An evaluation of pupil preferences in language arts activities in grades six and seven

Thesis (M.Ed.)--Boston Universit

Design, fabrication and testing of subscale propellant tanks with capillary traps Final report, 26 Jun. 1967 - 15 Mar. 1968

Hyrostatic stability characteristics of perforated plates and square-weave screens for fluid control during low-G operatio

A fast-initializing digital equalizer with on-line tracking for data communications

A theory is developed for a digital equalizer for use in reducing intersymbol interference (ISI) on high speed data communications channels. The equalizer is initialized with a single isolated transmitter pulse, provided the signal-to-noise ratio (SNR) is not unusually low, then switches to a decision directed, on-line mode of operation that allows tracking of channel variations. Conditions for optimal tap-gain settings are obtained first for a transversal equalizer structure by using a mean squared error (MSE) criterion, a first order gradient algorithm to determine the adjustable equalizer tap-gains, and a sequence of isolated initializing pulses. Since the rate of tap-gain convergence depends on the eigenvalues of a channel output correlation matrix, convergence can be improved by making a linear transformation on to obtain a new correlation matrix

Performance of a Stone Column Supported Embankment

The proposed expansion of ramps connecting Interstate Route 664 with Interstate Route 64 at Hampton, Virginia involved numerous high embankments and bridge structures over marshlands. Potential problems of embankment stability and excessive long term, post construction settlements were further complicated by very strict environmental constraints on acceptable construction methods. The solution chosen was stabilization of the in situ soils by the installation of stone columns. A description is given of stone column design, construction, field embankment instrumentation, and embankment performance for the first two years of operation. Four theories for predicting settlements of stone column reinforced ground are briefly reviewed. Calculated settlements of the embankment are then compared with the measured settlements. Although the settlements predicted by each method differ, they generally give good results

Advanced propellant management system for spacecraft propulsion systems. Phase 1 - Survey study and evaluation

Apollo spacecraft propulsion system propellant managemen

Passive Retention/Expulsion Methods for Subcritical Storage of Cryogens

Development of passive retention/expulsion system for subcritical storage of cryogenic material during low gravity situation

FDEMS Sensing for Automated Intelligent Processing of PMR-15

The purpose of this grant was to develop frequency dependent dielectric measurements, often called FDEMS (frequency dependent electromagnetic sensing), to monitor and intelligently control the cure process in PMR-15, a stoichiometric mixture of a nadic ester, dimethyl ester, and methylendianiline in a monomor ratio

Afferent specific role of NMDA receptors for the circuit integration of hippocampal neurogliaform cells.

This is the final version of the article. Available from Nature Publishing Group via the DOI in this record.Appropriate integration of GABAergic interneurons into nascent cortical circuits is critical for ensuring normal information processing within the brain. Network and cognitive deficits associated with neurological disorders, such as schizophrenia, that result from NMDA receptor-hypofunction have been mainly attributed to dysfunction of parvalbumin-expressing interneurons that paradoxically express low levels of synaptic NMDA receptors. Here, we reveal that throughout postnatal development, thalamic, and entorhinal cortical inputs onto hippocampal neurogliaform cells are characterized by a large NMDA receptor-mediated component. This NMDA receptor-signaling is prerequisite for developmental programs ultimately responsible for the appropriate long-range AMPAR-mediated recruitment of neurogliaform cells. In contrast, AMPAR-mediated input at local Schaffer-collateral synapses on neurogliaform cells remains normal following NMDA receptor-ablation. These afferent specific deficits potentially impact neurogliaform cell mediated inhibition within the hippocampus and our findings reveal circuit loci implicating this relatively understudied interneuron subtype in the etiology of neurodevelopmental disorders characterized by NMDA receptor-hypofunction.Proper brain function depends on the correct assembly of excitatory and inhibitory neurons into neural circuits. Here the authors show that during early postnatal development in mice, NMDAR signaling via activity of long-range synaptic inputs onto neurogliaform cells is required for their appropriate integration into the hippocampal circuitry.We thank Daniel Abebe for mouse colony maintenance and Kurt Auville for additional assistance with confocal imaging. We thank UNC Vector Core and Ed Boyden, MIT, Cambridge, MA, USA for generously providing AAV9-syn-Chrimson-TdTomato and AAV9-syn-Chronos-GFP. This work was supported by an intramural award to C.J.M. from the Eunice Kennedy–Shriver National Institute of Child Health and Human Development and a Competitive Fellowship Award to J.C.W. from the National Institute of Neurological Disorders and Strok

High Vibration Analysis of Eddy Current Drum Coupled Motor to a Vertical Centrifugal Pump : Solution Based on EMA, ODS and FEA

Case StudyThe 35-year old pump station moves up to 43 MGD of raw wastewater to the city’s treatment facility via two 1,500-hp high-capacity pumps for wet weather flows. After the motors were refurbished in 2011, excessive motor vibration occurred at certain pump speeds, thereby restricting the pumping system’s ability to handle various flow ranges. After multiple field balances to the motors and coupling drums, the City of Tampa set out to fix the vibration issue, instead of putting on a “Band-Aid” (field balancing) every time the vibration levels exceeded their limits. Prior to any finite element analysis (FEA), cladding and extra bracing were added to supporting I-beam structure to reduce vibration. This only made matters worse. The goal became to use FEA to identify and implement a practical fix that worked over the pump operating speed range

Pentraxins coordinate excitatory synapse maturation and circuit integration of parvalbumin interneurons

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Circuit computation requires precision in the timing, extent, and synchrony of principal cell (PC) firing that is largely enforced by parvalbumin-expressing, fast-spiking interneurons (PVFSIs). To reliably coordinate network activity, PVFSIs exhibit specialized synaptic and membrane properties that promote efficient afferent recruitment such as expression of high-conductance, rapidly gating, GluA4-containing AMPA receptors (AMPARs). We found that PVFSIs upregulate GluA4 during the second postnatal week coincident with increases in the AMPAR clustering proteins NPTX2 and NPTXR. Moreover, GluA4 is dramatically reduced in NPTX2(-/-)/NPTXR(-/-) mice with consequent reductions in PVFSI AMPAR function. Early postnatal NPTX2(-/-)/NPTXR(-/-) mice exhibit delayed circuit maturation with a prolonged critical period permissive for giant depolarizing potentials. Juvenile NPTX2(-/-)/NPTXR(-/-) mice display reduced feedforward inhibition yielding a circuit deficient in rhythmogenesis and prone to epileptiform discharges. Our findings demonstrate an essential role for NPTXs in controlling network dynamics highlighting potential therapeutic targets for disorders with inhibition/excitation imbalances such as schizophrenia.Work supported by a PRAT fellowship to M.S.W., an NICHD intramural award to C.J.M., NIDCD intramural research program funding to R.S.P., an NIMH intramural award to H.A.C., NIH grants (PAR-02-059, NS 039156) to P.F.W., and an NIH grant (EY022730) to M.T.