ternary patterns (ILTP) algorithm was proposed on the basis of the local ternary patterns (LTP) algorithm,and was combined with sparse representation-based classifier (SRC) to form a new algorithm to be applied to human facial expression recognition. Then facial expression features are extracted by ILTP algorithm, and the features are treated as the input of the SRC to complete facial expressions recognition. Experimental results based on JAFFE database prove that the new algorithm can get a facial expression recognition rate of 70.48% and is highly feasible.%为了提高实际应用中的人脸表情识别率，本文提出了改进局部三值模式算法（ILTP），并结合稀疏表达分类器（SRC）组成新的算法应用于人脸表情识别.该算法首先利用 ILTP 算法对人脸表情图像进行特征提取，然后将得到的图像顶层特征数据和图像底层特征数据作为SRC 的输入，从而完成人脸表情分类.基于 JAFFE 数据的实验结果表明：改进算法的人脸表情识别率达70.48%，具有较高的可行性.
Nora Prochnow
Full Text Available Harmful effects of electromagnetic fields (EMF on cognitive and behavioural features of humans and rodents have been controversially discussed and raised persistent concern about adverse effects of EMF on general brain functions. In the present study we applied radio-frequency (RF signals of the Universal Mobile Telecommunications System (UMTS to full brain exposed male Wistar rats in order to elaborate putative influences on stress hormone release (corticosteron; CORT and adrenocorticotropic hormone; ACTH and on hippocampal derived synaptic long-term plasticity (LTP and depression (LTD as electrophysiological hallmarks for memory storage and memory consolidation. Exposure was computer controlled providing blind conditions. Nominal brain-averaged specific absorption rates (SAR as a measure of applied mass-related dissipated RF power were 0, 2, and 10 W/kg over a period of 120 min. Comparison of cage exposed animals revealed, regardless of EMF exposure, significantly increased CORT and ACTH levels which corresponded with generally decreased field potential slopes and amplitudes in hippocampal LTP and LTD. Animals following SAR exposure of 2 W/kg (averaged over the whole brain of 2.3 g tissue mass did not differ from the sham-exposed group in LTP and LTD experiments. In contrast, a significant reduction in LTP and LTD was observed at the high power rate of SAR (10 W/kg. The results demonstrate that a rate of 2 W/kg displays no adverse impact on LTP and LTD, while 10 W/kg leads to significant effects on the electrophysiological parameters, which can be clearly distinguished from the stress derived background. Our findings suggest that UMTS exposure with SAR in the range of 2 W/kg is not harmful to critical markers for memory storage and memory consolidation, however, an influence of UMTS at high energy absorption rates (10 W/kg cannot be excluded.
Failure probability under parameter uncertainty.
Gerrard, R; Tsanakas, A
2011-05-01
In many problems of risk analysis, failure is equivalent to the event of a random risk factor exceeding a given threshold. Failure probabilities can be controlled if a decisionmaker is able to set the threshold at an appropriate level. This abstract situation applies, for example, to environmental risks with infrastructure controls; to supply chain risks with inventory controls; and to insurance solvency risks with capital controls. However, uncertainty around the distribution of the risk factor implies that parameter error will be present and the measures taken to control failure probabilities may not be effective. We show that parameter uncertainty increases the probability (understood as expected frequency) of failures. For a large class of loss distributions, arising from increasing transformations of location-scale families (including the log-normal, Weibull, and Pareto distributions), the article shows that failure probabilities can be exactly calculated, as they are independent of the true (but unknown) parameters. Hence it is possible to obtain an explicit measure of the effect of parameter uncertainty on failure probability. Failure probability can be controlled in two different ways: (1) by reducing the nominal required failure probability, depending on the size of the available data set, and (2) by modifying of the distribution itself that is used to calculate the risk control. Approach (1) corresponds to a frequentist/regulatory view of probability, while approach (2) is consistent with a Bayesian/personalistic view. We furthermore show that the two approaches are consistent in achieving the required failure probability. Finally, we briefly discuss the effects of data pooling and its systemic risk implications. © 2010 Society for Risk Analysis.
Probability with applications and R
Dobrow, Robert P
2013-01-01
An introduction to probability at the undergraduate level Chance and randomness are encountered on a daily basis. Authored by a highly qualified professor in the field, Probability: With Applications and R delves into the theories and applications essential to obtaining a thorough understanding of probability. With real-life examples and thoughtful exercises from fields as diverse as biology, computer science, cryptology, ecology, public health, and sports, the book is accessible for a variety of readers. The book's emphasis on simulation through the use of the popular R software language c
Probability Ranking in Vector Spaces
Melucci, Massimo
2011-01-01
The Probability Ranking Principle states that the document set with the highest values of probability of relevance optimizes information retrieval effectiveness given the probabilities are estimated as accurately as possible. The key point of the principle is the separation of the document set into two subsets with a given level of fallout and with the highest recall. The paper introduces the separation between two vector subspaces and shows that the separation yields a more effective performance than the optimal separation into subsets with the same available evidence, the performance being measured with recall and fallout. The result is proved mathematically and exemplified experimentally.
Holographic probabilities in eternal inflation.
Bousso, Raphael
2006-11-10
In the global description of eternal inflation, probabilities for vacua are notoriously ambiguous. The local point of view is preferred by holography and naturally picks out a simple probability measure. It is insensitive to large expansion factors or lifetimes and so resolves a recently noted paradox. Any cosmological measure must be complemented with the probability for observers to emerge in a given vacuum. In lieu of anthropic criteria, I propose to estimate this by the entropy that can be produced in a local patch. This allows for prior-free predictions.
Local Causality, Probability and Explanation
Healey, Richard A
2016-01-01
In papers published in the 25 years following his famous 1964 proof John Bell refined and reformulated his views on locality and causality. Although his formulations of local causality were in terms of probability, he had little to say about that notion. But assumptions about probability are implicit in his arguments and conclusions. Probability does not conform to these assumptions when quantum mechanics is applied to account for the particular correlations Bell argues are locally inexplicable. This account involves no superluminal action and there is even a sense in which it is local, but it is in tension with the requirement that the direct causes and effects of events are nearby.
A philosophical essay on probabilities
Laplace, Marquis de
1996-01-01
A classic of science, this famous essay by ""the Newton of France"" introduces lay readers to the concepts and uses of probability theory. It is of especial interest today as an application of mathematical techniques to problems in social and biological sciences.Generally recognized as the founder of the modern phase of probability theory, Laplace here applies the principles and general results of his theory ""to the most important questions of life, which are, in effect, for the most part, problems in probability."" Thus, without the use of higher mathematics, he demonstrates the application
John Porrill
2008-05-01
Full Text Available Computational analysis of neural systems is at its most useful when it uncovers principles that provide a unified account of phenomena across multiple scales and levels of description. Here we analyse a widely used model of the cerebellar contribution to sensori-motor learning to demonstrate both that its response to intrinsic and sensor noise is optimal, and that the unexpected synaptic and behavioural consequences of this optimality can explain a wide range of experimental data. The response of the Marr-Albus adaptive-filter model of the cerebellar microcircuit to noise was examined in the context of vestibulo-ocular reflex calibration. We found that, when appropriately connected, an adaptive-filter model using the covariance learning rule to adjust the weights of synapses between parallel fibres and Purkinje cells learns weight values that are optimal given the relative amount of signal and noise carried by each parallel fibre. This optimality principle is consistent with data on the cerebellar role in smooth pursuit eye movements, and predicts that many synaptic weights must be very small, providing an explanation for the experimentally observed preponderance of silent synapses. Such a preponderance has in its turn two further consequences. First, an additional inhibitory pathway from parallel fibre to Purkinje cell is required if Purkinje cell activity is to be altered in either direction from a starting point of silent synapses. Second, cerebellar learning tasks must often proceed via LTP, rather than LTD as is widely assumed. Taken together, these considerations have profound behavioural consequences, including the optimal combination of sensori-motor information, and asymmetry and hysteresis of sensori-motor learning rates.
Diurnal distribution of sunshine probability
Aydinli, S.
1982-01-01
The diurnal distribution of the sunshine probability is essential for the predetermination of average irradiances and illuminances by solar radiation on sloping surfaces. The most meteorological stations have only monthly average values of the sunshine duration available. It is, therefore, necessary to compute the diurnal distribution of sunshine probability starting from the average monthly values. It is shown how the symmetric component of the distribution of the sunshine probability which is a consequence of a ''sidescene effect'' of the clouds can be calculated. The asymmetric components of the sunshine probability depending on the location and the seasons and their influence on the predetermination of the global radiation are investigated and discussed.
Probability representation of classical states
Man'ko, OV; Man'ko, [No Value; Pilyavets, OV
2005-01-01
Probability representation of classical states described by symplectic tomograms is discussed. Tomographic symbols of classical observables which are functions on phase-space are studied. Explicit form of kernel of commutative star-product of the tomographic symbols is obtained.
Introduction to probability and measure
Parthasarathy, K R
2005-01-01
According to a remark attributed to Mark Kac 'Probability Theory is a measure theory with a soul'. This book with its choice of proofs, remarks, examples and exercises has been prepared taking both these aesthetic and practical aspects into account.
Free probability and random matrices
Mingo, James A
2017-01-01
This volume opens the world of free probability to a wide variety of readers. From its roots in the theory of operator algebras, free probability has intertwined with non-crossing partitions, random matrices, applications in wireless communications, representation theory of large groups, quantum groups, the invariant subspace problem, large deviations, subfactors, and beyond. This book puts a special emphasis on the relation of free probability to random matrices, but also touches upon the operator algebraic, combinatorial, and analytic aspects of the theory. The book serves as a combination textbook/research monograph, with self-contained chapters, exercises scattered throughout the text, and coverage of important ongoing progress of the theory. It will appeal to graduate students and all mathematicians interested in random matrices and free probability from the point of view of operator algebras, combinatorics, analytic functions, or applications in engineering and statistical physics.
The probabilities of unique events.
Sangeet S Khemlani
Full Text Available Many theorists argue that the probabilities of unique events, even real possibilities such as President Obama's re-election, are meaningless. As a consequence, psychologists have seldom investigated them. We propose a new theory (implemented in a computer program in which such estimates depend on an intuitive non-numerical system capable only of simple procedures, and a deliberative system that maps intuitions into numbers. The theory predicts that estimates of the probabilities of conjunctions should often tend to split the difference between the probabilities of the two conjuncts. We report two experiments showing that individuals commit such violations of the probability calculus, and corroborating other predictions of the theory, e.g., individuals err in the same way even when they make non-numerical verbal estimates, such as that an event is highly improbable.
Logic, probability, and human reasoning.
Johnson-Laird, P N; Khemlani, Sangeet S; Goodwin, Geoffrey P
2015-04-01
This review addresses the long-standing puzzle of how logic and probability fit together in human reasoning. Many cognitive scientists argue that conventional logic cannot underlie deductions, because it never requires valid conclusions to be withdrawn - not even if they are false; it treats conditional assertions implausibly; and it yields many vapid, although valid, conclusions. A new paradigm of probability logic allows conclusions to be withdrawn and treats conditionals more plausibly, although it does not address the problem of vapidity. The theory of mental models solves all of these problems. It explains how people reason about probabilities and postulates that the machinery for reasoning is itself probabilistic. Recent investigations accordingly suggest a way to integrate probability and deduction.
Default probabilities and default correlations
Erlenmaier, Ulrich; Gersbach, Hans
2001-01-01
Starting from the Merton framework for firm defaults, we provide the analytics and robustness of the relationship between default correlations. We show that loans with higher default probabilities will not only have higher variances but also higher correlations between loans. As a consequence, portfolio standard deviation can increase substantially when loan default probabilities rise. This result has two important implications. First, relative prices of loans with different default probabili...
Joint probabilities and quantum cognition
de Barros, J Acacio
2012-01-01
In this paper we discuss the existence of joint probability distributions for quantum-like response computations in the brain. We do so by focusing on a contextual neural-oscillator model shown to reproduce the main features of behavioral stimulus-response theory. We then exhibit a simple example of contextual random variables not having a joint probability distribution, and describe how such variables can be obtained from neural oscillators, but not from a quantum observable algebra.
Three lectures on free probability
2012-01-01
These are notes from a three-lecture mini-course on free probability given at MSRI in the Fall of 2010 and repeated a year later at Harvard. The lectures were aimed at mathematicians and mathematical physicists working in combinatorics, probability, and random matrix theory. The first lecture was a staged rediscovery of free independence from first principles, the second dealt with the additive calculus of free random variables, and the third focused on random matrix models.
Ning Wang
2014-01-01
Full Text Available Active calcium/calmodulin-dependent protein kinase II (CaMKII has been reported to take a critical role in the induction of long-term potentiation (LTP. Changes in CaMKII activity were detected in various ischemia models. It is tempting to know whether and how CaMKII takes a role in NMDA receptor (NMDAR-mediated postischemic long-term potentiation (NMDA i-LTP. Here, we monitored changes in NMDAR-mediated field excitatory postsynaptic potentials (NMDA fEPSPs at different time points following ischemia onset in vitro oxygen and glucose deprivation (OGD ischemia model. We found that 10 min OGD treatment induced significant i-LTP in NMDA fEPSPs, whereas shorter (3 min or longer (25 min OGD treatment failed to induce prominent NMDA i-LTP. CaMKII activity or CaMKII autophosphorylation displays a similar bifurcated trend at different time points following onset of ischemia both in vitro OGD or in vivo photothrombotic lesion (PT models, suggesting a correlation of increased CaMKII activity or CaMKII autophosphorylation with NMDA i-LTP. Disturbing the association between CaMKII and GluN2B subunit of NMDARs with short cell-permeable peptides Tat-GluN2B reversed NMDA i-LTP induced by OGD treatment. The results provide support to a notion that increased interaction between NMDAR and CaMKII following ischemia-induced increased CaMKII activity and autophosphorylation is essential for induction of NMDA i-LTP.
Nuclear energy release from fragmentation
Li, Cheng; Tsang, M B; Zhang, Feng-Shou
2015-01-01
Nuclear energy released by splitting Uranium and Thorium isotopes into two, three, four, up to eight fragments with nearly equal size are studied. We found that the energy released come from equally splitting the $^{235,238}$U and $^{230,232}$Th nuclei into to three fragments is largest. The statistical multifragmentation model is employed to calculate the probability of different breakup channels for the excited nuclei. Weighing the the probability distributions of fragments multiplicity at different excitation energies for the $^{238}$U nucleus, we found that an excitation energy between 1.2 and 2 MeV/u is optimal for the $^{235}$U, $^{238}$U, $^{230}$Th and $^{232}$Th nuclei to release nuclear energy of about 0.7-0.75 MeV/u.
Probably not future prediction using probability and statistical inference
Dworsky, Lawrence N
2008-01-01
An engaging, entertaining, and informative introduction to probability and prediction in our everyday lives Although Probably Not deals with probability and statistics, it is not heavily mathematical and is not filled with complex derivations, proofs, and theoretical problem sets. This book unveils the world of statistics through questions such as what is known based upon the information at hand and what can be expected to happen. While learning essential concepts including "the confidence factor" and "random walks," readers will be entertained and intrigued as they move from chapter to chapter. Moreover, the author provides a foundation of basic principles to guide decision making in almost all facets of life including playing games, developing winning business strategies, and managing personal finances. Much of the book is organized around easy-to-follow examples that address common, everyday issues such as: How travel time is affected by congestion, driving speed, and traffic lights Why different gambling ...
Cluster Membership Probability: Polarimetric Approach
Medhi, Biman J
2013-01-01
Interstellar polarimetric data of the six open clusters Hogg 15, NGC 6611, NGC 5606, NGC 6231, NGC 5749 and NGC 6250 have been used to estimate the membership probability for the stars within them. For proper-motion member stars, the membership probability estimated using the polarimetric data is in good agreement with the proper-motion cluster membership probability. However, for proper-motion non-member stars, the membership probability estimated by the polarimetric method is in total disagreement with the proper-motion cluster membership probability. The inconsistencies in the determined memberships may be because of the fundamental differences between the two methods of determination: one is based on stellar proper-motion in space and the other is based on selective extinction of the stellar output by the asymmetric aligned dust grains present in the interstellar medium. The results and analysis suggest that the scatter of the Stokes vectors q(%) and u(%) for the proper-motion member stars depends on the ...
Normal probability plots with confidence.
Chantarangsi, Wanpen; Liu, Wei; Bretz, Frank; Kiatsupaibul, Seksan; Hayter, Anthony J; Wan, Fang
2015-01-01
Normal probability plots are widely used as a statistical tool for assessing whether an observed simple random sample is drawn from a normally distributed population. The users, however, have to judge subjectively, if no objective rule is provided, whether the plotted points fall close to a straight line. In this paper, we focus on how a normal probability plot can be augmented by intervals for all the points so that, if the population distribution is normal, then all the points should fall into the corresponding intervals simultaneously with probability 1-α. These simultaneous 1-α probability intervals provide therefore an objective mean to judge whether the plotted points fall close to the straight line: the plotted points fall close to the straight line if and only if all the points fall into the corresponding intervals. The powers of several normal probability plot based (graphical) tests and the most popular nongraphical Anderson-Darling and Shapiro-Wilk tests are compared by simulation. Based on this comparison, recommendations are given in Section 3 on which graphical tests should be used in what circumstances. An example is provided to illustrate the methods.
Francisco J Rubio
2013-05-01
Full Text Available Antidepressant drugs are usually administered for long time for the treatment of major depressive disorder. However, they are also prescribed in several additional psychiatric conditions as well as during long term maintenance treatments. Antidepressants induce adaptive changes in several forebrain structures which include modifications at glutamatergic synapses. We recently found that repetitive administration of the selective serotonin reuptake inhibitor fluoxetine to naϊve adult male rats induced an increase of mature, mushroom-type dendritic spines in several forebrain regions. This was associated with an increase of GluA2-containing α-amino-3-hydroxy-5-methylisoxazole-4-propionate receptors (AMPA-Rs in telencephalic postsynaptic densities. To unravel the functional significance of such a synaptic re-arrangement, we focused on glutamate neurotransmission in the hippocampus. We evaluated the effect of four weeks of treatment with 0.7 mg/kg of fluoxetine on long-term potentiation (LTP and long-term depression (LTD in the Schaffer collateral-CA1 synapses and the perforant path-CA1 synapses. Recordings in hippocampal slices revealed profound deficits in LTP and LTD at Schaffer collateral-CA1 synapses associated to increased spine density and enhanced presence of mushroom-type spines, as revealed by Golgi staining. However, the same treatment had neither an effect on spine morphology, nor on LTP and LTD at perforant path-CA1 synapses. Cobalt staining experiments revealed decreased AMPA-R Ca2+ permeability in the stratum radiatum together with increased GluA2-containing, Ca2+-impermeable AMPA-Rs. Therefore, 4 weeks of fluoxetine treatment promoted structural and functional adaptations in CA1 neurons in a pathway-specific manner that were selectively associated with impairment of activity-dependent plasticity at Schaffer collateral-CA1 synapses.
Eleonora Distrutti
Full Text Available The intestinal microbiota is increasingly recognized as a complex signaling network that impacts on many systems beyond the enteric system modulating, among others, cognitive functions including learning, memory and decision-making processes. This has led to the concept of a microbiota-driven gut-brain axis, reflecting a bidirectional interaction between the central nervous system and the intestine. A deficit in synaptic plasticity is one of the many changes that occurs with age. Specifically, the archetypal model of plasticity, long-term potentiation (LTP, is reduced in hippocampus of middle-aged and aged rats. Because the intestinal microbiota might change with age, we have investigated whether the age-related deficit in LTP might be attenuated by changing the composition of intestinal microbiota with VSL#3, a probiotic mixture comprising 8 Gram-positive bacterial strains. Here, we report that treatment of aged rats with VSL#3 induced a robust change in the composition of intestinal microbiota with an increase in the abundance of Actinobacteria and Bacterioidetes, which was reduced in control-treated aged rats. VSL#3 administration modulated the expression of a large group of genes in brain tissue as assessed by whole gene expression, with evidence of a change in genes that impact on inflammatory and neuronal plasticity processes. The age-related deficit in LTP was attenuated in VSL#3-treated aged rats and this was accompanied by a modest decrease in markers of microglial activation and an increase in expression of BDNF and synapsin. The data support the notion that intestinal microbiota can be manipulated to positively impact on neuronal function.
Distrutti, Eleonora; O'Reilly, Julie-Ann; McDonald, Claire; Cipriani, Sabrina; Renga, Barbara; Lynch, Marina A; Fiorucci, Stefano
2014-01-01
The intestinal microbiota is increasingly recognized as a complex signaling network that impacts on many systems beyond the enteric system modulating, among others, cognitive functions including learning, memory and decision-making processes. This has led to the concept of a microbiota-driven gut-brain axis, reflecting a bidirectional interaction between the central nervous system and the intestine. A deficit in synaptic plasticity is one of the many changes that occurs with age. Specifically, the archetypal model of plasticity, long-term potentiation (LTP), is reduced in hippocampus of middle-aged and aged rats. Because the intestinal microbiota might change with age, we have investigated whether the age-related deficit in LTP might be attenuated by changing the composition of intestinal microbiota with VSL#3, a probiotic mixture comprising 8 Gram-positive bacterial strains. Here, we report that treatment of aged rats with VSL#3 induced a robust change in the composition of intestinal microbiota with an increase in the abundance of Actinobacteria and Bacterioidetes, which was reduced in control-treated aged rats. VSL#3 administration modulated the expression of a large group of genes in brain tissue as assessed by whole gene expression, with evidence of a change in genes that impact on inflammatory and neuronal plasticity processes. The age-related deficit in LTP was attenuated in VSL#3-treated aged rats and this was accompanied by a modest decrease in markers of microglial activation and an increase in expression of BDNF and synapsin. The data support the notion that intestinal microbiota can be manipulated to positively impact on neuronal function.
Rubio, Francisco J; Ampuero, Estíbaliz; Sandoval, Rodrigo; Toledo, Jorge; Pancetti, Floria; Wyneken, Ursula
2013-01-01
Antidepressant drugs are usually administered for several weeks for the treatment of major depressive disorder. However, they are also prescribed in several additional psychiatric conditions as well as during long-term maintenance treatments. Antidepressants induce adaptive changes in several forebrain structures which include modifications at glutamatergic synapses. We recently found that repetitive administration of the selective serotonin reuptake inhibitor (SSRI) fluoxetine to naïve adult male rats induced an increase of mature, mushroom-type dendritic spines in several forebrain regions. This was associated with an increase of GluA2-containing α-amino-3-hydroxy-5-methylisoxazole-4-propionate receptors (AMPA-Rs) in telencephalic postsynaptic densities. To unravel the functional significance of such a synaptic re-arrangement, we focused on glutamate neurotransmission in the hippocampus. We evaluated the effect of four weeks of 0.7 mg/kg fluoxetine on long-term potentiation (LTP) and long-term depression (LTD) in the CA1 hippocampal subfield. Recordings in hippocampal slices revealed profound deficits in LTP and LTD at Schaffer collateral-CA1 synapses associated to increased spine density and enhanced presence of mushroom-type spines, as revealed by Golgi staining. However, the same treatment had neither an effect on spine morphology, nor on LTP and LTD at perforant path-CA1 synapses. Cobalt staining and immunohistochemical experiments revealed decreased AMPA-R Ca(2+) permeability in the stratum radiatum (s.r.) together with increased GluA2-containing Ca(2+) impermeable AMPA-Rs. Therefore, 4 weeks of fluoxetine treatment promoted structural and functional adaptations in CA1 neurons in a pathway-specific manner that were selectively associated with impairment of activity-dependent plasticity at Schaffer collateral-CA1 synapses.
Li, C; Huang, P; Lu, Q; Zhou, M; Guo, L; Xu, X
2014-11-07
Spatial memory retrieval and hippocampal long-term potentiation (LTP) are impaired by stress. KCNQ/Kv7 channels are closely associated with memory and the KCNQ/Kv7 channel activator flupirtine represents neuroprotective effects. This study aims to test whether KCNQ/Kv7 channel activation prevents acute stress-induced impairments of spatial memory retrieval and hippocampal LTP. Rats were placed on an elevated platform in the middle of a bright room for 30 min to evoke acute stress. The expression of KCNQ/Kv7 subunits was analyzed at 1, 3 and 12 h after stress by Western blotting. Spatial memory was examined by the Morris water maze (MWM) and the field excitatory postsynaptic potential (fEPSP) in the hippocampal CA1 area was recorded in vivo. Acute stress transiently decreased the expression of KCNQ2 and KCNQ3 in the hippocampus. Acute stress impaired the spatial memory retrieval and hippocampal LTP, the KCNQ/Kv7 channel activator flupirtine prevented the impairments, and the protective effects of flupirtine were blocked by XE-991 (10,10-bis(4-Pyridinylmethyl)-9(10H)-anthracenone), a selective KCNQ channel blocker. Furthermore, acute stress decreased the phosphorylation of glycogen synthase kinase-3β (GSK-3β) at Ser9 in the hippocampus, and flupirtine inhibited the reduction. These results suggest that the KCNQ/Kv7 channels may be a potential target for protecting both hippocampal synaptic plasticity and spatial memory retrieval from acute stress influences. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.
Detonation probabilities of high explosives
Eisenhawer, S.W.; Bott, T.F.; Bement, T.R.
1995-07-01
The probability of a high explosive violent reaction (HEVR) following various events is an extremely important aspect of estimating accident-sequence frequency for nuclear weapons dismantlement. In this paper, we describe the development of response curves for insults to PBX 9404, a conventional high-performance explosive used in US weapons. The insults during dismantlement include drops of high explosive (HE), strikes of tools and components on HE, and abrasion of the explosive. In the case of drops, we combine available test data on HEVRs and the results of flooring certification tests to estimate the HEVR probability. For other insults, it was necessary to use expert opinion. We describe the expert solicitation process and the methods used to consolidate the responses. The HEVR probabilities obtained from both approaches are compared.
Probability theory a foundational course
Pakshirajan, R P
2013-01-01
This book shares the dictum of J. L. Doob in treating Probability Theory as a branch of Measure Theory and establishes this relation early. Probability measures in product spaces are introduced right at the start by way of laying the ground work to later claim the existence of stochastic processes with prescribed finite dimensional distributions. Other topics analysed in the book include supports of probability measures, zero-one laws in product measure spaces, Erdos-Kac invariance principle, functional central limit theorem and functional law of the iterated logarithm for independent variables, Skorohod embedding, and the use of analytic functions of a complex variable in the study of geometric ergodicity in Markov chains. This book is offered as a text book for students pursuing graduate programs in Mathematics and or Statistics. The book aims to help the teacher present the theory with ease, and to help the student sustain his interest and joy in learning the subject.
VIBRATION ISOLATION SYSTEM PROBABILITY ANALYSIS
Smirnov Vladimir Alexandrovich
2012-10-01
Full Text Available The article deals with the probability analysis for a vibration isolation system of high-precision equipment, which is extremely sensitive to low-frequency oscillations even of submicron amplitude. The external sources of low-frequency vibrations may include the natural city background or internal low-frequency sources inside buildings (pedestrian activity, HVAC. Taking Gauss distribution into account, the author estimates the probability of the relative displacement of the isolated mass being still lower than the vibration criteria. This problem is being solved in the three dimensional space, evolved by the system parameters, including damping and natural frequency. According to this probability distribution, the chance of exceeding the vibration criteria for a vibration isolation system is evaluated. Optimal system parameters - damping and natural frequency - are being developed, thus the possibility of exceeding vibration criteria VC-E and VC-D is assumed to be less than 0.04.
Approximation methods in probability theory
Čekanavičius, Vydas
2016-01-01
This book presents a wide range of well-known and less common methods used for estimating the accuracy of probabilistic approximations, including the Esseen type inversion formulas, the Stein method as well as the methods of convolutions and triangle function. Emphasising the correct usage of the methods presented, each step required for the proofs is examined in detail. As a result, this textbook provides valuable tools for proving approximation theorems. While Approximation Methods in Probability Theory will appeal to everyone interested in limit theorems of probability theory, the book is particularly aimed at graduate students who have completed a standard intermediate course in probability theory. Furthermore, experienced researchers wanting to enlarge their toolkit will also find this book useful.
Probability on real Lie algebras
Franz, Uwe
2016-01-01
This monograph is a progressive introduction to non-commutativity in probability theory, summarizing and synthesizing recent results about classical and quantum stochastic processes on Lie algebras. In the early chapters, focus is placed on concrete examples of the links between algebraic relations and the moments of probability distributions. The subsequent chapters are more advanced and deal with Wigner densities for non-commutative couples of random variables, non-commutative stochastic processes with independent increments (quantum Lévy processes), and the quantum Malliavin calculus. This book will appeal to advanced undergraduate and graduate students interested in the relations between algebra, probability, and quantum theory. It also addresses a more advanced audience by covering other topics related to non-commutativity in stochastic calculus, Lévy processes, and the Malliavin calculus.
Probability, Statistics, and Stochastic Processes
Olofsson, Peter
2011-01-01
A mathematical and intuitive approach to probability, statistics, and stochastic processes This textbook provides a unique, balanced approach to probability, statistics, and stochastic processes. Readers gain a solid foundation in all three fields that serves as a stepping stone to more advanced investigations into each area. This text combines a rigorous, calculus-based development of theory with a more intuitive approach that appeals to readers' sense of reason and logic, an approach developed through the author's many years of classroom experience. The text begins with three chapters that d
Innovation and social probable knowledge
Marco Crocco
2000-01-01
In this paper some elements of Keynes's theory of probability are used to understand the process of diffusion of an innovation. Based on a work done elsewhere (Crocco 1999, 2000), we argue that this process can be viewed as a process of dealing with the collective uncertainty about how to sort a technological problem. Expanding the concepts of weight of argument and probable knowledge to deal with this kind of uncertainty we argue that the concepts of social weight of argument and social prob...
Knowledge typology for imprecise probabilities.
Wilson, G. D. (Gregory D.); Zucker, L. J. (Lauren J.)
2002-01-01
When characterizing the reliability of a complex system there are often gaps in the data available for specific subsystems or other factors influencing total system reliability. At Los Alamos National Laboratory we employ ethnographic methods to elicit expert knowledge when traditional data is scarce. Typically, we elicit expert knowledge in probabilistic terms. This paper will explore how we might approach elicitation if methods other than probability (i.e., Dempster-Shafer, or fuzzy sets) prove more useful for quantifying certain types of expert knowledge. Specifically, we will consider if experts have different types of knowledge that may be better characterized in ways other than standard probability theory.
Probability, statistics, and queueing theory
Allen, Arnold O
1990-01-01
This is a textbook on applied probability and statistics with computer science applications for students at the upper undergraduate level. It may also be used as a self study book for the practicing computer science professional. The successful first edition of this book proved extremely useful to students who need to use probability, statistics and queueing theory to solve problems in other fields, such as engineering, physics, operations research, and management science. The book has also been successfully used for courses in queueing theory for operations research students. This second edit
马骋; 冯克辉; 闰丽萍
2009-01-01
Objective:To observe the inhibitive effects of electroacupuncture(EA)on long-term potentia- tion(LTP)of C-fiber evoked potentials in the spinal dorsal horn facilitated by excitomotor of NMDA or AMPA receptors,and explore the analgesia mechanism of acupuncture in neuropathic pain.Methods: Sprague-Dawley rats were divided into 7 groups:control,NMDA(NMDA)IntratheCal administration(i. t.),AMPA([±]-AMPA HBr)i.t.,EA+NMDA i.t.,EA+AMPA i.t.,NMDA i.t.+EA,and AMPA i.t+EA.The rats were fixed on stereotaxic instrument after anesthesia.C-fiber evoked field potentials in the spinal dorsal horn(L4/L5)were recorded by extracellular recording.The test stimulus was given in single pulse with 2mA,0.5ms,100Hz,5min each once on the sciatic nerve.The lower intensity high- frequency train plus stimulus(HFS)wag given in 4 trains of 1 S duration at 10s intervals with 2mA,0. 5ms,lOOHz on same place.The NMDA or[±]-AMPA HBr(40pg)was injected with i.t.,to excite the related receptor.On GB30 and BL40,EA Wag acupunctured with 1mA,2Hz,30min.Results:In the con- trol,the variation rate of evoked potentials showed no significant differences compared with before or after HFS.After excitomotor i.t then lower intensity HFS.the LTP was induced significantly and com- pared with control(P<0.01).The exeitomotor i.t.and HFS after EA,the LTP was inhibited markedly (P<0.01).After the LTP was steady kept lhr induced by the excitomotor i.t.and HFS,the EA was operated.In NMDA i.t.+EA,LTP was inhibited markedly(P<0.01);In AMPA i.t.+EA,the LTP was step down significantly(P
Schweda, Frank; Friis, Ulla; Wagner, Charlotte;
2007-01-01
The aspartyl-protease renin is the key regulator of the renin-angiotensin-aldosterone system, which is critically involved in salt, volume, and blood pressure homeostasis of the body. Renin is mainly produced and released into circulation by the so-called juxtaglomerular epithelioid cells, located......, salt, and volume overload. In contrast, the events controlling the function of renin-secreting cells at the organ and cellular level are markedly less clear and remain mysterious in certain aspects. The unravelling of these mysteries has led to new and interesting insights into the process of renin...
Comments on quantum probability theory.
Sloman, Steven
2014-01-01
Quantum probability theory (QP) is the best formal representation available of the most common form of judgment involving attribute comparison (inside judgment). People are capable, however, of judgments that involve proportions over sets of instances (outside judgment). Here, the theory does not do so well. I discuss the theory both in terms of descriptive adequacy and normative appropriateness.
Exact Probability Distribution versus Entropy
Kerstin Andersson
2014-10-01
Full Text Available The problem addressed concerns the determination of the average number of successive attempts of guessing a word of a certain length consisting of letters with given probabilities of occurrence. Both first- and second-order approximations to a natural language are considered. The guessing strategy used is guessing words in decreasing order of probability. When word and alphabet sizes are large, approximations are necessary in order to estimate the number of guesses. Several kinds of approximations are discussed demonstrating moderate requirements regarding both memory and central processing unit (CPU time. When considering realistic sizes of alphabets and words (100, the number of guesses can be estimated within minutes with reasonable accuracy (a few percent and may therefore constitute an alternative to, e.g., various entropy expressions. For many probability distributions, the density of the logarithm of probability products is close to a normal distribution. For those cases, it is possible to derive an analytical expression for the average number of guesses. The proportion of guesses needed on average compared to the total number decreases almost exponentially with the word length. The leading term in an asymptotic expansion can be used to estimate the number of guesses for large word lengths. Comparisons with analytical lower bounds and entropy expressions are also provided.
Stretching Probability Explorations with Geoboards
Wheeler, Ann; Champion, Joe
2016-01-01
Students are faced with many transitions in their middle school mathematics classes. To build knowledge, skills, and confidence in the key areas of algebra and geometry, students often need to practice using numbers and polygons in a variety of contexts. Teachers also want students to explore ideas from probability and statistics. Teachers know…
Conditional Independence in Applied Probability.
Pfeiffer, Paul E.
This material assumes the user has the background provided by a good undergraduate course in applied probability. It is felt that introductory courses in calculus, linear algebra, and perhaps some differential equations should provide the requisite experience and proficiency with mathematical concepts, notation, and argument. The document is…
Fuzzy Markov chains: uncertain probabilities
2002-01-01
We consider finite Markov chains where there are uncertainties in some of the transition probabilities. These uncertainties are modeled by fuzzy numbers. Using a restricted fuzzy matrix multiplication we investigate the properties of regular, and absorbing, fuzzy Markov chains and show that the basic properties of these classical Markov chains generalize to fuzzy Markov chains.
Stretching Probability Explorations with Geoboards
Wheeler, Ann; Champion, Joe
2016-01-01
Students are faced with many transitions in their middle school mathematics classes. To build knowledge, skills, and confidence in the key areas of algebra and geometry, students often need to practice using numbers and polygons in a variety of contexts. Teachers also want students to explore ideas from probability and statistics. Teachers know…
DECOFF Probabilities of Failed Operations
Gintautas, Tomas
A statistical procedure of estimation of Probabilities of Failed Operations is described and exemplified using ECMWF weather forecasts and SIMO output from Rotor Lift test case models. Also safety factor influence is investigated. DECOFF statistical method is benchmarked against standard Alpha...
A Novel Approach to Probability
Kafri, Oded
2016-01-01
When P indistinguishable balls are randomly distributed among L distinguishable boxes, and considering the dense system in which P much greater than L, our natural intuition tells us that the box with the average number of balls has the highest probability and that none of boxes are empty; however in reality, the probability of the empty box is always the highest. This fact is with contradistinction to sparse system in which the number of balls is smaller than the number of boxes (i.e. energy distribution in gas) in which the average value has the highest probability. Here we show that when we postulate the requirement that all possible configurations of balls in the boxes have equal probabilities, a realistic "long tail" distribution is obtained. This formalism when applied for sparse systems converges to distributions in which the average is preferred. We calculate some of the distributions resulted from this postulate and obtain most of the known distributions in nature, namely, Zipf law, Benford law, part...
Probability representations of fuzzy systems
LI Hongxing
2006-01-01
In this paper, the probability significance of fuzzy systems is revealed. It is pointed out that COG method, a defuzzification technique used commonly in fuzzy systems, is reasonable and is the optimal method in the sense of mean square. Based on different fuzzy implication operators, several typical probability distributions such as Zadeh distribution, Mamdani distribution, Lukasiewicz distribution, etc. are given. Those distributions act as "inner kernels" of fuzzy systems. Furthermore, by some properties of probability distributions of fuzzy systems, it is also demonstrated that CRI method, proposed by Zadeh, for constructing fuzzy systems is basically reasonable and effective. Besides, the special action of uniform probability distributions in fuzzy systems is characterized. Finally, the relationship between CRI method and triple I method is discussed. In the sense of construction of fuzzy systems, when restricting three fuzzy implication operators in triple I method to the same operator, CRI method and triple I method may be related in the following three basic ways: 1) Two methods are equivalent; 2) the latter is a degeneration of the former; 3) the latter is trivial whereas the former is not. When three fuzzy implication operators in triple I method are not restricted to the same operator, CRI method is a special case of triple I method; that is, triple I method is a more comprehensive algorithm. Since triple I method has a good logical foundation and comprises an idea of optimization of reasoning, triple I method will possess a beautiful vista of application.
刘志勇; 叶雪凌; 李承彧; 冯辉
2011-01-01
利用cDNA-AFLP技术分析大白菜核雄性不育两用系'AB02'可育株(msms)和不育株(Msms)花蕾的基因表达谱,在可育株混合花蕾cDNA中扩增出1条特异条带TDF-25,通过RACE和RT-PCR技术克隆了该基因的全长cDNA序列.序列分析表明,该基因编码脂质转移蛋白,命名为BrLTP1.BrLTP1全长cDNA序列为750 bp,推测编码1个包含183个氨基酸残基的前体蛋白.BrLTP1蛋白含有典型的脂质转移蛋白N端信号肽,保守的AAI结构域和半胱氨酸位点.预测BrLTP1蛋白含有多种修饰性位点,包括1个PKC磷酸化位点,2个N-糖基化位点和10个N-端豆蔻酰基化位点.基因表达模式表明,BrLTP1在两用系不育株花蕾中受到强烈抑制,在可育株的大花蕾、成熟花药以及花瓣中高水平表达.%The gene differential expression analysis was performed by cDNA-AFLP in the genic male sterile line ‘AB02' of Chinese cabbage, and a differentially expressed cDNA fragment, TDF-25, was only found in fertile plants. The full-length cDNA of BrLTPl, coding lipid transfer protein in Chinese cabbage, was amplified by RACE and RT-PCR. The BrLTPl gene was 750 bp long in cDNA and hypothetical protein BrLTPl included 183 amino acids with a signal peptide of 22 amino acids. Sequence analysis revealed that the BrLTPl protein has ten N-myristoylation sites, two N-myristoylation sites, and one PKC phosphorylation site. Gene expression characteristics indicated that BrLTPl was highly expressed in big flower buds and mature anthers of fertile plants, with a extremely low expression level in sterile buds.
Understanding Y haplotype matching probability.
Brenner, Charles H
2014-01-01
The Y haplotype population-genetic terrain is better explored from a fresh perspective rather than by analogy with the more familiar autosomal ideas. For haplotype matching probabilities, versus for autosomal matching probabilities, explicit attention to modelling - such as how evolution got us where we are - is much more important while consideration of population frequency is much less so. This paper explores, extends, and explains some of the concepts of "Fundamental problem of forensic mathematics - the evidential strength of a rare haplotype match". That earlier paper presented and validated a "kappa method" formula for the evidential strength when a suspect matches a previously unseen haplotype (such as a Y-haplotype) at the crime scene. Mathematical implications of the kappa method are intuitive and reasonable. Suspicions to the contrary raised in rest on elementary errors. Critical to deriving the kappa method or any sensible evidential calculation is understanding that thinking about haplotype population frequency is a red herring; the pivotal question is one of matching probability. But confusion between the two is unfortunately institutionalized in much of the forensic world. Examples make clear why (matching) probability is not (population) frequency and why uncertainty intervals on matching probabilities are merely confused thinking. Forensic matching calculations should be based on a model, on stipulated premises. The model inevitably only approximates reality, and any error in the results comes only from error in the model, the inexactness of the approximation. Sampling variation does not measure that inexactness and hence is not helpful in explaining evidence and is in fact an impediment. Alternative haplotype matching probability approaches that various authors have considered are reviewed. Some are based on no model and cannot be taken seriously. For the others, some evaluation of the models is discussed. Recent evidence supports the adequacy of
Probability biases as Bayesian inference
Andre; C. R. Martins
2006-11-01
Full Text Available In this article, I will show how several observed biases in human probabilistic reasoning can be partially explained as good heuristics for making inferences in an environment where probabilities have uncertainties associated to them. Previous results show that the weight functions and the observed violations of coalescing and stochastic dominance can be understood from a Bayesian point of view. We will review those results and see that Bayesian methods should also be used as part of the explanation behind other known biases. That means that, although the observed errors are still errors under the be understood as adaptations to the solution of real life problems. Heuristics that allow fast evaluations and mimic a Bayesian inference would be an evolutionary advantage, since they would give us an efficient way of making decisions. %XX In that sense, it should be no surprise that humans reason with % probability as it has been observed.
Cluster pre-existence probability
Rajeswari, N.S.; Vijayaraghavan, K.R.; Balasubramaniam, M. [Bharathiar University, Department of Physics, Coimbatore (India)
2011-10-15
Pre-existence probability of the fragments for the complete binary spectrum of different systems such as {sup 56}Ni, {sup 116}Ba, {sup 226}Ra and {sup 256}Fm are calculated, from the overlapping part of the interaction potential using the WKB approximation. The role of reduced mass as well as the classical hydrodynamical mass in the WKB method is analysed. Within WKB, even for negative Q -value systems, the pre-existence probability is calculated. The calculations reveal rich structural information. The calculated results are compared with the values of preformed cluster model of Gupta and collaborators. The mass asymmetry motion is shown here for the first time as a part of relative separation motion. (orig.)
Large deviations and idempotent probability
Puhalskii, Anatolii
2001-01-01
In the view of many probabilists, author Anatolii Puhalskii''s research results stand among the most significant achievements in the modern theory of large deviations. In fact, his work marked a turning point in the depth of our understanding of the connections between the large deviation principle (LDP) and well-known methods for establishing weak convergence results.Large Deviations and Idempotent Probability expounds upon the recent methodology of building large deviation theory along the lines of weak convergence theory. The author develops an idempotent (or maxitive) probability theory, introduces idempotent analogues of martingales (maxingales), Wiener and Poisson processes, and Ito differential equations, and studies their properties. The large deviation principle for stochastic processes is formulated as a certain type of convergence of stochastic processes to idempotent processes. The author calls this large deviation convergence.The approach to establishing large deviation convergence uses novel com...
Sm Transition Probabilities and Abundances
Lawler, J E; Sneden, C; Cowan, J J
2005-01-01
Radiative lifetimes, accurate to +/- 5%, have been measured for 212 odd-parity levels of Sm II using laser-induced fluorescence. The lifetimes are combined with branching fractions measured using Fourier-transform spectrometry to determine transition probabilities for more than 900 lines of Sm II. This work is the largest-scale laboratory study to date of Sm II transition probabilities using modern methods. This improved data set has been used to determine a new solar photospheric Sm abundance, log epsilon = 1.00 +/- 0.03, from 26 lines. The spectra of three very metal-poor, neutron-capture-rich stars also have been analyzed, employing between 55 and 72 Sm II lines per star. The abundance ratios of Sm relative to other rare earth elements in these stars are in agreement, and are consistent with ratios expected from rapid neutron-capture nucleosynthesis (the r-process).
Knot probabilities in random diagrams
Cantarella, Jason; Chapman, Harrison; Mastin, Matt
2016-10-01
We consider a natural model of random knotting—choose a knot diagram at random from the finite set of diagrams with n crossings. We tabulate diagrams with 10 and fewer crossings and classify the diagrams by knot type, allowing us to compute exact probabilities for knots in this model. As expected, most diagrams with 10 and fewer crossings are unknots (about 78% of the roughly 1.6 billion 10 crossing diagrams). For these crossing numbers, the unknot fraction is mostly explained by the prevalence of ‘tree-like’ diagrams which are unknots for any assignment of over/under information at crossings. The data shows a roughly linear relationship between the log of knot type probability and the log of the frequency rank of the knot type, analogous to Zipf’s law for word frequency. The complete tabulation and all knot frequencies are included as supplementary data.
Probability distributions for multimeric systems.
Albert, Jaroslav; Rooman, Marianne
2016-01-01
We propose a fast and accurate method of obtaining the equilibrium mono-modal joint probability distributions for multimeric systems. The method necessitates only two assumptions: the copy number of all species of molecule may be treated as continuous; and, the probability density functions (pdf) are well-approximated by multivariate skew normal distributions (MSND). Starting from the master equation, we convert the problem into a set of equations for the statistical moments which are then expressed in terms of the parameters intrinsic to the MSND. Using an optimization package on Mathematica, we minimize a Euclidian distance function comprising of a sum of the squared difference between the left and the right hand sides of these equations. Comparison of results obtained via our method with those rendered by the Gillespie algorithm demonstrates our method to be highly accurate as well as efficient.
Off-site ignition probability of flammable gases.
Rew, P J; Spencer, H; Daycock, J
2000-01-07
A key step in the assessment of risk for installations where flammable liquids or gases are stored is the estimation of ignition probability. A review of current modelling and data confirmed that ignition probability values used in risk analyses tend to be based on extrapolation of limited incident data or, in many cases, on the judgement of those conducting the safety assessment. Existing models tend to assume that ignition probability is a function of release rate (or flammable gas cloud size) alone and they do not consider location, density or type of ignition source. An alternative mathematical framework for calculating ignition probability is outlined in which the approach used is to model the distribution of likely ignition sources and to calculate ignition probability by considering whether the flammable gas cloud will reach these sources. Data are collated on the properties of ignition sources within three generic land-use types: industrial, urban and rural. These data are then incorporated into a working model for ignition probability in a form capable of being implemented within risk analysis models. The sensitivity of the model results to assumptions made in deriving the ignition source properties is discussed and the model is compared with other available ignition probability methods.
Asbestos and Probable Microscopic Polyangiitis
George S Rashed Philteos
2004-01-01
Full Text Available Several inorganic dust lung diseases (pneumoconioses are associated with autoimmune diseases. Although autoimmune serological abnormalities are common in asbestosis, clinical autoimmune/collagen vascular diseases are not commonly reported. A case of pulmonary asbestosis complicated by perinuclear-antineutrophil cytoplasmic antibody (myeloperoxidase positive probable microscopic polyangiitis (glomerulonephritis, pericarditis, alveolitis, multineuritis multiplex is described and the possible immunological mechanisms whereby asbestosis fibres might be relevant in induction of antineutrophil cytoplasmic antibodies are reviewed in the present report.
Logic, Probability, and Human Reasoning
2015-01-01
3–6] and they underlie mathematics , science, and tech- nology [7–10]. Plato claimed that emotions upset reason - ing. However, individuals in the grip...Press 10 Nickerson, R. (2011) Mathematical Reasoning : Patterns, Problems, Conjectures, and Proofs, Taylor & Francis 11 Blanchette, E. and Richards, A...Logic, probability, and human reasoning P.N. Johnson-Laird1,2, Sangeet S. Khemlani3, and Geoffrey P. Goodwin4 1 Princeton University, Princeton, NJ
Probability and statistics: A reminder
Clément Benoit
2013-07-01
Full Text Available The main purpose of these lectures is to provide the reader with the tools needed to data analysis in the framework of physics experiments. Basic concepts are introduced together with examples of application in experimental physics. The lecture is divided into two parts: probability and statistics. It is build on the introduction from “data analysis in experimental sciences” given in [1
Probability Measures on Groups IX
1989-01-01
The latest in this series of Oberwolfach conferences focussed on the interplay between structural probability theory and various other areas of pure and applied mathematics such as Tauberian theory, infinite-dimensional rotation groups, central limit theorems, harmonizable processes, and spherical data. Thus it was attended by mathematicians whose research interests range from number theory to quantum physics in conjunction with structural properties of probabilistic phenomena. This volume contains 5 survey articles submitted on special invitation and 25 original research papers.
Objective probability and quantum fuzziness
Mohrhoff, U
2007-01-01
This paper offers a critique of the Bayesian approach to quantum mechanics in general and of a recent paper by Caves, Fuchs, and Schack in particular (quant-ph/0608190 v2). In this paper the Bayesian interpretation of Born probabilities is defended against what the authors call the "objective-preparations view". The fact that Caves et al. and the proponents of this view equally misconstrue the time dependence of quantum states, voids the arguments pressed by the former against the latter. After tracing the genealogy of this common error, I argue that the real oxymoron is not an unknown quantum state, as the Bayesians hold, but an unprepared quantum state. I further argue that the essential role of probability in quantum theory is to define and quantify an objective fuzziness. This, more than anything, legitimizes conjoining "objective" to "probability". The measurement problem is essentially the problem of finding a coherent way of thinking about this objective fuzziness, and about the supervenience of the ma...
The neurologic examination in patients with probable Alzheimer's disease.
Huff, F J; Boller, F; Lucchelli, F; Querriera, R; Beyer, J; Belle, S
1987-09-01
Abnormal findings on a standardized neurologic examination were compared between patients with a clinical diagnosis of probable Alzheimer's disease (AD) and healthy control subjects. Aside from mental status findings, the most useful examination findings for differentiating AD from control subjects were the presence of release signs, olfactory deficit, impaired stereognosis or graphesthesia, gait disorder, tremor, and abnormalities on cerebellar testing. These abnormalities probably reflect the different areas of the central nervous system that are affected pathologically in AD. In the clinical diagnosis of AD, particular attention should be given to these aspects of the neurologic examination.
Empirical and Computational Tsunami Probability
Geist, E. L.; Parsons, T.; ten Brink, U. S.; Lee, H. J.
2008-12-01
A key component in assessing the hazard posed by tsunamis is quantification of tsunami likelihood or probability. To determine tsunami probability, one needs to know the distribution of tsunami sizes and the distribution of inter-event times. Both empirical and computational methods can be used to determine these distributions. Empirical methods rely on an extensive tsunami catalog and hence, the historical data must be carefully analyzed to determine whether the catalog is complete for a given runup or wave height range. Where site-specific historical records are sparse, spatial binning techniques can be used to perform a regional, empirical analysis. Global and site-specific tsunami catalogs suggest that tsunami sizes are distributed according to a truncated or tapered power law and inter-event times are distributed according to an exponential distribution modified to account for clustering of events in time. Computational methods closely follow Probabilistic Seismic Hazard Analysis (PSHA), where size and inter-event distributions are determined for tsunami sources, rather than tsunamis themselves as with empirical analysis. In comparison to PSHA, a critical difference in the computational approach to tsunami probabilities is the need to account for far-field sources. The three basic steps in computational analysis are (1) determination of parameter space for all potential sources (earthquakes, landslides, etc.), including size and inter-event distributions; (2) calculation of wave heights or runup at coastal locations, typically performed using numerical propagation models; and (3) aggregation of probabilities from all sources and incorporation of uncertainty. It is convenient to classify two different types of uncertainty: epistemic (or knowledge-based) and aleatory (or natural variability). Correspondingly, different methods have been traditionally used to incorporate uncertainty during aggregation, including logic trees and direct integration. Critical
Probability for Weather and Climate
Smith, L. A.
2013-12-01
Over the last 60 years, the availability of large-scale electronic computers has stimulated rapid and significant advances both in meteorology and in our understanding of the Earth System as a whole. The speed of these advances was due, in large part, to the sudden ability to explore nonlinear systems of equations. The computer allows the meteorologist to carry a physical argument to its conclusion; the time scales of weather phenomena then allow the refinement of physical theory, numerical approximation or both in light of new observations. Prior to this extension, as Charney noted, the practicing meteorologist could ignore the results of theory with good conscience. Today, neither the practicing meteorologist nor the practicing climatologist can do so, but to what extent, and in what contexts, should they place the insights of theory above quantitative simulation? And in what circumstances can one confidently estimate the probability of events in the world from model-based simulations? Despite solid advances of theory and insight made possible by the computer, the fidelity of our models of climate differs in kind from the fidelity of models of weather. While all prediction is extrapolation in time, weather resembles interpolation in state space, while climate change is fundamentally an extrapolation. The trichotomy of simulation, observation and theory which has proven essential in meteorology will remain incomplete in climate science. Operationally, the roles of probability, indeed the kinds of probability one has access too, are different in operational weather forecasting and climate services. Significant barriers to forming probability forecasts (which can be used rationally as probabilities) are identified. Monte Carlo ensembles can explore sensitivity, diversity, and (sometimes) the likely impact of measurement uncertainty and structural model error. The aims of different ensemble strategies, and fundamental differences in ensemble design to support of
Estimating Probabilities in Recommendation Systems
Sun, Mingxuan; Kidwell, Paul
2010-01-01
Recommendation systems are emerging as an important business application with significant economic impact. Currently popular systems include Amazon's book recommendations, Netflix's movie recommendations, and Pandora's music recommendations. In this paper we address the problem of estimating probabilities associated with recommendation system data using non-parametric kernel smoothing. In our estimation we interpret missing items as randomly censored observations and obtain efficient computation schemes using combinatorial properties of generating functions. We demonstrate our approach with several case studies involving real world movie recommendation data. The results are comparable with state-of-the-art techniques while also providing probabilistic preference estimates outside the scope of traditional recommender systems.
Probability, Statistics, and Stochastic Processes
Olofsson, Peter
2012-01-01
This book provides a unique and balanced approach to probability, statistics, and stochastic processes. Readers gain a solid foundation in all three fields that serves as a stepping stone to more advanced investigations into each area. The Second Edition features new coverage of analysis of variance (ANOVA), consistency and efficiency of estimators, asymptotic theory for maximum likelihood estimators, empirical distribution function and the Kolmogorov-Smirnov test, general linear models, multiple comparisons, Markov chain Monte Carlo (MCMC), Brownian motion, martingales, and
PROBABILITY MODEL OF GUNTHER GENERATOR
无
2007-01-01
This paper constructs the probability model of Gunther generator at first, and the finite dimension union distribution of the output sequence is presented. The result shows that the output sequence is an independent and uniformly distributed 0,1 random variable sequence.It gives the theoretical foundation about why Gunther generator can avoid the statistic weakness of the output sequence of stop-and-go generator, and analyzes the coincidence between output sequence and input sequences of Gunther generator. The conclusions of this paper would offer theoretical references for designers and analyzers of clock-controlled generators.
Probability, statistics, and computational science.
Beerenwinkel, Niko; Siebourg, Juliane
2012-01-01
In this chapter, we review basic concepts from probability theory and computational statistics that are fundamental to evolutionary genomics. We provide a very basic introduction to statistical modeling and discuss general principles, including maximum likelihood and Bayesian inference. Markov chains, hidden Markov models, and Bayesian network models are introduced in more detail as they occur frequently and in many variations in genomics applications. In particular, we discuss efficient inference algorithms and methods for learning these models from partially observed data. Several simple examples are given throughout the text, some of which point to models that are discussed in more detail in subsequent chapters.
Probability of Detection Demonstration Transferability
Parker, Bradford H.
2008-01-01
The ongoing Mars Science Laboratory (MSL) Propellant Tank Penetrant Nondestructive Evaluation (NDE) Probability of Detection (POD) Assessment (NESC activity) has surfaced several issues associated with liquid penetrant POD demonstration testing. This presentation lists factors that may influence the transferability of POD demonstration tests. Initial testing will address the liquid penetrant inspection technique. Some of the factors to be considered in this task are crack aspect ratio, the extent of the crack opening, the material and the distance between the inspection surface and the inspector's eye.
Hf Transition Probabilities and Abundances
Lawler, J E; Labby, Z E; Sneden, C; Cowan, J J; Ivans, I I
2006-01-01
Radiative lifetimes from laser-induced fluorescence measurements, accurate to about +/- 5 percent, are reported for 41 odd-parity levels of Hf II. The lifetimes are combined with branching fractions measured using Fourier transform spectrometry to determine transition probabilities for 150 lines of Hf II. Approximately half of these new transition probabilities overlap with recent independent measurements using a similar approach. The two sets of measurements are found to be in good agreement for measurements in common. Our new laboratory data are applied to refine the hafnium photospheric solar abundance and to determine hafnium abundances in 10 metal-poor giant stars with enhanced r-process abundances. For the Sun we derive log epsilon (Hf) = 0.88 +/- 0.08 from four lines; the uncertainty is dominated by the weakness of the lines and their blending by other spectral features. Within the uncertainties of our analysis, the r-process-rich stars possess constant Hf/La and Hf/Eu abundance ratios, log epsilon (Hf...
Gd Transition Probabilities and Abundances
Den Hartog, E A; Sneden, C; Cowan, J J
2006-01-01
Radiative lifetimes, accurate to +/- 5%, have been measured for 49 even-parity and 14 odd-parity levels of Gd II using laser-induced fluorescence. The lifetimes are combined with branching fractions measured using Fourier transform spectrometry to determine transition probabilities for 611 lines of Gd II. This work is the largest-scale laboratory study to date of Gd II transition probabilities and the first using a high performance Fourier transform spectrometer. This improved data set has been used to determine a new solar photospheric Gd abundance, log epsilon = 1.11 +/- 0.03. Revised Gd abundances have also been derived for the r-process-rich metal-poor giant stars CS 22892-052, BD+17 3248, and HD 115444. The resulting Gd/Eu abundance ratios are in very good agreement with the solar-system r-process ratio. We have employed the increasingly accurate stellar abundance determinations, resulting in large part from the more precise laboratory atomic data, to predict directly the Solar System r-process elemental...
Aven, Terje; Sklet, Snorre; Vinnem, Jan Erik
2006-09-21
Investigations of major accidents show that technical, human, operational, as well as organisational factors influence the accident sequences. In spite of these facts, quantitative risk analyses of offshore oil and gas production platforms have focused on technical safety systems. This paper presents a method (called BORA-Release) for qualitative and quantitative risk analysis of the platform specific hydrocarbon release frequency. By using BORA-Release it is possible to analyse the effect of safety barriers introduced to prevent hydrocarbon releases, and how platform specific conditions of technical, human, operational, and organisational risk influencing factors influence the barrier performance. BORA-Release comprises the following main steps: (1) development of a basic risk model including release scenarios, (2) modelling the performance of safety barriers, (3) assignment of industry average probabilities/frequencies and risk quantification based on these probabilities/frequencies, (4) development of risk influence diagrams, (5) scoring of risk influencing factors, (6) weighting of risk influencing factors, (7) adjustment of industry average probabilities/frequencies, and (8) recalculation of the risk in order to determine the platform specific risk related to hydrocarbon release. The various steps in BORA-Release are presented and discussed. Part II of the paper presents results from a case study where BORA-Release is applied.
8-Br-cAMP对脊髓背角C-纤维诱发电位LTP的影响%The effects of 8-Br-Camp on LTP of C-fiber evoked field potentials
杨红卫; 张红梅; 信文君; 张彤; 刘先国
2005-01-01
目的探讨cAMP类似物8-Br-cAMP对脊髓长时程增强(LTP)的诱导和维持的影响.方法采用SD大鼠,常规细胞外记录技术记录脊髓背角腰膨大部位浅层C-纤维诱发电位.结果①8-Br-cAMP(1 mmol/L)可诱发脊髓背角C-纤维诱发电位的LTP.②强直刺激坐骨神经可诱导脊髓LTP.③8-Br-cAMP诱发的脊髓突触增强未能咬合强直刺激诱导的脊髓LTP.④强直刺激诱导的脊髓LTP后30 min,脊髓表面加入8-Br-cAMP(1 mmol/L)可使C-纤维诱发电位显著增大.结论强直电刺激诱导的LTP与8-Br-cAMP诱导的LTP可能是通过不同的机制实现的;8-Br-cAMP诱导的LTP可能是通过cAMP信号转导途径起作用.
Jin, Shan-Xue; Arai, Junko; Tian, Xuejun; Kumar-Singh, Rajendra; Feig, Larry A
2013-07-26
RAS-GRF1 is a guanine nucleotide exchange factor with the ability to activate RAS and RAC GTPases in response to elevated calcium levels. We previously showed that beginning at 1 month of age, RAS-GRF1 mediates NMDA-type glutamate receptor (NMDAR)-induction of long term depression in the CA1 region of the hippocampus of mice. Here we show that beginning at 2 months of age, when mice first acquire the ability to discriminate between closely related contexts, RAS-GRF1 begins to contribute to the induction of long term potentiation (LTP) in the CA1 hippocampus by mediating the action of calcium-permeable, AMPA-type glutamate receptors (CP-AMPARs). Surprisingly, LTP induction by CP-AMPARs through RAS-GRF1 occurs via activation of p38 MAP kinase rather than ERK MAP kinase, which has more frequently been linked to LTP. Moreover, contextual discrimination is blocked by knockdown of Ras-Grf1 expression specifically in the CA1 hippocampus, infusion of a p38 MAP kinase inhibitor into the CA1 hippocampus, or the injection of an inhibitor of CP-AMPARs. These findings implicate the CA1 hippocampus in the developmentally dependent capacity to distinguish closely related contexts through the appearance of a novel LTP-supporting signaling pathway.
Post-Classical Probability Theory
Barnum, Howard
2012-01-01
This paper offers a brief introduction to the framework of "general probabilistic theories", otherwise known as the "convex-operational" approach the foundations of quantum mechanics. Broadly speaking, the goal of research in this vein is to locate quantum mechanics within a very much more general, but conceptually very straightforward, generalization of classical probability theory. The hope is that, by viewing quantum mechanics "from the outside", we may be able better to understand it. We illustrate several respects in which this has proved to be the case, reviewing work on cloning and broadcasting, teleportation and entanglement swapping, key distribution, and ensemble steering in this general framework. We also discuss a recent derivation of the Jordan-algebraic structure of finite-dimensional quantum theory from operationally reasonable postulates.
Associativity and normative credal probability.
Snow, P
2002-01-01
Cox's Theorem is a widely cited motivation for probabilistic models of uncertain belief. The theorem relates the associativity of the logical connectives to that of the arithmetic operations of probability. Recent questions about the correctness of Cox's Theorem have been resolved, but there are new questions about one functional equation used by Cox in 1946. This equation is missing from his later work. Advances in knowledge since 1946 and changes in Cox's research interests explain the equation's disappearance. Other associativity-based motivations avoid functional equations altogether, and so may be more transparently applied to finite domains and discrete beliefs. A discrete counterpart of Cox's Theorem can be assembled from results that have been in the literature since 1959.
Probability theory a comprehensive course
Klenke, Achim
2014-01-01
This second edition of the popular textbook contains a comprehensive course in modern probability theory. Overall, probabilistic concepts play an increasingly important role in mathematics, physics, biology, financial engineering and computer science. They help us in understanding magnetism, amorphous media, genetic diversity and the perils of random developments at financial markets, and they guide us in constructing more efficient algorithms. To address these concepts, the title covers a wide variety of topics, many of which are not usually found in introductory textbooks, such as: • limit theorems for sums of random variables • martingales • percolation • Markov chains and electrical networks • construction of stochastic processes • Poisson point process and infinite divisibility • large deviation principles and statistical physics • Brownian motion • stochastic integral and stochastic differential equations. The theory is developed rigorously and in a self-contained way, with the c...
The Inductive Applications of Probability Calculus
Corrado Gini
2015-06-01
Full Text Available The Author goes back to Founders of Probability calculus to investigate their original interpretation of the probability measure in the applications of the probability theory to real problems. The Author puts in evidence some misunderstandings related to the inversion of deductions derived by the use of probability distributions for investigating the causes of events.
Ali, Zulfiqar [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Yashchuk, Valeriy V. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2011-07-11
Systematic error and instrumental drift are the major limiting factors of sub-microradian slope metrology with state-of-the-art x-ray optics. Significant suppression of the errors can be achieved by using an optimal measurement strategy suggested in [Rev. Sci. Instrum. 80, 115101 (2009)]. With this series of LSBL Notes, we report on development of an automated, kinematic, rotational system that provides fully controlled flipping, tilting, and shifting of a surface under test. The system is integrated into the Advanced Light Source long trace profiler, LTP-II, allowing for complete realization of the advantages of the optimal measurement strategy method. We provide details of the system?s design, operational control and data acquisition. The high performance of the system is demonstrated via the results of high precision measurements with a spherical test mirror.
Hell, Johannes W
2016-04-26
Both synaptic long-term potentiation (LTP) and long-term depression (LTD) are thought to be critical for memory formation. Dell'Acqua and co-workers now demonstrate that transient postsynaptic incorporation of Ca(2+)-permeable (CP) α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) is required for LTD in the exemplary hippocampal CA1 region in 2-week-old mice. Mechanistically, LTD depends on AKAP150-anchored protein kinase A (PKA) to promote the initial functional recruitment of CP-AMPARs during LTD induction and on AKAP150-anchored protein phosphatase 2B (PP2B) to trigger their subsequent removal as part of the lasting depression of synaptic transmission.
Probability landscapes for integrative genomics
Benecke Arndt
2008-05-01
Full Text Available Abstract Background The comprehension of the gene regulatory code in eukaryotes is one of the major challenges of systems biology, and is a requirement for the development of novel therapeutic strategies for multifactorial diseases. Its bi-fold degeneration precludes brute force and statistical approaches based on the genomic sequence alone. Rather, recursive integration of systematic, whole-genome experimental data with advanced statistical regulatory sequence predictions needs to be developed. Such experimental approaches as well as the prediction tools are only starting to become available and increasing numbers of genome sequences and empirical sequence annotations are under continual discovery-driven change. Furthermore, given the complexity of the question, a decade(s long multi-laboratory effort needs to be envisioned. These constraints need to be considered in the creation of a framework that can pave a road to successful comprehension of the gene regulatory code. Results We introduce here a concept for such a framework, based entirely on systematic annotation in terms of probability profiles of genomic sequence using any type of relevant experimental and theoretical information and subsequent cross-correlation analysis in hypothesis-driven model building and testing. Conclusion Probability landscapes, which include as reference set the probabilistic representation of the genomic sequence, can be used efficiently to discover and analyze correlations amongst initially heterogeneous and un-relatable descriptions and genome-wide measurements. Furthermore, this structure is usable as a support for automatically generating and testing hypotheses for alternative gene regulatory grammars and the evaluation of those through statistical analysis of the high-dimensional correlations between genomic sequence, sequence annotations, and experimental data. Finally, this structure provides a concrete and tangible basis for attempting to formulate a
Maria Livia Bernardi
Full Text Available BACKGROUND: Food allergy is increasingly common worldwide. Tools for allergy diagnosis measuring IgE improved much since allergenic molecules and microarrays started to be used. IgE response toward allergens belonging to the same group of molecules has not been comprehensively explored using such approach yet. OBJECTIVE: Using the model of lipid transfer proteins (LTPs from plants as allergens, including two new structures, we sought to define how heterogeneous is the behavior of homologous proteins. METHODS: Two new allergenic LTPs, Act d 10 and Act c 10, have been identified in green (Actinidia deliciosa and gold (Actinidia chinensis kiwifruit (KF, respectively, using clinically characterized allergic patients, and their biochemical features comparatively evaluated by means of amino acid sequence alignments. Along with other five LTPs from peach, mulberry, hazelnut, peanut, mugwort, KF LTPs, preliminary tested positive for IgE, have been immobilized on a microarray, used for IgE testing 1,003 allergic subjects. Comparative analysis has been carried out. RESULTS: Alignment of Act d 10 primary structure with the other allergenic LTPs shows amino acid identities to be in a narrow range between 40 and 55%, with a number of substitutions making the sequences quite different from each other. Although peach LTP dominates the IgE immune response in terms of prevalence, epitope recognition driven by sequence heterogeneity has been recorded to be distributed in a wide range of behaviors. KF LTPs IgE positive results were obtained in a patient subset IgE positive for the peach LTP. Anyhow, the negative results on homologous molecules allowed us to reintroduce KF in patients' diet. CONCLUSION: The biochemical nature of allergenic molecule belonging to a group of homologous ones should not be taken as proof of immunological recognition as well. The availability of panels of homologous molecules to be tested using microarrays is valuable to address the
Xia, Weiwei; Mørch, Carsten Dahl; Andersen, Ole Kæseler
2016-01-01
Background 10 Hz conditioning electrical stimulation (CES) has been shown to induce long-term potentiation (LTP)-like pain amplification similar to traditional 100 Hz CES in healthy humans. The aim of this study was to assess the test-retest reliability and to estimate sample sizes required for future crossover and parallel study designs. Methods The 10 Hz paradigm (500 rectangular pulses lasting 50 s) was repeated on two separate days with one week interval in twenty volunteers. Perceptual intensities to single electrical stimulation (SES) at the conditioned skin site and to mechanical stimuli (pinprick and light stroking) in immediate vicinity to the conditioned skin site were recorded. Superficial blood flow (SBF) was assessed as indicator of neurogenic inflammation. All outcome measures were assessed with 10 min interval three times before and six times after the CES. The coefficient of variation and intra-class correlation coefficient were calculated within session and between sessions. Sample sizes were estimated for future crossover (Ncr) and parallel (Np) drug testing studies expected to detect a 30% decrease for the individual outcome measure following 10 Hz CES. Results Perceptual intensity ratings to light stroking (Ncr = 2, Np = 33) and pinprick stimulation (491 mN) (Ncr = 6, Np = 54) increased after CES and showed better reliability in crossover than parallel design. The SBF increased after CES, and then declined until reaching a plateau 20 minutes postCES. SBF showed acceptable reliability both in crossover and parallel designs (Ncr = 3, Np = 13). Pain ratings to SES were reliable, but with large estimated sample sizes (Ncr = 634, Np = 11310) due to the minor pain amplification. Conclusions The reliability of 10 Hz CES was acceptable in inducing LTP-like effects in the assessments of superficial blood flow, heterotopic mechanical hyperalgesia, and dysesthesia in terms of sample sizes for future crossover study designs. PMID:27529175
Srivareerat, Marisa; Tran, Trinh T; Salim, Samina; Aleisa, Abdulaziz M; Alkadhi, Karim A
2011-05-01
Alzheimer's disease (AD) is a devastating neurodegenerative disorder characterized by increased deposition of beta-amyloid (Aβ) peptides and progressive cholinergic dysfunction in regions of the brain involved in learning and memory processing. In AD, progressive accumulation of Aβ peptide impairs nicotinic acetylcholine receptor (nAChR) function by an unknown mechanism believed to involve α(7)- and α(4)β(2)-nAChR blockade. The three approaches of the current study evaluated the effects of chronic nicotine treatment in the prevention of Aβ-induced impairment of learning and short-term memory. Rat AD model was induced by 14-day i.c.v. osmotic pump infusion of a 1:1 mixture of 300 pmol/day Aβ(1-40)/Aβ(1-42) or Aβ(40-1) (inactive peptide, control). The effect of nicotine (2 mg/(kg day)) on Aβ-induced spatial learning and memory impairments was assessed by evaluation of performance in the radial arm water maze (RAWM), in vivo electrophysiological recordings of early-phase long-term potentiation (E-LTP) in urethane-anesthetized rats, and immunoblot analysis to determine changes in the levels of beta-site amyloid precursor protein (APP)-cleaving enzyme (BACE), Aβ and memory-related proteins. The results indicate that 6 weeks of nicotine treatment reduced the levels of Aβ(1-40) and BACE1 peptides in hippocampal area CA1 and prevented Aβ-induced impairment of learning and short-term memory. Chronic nicotine also prevented the Aβ-induced inhibition of basal synaptic transmission and LTP in hippocampal area CA1. Furthermore, chronic nicotine treatment prevented the Aβ-induced reduction of α(7)- and α(4)-nAChR. These effects of nicotine may be due, at least in part, to upregulation of brain derived neurotropic factor (BDNF).
Gamboa-Becerra, Roberto; Ramírez-Chávez, Enrique; Molina-Torres, Jorge; Winkler, Robert
2015-07-01
In cartography, the combination of colour and contour lines is used to express a three-dimensional landscape on a two-dimensional map. We transferred this concept to the analysis of mass spectrometry imaging (MSI) data and developed a collection of R scripts for the efficient evaluation of .imzML archives in a four-step strategy: (1) calculation of the density distribution of mass-to-charge ratio (m/z) signals in the .imzML file and assembling of a pseudo-master spectrum with peak list, (2) automated generation of mass images for a defined scan range and subsequent visual inspection, (3) visualisation of individual ion distributions and export of relevant .mzML spectra and (4) creation of overlay graphics of ion images and photographies. The use of a Hue-Chroma-Luminance (HCL) colour model in MSI graphics takes into account the human perception for colours and supports the correct evaluation of signal intensities. Further, readers with colour blindness are supported. Contour maps promote the visual recognition of patterns in MSI data, which is particularly useful for noisy data sets. We demonstrate the scalability of MSI.R scripts by running them on different systems: on a personal computer, on Amazon Web Services (AWS) instances and on an institutional cluster. By implementing a parallel computing strategy, the execution speed for .imzML data scanning with image generation could be improved by more than an order of magnitude. Applying our MSI.R scripts ( http://www.bioprocess.org/MSI.R ) to low-temperature plasma (LTP)-MSI data shows the localisation of volatile and semi-volatile compounds in the cross-cut of a chilli (Capsicum annuum) fruit. The subsequent identification of compounds by gas and liquid chromatography coupled to mass spectrometry (GC-MS, LC-MS) proves that LTP-MSI enables the direct measurement of volatile organic compound (VOC) distributions from biological tissues.
Probability theory and mathematical statistics for engineers
Pugachev, V S
1984-01-01
Probability Theory and Mathematical Statistics for Engineers focuses on the concepts of probability theory and mathematical statistics for finite-dimensional random variables.The publication first underscores the probabilities of events, random variables, and numerical characteristics of random variables. Discussions focus on canonical expansions of random vectors, second-order moments of random vectors, generalization of the density concept, entropy of a distribution, direct evaluation of probabilities, and conditional probabilities. The text then examines projections of random vector
Introduction to probability theory with contemporary applications
Helms, Lester L
2010-01-01
This introduction to probability theory transforms a highly abstract subject into a series of coherent concepts. Its extensive discussions and clear examples, written in plain language, expose students to the rules and methods of probability. Suitable for an introductory probability course, this volume requires abstract and conceptual thinking skills and a background in calculus.Topics include classical probability, set theory, axioms, probability functions, random and independent random variables, expected values, and covariance and correlations. Additional subjects include stochastic process
Statistical convergence of order $\\alpha$ in probability
Pratulananda Das; Sanjoy Ghosal; Sumit Som
2016-01-01
In this paper ideas of different types of convergence of a sequence of random variables in probability, namely, statistical convergence of order $\\alpha$ in probability, strong $p$-Ces$\\grave{\\mbox{a}}$ro summability of order $\\alpha$ in probability, lacunary statistical convergence or $S_{\\theta}$-convergence of order $\\alpha$ in probability, ${N_{\\theta}}$-convergence of order $\\alpha$ in probability have been introduced and their certain basic properties have been studied.
Fusion probability in heavy nuclei
Banerjee, Tathagata; Nath, S.; Pal, Santanu
2015-03-01
Background: Fusion between two massive nuclei is a very complex process and is characterized by three stages: (a) capture inside the potential barrier, (b) formation of an equilibrated compound nucleus (CN), and (c) statistical decay of the CN leading to a cold evaporation residue (ER) or fission. The second stage is the least understood of the three and is the most crucial in predicting yield of superheavy elements (SHE) formed in complete fusion reactions. Purpose: A systematic study of average fusion probability, PCN> , is undertaken to obtain a better understanding of its dependence on various reaction parameters. The study may also help to clearly demarcate onset of non-CN fission (NCNF), which causes fusion probability, PCN, to deviate from unity. Method: ER excitation functions for 52 reactions leading to CN in the mass region 170-220, which are available in the literature, have been compared with statistical model (SM) calculations. Capture cross sections have been obtained from a coupled-channels code. In the SM, shell corrections in both the level density and the fission barrier have been included. PCN> for these reactions has been extracted by comparing experimental and theoretical ER excitation functions in the energy range ˜5 %-35% above the potential barrier, where known effects of nuclear structure are insignificant. Results: PCN> has been shown to vary with entrance channel mass asymmetry, η (or charge product, ZpZt ), as well as with fissility of the CN, χCN. No parameter has been found to be adequate as a single scaling variable to determine PCN> . Approximate boundaries have been obtained from where PCN> starts deviating from unity. Conclusions: This study quite clearly reveals the limits of applicability of the SM in interpreting experimental observables from fusion reactions involving two massive nuclei. Deviation of PCN> from unity marks the beginning of the domain of dynamical models of fusion. Availability of precise ER cross sections
Combined statistical analysis of landslide release and propagation
Mergili, Martin; Rohmaneo, Mohammad; Chu, Hone-Jay
2016-04-01
Statistical methods - often coupled with stochastic concepts - are commonly employed to relate areas affected by landslides with environmental layers, and to estimate spatial landslide probabilities by applying these relationships. However, such methods only concern the release of landslides, disregarding their motion. Conceptual models for mass flow routing are used for estimating landslide travel distances and possible impact areas. Automated approaches combining release and impact probabilities are rare. The present work attempts to fill this gap by a fully automated procedure combining statistical and stochastic elements, building on the open source GRASS GIS software: (1) The landslide inventory is subset into release and deposition zones. (2) We employ a traditional statistical approach to estimate the spatial release probability of landslides. (3) We back-calculate the probability distribution of the angle of reach of the observed landslides, employing the software tool r.randomwalk. One set of random walks is routed downslope from each pixel defined as release area. Each random walk stops when leaving the observed impact area of the landslide. (4) The cumulative probability function (cdf) derived in (3) is used as input to route a set of random walks downslope from each pixel in the study area through the DEM, assigning the probability gained from the cdf to each pixel along the path (impact probability). The impact probability of a pixel is defined as the average impact probability of all sets of random walks impacting a pixel. Further, the average release probabilities of the release pixels of all sets of random walks impacting a given pixel are stored along with the area of the possible release zone. (5) We compute the zonal release probability by increasing the release probability according to the size of the release zone - the larger the zone, the larger the probability that a landslide will originate from at least one pixel within this zone. We
Probable Linezolid-Induced Pancytopenia
Nita Lakhani
2005-01-01
Full Text Available A 75-year-old male outpatient with cardiac disease, diabetes, chronic renal insufficiency and iron deficiency anemia was prescribed linezolid 600 mg twice daily for a methicillin-resistant Staphylococcus aureus diabetic foot osteomyelitis. After one week, his blood counts were consistent with baseline values. The patient failed to return for subsequent blood work. On day 26, he was admitted to hospital with acute renal failure secondary to dehydration, and was found to be pancytopenic (erythrocytes 2.5x1012/L, leukocytes 2.9x109/L, platelets 59x109/L, hemoglobin 71 g/L. The patient was transfused, and linezolid was discontinued. His blood counts improved over the week and remained at baseline two months later. The patient's decline in blood counts from baseline levels met previously established criteria for clinical significance. Application of the Naranjo scale indicated a probable relationship between pancytopenia and linezolid. Clinicians should be aware of this rare effect with linezolid, and prospectively identify patients at risk and emphasize weekly hematological monitoring.
The Black Hole Formation Probability
Clausen, Drew; Ott, Christian D
2014-01-01
A longstanding question in stellar evolution is which massive stars produce black holes (BHs) rather than neutron stars (NSs) upon death. It has been common practice to assume that a given zero-age main sequence (ZAMS) mass star (and perhaps a given metallicity) simply produces either an NS or a BH, but this fails to account for a myriad of other variables that may effect this outcome, such as spin, binarity, or even stochastic differences in the stellar structure near core collapse. We argue that instead a probabilistic description of NS versus BH formation may be better suited to account for the current uncertainties in understanding how massive stars die. Using the observed BH mass distribution from Galactic X-ray binaries, we derive the probability that a star will make a BH as a function of its ZAMS mass, $P_{\\rm BH}(M_{\\rm ZAMS})$. We explore possible biases in the observed BH mass distribution and find that this sample is best suited for studying BH formation in stars with ZAMS masses in the range $12-...
Avoiding Negative Probabilities in Quantum Mechanics
Nyambuya, Golden Gadzirayi
2013-01-01
As currently understood since its discovery, the bare Klein-Gordon theory consists of negative quantum probabilities which are considered to be physically meaningless if not outright obsolete. Despite this annoying setback, these negative probabilities are what led the great Paul Dirac in 1928 to the esoteric discovery of the Dirac Equation. The Dirac Equation led to one of the greatest advances in our understanding of the physical world. In this reading, we ask the seemingly senseless question, "Do negative probabilities exist in quantum mechanics?" In an effort to answer this question, we arrive at the conclusion that depending on the choice one makes of the quantum probability current, one will obtain negative probabilities. We thus propose a new quantum probability current of the Klein-Gordon theory. This quantum probability current leads directly to positive definite quantum probabilities. Because these negative probabilities are in the bare Klein-Gordon theory, intrinsically a result of negative energie...
Psychophysics of the probability weighting function
Takahashi, Taiki
2011-03-01
A probability weighting function w(p) for an objective probability p in decision under risk plays a pivotal role in Kahneman-Tversky prospect theory. Although recent studies in econophysics and neuroeconomics widely utilized probability weighting functions, psychophysical foundations of the probability weighting functions have been unknown. Notably, a behavioral economist Prelec (1998) [4] axiomatically derived the probability weighting function w(p)=exp(-() (01e)=1e,w(1)=1), which has extensively been studied in behavioral neuroeconomics. The present study utilizes psychophysical theory to derive Prelec's probability weighting function from psychophysical laws of perceived waiting time in probabilistic choices. Also, the relations between the parameters in the probability weighting function and the probability discounting function in behavioral psychology are derived. Future directions in the application of the psychophysical theory of the probability weighting function in econophysics and neuroeconomics are discussed.
张嘉伟; 叶桂兰
2002-01-01
LTP研究在近十余年来一直是热点课题.尽管LTP是否是学习和记忆的基础仍有争议,肯定性的研究结果日趋增加,所以LTP仍吸引着大量研究工作者.近年来随着分子生物学技术的进步,人们得以借助转基因手段研究疾病相关性基因及其蛋白质,以及不明功能的基因和蛋白.转基因动物模型更是给难以模拟的Alzheimer氏病的研究极大推动.2001年人类基因组序列研究结果报告对医学科学的发展影响深远.应用转基因模型的手段进一步深入各研究领域.近几年来神经工作者借助转基因手段,对LTP的分子机制有了进一步认识.本文概括性介绍了这方面的有趣研究,希望读者能大致了解LTP研究进展,同时领悟转基因技术的推动力.%There is more and more evidence showing long term potentiation (LTP) is underling learning and memory even though it is still controversy and the mechanism behind LTP has not yet been completely understood. It is known that memory processes and long-term potentiation (LTP) are blocked at the time of their initiation by antagonists of glutamate NMDA or metabotropic receptors, and GABA-A receptor agonists. Following initiation, memory and LTP are accompanied by an enhancement of the activity of calcium/calmodulin-dependent protein kinase II and of protein kinase C. At the time of expression, LTP is blocked by antagonists of glutamate AMPA receptors. In recent five years, with advanced molecular biology techniques, scientist could use transgenic and knock out mice to explore what happens to LTP and learning and memory when specific disease related or novel gene was overexpressed or deleted. Therefore cellular and molecular mechanisms of activity-dependent synaptic plasticity are understood in a new level. Here we introduced recent research work on LTP with transgenic approach in hope to inspire interest in genomic and protenomic technology. We will continue to discuss BDNF and LTP and
Office of Personnel Management — A press release, news release, media release, press statement is written communication directed at members of the news media for the purpose of announcing programs...
The Probability Distribution for a Biased Spinner
Foster, Colin
2012-01-01
This article advocates biased spinners as an engaging context for statistics students. Calculating the probability of a biased spinner landing on a particular side makes valuable connections between probability and other areas of mathematics. (Contains 2 figures and 1 table.)
Conditional probability modulates visual search efficiency.
Cort, Bryan; Anderson, Britt
2013-01-01
We investigated the effects of probability on visual search. Previous work has shown that people can utilize spatial and sequential probability information to improve target detection. We hypothesized that performance improvements from probability information would extend to the efficiency of visual search. Our task was a simple visual search in which the target was always present among a field of distractors, and could take one of two colors. The absolute probability of the target being either color was 0.5; however, the conditional probability-the likelihood of a particular color given a particular combination of two cues-varied from 0.1 to 0.9. We found that participants searched more efficiently for high conditional probability targets and less efficiently for low conditional probability targets, but only when they were explicitly informed of the probability relationship between cues and target color.
Conditional Probability Modulates Visual Search Efficiency
Bryan eCort
2013-10-01
Full Text Available We investigated the effects of probability on visual search. Previous work has shown that people can utilize spatial and sequential probability information to improve target detection. We hypothesized that performance improvements from probability information would extend to the efficiency of visual search. Our task was a simple visual search in which the target was always present among a field of distractors, and could take one of two colors. The absolute probability of the target being either color was 0.5; however, the conditional probability – the likelihood of a particular color given a particular combination of two cues – varied from 0.1 to 0.9. We found that participants searched more efficiently for high conditional probability targets and less efficiently for low conditional probability targets, but only when they were explicitly informed of the probability relationship between cues and target color.
The Probability Distribution for a Biased Spinner
Foster, Colin
2012-01-01
This article advocates biased spinners as an engaging context for statistics students. Calculating the probability of a biased spinner landing on a particular side makes valuable connections between probability and other areas of mathematics. (Contains 2 figures and 1 table.)
Pre-Service Teachers' Conceptions of Probability
Odafe, Victor U.
2011-01-01
Probability knowledge and skills are needed in science and in making daily decisions that are sometimes made under uncertain conditions. Hence, there is the need to ensure that the pre-service teachers of our children are well prepared to teach probability. Pre-service teachers' conceptions of probability are identified, and ways of helping them…
Using Playing Cards to Differentiate Probability Interpretations
López Puga, Jorge
2014-01-01
The aprioristic (classical, naïve and symmetric) and frequentist interpretations of probability are commonly known. Bayesian or subjective interpretation of probability is receiving increasing attention. This paper describes an activity to help students differentiate between the three types of probability interpretations.
47 CFR 1.1623 - Probability calculation.
2010-10-01
... 47 Telecommunication 1 2010-10-01 2010-10-01 false Probability calculation. 1.1623 Section 1.1623... Mass Media Services General Procedures § 1.1623 Probability calculation. (a) All calculations shall be computed to no less than three significant digits. Probabilities will be truncated to the number of...
Eliciting Subjective Probabilities with Binary Lotteries
Harrison, Glenn W.; Martínez-Correa, Jimmy; Swarthout, J. Todd
objective probabilities. Drawing a sample from the same subject population, we find evidence that the binary lottery procedure induces linear utility in a subjective probability elicitation task using the Quadratic Scoring Rule. We also show that the binary lottery procedure can induce direct revelation...... of subjective probabilities in subjects with certain Non-Expected Utility preference representations that satisfy weak conditions that we identify....
Inferring Beliefs as Subjectively Imprecise Probabilities
Andersen, Steffen; Fountain, John; Harrison, Glenn W.;
2012-01-01
We propose a method for estimating subjective beliefs, viewed as a subjective probability distribution. The key insight is to characterize beliefs as a parameter to be estimated from observed choices in a well-defined experimental task and to estimate that parameter as a random coefficient. The e...... probabilities are indeed best characterized as probability distributions with non-zero variance....
Scoring Rules for Subjective Probability Distributions
Harrison, Glenn W.; Martínez-Correa, Jimmy; Swarthout, J. Todd;
report the true subjective probability of a binary event, even under Subjective Expected Utility. To address this one can “calibrate” inferences about true subjective probabilities from elicited subjective probabilities over binary events, recognizing the incentives that risk averse agents have...
Using Playing Cards to Differentiate Probability Interpretations
López Puga, Jorge
2014-01-01
The aprioristic (classical, naïve and symmetric) and frequentist interpretations of probability are commonly known. Bayesian or subjective interpretation of probability is receiving increasing attention. This paper describes an activity to help students differentiate between the three types of probability interpretations.
The trajectory of the target probability effect.
Hon, Nicholas; Yap, Melvin J; Jabar, Syaheed B
2013-05-01
The effect of target probability on detection times is well-established: Even when detection accuracy is high, lower probability targets are detected more slowly than higher probability ones. Although this target probability effect on detection times has been well-studied, one aspect of it has remained largely unexamined: How the effect develops over the span of an experiment. Here, we investigated this issue with two detection experiments that assessed different target probability ratios. Conventional block segment analysis and linear mixed-effects modeling converged on two key findings. First, we found that the magnitude of the target probability effect increases as one progresses through a block of trials. Second, we found, by examining the trajectories of the low- and high-probability targets, that this increase in effect magnitude was driven by the low-probability targets. Specifically, we found that low-probability targets were detected more slowly as a block of trials progressed. Performance to high-probability targets, on the other hand, was largely invariant across the block. The latter finding is of particular interest because it cannot be reconciled with accounts that propose that the target probability effect is driven by the high-probability targets.
Pre-Service Teachers' Conceptions of Probability
Odafe, Victor U.
2011-01-01
Probability knowledge and skills are needed in science and in making daily decisions that are sometimes made under uncertain conditions. Hence, there is the need to ensure that the pre-service teachers of our children are well prepared to teach probability. Pre-service teachers' conceptions of probability are identified, and ways of helping them…
Paraconsistent Probabilities: Consistency, Contradictions and Bayes’ Theorem
Juliana Bueno-Soler
2016-09-01
Full Text Available This paper represents the first steps towards constructing a paraconsistent theory of probability based on the Logics of Formal Inconsistency (LFIs. We show that LFIs encode very naturally an extension of the notion of probability able to express sophisticated probabilistic reasoning under contradictions employing appropriate notions of conditional probability and paraconsistent updating, via a version of Bayes’ theorem for conditionalization. We argue that the dissimilarity between the notions of inconsistency and contradiction, one of the pillars of LFIs, plays a central role in our extended notion of probability. Some critical historical and conceptual points about probability theory are also reviewed.
An Objective Theory of Probability (Routledge Revivals)
Gillies, Donald
2012-01-01
This reissue of D. A. Gillies highly influential work, first published in 1973, is a philosophical theory of probability which seeks to develop von Mises' views on the subject. In agreement with von Mises, the author regards probability theory as a mathematical science like mechanics or electrodynamics, and probability as an objective, measurable concept like force, mass or charge. On the other hand, Dr Gillies rejects von Mises' definition of probability in terms of limiting frequency and claims that probability should be taken as a primitive or undefined term in accordance with modern axioma
Fundamentals of applied probability and random processes
Ibe, Oliver
2014-01-01
The long-awaited revision of Fundamentals of Applied Probability and Random Processes expands on the central components that made the first edition a classic. The title is based on the premise that engineers use probability as a modeling tool, and that probability can be applied to the solution of engineering problems. Engineers and students studying probability and random processes also need to analyze data, and thus need some knowledge of statistics. This book is designed to provide students with a thorough grounding in probability and stochastic processes, demonstrate their applicability t
Probability of Failure in Random Vibration
Nielsen, Søren R.K.; Sørensen, John Dalsgaard
1988-01-01
Close approximations to the first-passage probability of failure in random vibration can be obtained by integral equation methods. A simple relation exists between the first-passage probability density function and the distribution function for the time interval spent below a barrier before out......-crossing. An integral equation for the probability density function of the time interval is formulated, and adequate approximations for the kernel are suggested. The kernel approximation results in approximate solutions for the probability density function of the time interval and thus for the first-passage probability...
On the computability of conditional probability
Ackerman, Nathanael L; Roy, Daniel M
2010-01-01
We study the problem of computing conditional probabilities, a fundamental operation in statistics and machine learning. In the elementary discrete setting, a ratio of probabilities defines conditional probability. In the abstract setting, conditional probability is defined axiomatically and the search for more constructive definitions is the subject of a rich literature in probability theory and statistics. In the discrete or dominated setting, under suitable computability hypotheses, conditional probabilities are computable. However, we show that in general one cannot compute conditional probabilities. We do this by constructing a pair of computable random variables in the unit interval whose conditional distribution encodes the halting problem at almost every point. We show that this result is tight, in the sense that given an oracle for the halting problem, one can compute this conditional distribution. On the other hand, we show that conditioning in abstract settings is computable in the presence of cert...
Xu Zhao-Hui
2012-05-01
Full Text Available Abstract Background Fragile X syndrome (FXS is caused by the absence of the mRNA-binding protein Fragile X mental retardation protein (FMRP, encoded by the Fmr1 gene. Overactive signaling by group 1 metabotropic glutamate receptor (Grp1 mGluR could contribute to slowed synaptic development and other symptoms of FXS. Our previous study has identified that facilitation of synaptic long-term potentiation (LTP by D1 receptor is impaired in Fmr1 knockout (KO mice. However, the contribution of Grp1 mGluR to the facilitation of synaptic plasticity by D1 receptor stimulation in the prefrontal cortex has been less extensively studied. Results Here we demonstrated that DL-AP3, a Grp1 mGluR antagonist, rescued LTP facilitation by D1 receptor agonist SKF81297 in Fmr1KO mice. Grp1 mGluR inhibition restored the GluR1-subtype AMPA receptors surface insertion by D1 activation in the cultured Fmr1KO neurons. Simultaneous treatment of Grp1 mGluR antagonist with D1 agonist recovered the D1 receptor signaling by reversing the subcellular redistribution of G protein-coupled receptor kinase 2 (GRK2 in the Fmr1KO neurons. Treatment of SKF81297 alone failed to increase the phosphorylation of NR2B-containing N-methyl D-aspartate receptors (NMDARs at Tyr-1472 (p-NR2B-Tyr1472 in the cultures from KO mice. However, simultaneous treatment of DL-AP3 could rescue the level of p-NR2B-Tyr1472 by SKF81297 in the cultures from KO mice. Furthermore, behavioral tests indicated that simultaneous treatment of Grp1 mGluR antagonist with D1 agonist inhibited hyperactivity and improved the learning ability in the Fmr1KO mice. Conclusion The findings demonstrate that mGluR1 inhibition is a useful strategy to recover D1 receptor signaling in the Fmr1KO mice, and combination of Grp1 mGluR antagonist and D1 agonist is a potential drug therapy for the FXS.
Bell Could Become the Copernicus of Probability
Khrennikov, Andrei
2016-07-01
Our aim is to emphasize the role of mathematical models in physics, especially models of geometry and probability. We briefly compare developments of geometry and probability by pointing to similarities and differences: from Euclid to Lobachevsky and from Kolmogorov to Bell. In probability, Bell could play the same role as Lobachevsky in geometry. In fact, violation of Bell’s inequality can be treated as implying the impossibility to apply the classical probability model of Kolmogorov (1933) to quantum phenomena. Thus the quantum probabilistic model (based on Born’s rule) can be considered as the concrete example of the non-Kolmogorovian model of probability, similarly to the Lobachevskian model — the first example of the non-Euclidean model of geometry. This is the “probability model” interpretation of the violation of Bell’s inequality. We also criticize the standard interpretation—an attempt to add to rigorous mathematical probability models additional elements such as (non)locality and (un)realism. Finally, we compare embeddings of non-Euclidean geometries into the Euclidean space with embeddings of the non-Kolmogorovian probabilities (in particular, quantum probability) into the Kolmogorov probability space. As an example, we consider the CHSH-test.
Arcangeli, Sara; Amoroso, Salvatore; Calabresi, Paolo; Costa, Cinzia; Fusco, Francesca Romana; Di Filippo, Massimiliano; Spaccatini, Cristiano; de Iure, Antonio; Picconi, Barbara; Giampa, Carmen; Tantucci, Michela; Tozzi, Alessandro
2013-01-01
Striatal medium-sized spiny neurons (MSNs) are highly vulnerable to ischemia. A brief ischemic insult, produced by oxygen and glucose deprivation (OGD), can induce ischemic long-term potentiation (i-LTP) of corticostriatal excitatory postsynaptic response. Since nitric oxide (NO) is involved in the pathophysiology of brain ischemia and the dopamine D1/D5-receptors (D1-like-R) are expressed in striatal NOS-positive interneurons, we hypothesized a relation between NOS-positive interneurons and ...
Ma, Yue; Sun, Xiaolong; Li, Juan; Jia, Ruihua; Yuan, Fang; Wei, Dong; Jiang, Wen
2017-02-18
Epilepsy-associated cognitive impairment is common, and negatively impacts patients' quality of life. However, most antiepileptic drugs focus on the suppression of seizures, and fewer emphasize treatment of cognitive dysfunction. Melatonin, an indolamine synthesized primarily in the pineal grand, is reported to be neuroprotective against several central nervous system disorders. In this study, we investigated whether melatonin could reverse cognitive dysfunction in lithium-pilocarpine treated rats. Chronic treatment with melatonin (8 mg/kg daily for 15 days) after induction of status epilepticus significantly alleviated seizure severity, reduced neuronal death in the CA1 region of the hippocampus, improved spatial learning (as measured by the Morris water maze test), and reversed LTP impairments, compared to vehicle treatment. Furthermore, we found that melatonin rescued the decreased surface levels of GluR2 in the CA1 region observed in epilepsy, which might be the underlying mechanism of the neuroprotective and synapse-modulating function of melatonin. Our study provides experimental evidence for the possible clinical utility of melatonin as an adjunctive therapy to prevent epilepsy-associated cognitive impairments.
Towards a Categorical Account of Conditional Probability
Robert Furber
2015-11-01
Full Text Available This paper presents a categorical account of conditional probability, covering both the classical and the quantum case. Classical conditional probabilities are expressed as a certain "triangle-fill-in" condition, connecting marginal and joint probabilities, in the Kleisli category of the distribution monad. The conditional probabilities are induced by a map together with a predicate (the condition. The latter is a predicate in the logic of effect modules on this Kleisli category. This same approach can be transferred to the category of C*-algebras (with positive unital maps, whose predicate logic is also expressed in terms of effect modules. Conditional probabilities can again be expressed via a triangle-fill-in property. In the literature, there are several proposals for what quantum conditional probability should be, and also there are extra difficulties not present in the classical case. At this stage, we only describe quantum systems with classical parametrization.
UT Biomedical Informatics Lab (BMIL probability wheel
Sheng-Cheng Huang
2016-01-01
Full Text Available A probability wheel app is intended to facilitate communication between two people, an “investigator” and a “participant”, about uncertainties inherent in decision-making. Traditionally, a probability wheel is a mechanical prop with two colored slices. A user adjusts the sizes of the slices to indicate the relative value of the probabilities assigned to them. A probability wheel can improve the adjustment process and attenuate the effect of anchoring bias when it is used to estimate or communicate probabilities of outcomes. The goal of this work was to develop a mobile application of the probability wheel that is portable, easily available, and more versatile. We provide a motivating example from medical decision-making, but the tool is widely applicable for researchers in the decision sciences.
Fundamentals of applied probability and random processes
Ibe, Oliver
2005-01-01
This book is based on the premise that engineers use probability as a modeling tool, and that probability can be applied to the solution of engineering problems. Engineers and students studying probability and random processes also need to analyze data, and thus need some knowledge of statistics. This book is designed to provide students with a thorough grounding in probability and stochastic processes, demonstrate their applicability to real-world problems, and introduce the basics of statistics. The book''s clear writing style and homework problems make it ideal for the classroom or for self-study.* Good and solid introduction to probability theory and stochastic processes * Logically organized; writing is presented in a clear manner * Choice of topics is comprehensive within the area of probability * Ample homework problems are organized into chapter sections
Total variation denoising of probability measures using iterated function systems with probabilities
La Torre, Davide; Mendivil, Franklin; Vrscay, Edward R.
2017-01-01
In this paper we present a total variation denoising problem for probability measures using the set of fixed point probability measures of iterated function systems with probabilities IFSP. By means of the Collage Theorem for contraction mappings, we provide an upper bound for this problem that can be solved by determining a set of probabilities.
Bayesian Probabilities and the Histories Algebra
Marlow, Thomas
2006-01-01
We attempt a justification of a generalisation of the consistent histories programme using a notion of probability that is valid for all complete sets of history propositions. This consists of introducing Cox's axioms of probability theory and showing that our candidate notion of probability obeys them. We also give a generalisation of Bayes' theorem and comment upon how Bayesianism should be useful for the quantum gravity/cosmology programmes.
Non-Boolean probabilities and quantum measurement
Niestegge, Gerd
2001-08-03
A non-Boolean extension of the classical probability model is proposed. The non-Boolean probabilities reproduce typical quantum phenomena. The proposed model is more general and more abstract, but easier to interpret, than the quantum mechanical Hilbert space formalism and exhibits a particular phenomenon (state-independent conditional probabilities) which may provide new opportunities for an understanding of the quantum measurement process. Examples of the proposed model are provided, using Jordan operator algebras. (author)
Data analysis recipes: Probability calculus for inference
Hogg, David W
2012-01-01
In this pedagogical text aimed at those wanting to start thinking about or brush up on probabilistic inference, I review the rules by which probability distribution functions can (and cannot) be combined. I connect these rules to the operations performed in probabilistic data analysis. Dimensional analysis is emphasized as a valuable tool for helping to construct non-wrong probabilistic statements. The applications of probability calculus in constructing likelihoods, marginalized likelihoods, posterior probabilities, and posterior predictions are all discussed.
Spatial probability aids visual stimulus discrimination
Michael Druker
2010-08-01
Full Text Available We investigated whether the statistical predictability of a target's location would influence how quickly and accurately it was classified. Recent results have suggested that spatial probability can be a cue for the allocation of attention in visual search. One explanation for probability cuing is spatial repetition priming. In our two experiments we used probability distributions that were continuous across the display rather than relying on a few arbitrary screen locations. This produced fewer spatial repeats and allowed us to dissociate the effect of a high probability location from that of short-term spatial repetition. The task required participants to quickly judge the color of a single dot presented on a computer screen. In Experiment 1, targets were more probable in an off-center hotspot of high probability that gradually declined to a background rate. Targets garnered faster responses if they were near earlier target locations (priming and if they were near the high probability hotspot (probability cuing. In Experiment 2, target locations were chosen on three concentric circles around fixation. One circle contained 80% of targets. The value of this ring distribution is that it allowed for a spatially restricted high probability zone in which sequentially repeated trials were not likely to be physically close. Participant performance was sensitive to the high-probability circle in addition to the expected effects of eccentricity and the distance to recent targets. These two experiments suggest that inhomogeneities in spatial probability can be learned and used by participants on-line and without prompting as an aid for visual stimulus discrimination and that spatial repetition priming is not a sufficient explanation for this effect. Future models of attention should consider explicitly incorporating the probabilities of targets locations and features.
Some New Results on Transition Probability
Yu Quan XIE
2008-01-01
In this paper, we study the basic properties of stationary transition probability of Markov processes on a general measurable space (E, ε), such as the continuity, maximum probability, zero point, positive probability set standardization, and obtain a series of important results such as Continuity Theorem, Representation Theorem, Levy Theorem and so on. These results are very useful for us to study stationary tri-point transition probability on a general measurable space (E, ε). Our main tools such as Egoroff's Theorem, Vitali-Hahn-Saks's Theorem and the theory of atomic set and well-posedness of measure are also very interesting and fashionable.
Probabilities are single-case, or nothing
Appleby, D M
2004-01-01
Physicists have, hitherto, mostly adopted a frequentist conception of probability, according to which probability statements apply only to ensembles. It is argued that we should, instead, adopt an epistemic, or Bayesian conception, in which probabilities are conceived as logical constructs rather than physical realities, and in which probability statements do apply directly to individual events. The question is closely related to the disagreement between the orthodox school of statistical thought and the Bayesian school. It has important technical implications (it makes a difference, what statistical methodology one adopts). It may also have important implications for the interpretation of the quantum state.
Real analysis and probability solutions to problems
Ash, Robert P
1972-01-01
Real Analysis and Probability: Solutions to Problems presents solutions to problems in real analysis and probability. Topics covered range from measure and integration theory to functional analysis and basic concepts of probability; the interplay between measure theory and topology; conditional probability and expectation; the central limit theorem; and strong laws of large numbers in terms of martingale theory.Comprised of eight chapters, this volume begins with problems and solutions for the theory of measure and integration, followed by various applications of the basic integration theory.
Performance of Male Psychopaths Following Conditional Release from Prison.
Hart, Stephen D.; And Others
1988-01-01
Administered Psychopathy Checklist (PCL) to criminals being released from prison on parole or mandatory supervision, then examined official parole supervision files for postrelease behavior. Violation of release conditions, suspensions, and presentation of supervisory problems were directly proportional, and the probability of subjects remaining…
Melucci, Massimo
2012-01-01
Probabilistic models require the notion of event space for defining a probability measure. An event space has a probability measure which ensues the Kolmogorov axioms. However, the probabilities observed from distinct sources, such as that of relevance of documents, may not admit a single event space thus causing some issues. In this article, some results are introduced for ensuring whether the observed prob- abilities of relevance of documents admit a single event space. More- over, an alternative framework of probability is introduced, thus chal- lenging the use of classical probability for ranking documents. Some reflections on the convenience of extending the classical probabilis- tic retrieval toward a more general framework which encompasses the issues are made.
Nuclear energy release from fragmentation
Li, Cheng [The Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Souza, S.R. [Instituto de Física, Universidade Federal do Rio de Janeiro Cidade Universitária, Caixa Postal 68528, 21945-970 Rio de Janeiro (Brazil); Tsang, M.B. [The Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); National Superconducting Cyclotron Laboratory and Physics and Astronomy Department, Michigan State University, East Lansing, MI 48824 (United States); Zhang, Feng-Shou, E-mail: fszhang@bnu.edu.cn [The Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator of Lanzhou, Lanzhou 730000 (China)
2016-08-15
It is well known that binary fission occurs with positive energy gain. In this article we examine the energetics of splitting uranium and thorium isotopes into various numbers of fragments (from two to eight) with nearly equal size. We find that the energy released by splitting {sup 230,232}Th and {sup 235,238}U into three equal size fragments is largest. The statistical multifragmentation model (SMM) is applied to calculate the probability of different breakup channels for excited nuclei. By weighing the probability distributions of fragment multiplicity at different excitation energies, we find the peaks of energy release for {sup 230,232}Th and {sup 235,238}U are around 0.7–0.75 MeV/u at excitation energy between 1.2 and 2 MeV/u in the primary breakup process. Taking into account the secondary de-excitation processes of primary fragments with the GEMINI code, these energy peaks fall to about 0.45 MeV/u.
Nuclear energy release from fragmentation
Li, Cheng; Souza, S. R.; Tsang, M. B.; Zhang, Feng-Shou
2016-08-01
It is well known that binary fission occurs with positive energy gain. In this article we examine the energetics of splitting uranium and thorium isotopes into various numbers of fragments (from two to eight) with nearly equal size. We find that the energy released by splitting 230,232Th and 235,238U into three equal size fragments is largest. The statistical multifragmentation model (SMM) is applied to calculate the probability of different breakup channels for excited nuclei. By weighing the probability distributions of fragment multiplicity at different excitation energies, we find the peaks of energy release for 230,232Th and 235,238U are around 0.7-0.75 MeV/u at excitation energy between 1.2 and 2 MeV/u in the primary breakup process. Taking into account the secondary de-excitation processes of primary fragments with the GEMINI code, these energy peaks fall to about 0.45 MeV/u.
Comparing linear probability model coefficients across groups
Holm, Anders; Ejrnæs, Mette; Karlson, Kristian Bernt
2015-01-01
This article offers a formal identification analysis of the problem in comparing coefficients from linear probability models between groups. We show that differences in coefficients from these models can result not only from genuine differences in effects, but also from differences in one or more...... these limitations, and we suggest a restricted approach to using linear probability model coefficients in group comparisons....
Stimulus Probability Effects in Absolute Identification
Kent, Christopher; Lamberts, Koen
2016-01-01
This study investigated the effect of stimulus presentation probability on accuracy and response times in an absolute identification task. Three schedules of presentation were used to investigate the interaction between presentation probability and stimulus position within the set. Data from individual participants indicated strong effects of…
Probability numeracy and health insurance purchase
Dillingh, Rik; Kooreman, Peter; Potters, Jan
2016-01-01
This paper provides new field evidence on the role of probability numeracy in health insurance purchase. Our regression results, based on rich survey panel data, indicate that the expenditure on two out of three measures of health insurance first rises with probability numeracy and then falls again.
Recent Developments in Applied Probability and Statistics
Devroye, Luc; Kohler, Michael; Korn, Ralf
2010-01-01
This book presents surveys on recent developments in applied probability and statistics. The contributions include topics such as nonparametric regression and density estimation, option pricing, probabilistic methods for multivariate interpolation, robust graphical modelling and stochastic differential equations. Due to its broad coverage of different topics the book offers an excellent overview of recent developments in applied probability and statistics.
Examples of Neutrosophic Probability in Physics
Fu Yuhua
2015-01-01
Full Text Available This paper re-discusses the problems of the so-called “law of nonconservation of parity” and “accelerating expansion of the universe”, and presents the examples of determining Neutrosophic Probability of the experiment of Chien-Shiung Wu et al in 1957, and determining Neutrosophic Probability of accelerating expansion of the partial universe.
Average Transmission Probability of a Random Stack
Lu, Yin; Miniatura, Christian; Englert, Berthold-Georg
2010-01-01
The transmission through a stack of identical slabs that are separated by gaps with random widths is usually treated by calculating the average of the logarithm of the transmission probability. We show how to calculate the average of the transmission probability itself with the aid of a recurrence relation and derive analytical upper and lower…
Probability: A Matter of Life and Death
Hassani, Mehdi; Kippen, Rebecca; Mills, Terence
2016-01-01
Life tables are mathematical tables that document probabilities of dying and life expectancies at different ages in a society. Thus, the life table contains some essential features of the health of a population. Probability is often regarded as a difficult branch of mathematics. Life tables provide an interesting approach to introducing concepts…
Teaching Probability: A Socio-Constructivist Perspective
Sharma, Sashi
2015-01-01
There is a considerable and rich literature on students' misconceptions in probability. However, less attention has been paid to the development of students' probabilistic thinking in the classroom. This paper offers a sequence, grounded in socio-constructivist perspective for teaching probability.
Probability numeracy and health insurance purchase
Dillingh, Rik; Kooreman, Peter; Potters, Jan
2016-01-01
This paper provides new field evidence on the role of probability numeracy in health insurance purchase. Our regression results, based on rich survey panel data, indicate that the expenditure on two out of three measures of health insurance first rises with probability numeracy and then falls again.
Selected papers on probability and statistics
2009-01-01
This volume contains translations of papers that originally appeared in the Japanese journal Sūgaku. The papers range over a variety of topics in probability theory, statistics, and applications. This volume is suitable for graduate students and research mathematicians interested in probability and statistics.
Analytical Study of Thermonuclear Reaction Probability Integrals
Chaudhry, M A; Mathai, A M
2000-01-01
An analytic study of the reaction probability integrals corresponding to the various forms of the slowly varying cross-section factor $S(E)$ is attempted. Exact expressions for reaction probability integrals are expressed in terms of the extended gamma functions.
Probability Issues in without Replacement Sampling
Joarder, A. H.; Al-Sabah, W. S.
2007-01-01
Sampling without replacement is an important aspect in teaching conditional probabilities in elementary statistics courses. Different methods proposed in different texts for calculating probabilities of events in this context are reviewed and their relative merits and limitations in applications are pinpointed. An alternative representation of…
Simulations of Probabilities for Quantum Computing
Zak, M.
1996-01-01
It has been demonstrated that classical probabilities, and in particular, probabilistic Turing machine, can be simulated by combining chaos and non-LIpschitz dynamics, without utilization of any man-made devices (such as random number generators). Self-organizing properties of systems coupling simulated and calculated probabilities and their link to quantum computations are discussed.
Stimulus Probability Effects in Absolute Identification
Kent, Christopher; Lamberts, Koen
2016-01-01
This study investigated the effect of stimulus presentation probability on accuracy and response times in an absolute identification task. Three schedules of presentation were used to investigate the interaction between presentation probability and stimulus position within the set. Data from individual participants indicated strong effects of…
Probability: A Matter of Life and Death
Hassani, Mehdi; Kippen, Rebecca; Mills, Terence
2016-01-01
Life tables are mathematical tables that document probabilities of dying and life expectancies at different ages in a society. Thus, the life table contains some essential features of the health of a population. Probability is often regarded as a difficult branch of mathematics. Life tables provide an interesting approach to introducing concepts…
Average Transmission Probability of a Random Stack
Lu, Yin; Miniatura, Christian; Englert, Berthold-Georg
2010-01-01
The transmission through a stack of identical slabs that are separated by gaps with random widths is usually treated by calculating the average of the logarithm of the transmission probability. We show how to calculate the average of the transmission probability itself with the aid of a recurrence relation and derive analytical upper and lower…
Probability of Grounding and Collision Events
Pedersen, Preben Terndrup
1996-01-01
To quantify the risks involved in ship traffic, rational criteria for collision and grounding accidents have to be developed. This implies that probabilities as well as inherent consequences have to be analyzed and assessed.The present notes outline a method for evaluation of the probability...
Teaching Probability: A Socio-Constructivist Perspective
Sharma, Sashi
2015-01-01
There is a considerable and rich literature on students' misconceptions in probability. However, less attention has been paid to the development of students' probabilistic thinking in the classroom. This paper offers a sequence, grounded in socio-constructivist perspective for teaching probability.
Probability of Grounding and Collision Events
Pedersen, Preben Terndrup
1996-01-01
To quantify the risks involved in ship traffic, rational criteria for collision and grounding accidents are developed. This implies that probabilities as well as inherent consequences can be analysed and assessed. The presnt paper outlines a method for evaluation of the probability of ship...
An introduction to probability and stochastic processes
Melsa, James L
2013-01-01
Geared toward college seniors and first-year graduate students, this text is designed for a one-semester course in probability and stochastic processes. Topics covered in detail include probability theory, random variables and their functions, stochastic processes, linear system response to stochastic processes, Gaussian and Markov processes, and stochastic differential equations. 1973 edition.
Toxics Release Inventory (TRI)
U.S. Environmental Protection Agency — The Toxics Release Inventory (TRI) is a dataset compiled by the U.S. Environmental Protection Agency (EPA). It contains information on the release and waste...
Laboratory-Tutorial activities for teaching probability
Wittmann, M C; Morgan, J T; Feeley, Roger E.; Morgan, Jeffrey T.; Wittmann, Michael C.
2006-01-01
We report on the development of students' ideas of probability and probability density in a University of Maine laboratory-based general education physics course called Intuitive Quantum Physics. Students in the course are generally math phobic with unfavorable expectations about the nature of physics and their ability to do it. We describe a set of activities used to teach concepts of probability and probability density. Rudimentary knowledge of mechanics is needed for one activity, but otherwise the material requires no additional preparation. Extensions of the activities include relating probability density to potential energy graphs for certain "touchstone" examples. Students have difficulties learning the target concepts, such as comparing the ratio of time in a region to total time in all regions. Instead, they often focus on edge effects, pattern match to previously studied situations, reason about necessary but incomplete macroscopic elements of the system, use the gambler's fallacy, and use expectati...
Alternative probability theories for cognitive psychology.
Narens, Louis
2014-01-01
Various proposals for generalizing event spaces for probability functions have been put forth in the mathematical, scientific, and philosophic literatures. In cognitive psychology such generalizations are used for explaining puzzling results in decision theory and for modeling the influence of context effects. This commentary discusses proposals for generalizing probability theory to event spaces that are not necessarily boolean algebras. Two prominent examples are quantum probability theory, which is based on the set of closed subspaces of a Hilbert space, and topological probability theory, which is based on the set of open sets of a topology. Both have been applied to a variety of cognitive situations. This commentary focuses on how event space properties can influence probability concepts and impact cognitive modeling.
Optimizing Probability of Detection Point Estimate Demonstration
Koshti, Ajay M.
2017-01-01
Probability of detection (POD) analysis is used in assessing reliably detectable flaw size in nondestructive evaluation (NDE). MIL-HDBK-18231and associated mh18232POD software gives most common methods of POD analysis. Real flaws such as cracks and crack-like flaws are desired to be detected using these NDE methods. A reliably detectable crack size is required for safe life analysis of fracture critical parts. The paper provides discussion on optimizing probability of detection (POD) demonstration experiments using Point Estimate Method. POD Point estimate method is used by NASA for qualifying special NDE procedures. The point estimate method uses binomial distribution for probability density. Normally, a set of 29 flaws of same size within some tolerance are used in the demonstration. The optimization is performed to provide acceptable value for probability of passing demonstration (PPD) and achieving acceptable value for probability of false (POF) calls while keeping the flaw sizes in the set as small as possible.
Multinomial mixture model with heterogeneous classification probabilities
Holland, M.D.; Gray, B.R.
2011-01-01
Royle and Link (Ecology 86(9):2505-2512, 2005) proposed an analytical method that allowed estimation of multinomial distribution parameters and classification probabilities from categorical data measured with error. While useful, we demonstrate algebraically and by simulations that this method yields biased multinomial parameter estimates when the probabilities of correct category classifications vary among sampling units. We address this shortcoming by treating these probabilities as logit-normal random variables within a Bayesian framework. We use Markov chain Monte Carlo to compute Bayes estimates from a simulated sample from the posterior distribution. Based on simulations, this elaborated Royle-Link model yields nearly unbiased estimates of multinomial and correct classification probability estimates when classification probabilities are allowed to vary according to the normal distribution on the logit scale or according to the Beta distribution. The method is illustrated using categorical submersed aquatic vegetation data. ?? 2010 Springer Science+Business Media, LLC.
Transition probability spaces in loop quantum gravity
Guo, Xiao-Kan
2016-01-01
We study the (generalized) transition probability spaces, in the sense of Mielnik and Cantoni, for spacetime quantum states in loop quantum gravity. First, we show that loop quantum gravity admits the structures of transition probability spaces. This is achieved by first checking such structures in covariant quantum mechanics, and then passing to spin foam models via the general boundary formulation. The transition probability space thus defined gives a simple way to reconstruct the Hilbert space of the canonical theory and the relevant quantum logical structure. Second, we show that the transition probability space and in particular the spin foam model are 2-categories. Then we discuss how to realize property transitions and causality in this categorical context in connection with presheaves on quantaloids and respectively causal categories. We conclude that transition probability spaces provide us with an alternative framework to understand various foundational questions of loop quantum gravity.
Domestic wells have high probability of pumping septic tank leachate
J. E. Bremer
2012-08-01
Full Text Available Onsite wastewater treatment systems are common in rural and semi-rural areas around the world; in the US, about 25–30% of households are served by a septic (onsite wastewater treatment system, and many property owners also operate their own domestic well nearby. Site-specific conditions and local groundwater flow are often ignored when installing septic systems and wells. In areas with small lots (thus high spatial septic system densities, shallow domestic wells are prone to contamination by septic system leachate. Mass balance approaches have been used to determine a maximum septic system density that would prevent contamination of groundwater resources. In this study, a source area model based on detailed groundwater flow and transport modeling is applied for a stochastic analysis of domestic well contamination by septic leachate. Specifically, we determine the probability that a source area overlaps with a septic system drainfield as a function of aquifer properties, septic system density and drainfield size. We show that high spatial septic system density poses a high probability of pumping septic system leachate. The hydraulic conductivity of the aquifer has a strong influence on the intersection probability. We find that mass balance calculations applied on a regional scale underestimate the contamination risk of individual drinking water wells by septic systems. This is particularly relevant for contaminants released at high concentrations, for substances that experience limited attenuation, and those that are harmful even at low concentrations (e.g., pathogens.
Survival probability in patients with liver trauma.
Buci, Skender; Kukeli, Agim
2016-08-01
Purpose - The purpose of this paper is to assess the survival probability among patients with liver trauma injury using the anatomical and psychological scores of conditions, characteristics and treatment modes. Design/methodology/approach - A logistic model is used to estimate 173 patients' survival probability. Data are taken from patient records. Only emergency room patients admitted to University Hospital of Trauma (former Military Hospital) in Tirana are included. Data are recorded anonymously, preserving the patients' privacy. Findings - When correctly predicted, the logistic models show that survival probability varies from 70.5 percent up to 95.4 percent. The degree of trauma injury, trauma with liver and other organs, total days the patient was hospitalized, and treatment method (conservative vs intervention) are statistically important in explaining survival probability. Practical implications - The study gives patients, their relatives and physicians ample and sound information they can use to predict survival chances, the best treatment and resource management. Originality/value - This study, which has not been done previously, explores survival probability, success probability for conservative and non-conservative treatment, and success probability for single vs multiple injuries from liver trauma.
EphA4 Activation of c-Abl Mediates Synaptic Loss and LTP Blockade Caused by Amyloid-β Oligomers
M. Vargas, Lina; Leal, Nancy; Estrada, Lisbell D.; González, Adrian; Serrano, Felipe; Araya, Katherine; Gysling, Katia; Inestrosa, Nibaldo C.; Pasquale, Elena B.; Alvarez, Alejandra R.
2014-01-01
The early stages of Alzheimer's disease are characterised by impaired synaptic plasticity and synapse loss. Here, we show that amyloid-β oligomers (AβOs) activate the c-Abl kinase in dendritic spines of cultured hippocampal neurons and that c-Abl kinase activity is required for AβOs-induced synaptic loss. We also show that the EphA4 receptor tyrosine kinase is upstream of c-Abl activation by AβOs. EphA4 tyrosine phosphorylation (activation) is increased in cultured neurons and synaptoneurosomes exposed to AβOs, and in Alzheimer-transgenic mice brain. We do not detect c-Abl activation in EphA4-knockout neurons exposed to AβOs. More interestingly, we demonstrate EphA4/c-Abl activation is a key-signalling event that mediates the synaptic damage induced by AβOs. According to this results, the EphA4 antagonistic peptide KYL and c-Abl inhibitor STI prevented i) dendritic spine reduction, ii) the blocking of LTP induction and iii) neuronal apoptosis caused by AβOs. Moreover, EphA4-/- neurons or sh-EphA4-transfected neurons showed reduced synaptotoxicity by AβOs. Our results are consistent with EphA4 being a novel receptor that mediates synaptic damage induced by AβOs. EphA4/c-Abl signalling could be a relevant pathway involved in the early cognitive decline observed in Alzheimer's disease patients. PMID:24658113
Analysis of LNG import terminal release prevention systems
Baker, E G
1982-04-01
The release prevention systems of liquefied natural gas (LNG) import terminal were analyzed. A series of potential release scenarios were analyzed to determine the frequency of the release events, the probability these releases are not stopped or isolated by emergency shutdown systems, the estimated release quantities, and the critical components of the system. The two plant areas identified as being most significant with respect to safety are the unloading system and the storage system. Rupture of the main transfer line and gross failure of the storage tanks are the two release scenarios of primary safety interest. Reducing the rate of failure by improved design, better maintenance and testing, or adding redundancy of the critical system components for these plant areas and release scenarios will result in improved safety. Several design alternatives which have the potential to significantly reduce the probability of a large release of LNG occurring at an import terminal are identified. These design alternatives would reduce the probability of a large release of LNG by reducing the expected number of failures which could cause a release or by reducing the magnitude of releases that do occur. All of these alternatives are technically feasible and have been used or considered for use in at least one LNG facility. A more rigorous analysis of the absolute risk of LNG import terminal operation is necessary before the benefits of these design alternatives can be determined. In addition, an economic evaluation of these alternatives must be made so the costs and benefits can be compared. It is concludd that for remotely located facilities many of these alternatives are probably not justified; however, for facilities located in highly populated areas, these alternatives deserve serious consideration.
Probability an introduction with statistical applications
Kinney, John J
2014-01-01
Praise for the First Edition""This is a well-written and impressively presented introduction to probability and statistics. The text throughout is highly readable, and the author makes liberal use of graphs and diagrams to clarify the theory."" - The StatisticianThoroughly updated, Probability: An Introduction with Statistical Applications, Second Edition features a comprehensive exploration of statistical data analysis as an application of probability. The new edition provides an introduction to statistics with accessible coverage of reliability, acceptance sampling, confidence intervals, h
Pre-aggregation for Probability Distributions
Timko, Igor; Dyreson, Curtis E.; Pedersen, Torben Bach
Motivated by the increasing need to analyze complex uncertain multidimensional data (e.g., in order to optimize and personalize location-based services), this paper proposes novel types of {\\em probabilistic} OLAP queries that operate on aggregate values that are probability distributions...... and the techniques to process these queries. The paper also presents the methods for computing the probability distributions, which enables pre-aggregation, and for using the pre-aggregated distributions for further aggregation. In order to achieve good time and space efficiency, the methods perform approximate...... multidimensional data analysis that is considered in this paper (i.e., approximate processing of probabilistic OLAP queries over probability distributions)....
Are All Probabilities Fundamentally Quantum Mechanical?
Pradhan, Rajat Kumar
2011-01-01
The subjective and the objective aspects of probabilities are incorporated in a simple duality axiom inspired by observer participation in quantum theory. Transcending the classical notion of probabilities, it is proposed and demonstrated that all probabilities may be fundamentally quantum mechanical in the sense that they may all be derived from the corresponding amplitudes. The classical coin-toss and the quantum double slit interference experiments are discussed as illustrative prototype examples. Absence of multi-order quantum interference effects in multiple-slit experiments and the Experimental tests of complementarity in Wheeler's delayed-choice type experiments are explained using the involvement of the observer.
Eliciting Subjective Probabilities with Binary Lotteries
Harrison, Glenn W.; Martínez-Correa, Jimmy; Swarthout, J. Todd
2014-01-01
We evaluate a binary lottery procedure for inducing risk neutral behavior in a subjective belief elicitation task. Prior research has shown this procedure to robustly induce risk neutrality when subjects are given a single risk task defined over objective probabilities. Drawing a sample from...... the same subject population, we find evidence that the binary lottery procedure also induces linear utility in a subjective probability elicitation task using the Quadratic Scoring Rule. We also show that the binary lottery procedure can induce direct revelation of subjective probabilities in subjects...... with popular non-expected utility preference representations that satisfy weak conditions....
Concept of probability in statistical physics
Guttmann, Y M
1999-01-01
Foundational issues in statistical mechanics and the more general question of how probability is to be understood in the context of physical theories are both areas that have been neglected by philosophers of physics. This book fills an important gap in the literature by providing a most systematic study of how to interpret probabilistic assertions in the context of statistical mechanics. The book explores both subjectivist and objectivist accounts of probability, and takes full measure of work in the foundations of probability theory, in statistical mechanics, and in mathematical theory. It will be of particular interest to philosophers of science, physicists and mathematicians interested in foundational issues, and also to historians of science.
Computation of the Complex Probability Function
Trainer, Amelia Jo [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ledwith, Patrick John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2017-08-22
The complex probability function is important in many areas of physics and many techniques have been developed in an attempt to compute it for some z quickly and e ciently. Most prominent are the methods that use Gauss-Hermite quadrature, which uses the roots of the n^{th} degree Hermite polynomial and corresponding weights to approximate the complex probability function. This document serves as an overview and discussion of the use, shortcomings, and potential improvements on the Gauss-Hermite quadrature for the complex probability function.
Eliciting Subjective Probabilities with Binary Lotteries
Harrison, Glenn W.; Martínez-Correa, Jimmy; Swarthout, J. Todd
We evaluate the binary lottery procedure for inducing risk neutral behavior in a subjective belief elicitation task. Harrison, Martínez-Correa and Swarthout [2013] found that the binary lottery procedure works robustly to induce risk neutrality when subjects are given one risk task defined over...... objective probabilities. Drawing a sample from the same subject population, we find evidence that the binary lottery procedure induces linear utility in a subjective probability elicitation task using the Quadratic Scoring Rule. We also show that the binary lottery procedure can induce direct revelation...... of subjective probabilities in subjects with certain Non-Expected Utility preference representations that satisfy weak conditions that we identify....
Probability amplitude in quantum like games
Grib, A A; Starkov, K
2003-01-01
Examples of games between two partners with mixed strategies, calculated by the use of the probability amplitude are given. The first game is described by the quantum formalism of spin one half system for which two noncommuting observables are measured. The second game corresponds to the spin one case. Quantum logical orthocomplemented nondistributive lattices for these two games are presented. Interference terms for the probability amplitudes are analyzed by using so called contextual approach to probability (in the von Mises frequency approach). We underline that our games are not based on using of some microscopic systems. The whole scenario is macroscopic.
Basic Probability Theory for Biomedical Engineers
Enderle, John
2006-01-01
This is the first in a series of short books on probability theory and random processes for biomedical engineers. This text is written as an introduction to probability theory. The goal was to prepare students, engineers and scientists at all levels of background and experience for the application of this theory to a wide variety of problems--as well as pursue these topics at a more advanced level. The approach is to present a unified treatment of the subject. There are only a few key concepts involved in the basic theory of probability theory. These key concepts are all presented in the first
Advanced Probability Theory for Biomedical Engineers
Enderle, John
2006-01-01
This is the third in a series of short books on probability theory and random processes for biomedical engineers. This book focuses on standard probability distributions commonly encountered in biomedical engineering. The exponential, Poisson and Gaussian distributions are introduced, as well as important approximations to the Bernoulli PMF and Gaussian CDF. Many important properties of jointly Gaussian random variables are presented. The primary subjects of the final chapter are methods for determining the probability distribution of a function of a random variable. We first evaluate the prob
Comparing linear probability model coefficients across groups
Holm, Anders; Ejrnæs, Mette; Karlson, Kristian Bernt
2015-01-01
This article offers a formal identification analysis of the problem in comparing coefficients from linear probability models between groups. We show that differences in coefficients from these models can result not only from genuine differences in effects, but also from differences in one or more...... of the following three components: outcome truncation, scale parameters and distributional shape of the predictor variable. These results point to limitations in using linear probability model coefficients for group comparisons. We also provide Monte Carlo simulations and real examples to illustrate...... these limitations, and we suggest a restricted approach to using linear probability model coefficients in group comparisons....
Tomographic probability representation for quantum fermion fields
Andreev, V A; Man'ko, V I; Son, Nguyen Hung; Thanh, Nguyen Cong; Timofeev, Yu P; Zakharov, S D
2009-01-01
Tomographic probability representation is introduced for fermion fields. The states of the fermions are mapped onto probability distribution of discrete random variables (spin projections). The operators acting on the fermion states are described by fermionic tomographic symbols. The product of the operators acting on the fermion states is mapped onto star-product of the fermionic symbols. The kernel of the star-product is obtained. The antisymmetry of the fermion states is formulated as the specific symmetry property of the tomographic joint probability distribution associated with the states.
Pre-aggregation for Probability Distributions
Timko, Igor; Dyreson, Curtis E.; Pedersen, Torben Bach
Motivated by the increasing need to analyze complex uncertain multidimensional data (e.g., in order to optimize and personalize location-based services), this paper proposes novel types of {\\em probabilistic} OLAP queries that operate on aggregate values that are probability distributions...... and the techniques to process these queries. The paper also presents the methods for computing the probability distributions, which enables pre-aggregation, and for using the pre-aggregated distributions for further aggregation. In order to achieve good time and space efficiency, the methods perform approximate...... multidimensional data analysis that is considered in this paper (i.e., approximate processing of probabilistic OLAP queries over probability distributions)....
Handbook of probability theory and applications
Rudas, Tamas
2008-01-01
""This is a valuable reference guide for readers interested in gaining a basic understanding of probability theory or its applications in problem solving in the other disciplines.""-CHOICEProviding cutting-edge perspectives and real-world insights into the greater utility of probability and its applications, the Handbook of Probability offers an equal balance of theory and direct applications in a non-technical, yet comprehensive, format. Editor Tamás Rudas and the internationally-known contributors present the material in a manner so that researchers of vari
ELECTROMAGNETIC RELEASE MECHANISM
Michelson, C.
1960-09-13
An electromagnetic release mechanism is offered that may be used, for example, for supporting a safety rod for a nuclear reactor. The release mechanism is designed to have a large excess holding force and a rapid, uniform, and dependable release. The fast release is accomplished by providing the electromagnet with slotttd polts separated by an insulating potting resin, and by constructing the poles with a ferro-nickel alloy. The combination of these two features materially reduces the eddy current power density whenever the magnetic field changes during a release operation. In addition to these features, the design of the armature is such as to provide ready entrance of fluid into any void that might tend to form during release of the armature. This also improves the release time for the mechanism. The large holding force for the mechanism is accomplished by providing a small, selected, uniform air gap between the inner pole piece and the armature.
Zika Probably Not Spread Through Saliva: Study
... page: https://medlineplus.gov/news/fullstory_167531.html Zika Probably Not Spread Through Saliva: Study Research with ... HealthDay News) -- Scientists have some interesting news about Zika: You're unlikely to get the virus from ...
Teaching Elementary Probability Through its History.
Kunoff, Sharon; Pines, Sylvia
1986-01-01
Historical problems are presented which can readily be solved by students once some elementary probability concepts are developed. The Duke of Tuscany's Problem; the problem of points; and the question of proportions, divination, and Bertrand's Paradox are included. (MNS)
Probability and statistics with integrated software routines
Deep, Ronald
2005-01-01
Probability & Statistics with Integrated Software Routines is a calculus-based treatment of probability concurrent with and integrated with statistics through interactive, tailored software applications designed to enhance the phenomena of probability and statistics. The software programs make the book unique.The book comes with a CD containing the interactive software leading to the Statistical Genie. The student can issue commands repeatedly while making parameter changes to observe the effects. Computer programming is an excellent skill for problem solvers, involving design, prototyping, data gathering, testing, redesign, validating, etc, all wrapped up in the scientific method.See also: CD to accompany Probability and Stats with Integrated Software Routines (0123694698)* Incorporates more than 1,000 engaging problems with answers* Includes more than 300 solved examples* Uses varied problem solving methods
Encounter Probability of Individual Wave Height
Liu, Z.; Burcharth, H. F.
1998-01-01
wave height corresponding to a certain exceedence probability within a structure lifetime (encounter probability), based on the statistical analysis of long-term extreme significant wave height. Then the design individual wave height is calculated as the expected maximum individual wave height...... associated with the design significant wave height, with the assumption that the individual wave heights follow the Rayleigh distribution. However, the exceedence probability of such a design individual wave height within the structure lifetime is unknown. The paper presents a method for the determination...... of the design individual wave height corresponding to an exceedence probability within the structure lifetime, given the long-term extreme significant wave height. The method can also be applied for estimation of the number of relatively large waves for fatigue analysis of constructions....
Pre-Aggregation with Probability Distributions
Timko, Igor; Dyreson, Curtis E.; Pedersen, Torben Bach
2006-01-01
Motivated by the increasing need to analyze complex, uncertain multidimensional data this paper proposes probabilistic OLAP queries that are computed using probability distributions rather than atomic values. The paper describes how to create probability distributions from base data, and how...... the distributions can be subsequently used in pre-aggregation. Since the probability distributions can become large, we show how to achieve good time and space efficiency by approximating the distributions. We present the results of several experiments that demonstrate the effectiveness of our methods. The work...... is motivated with a real-world case study, based on our collaboration with a leading Danish vendor of location-based services. This paper is the first to consider the approximate processing of probabilistic OLAP queries over probability distributions....
Modelling the probability of building fires
Vojtěch Barták
2014-12-01
Full Text Available Systematic spatial risk analysis plays a crucial role in preventing emergencies.In the Czech Republic, risk mapping is currently based on the risk accumulationprinciple, area vulnerability, and preparedness levels of Integrated Rescue Systemcomponents. Expert estimates are used to determine risk levels for individualhazard types, while statistical modelling based on data from actual incidents andtheir possible causes is not used. Our model study, conducted in cooperation withthe Fire Rescue Service of the Czech Republic as a model within the Liberec andHradec Králové regions, presents an analytical procedure leading to the creation ofbuilding fire probability maps based on recent incidents in the studied areas andon building parameters. In order to estimate the probability of building fires, aprediction model based on logistic regression was used. Probability of fire calculatedby means of model parameters and attributes of specific buildings can subsequentlybe visualized in probability maps.
Probability calculations under the IAC hypothesis
Wilson, Mark C; 10.1016/j.mathsocsci.2007.05.003
2012-01-01
We show how powerful algorithms recently developed for counting lattice points and computing volumes of convex polyhedra can be used to compute probabilities of a wide variety of events of interest in social choice theory. Several illustrative examples are given.
Inclusion probability with dropout: an operational formula.
Milot, E; Courteau, J; Crispino, F; Mailly, F
2015-05-01
In forensic genetics, a mixture of two or more contributors to a DNA profile is often interpreted using the inclusion probabilities theory. In this paper, we present a general formula for estimating the probability of inclusion (PI, also known as the RMNE probability) from a subset of visible alleles when dropouts are possible. This one-locus formula can easily be extended to multiple loci using the cumulative probability of inclusion. We show that an exact formulation requires fixing the number of contributors, hence to slightly modify the classic interpretation of the PI. We discuss the implications of our results for the enduring debate over the use of PI vs likelihood ratio approaches within the context of low template amplifications.
Pre-Aggregation with Probability Distributions
Timko, Igor; Dyreson, Curtis E.; Pedersen, Torben Bach
2006-01-01
Motivated by the increasing need to analyze complex, uncertain multidimensional data this paper proposes probabilistic OLAP queries that are computed using probability distributions rather than atomic values. The paper describes how to create probability distributions from base data, and how...... the distributions can be subsequently used in pre-aggregation. Since the probability distributions can become large, we show how to achieve good time and space efficiency by approximating the distributions. We present the results of several experiments that demonstrate the effectiveness of our methods. The work...... is motivated with a real-world case study, based on our collaboration with a leading Danish vendor of location-based services. This paper is the first to consider the approximate processing of probabilistic OLAP queries over probability distributions....
Survival probability for open spherical billiards
Dettmann, Carl P.; Rahman, Mohammed R.
2014-12-01
We study the survival probability for long times in an open spherical billiard, extending previous work on the circular billiard. We provide details of calculations regarding two billiard configurations, specifically a sphere with a circular hole and a sphere with a square hole. The constant terms of the long-time survival probability expansions have been derived analytically. Terms that vanish in the long time limit are investigated analytically and numerically, leading to connections with the Riemann hypothesis.
Data analysis recipes: Probability calculus for inference
Hogg, David W.
2012-01-01
In this pedagogical text aimed at those wanting to start thinking about or brush up on probabilistic inference, I review the rules by which probability distribution functions can (and cannot) be combined. I connect these rules to the operations performed in probabilistic data analysis. Dimensional analysis is emphasized as a valuable tool for helping to construct non-wrong probabilistic statements. The applications of probability calculus in constructing likelihoods, marginalized likelihoods,...
Ruin Probability in Linear Time Series Model
ZHANG Lihong
2005-01-01
This paper analyzes a continuous time risk model with a linear model used to model the claim process. The time is discretized stochastically using the times when claims occur, using Doob's stopping time theorem and martingale inequalities to obtain expressions for the ruin probability as well as both exponential and non-exponential upper bounds for the ruin probability for an infinite time horizon. Numerical results are included to illustrate the accuracy of the non-exponential bound.
Representing Uncertainty by Probability and Possibility
Uncertain parameters in modeling are usually represented by probability distributions reflecting either the objective uncertainty of the parameters or the subjective belief held by the model builder. This approach is particularly suited for representing the statistical nature or variance of uncer......Uncertain parameters in modeling are usually represented by probability distributions reflecting either the objective uncertainty of the parameters or the subjective belief held by the model builder. This approach is particularly suited for representing the statistical nature or variance...
Probabilities and health risks: a qualitative approach.
Heyman, B; Henriksen, M; Maughan, K
1998-11-01
Health risks, defined in terms of the probability that an individual will suffer a particular type of adverse health event within a given time period, can be understood as referencing either natural entities or complex patterns of belief which incorporate the observer's values and knowledge, the position adopted in the present paper. The subjectivity inherent in judgements about adversity and time frames can be easily recognised, but social scientists have tended to accept uncritically the objectivity of probability. Most commonly in health risk analysis, the term probability refers to rates established by induction, and so requires the definition of a numerator and denominator. Depending upon their specification, many probabilities may be reasonably postulated for the same event, and individuals may change their risks by deciding to seek or avoid information. These apparent absurdities can be understood if probability is conceptualised as the projection of expectation onto the external world. Probabilities based on induction from observed frequencies provide glimpses of the future at the price of acceptance of the simplifying heuristic that statistics derived from aggregate groups can be validly attributed to individuals within them. The paper illustrates four implications of this conceptualisation of probability with qualitative data from a variety of sources, particularly a study of genetic counselling for pregnant women in a U.K. hospital. Firstly, the official selection of a specific probability heuristic reflects organisational constraints and values as well as predictive optimisation. Secondly, professionals and service users must work to maintain the facticity of an established heuristic in the face of alternatives. Thirdly, individuals, both lay and professional, manage probabilistic information in ways which support their strategic objectives. Fourthly, predictively sub-optimum schema, for example the idea of AIDS as a gay plague, may be selected because
De Finetti's contribution to probability and statistics
Cifarelli, Donato Michele; Regazzini, Eugenio
1996-01-01
This paper summarizes the scientific activity of de Finetti in probability and statistics. It falls into three sections: Section 1 includes an essential biography of de Finetti and a survey of the basic features of the scientific milieu in which he took the first steps of his scientific career; Section 2 concerns de Finetti's work in probability: (a) foundations, (b) processes with independent increments, (c) sequences of exchangeable random variables, and (d) contributions which fall within ...
Characteristic Functions over C*-Probability Spaces
王勤; 李绍宽
2003-01-01
Various properties of the characteristic functions of random variables in a non-commutative C*-probability space are studied in this paper. It turns out that the distributions of random variables are uniquely determined by their characteristic functions. By using the properties of characteristic functions, a central limit theorem for a sequence of independent identically distributed random variables in a C*-probability space is established as well.
Imprecise Probability Methods for Weapons UQ
Picard, Richard Roy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vander Wiel, Scott Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2016-05-13
Building on recent work in uncertainty quanti cation, we examine the use of imprecise probability methods to better characterize expert knowledge and to improve on misleading aspects of Bayesian analysis with informative prior distributions. Quantitative approaches to incorporate uncertainties in weapons certi cation are subject to rigorous external peer review, and in this regard, certain imprecise probability methods are well established in the literature and attractive. These methods are illustrated using experimental data from LANL detonator impact testing.
Probability, clinical decision making and hypothesis testing
A Banerjee
2009-01-01
Full Text Available Few clinicians grasp the true concept of probability expressed in the ′P value.′ For most, a statistically significant P value is the end of the search for truth. In fact, the opposite is the case. The present paper attempts to put the P value in proper perspective by explaining different types of probabilities, their role in clinical decision making, medical research and hypothesis testing.
Probability and statistics for computer science
Johnson, James L
2011-01-01
Comprehensive and thorough development of both probability and statistics for serious computer scientists; goal-oriented: ""to present the mathematical analysis underlying probability results"" Special emphases on simulation and discrete decision theory Mathematically-rich, but self-contained text, at a gentle pace Review of calculus and linear algebra in an appendix Mathematical interludes (in each chapter) which examine mathematical techniques in the context of probabilistic or statistical importance Numerous section exercises, summaries, historical notes, and Further Readings for reinforcem
Representing Uncertainty by Probability and Possibility
Uncertain parameters in modeling are usually represented by probability distributions reflecting either the objective uncertainty of the parameters or the subjective belief held by the model builder. This approach is particularly suited for representing the statistical nature or variance of uncer......Uncertain parameters in modeling are usually represented by probability distributions reflecting either the objective uncertainty of the parameters or the subjective belief held by the model builder. This approach is particularly suited for representing the statistical nature or variance...
Site occupancy models with heterogeneous detection probabilities
Royle, J. Andrew
2006-01-01
Models for estimating the probability of occurrence of a species in the presence of imperfect detection are important in many ecological disciplines. In these ?site occupancy? models, the possibility of heterogeneity in detection probabilities among sites must be considered because variation in abundance (and other factors) among sampled sites induces variation in detection probability (p). In this article, I develop occurrence probability models that allow for heterogeneous detection probabilities by considering several common classes of mixture distributions for p. For any mixing distribution, the likelihood has the general form of a zero-inflated binomial mixture for which inference based upon integrated likelihood is straightforward. A recent paper by Link (2003, Biometrics 59, 1123?1130) demonstrates that in closed population models used for estimating population size, different classes of mixture distributions are indistinguishable from data, yet can produce very different inferences about population size. I demonstrate that this problem can also arise in models for estimating site occupancy in the presence of heterogeneous detection probabilities. The implications of this are discussed in the context of an application to avian survey data and the development of animal monitoring programs.
Influence of synaptic vesicle position on release probability and exocytotic fusion mode.
Park, Hyokeun; Li, Yulong; Tsien, Richard W
2012-03-16
Neurotransmission depends on movements of transmitter-laden synaptic vesicles, but accurate, nanometer-scale monitoring of vesicle dynamics in presynaptic terminals has remained elusive. Here, we report three-dimensional, real-time tracking of quantum dot-loaded single synaptic vesicles with an accuracy of 20 to 30 nanometers, less than a vesicle diameter. Determination of the time, position, and mode of fusion, aided by trypan blue quenching of Qdot fluorescence, revealed that vesicles starting close to their ultimate fusion sites tended to fuse earlier than those positioned farther away. The mode of fusion depended on the prior motion of vesicles, with long-dwelling vesicles preferring kiss-and-run rather than full-collapse fusion. Kiss-and-run fusion events were concentrated near the center of the synapse, whereas full-collapse fusion events were broadly spread.
Release the Body, Release the Mind.
Stoner, Martha Goff
1998-01-01
A college English teacher describes the anxiety and resentment of students during in-class writing assignments and the successful classroom use of meditation and body movement. Movement seemed to relax the students, change their attitudes, and release their creative impulses to write. Implications related to the body-mind connection are pondered.…
Laboratory-tutorial activities for teaching probability
Roger E. Feeley
2006-08-01
Full Text Available We report on the development of students’ ideas of probability and probability density in a University of Maine laboratory-based general education physics course called Intuitive Quantum Physics. Students in the course are generally math phobic with unfavorable expectations about the nature of physics and their ability to do it. We describe a set of activities used to teach concepts of probability and probability density. Rudimentary knowledge of mechanics is needed for one activity, but otherwise the material requires no additional preparation. Extensions of the activities include relating probability density to potential energy graphs for certain “touchstone” examples. Students have difficulties learning the target concepts, such as comparing the ratio of time in a region to total time in all regions. Instead, they often focus on edge effects, pattern match to previously studied situations, reason about necessary but incomplete macroscopic elements of the system, use the gambler’s fallacy, and use expectations about ensemble results rather than expectation values to predict future events. We map the development of their thinking to provide examples of problems rather than evidence of a curriculum’s success.
Causal inference, probability theory, and graphical insights.
Baker, Stuart G
2013-11-10
Causal inference from observational studies is a fundamental topic in biostatistics. The causal graph literature typically views probability theory as insufficient to express causal concepts in observational studies. In contrast, the view here is that probability theory is a desirable and sufficient basis for many topics in causal inference for the following two reasons. First, probability theory is generally more flexible than causal graphs: Besides explaining such causal graph topics as M-bias (adjusting for a collider) and bias amplification and attenuation (when adjusting for instrumental variable), probability theory is also the foundation of the paired availability design for historical controls, which does not fit into a causal graph framework. Second, probability theory is the basis for insightful graphical displays including the BK-Plot for understanding Simpson's paradox with a binary confounder, the BK2-Plot for understanding bias amplification and attenuation in the presence of an unobserved binary confounder, and the PAD-Plot for understanding the principal stratification component of the paired availability design.
Laboratory-tutorial activities for teaching probability
Michael C. Wittmann
2006-08-01
Full Text Available We report on the development of students’ ideas of probability and probability density in a University of Maine laboratory-based general education physics course called Intuitive Quantum Physics. Students in the course are generally math phobic with unfavorable expectations about the nature of physics and their ability to do it. We describe a set of activities used to teach concepts of probability and probability density. Rudimentary knowledge of mechanics is needed for one activity, but otherwise the material requires no additional preparation. Extensions of the activities include relating probability density to potential energy graphs for certain “touchstone” examples. Students have difficulties learning the target concepts, such as comparing the ratio of time in a region to total time in all regions. Instead, they often focus on edge effects, pattern match to previously studied situations, reason about necessary but incomplete macroscopic elements of the system, use the gambler’s fallacy, and use expectations about ensemble results rather than expectation values to predict future events. We map the development of their thinking to provide examples of problems rather than evidence of a curriculum’s success.
Approximation of Failure Probability Using Conditional Sampling
Giesy. Daniel P.; Crespo, Luis G.; Kenney, Sean P.
2008-01-01
In analyzing systems which depend on uncertain parameters, one technique is to partition the uncertain parameter domain into a failure set and its complement, and judge the quality of the system by estimating the probability of failure. If this is done by a sampling technique such as Monte Carlo and the probability of failure is small, accurate approximation can require so many sample points that the computational expense is prohibitive. Previous work of the authors has shown how to bound the failure event by sets of such simple geometry that their probabilities can be calculated analytically. In this paper, it is shown how to make use of these failure bounding sets and conditional sampling within them to substantially reduce the computational burden of approximating failure probability. It is also shown how the use of these sampling techniques improves the confidence intervals for the failure probability estimate for a given number of sample points and how they reduce the number of sample point analyses needed to achieve a given level of confidence.
Computing Earthquake Probabilities on Global Scales
Holliday, James R.; Graves, William R.; Rundle, John B.; Turcotte, Donald L.
2016-03-01
Large devastating events in systems such as earthquakes, typhoons, market crashes, electricity grid blackouts, floods, droughts, wars and conflicts, and landslides can be unexpected and devastating. Events in many of these systems display frequency-size statistics that are power laws. Previously, we presented a new method for calculating probabilities for large events in systems such as these. This method counts the number of small events since the last large event and then converts this count into a probability by using a Weibull probability law. We applied this method to the calculation of large earthquake probabilities in California-Nevada, USA. In that study, we considered a fixed geographic region and assumed that all earthquakes within that region, large magnitudes as well as small, were perfectly correlated. In the present article, we extend this model to systems in which the events have a finite correlation length. We modify our previous results by employing the correlation function for near mean field systems having long-range interactions, an example of which is earthquakes and elastic interactions. We then construct an application of the method and show examples of computed earthquake probabilities.
Genefer: Programs for Finding Large Probable Generalized Fermat Primes
Iain Arthur Bethune
2015-11-01
Full Text Available Genefer is a suite of programs for performing Probable Primality (PRP tests of Generalised Fermat numbers 'b'2'n'+1 (GFNs using a Fermat test. Optimised implementations are available for modern CPUs using single instruction, multiple data (SIMD instructions, as well as for GPUs using CUDA or OpenCL. Genefer has been extensively used by PrimeGrid – a volunteer computing project searching for large prime numbers of various kinds, including GFNs. Genefer’s architecture separates the high level logic such as checkpointing and user interface from the architecture-specific performance-critical parts of the implementation, which are suitable for re-use. Genefer is released under the MIT license. Source and binaries are available from www.assembla.com/spaces/genefer.
Tritium release from neutron irradiated beryllium pebbles
Scaffidi-Argentina, F.; Werle, H. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Neutronenphysik und Reactortechnik
1998-01-01
One of the most important open issues related to beryllium for fusion applications refers to the kinetics of the tritium release as a function of neutron fluence and temperature. The EXOTIC-7 as well as the `Beryllium` experiments carried out in the HFR reactor in Petten are considered as the most detailed and significant tests for investigating the beryllium response under neutron irradiation. This paper reviews the present status of beryllium post-irradiation examinations performed at the Forschungszentrum Karlsruhe with samples from the above mentioned irradiation experiments, trying to elucidate the tritium release controlling processes. In agreement with previous studies it has been found that release starts at about 500-550degC and achieves a maximum at about 700-750degC. The observed release at about 500-550degC is probably due to tritium escaping from chemical traps, while the maximum release at about 700-750degC is due to tritium escaping from physical traps. The consequences of a direct contact between beryllium and ceramics during irradiation, causing tritium implanting in a surface layer of beryllium up to a depth of about 40 mm and leading to an additional inventory which is usually several times larger than the neutron-produced one, are also presented and the effects on the tritium release are discussed. (author)