314 research outputs found

    Gravin orchestrates protein kinase A and 2-adrenergic receptor signaling critical for synaptic plasticity and memory

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    A kinase-anchoring proteins (AKAPs) organize compartmentalized pools of protein kinase A (PKA) to enable localized signaling events within neurons. However, it is unclear which of the many expressed AKAPs in neurons target PKA to signaling complexes important for long-lasting forms of synaptic plasticity and memory storage. In the forebrain, the anchoring protein gravin recruits a signaling complex containing PKA, PKC, calmodulin, and PDE4D (phosphodiesterase 4D) to the β2-adrenergic receptor. Here, we show that mice lacking the α-isoform of gravin have deficits in PKA-dependent long-lasting forms of hippocampal synaptic plasticity including β2-adrenergic receptor-mediated plasticity, and selective impairments of long-term memory storage. Furthermore, both hippocampal β2-adrenergic receptor phosphorylation by PKA, and learning-induced activation of ERK in the CA1 region of the hippocampus are attenuated in mice lacking gravin-α. We conclude that gravin compartmentalizes a significant pool of PKA that regulates learning-induced β2-adrenergic receptor signaling and ERK activation in the hippocampus in vivo, thereby organizing molecular interactions between glutamatergic and noradrenergic signaling pathways for long-lasting synaptic plasticity, and memory storage

    Witness: The Modern Writer as Witness

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    Editor\u27s Note [Excerpt] Magic can mean many different things, especially for writers. Magic can be an illusion, a sleight of hand designed to trick onlookers into believing the impossible. Or magic can be a supernatural force in a world of harsh reality, a set of beliefs that sits just outside the realms of organized religion and advanced technology. Wizards and demons, Las Vegas entertainers and houngans --they all practice a kind of sorcery. For poets and prose writers, though, magic affords an opportunity for us to stretch the limitations of the physical world in search of new themes, settings, and characters. Magic is a door we eagerly walk through to reach new lands. We at Witness have thoroughly enjoyed the process of selecting the themed works we have collected here, mainly because the idea of enchantment is inspiring. There is the possibility of positive charms; there is a chance for dark witchery. And sometimes the spell cast by a character is nebulous, difficult to categorize. It’s arguable that we cherish these incantations the most, since they leave us in a state of wonderment bordering on disorientation. Yes, magic can also leave us bewildered and thankful for the bewilderment.https://digitalscholarship.unlv.edu/witness/1001/thumbnail.jp

    Fluorapophyllite-(Cs), CsCa₄(Si₈O₂₀)F(H₂O)₈, a new apophyllite-group mineral from the Darai-Pioz Massif, Tien-Shan, Northern Tajikistan

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    Fluorapophyllite-(Cs) (IMA 2018-108a), ideally CsCa4(Si8O20)F(H2O)(8), is an apophyllite-group mineral from the moraine of the Darai-Pioz glacier, Tien-Shan, Northern Tajikistan. Associated minerals are quartz, pectolite, baratovite, aegirine, leucosphenite, pyrochlore, neptunite, fluorapophyllite-(K), and reedmergnerite. Fluorapophyllite-(Cs) is a hydrothermal mineral. It is colorless and has a vitreous luster and a white streak. Cleavage is perfect; it is brittle and has a stepped fracture. Mohs hardness is 4.5-5. D-meas. = 2.54(2) g/cm(3), D-calc. = 2.513 g/cm(3). Fluorapophyllite-(Cs) is unixial (+) with refractive indices (lambda = 589 nm) omega = 1.540(2), epsilon = 1.544(2). It is non-pleochroic. Chemical analysis by electron microprobe gave SiO2 48.78, Al2O3 0.05, CaO 22.69, Cs2O 10.71, K2O 1.13, Na2O 0.04, F 1.86, H2Ocalc. 14.61, -O=F2 -0.78, sum 99.09 wt.%; H2O was calculated from crystal-structure analysis. The empirical formula based on 29 (O + F) apfu, H2O = 8 pfu, is (Cs0.75K0.24)Sigma(0.99)(Ca3.99Na0.01)Sigma(4)(Si8.01Al0.01)Sigma 8.02O20.03F0.97(H2O)8, Z = 2. The simplified formula is (Cs,K)(Ca,Na)(4)(Si,Al) 8 O20F(H2O)(8). Fluorapophyllite-(Cs) is tetragonal, space group P4/mnc, a 9.060(6), c 15.741(11) angstrom, V 1292.10(19) angstrom(3). The crystal structure has been refined to R-1 = 4.31% based on 498 unique (F-o > 4 sigma F) reflections. In the crystal structure of fluorapophyllite-(Cs), there is one [4] T site occupied solely by Si,,T-O. = 1.615 angstrom. SiO4 tetrahedra link to form a (Si8O20)(8-)sheet perpendicular to [001]. Between the Si-O sheets, there are two cation sites: A and B. The A site is coordinated by eight H2O groups [O(4) site], A-O(4) = 3.152(4) angstrom; the A site contains Cs(0.75)K(0.24)A(0.01 square 0.01), ideally Cs apfu. The Cs-O bond length of 3.152 angstrom is definitely larger than the K-O bond length of 2.966-2.971 angstrom in fluorapophyllite-(K), KCa4(Si8O20)F(H2O)8. The [7]B site contains Ca3.99Na0.01, ideally Ca-4 apfu; < B-phi > = 2.417 angstrom (phi = O, F, H2O). The Si-O sheets connect via A and B polyhedra and hydrogen bonding; two H atoms have been included in the refinement. Fluorapophyllite-(Cs) is isostructural with fluorapophyllite-(K). Fluorapophyllite-(Cs) is a Cs-analogue of fluorapophyllite-(K)

    Entropic Interactions in Suspensions of Semi-Flexible Rods: Short-Range Effects of Flexibility

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    We compute the entropic interactions between two colloidal spheres immersed in a dilute suspension of semi-flexible rods. Our model treats the semi-flexible rod as a bent rod at fixed angle, set by the rod contour and persistence lengths. The entropic forces arising from this additional rotational degree of freedom are captured quantitatively by the model, and account for observations at short range in a recent experiment. Global fits to the interaction potential data suggest the persistence length of fd-virus is about two to three times smaller than the commonly used value of 2.2μm2.2 \mu {m}.Comment: 4 pages, 5 figures, submitted to PRE rapid communication

    Nuclear Structure Functions in the Large x Large Q^2 Kinematic Region in Neutrino Deep Inelastic Scattering

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    Data from the CCFR E770 Neutrino Deep Inelastic Scattering (DIS) experiment at Fermilab contain events with large Bjorken x (x>0.7) and high momentum transfer (Q^2>50 (GeV/c)^2). A comparison of the data with a model based on no nuclear effects at large x, shows a significant excess of events in the data. Addition of Fermi gas motion of the nucleons in the nucleus to the model does not explain the excess. Adding a higher momentum tail due to the formation of ``quasi-deuterons'' makes some improvement. An exponentially falling F_2 \propto e^-s(x-x_0) at large x, predicted by ``multi-quark clusters'' and ``few-nucleon correlations'', can describe the data. A value of s=8.3 \pm 0.7(stat.)\pm 0.7(sys.) yields the best agreement with the data.Comment: 4 pages, 4 figures, 1 table. Sibmitted to PR

    Complex relationships among personality traits, job characteristics, and work behaviors

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    The aim of the study was to investigate the additive, mediating, and moderating effects of personality traits and job characteristics on work behaviors. Job applicants (N = 161) completed personality questionnaires measuring extraversion, neuroticism, achievement motivation, and experience seeking. One and a half years later, supervisors rated the applicants' job performance, and the job incumbents completed questionnaires about skill variety, autonomy, and feedback, work stress, job satisfaction, work self-efficacy, and propensity to leave. LISREL was used to test 15 hypotheses. Perceived feedback mediated the relationship between achievement motivation and job performance. Extraversion predicted work self-efficacy and job satisfaction. Work stress mediated the relationship between neuroticism and job satisfaction. Job satisfaction and experience seeking were related to propensity to leave. Autonomy, skill variety, and feedback were related to job satisfaction

    Quasielastic axial-vector mass from experiments on neutrino-nucleus scattering

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    We analyze available experimental data on the total and differential charged-current cross sections for quasielastic neutrino and antineutrino scattering off nucleons, measured with a variety of nuclear targets in the accelerator experiments at ANL, BNL, FNAL, CERN, and IHEP, dating from the end of sixties to the present day. The data are used to adjust the poorly known value of the axial-vector mass of the nucleon.Comment: 27 pages, 19 figures. Typos corrected; tables, figures and references added, discussion extended; matches published versio
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