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Sample records for active zone density

  1. Unc-51 controls active zone density and protein composition by downregulating ERK signaling.

    PubMed

    Wairkar, Yogesh P; Toda, Hirofumi; Mochizuki, Hiroaki; Furukubo-Tokunaga, Katsuo; Tomoda, Toshifumi; Diantonio, Aaron

    2009-01-14

    Efficient synaptic transmission requires the apposition of neurotransmitter release sites opposite clusters of postsynaptic neurotransmitter receptors. Transmitter is released at active zones, which are composed of a large complex of proteins necessary for synaptic development and function. Many active zone proteins have been identified, but little is known of the mechanisms that ensure that each active zone receives the proper complement of proteins. Here we use a genetic analysis in Drosophila to demonstrate that the serine threonine kinase Unc-51 acts in the presynaptic motoneuron to regulate the localization of the active zone protein Bruchpilot opposite to glutamate receptors at each synapse. In the absence of Unc-51, many glutamate receptor clusters are unapposed to Bruchpilot, and ultrastructural analysis demonstrates that fewer active zones contain dense body T-bars. In addition to the presence of these aberrant synapses, there is also a decrease in the density of all synapses. This decrease in synaptic density and abnormal active zone composition is associated with impaired evoked transmitter release. Mechanistically, Unc-51 inhibits the activity of the MAP kinase ERK to promote synaptic development. In the unc-51 mutant, increased ERK activity leads to the decrease in synaptic density and the absence of Bruchpilot from many synapses. Hence, activated ERK negatively regulates synapse formation, resulting in either the absence of active zones or the formation of active zones without their proper complement of proteins. The Unc-51-dependent inhibition of ERK activity provides a potential mechanism for synapse-specific control of active zone protein composition and release probability.

  2. RIM determines Ca2+ channel density and vesicle docking at the presynaptic active zone

    PubMed Central

    Han, Yunyun; Kaeser, Pascal S.; Südhof, Thomas C.; Schneggenburger, Ralf

    2012-01-01

    At presynaptic active zones, neurotransmitter release is initiated by the opening of voltage-gated Ca2+ channels close to docked vesicles. The mechanisms that enrich Ca2+ channels at active zones are, however, largely unknown, possibly because of the limited presynaptic accessibility of most synapses. Here, we have established a Cre-lox based conditional knock-out approach at a presynaptically accessible CNS synapse, the calyx of Held, to directly study the functions of RIM proteins. Removal of all RIM1/2 isoforms strongly reduced the presynaptic Ca2+ channel density, revealing a new role of RIM proteins in Ca2+ channel targeting. Removal of RIMs also reduced the readily-releasable pool, paralleled by a similar reduction of the number of docked vesicles, and the Ca2+ channel - vesicle coupling was decreased. Thus, RIM proteins co-ordinately regulate key functions for fast transmitter release: enabling a high presynaptic Ca2+ channel density, and vesicle docking at the active zone. PMID:21262468

  3. Density Effect on Detonation Reaction Zone Length in Solid Explosives

    NASA Astrophysics Data System (ADS)

    Lubyatinsky, S. N.; Loboiko, B. G.

    1997-07-01

    Density effect on detonation reaction zone length have been studied on RDX and PETN using a photoelectric technique to record the radiation intensity history of the shock front in chloroform placed on the charge face. Charge density was found to drastically affect the reaction zone length as well as the charge appearance. The charges pressed to 0.92 of crystal density were completely opaque and exhibited the von Neumann spike of 0.3 mm in length, typical for high explosives. The charges solvent-pressed to 0.99 of crystal density were agated (semi-transparent, resembling agates) and did not exhibited the von Neumann spike, which implies that its length did not exceed 0.03 mm. The following explanation was offered. In agated, practically non-porous, charges the detonation front is a strong plane shock inducing almost instant reaction. In charges consisting of separate crystals the detonation front becomes three-dimensional. As a result some fraction of explosive is compressed by a sequence of shocks almost isentropically and reacts relatively slowly, so that it can be measured.

  4. 47 CFR 69.123 - Density pricing zones for special access and switched transport.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Density pricing zones for special access and...) COMMON CARRIER SERVICES (CONTINUED) ACCESS CHARGES Computation of Charges § 69.123 Density pricing zones... price cap regulation may establish any number of density zones within a study area that is used...

  5. 47 CFR 69.123 - Density pricing zones for special access and switched transport.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 3 2013-10-01 2013-10-01 false Density pricing zones for special access and...) COMMON CARRIER SERVICES (CONTINUED) ACCESS CHARGES Computation of Charges § 69.123 Density pricing zones... price cap regulation may establish any number of density zones within a study area that is used...

  6. 47 CFR 69.123 - Density pricing zones for special access and switched transport.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 3 2012-10-01 2012-10-01 false Density pricing zones for special access and...) COMMON CARRIER SERVICES (CONTINUED) ACCESS CHARGES Computation of Charges § 69.123 Density pricing zones... price cap regulation may establish any number of density zones within a study area that is used...

  7. 47 CFR 69.123 - Density pricing zones for special access and switched transport.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 3 2011-10-01 2011-10-01 false Density pricing zones for special access and...) COMMON CARRIER SERVICES (CONTINUED) ACCESS CHARGES Computation of Charges § 69.123 Density pricing zones... price cap regulation may establish any number of density zones within a study area that is used...

  8. 47 CFR 69.123 - Density pricing zones for special access and switched transport.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 3 2014-10-01 2014-10-01 false Density pricing zones for special access and...) COMMON CARRIER SERVICES (CONTINUED) ACCESS CHARGES Computation of Charges § 69.123 Density pricing zones... price cap regulation may establish any number of density zones within a study area that is used...

  9. Active Free Surface Density Maps

    NASA Astrophysics Data System (ADS)

    Çelen, S.

    2016-10-01

    Percolation problems were occupied to many physical problems after their establishment in 1957 by Broadbent and Hammersley. They can be used to solve complex systems such as bone remodeling. Volume fraction method was adopted to set some algorithms in the literature. However, different rate of osteoporosis could be observed for different microstructures which have the same mass density, mechanical stimuli, hormonal stimuli and nutrition. Thus it was emphasized that the bone might have identical porosity with different specific surfaces. Active free surface density of bone refers the used total area for its effective free surface. The purpose of this manuscript is to consolidate a mathematical approach which can be called as “active free surface density maps” for different surface patterns and derive their formulations. Active free surface density ratios were calculated for different Archimedean lattice models according to Helmholtz free energy and they were compared with their site and bond percolation thresholds from the background studies to derive their potential probability for bone remodeling.

  10. Presynaptic active zones in invertebrates and vertebrates

    PubMed Central

    Ackermann, Frauke; Waites, Clarissa L; Garner, Craig C

    2015-01-01

    The regulated release of neurotransmitter occurs via the fusion of synaptic vesicles (SVs) at specialized regions of the presynaptic membrane called active zones (AZs). These regions are defined by a cytoskeletal matrix assembled at AZs (CAZ), which functions to direct SVs toward docking and fusion sites and supports their maturation into the readily releasable pool. In addition, CAZ proteins localize voltage-gated Ca2+ channels at SV release sites, bringing the fusion machinery in close proximity to the calcium source. Proteins of the CAZ therefore ensure that vesicle fusion is temporally and spatially organized, allowing for the precise and reliable release of neurotransmitter. Importantly, AZs are highly dynamic structures, supporting presynaptic remodeling, changes in neurotransmitter release efficacy, and thus presynaptic forms of plasticity. In this review, we discuss recent advances in the study of active zones, highlighting how the CAZ molecularly defines sites of neurotransmitter release, endocytic zones, and the integrity of synapses. PMID:26160654

  11. Nicotinamide mononucleotide adenylyltransferase maintains active zone structure by stabilizing Bruchpilot

    PubMed Central

    Zang, Shaoyun; Ali, Yousuf O; Ruan, Kai; Zhai, R Grace

    2013-01-01

    Active zones are specialized presynaptic structures critical for neurotransmission. We show that a neuronal maintenance factor, nicotinamide mononucleotide adenylyltransferase (NMNAT), is required for maintaining active zone structural integrity in Drosophila by interacting with the active zone protein, Bruchpilot (BRP), and shielding it from activity-induced ubiquitin–proteasome-mediated degradation. NMNAT localizes to the peri-active zone and interacts biochemically with BRP in an activity-dependent manner. Loss of NMNAT results in ubiquitination, mislocalization and aggregation of BRP, and subsequent active zone degeneration. We propose that, as a neuronal maintenance factor, NMNAT specifically maintains active zone structure by direct protein–protein interaction. PMID:23154466

  12. THE EFFECT OF DENSITY ZONING ON RACIAL SEGREGATION IN U.S. URBAN AREAS.

    PubMed

    Rothwell, Jonathan; Massey, Douglas S

    2009-07-01

    We argue that anti-density zoning increases black residential segregation in U.S. metropolitan areas by reducing the quantity of affordable housing in white jurisdictions. Drawing on census data and local regulation indicators compiled by Pendall, we estimate a series of regression models to measure the effect of maximum density zoning on black segregation. Results estimated using ordinary least squares indicate a strong and significant cross-sectional relationship between low-density zoning and racial segregation, even after controlling for other zoning policies and a variety of metropolitan characteristics, a relationship that persists under two-stage least squares estimation. Both estimation strategies also suggest that anti-density zoning inhibits desegregation over time.

  13. Synaptic Vesicle Proteins and Active Zone Plasticity

    PubMed Central

    Kittel, Robert J.; Heckmann, Manfred

    2016-01-01

    Neurotransmitter is released from synaptic vesicles at the highly specialized presynaptic active zone (AZ). The complex molecular architecture of AZs mediates the speed, precision and plasticity of synaptic transmission. Importantly, structural and functional properties of AZs vary significantly, even for a given connection. Thus, there appear to be distinct AZ states, which fundamentally influence neuronal communication by controlling the positioning and release of synaptic vesicles. Vice versa, recent evidence has revealed that synaptic vesicle components also modulate organizational states of the AZ. The protein-rich cytomatrix at the active zone (CAZ) provides a structural platform for molecular interactions guiding vesicle exocytosis. Studies in Drosophila have now demonstrated that the vesicle proteins Synaptotagmin-1 (Syt1) and Rab3 also regulate glutamate release by shaping differentiation of the CAZ ultrastructure. We review these unexpected findings and discuss mechanistic interpretations of the reciprocal relationship between synaptic vesicles and AZ states, which has heretofore received little attention. PMID:27148040

  14. The Interfacial Transition Zone in Alkali-Activated Slag Mortars

    NASA Astrophysics Data System (ADS)

    San Nicolas, Rackel; Provis, John

    2015-12-01

    The interfacial transition zone (ITZ) is known to strongly influence the mechanical and transport properties of mortars and concretes. This paper studies the ITZ between siliceous (quartz) aggregates and alkali activated slag binders in the context of mortar specimens. Backscattered electron images (BSE) generated in an environmental scanning electron microscope (ESEM) are used to identify unreacted binder components, reaction products and porosity in the zone surrounding aggregate particles, by composition and density contrast. X-ray mapping is used to exclude the regions corresponding to the aggregates from the BSE image of the ITZ, thus enabling analysis of only the binder phases, which are segmented into binary images by grey level discrimination. A distinct yet dense ITZ region is present in the alkali-activated slag mortars, containing a reduced content of unreacted slag particles compared to the bulk binder. The elemental analysis of this region shows that it contains a (C,N)-A-S-H gel which seems to have a higher content of Na (potentially deposited through desiccation of the pore solution) and a lower content of Ca than the bulk inner and outer products forming in the main binding region. These differences are potentially important in terms of long-term concrete performance, as the absence of a highly porous interfacial transition zone region is expected to provide a positive influence on the mechanical and transport properties of alkali-activated slag concretes.

  15. Physical Activity and Bone Density in Women

    NASA Technical Reports Server (NTRS)

    Bowley, Susan M.; Whalen, R. T.

    2000-01-01

    A mathematical model of bone density regulation as a function of the daily tissue "effective" stress has been derived. Using the model, the influence of daily activity in the form of a daily loading history has been related to bone density of the calcaneus. The theory incorporates a stress exponent m to account for differences in the importance of magnitude and number of load cycles experienced during daily activity. We have derived a parameter from the model, the "Bone Density Index" (BDI). We have developed a method of collecting daily habitual loading histories using an insole force sensor interfaced to a portable digital data logger carried in a fanny pack. Our goal for this study was to determine a stress exponent, m, relating GRFz history to Calcaneal Bone Mineral Density (CBMD).

  16. Densities and mass motions in transition-zone plasmas in solar flares observed from Skylab

    NASA Technical Reports Server (NTRS)

    Cheng, C.-C.

    1980-01-01

    The electron densities and bulk motions in the transition-zone plasma of a solar flare are investigated by an analysis of EUV emission line spectra taken on Skylab. Spectra of three flares were obtained with the NRL normal incidence grating slit spectrograph in the ranges 1100-1940 and 1940-3940 A. The line ratios of transition-zone Si III lines and the intensity of the forbidden O IV 1401-A lines during flare maximum indicate electron densities on the order of 10 to the 12th/cu cm, decreasing by a factor of 2 to 3 in the flare decay phase. Line broadening of the transition-zone ions such as Si III, O IV, C IV and N V is noted, and the observed asymmetrical N V line profiles are approximated by a bi-Gaussian model of a stationary and a moving plasma component with a bulk velocity of 12 to 70 km/sec. Turbulent velocities of from 45 to 85 km/sec and from 20 to 40 km/sec are also indicated for the moving and stationary components of the transition-zone plasma, respectively.

  17. Residual stress and dislocations density in silicon ribbons grown via optical zone melting

    NASA Astrophysics Data System (ADS)

    Augusto, A.; Pera, D.; Choi, H. J.; Bellanger, P.; Brito, M. C.; Maia Alves, J.; Vallêra, A. M.; Buonassisi, T.; Serra, J. M.

    2013-02-01

    We investigate the relationships between growth rate, time-temperature profile, residual stress, dislocation density, and electrical performance of silicon ribbons grown via optical zone melting. The time-temperature profiles of ribbons grown at different velocities were investigated using direct measurements and computational fluid dynamics (CFD) modeling. Residual stresses up to 20 MPa were measured using infrared birefringence imaging. The effect of crystallization speed on dislocation density and residual stress is discussed from the context of thermal stresses during growth. More broadly, we demonstrate the usefulness of combining spatially resolved stress and microstructure measurements with CFD simulations toward optimizing kerfless silicon wafer quality.

  18. Insect pest densities across site-specific management zones of irrigated corn in northeastern Colorado.

    PubMed

    Davidson, Silas A; Peairs, Frank B; Khosla, Rajiv

    2007-06-01

    The ability to manage insect pests in a site-specific manner is hindered by the costs and time required to describe pest densities and distributions. The purpose of this study was to determine whether insect pest distributions are related to site-specific management zones (SSMZs). Site-specific management zones, as described in this study, delineate fields into three zones of similar yield potential: high, medium, and low productivity. If insect densities vary across SSMZs, it is possible that management decisions could be made at the SSMZ level instead of treating the whole field. This research was conducted during summers 2001 and 2002 on cooperators' farms in northeastern Colorado. Surveys were conducted within corn, Zea mays L., fields, so that densities of three common insect pests of Colorado corn could be compared across SSMZ. The three insect pests were western corn rootworm, Diabrotica virgifera virgifera LeConte; European corn borer, Ostrinia nubilalis (HiAbner); and western bean cutworm, Richia albicosta (Smith). D. v. virgifera larvae and adults were most common in the high-productivity SSMZ. O. nubilalis larval abundance was similar at three fields, whereas in a fourth field the larvae were most common in the high-productivity SSMZ. In one field that contained substantial numbers of R. albicosta, egg abundance was similar across SSMZs, whereas larvae were most common in the high-productivity SSMZ. Site-specific management zones seemed to correlate well with the abundance of some insect pests and might prove useful for managing insects in a site-specific manner.

  19. Seizure Onset Zone Localization from Ictal High-Density EEG in Refractory Focal Epilepsy.

    PubMed

    Staljanssens, Willeke; Strobbe, Gregor; Holen, Roel Van; Birot, Gwénaël; Gschwind, Markus; Seeck, Margitta; Vandenberghe, Stefaan; Vulliémoz, Serge; van Mierlo, Pieter

    2017-03-01

    Epilepsy surgery is the most efficient treatment option for patients with refractory epilepsy. Before surgery, it is of utmost importance to accurately delineate the seizure onset zone (SOZ). Non-invasive EEG is the most used neuroimaging technique to diagnose epilepsy, but it is hard to localize the SOZ from EEG due to its low spatial resolution and because epilepsy is a network disease, with several brain regions becoming active during a seizure. In this work, we propose and validate an approach based on EEG source imaging (ESI) combined with functional connectivity analysis to overcome these problems. We considered both simulations and real data of patients. Ictal epochs of 204-channel EEG and subsets down to 32 channels were analyzed. ESI was done using realistic head models and LORETA was used as inverse technique. The connectivity pattern between the reconstructed sources was calculated, and the source with the highest number of outgoing connections was selected as SOZ. We compared this algorithm with a more straightforward approach, i.e. selecting the source with the highest power after ESI as the SOZ. We found that functional connectivity analysis estimated the SOZ consistently closer to the simulated EZ/RZ than localization based on maximal power. Performance, however, decreased when 128 electrodes or less were used, especially in the realistic data. The results show the added value of functional connectivity analysis for SOZ localization, when the EEG is obtained with a high-density setup. Next to this, the method can potentially be used as objective tool in clinical settings.

  20. Prediction of fault-related damage zones in porous granular rock using strain energy density criteria

    NASA Astrophysics Data System (ADS)

    Okubo, C. H.; Schultz, R. A.

    2004-12-01

    In granular geologic materials such as porous sandstone, fault-related damage zones are formed by deformation bands, which are tabular discontinuities characterized by pore space collapse and shear. We present results of a study in which separate strain energy density-based criteria are used to successfully predict the tendencies for the nucleation and for the propagation of deformation bands in a classic outcrop of fault-related damage zones within the brittlely-deformed Jurassic Wingate sandstone exposed in the Laramide-aged Uncompahgre Uplift, in western Colorado. The separate distributions of volumetric and distortional strain energy density are calculated for the geometry and stress state of the causative Laramide-aged thrust fault displacements from boundary element calculations of the attendant slip-induced local stresses. Volumetric strain energy density predicts the tendency for deformation band nucleation, the growth stage at which the deformation bands are defined by pore space collapse. Deformation band propagation, where shear occurs along the band, is predicted by distortional strain energy density. The relative magnitudes of elevated volumetric and distortional strain energy density are correlated with deformation band intensity (i.e. the mapped fracture intensity). Within a damage zone, enhanced deformation band nucleation tendencies are predicted and observed to occur within the upper hanging wall and ahead of the causative thrust fault, as well as along the frictionally-slipping base of the Wingate. Additionally, enhanced deformation band propagation tendencies are predicted ahead of and slightly within the footwall of the thrust. Here, propagation would occur along deformation bands that nucleated at an earlier stage of fault growth. The predicted tendencies for deformation band propagation are consistent with the observed distributions of compressive mode II deformation band stepover structures, which occur solely between propagating deformation

  1. Dynamics of nascent and active zone ultrastructure as synapses enlarge during long-term potentiation in mature hippocampus.

    PubMed

    Bell, Maria Elizabeth; Bourne, Jennifer N; Chirillo, Michael A; Mendenhall, John M; Kuwajima, Masaaki; Harris, Kristen M

    2014-12-01

    Nascent zones and active zones are adjacent synaptic regions that share a postsynaptic density, but nascent zones lack the presynaptic vesicles found at active zones. Here dendritic spine synapses were reconstructed through serial section electron microscopy (3DEM) and EM tomography to investigate nascent zone dynamics during long-term potentiation (LTP) in mature rat hippocampus. LTP was induced with theta-burst stimulation, and comparisons were made with control stimulation in the same hippocampal slices at 5 minutes, 30 minutes, and 2 hours post-induction and to perfusion-fixed hippocampus in vivo. Nascent zones were present at the edges of ∼35% of synapses in perfusion-fixed hippocampus and as many as ∼50% of synapses in some hippocampal slice conditions. By 5 minutes, small dense-core vesicles known to transport active zone proteins moved into more presynaptic boutons. By 30 minutes, nascent zone area decreased, without significant change in synapse area, suggesting that presynaptic vesicles were recruited to preexisting nascent zones. By 2 hours, both nascent and active zones were enlarged. Immunogold labeling revealed glutamate receptors in nascent zones; however, average distances from nascent zones to docked presynaptic vesicles ranged from 170 ± 5 nm in perfusion-fixed hippocampus to 251 ± 4 nm at enlarged synapses by 2 hours during LTP. Prior stochastic modeling suggests that decrease in glutamate concentration reduces the probability of glutamate receptor activation from 0.4 at the center of release to 0.1 just 200 nm away. Thus, conversion of nascent zones to functional active zones likely requires the recruitment of presynaptic vesicles during LTP.

  2. Deer-vehicle collisions, deer density, and land use in Iowa's urban deer herd management zones.

    PubMed

    Gkritza, Konstantina; Baird, Michael; Hans, Zachary N

    2010-11-01

    Many states are striving to keep their deer population to a sustainable and controllable level, while maximizing public safety. In Iowa, measures to control the deer population include annual deer hunts and special deer herd management plans in urban areas. While these plans may in effect reduce the deer population, traffic safety in these areas has not been fully assessed. Using deer population data from the Iowa Department of Natural Resources and data on deer-vehicle crashes and deer carcass removals from the Iowa Department of Transportation, we examine the relationship between deer-vehicle collisions, deer density, and land use in select urban deer management zones in Iowa. Further, we estimate models to investigate the factors that influence the frequency and severity of deer-vehicle crashes in these zones. The estimation results showed that multiple factors affect deer-vehicle crashes and corresponding injury outcomes in urban management zones. The identified roadway and non-roadway factors could be useful for identifying locations on the transportation system that significantly impact deer species and safety, and determining appropriate countermeasures for mitigation.

  3. [Validity of PSA density of the transition zone in the diagnosis of prostate cancer].

    PubMed

    Anastasi, G; Magno, C; Carmignani, A; Inferrera, A; Petrelli, A; Broccio, G

    2000-12-01

    One hundred four patients (mean age 70.6 years) with prostatic specific antigen (PSA) values between 4 and 10 ng/ml (average 7.9 ng/ml), and with no suspects for neoplasia by digital rectal examination (DRE) and transrectal ultrasound (TRUS) were studied. In all patients PSA density for the entire prostate (PSAD) and PSA density for the transition zone (PSAT) were calculated. TRUS was performed using a 5 MHz probe. Prostate and transition zone volumes were obtained by ellipsoid formula. Aim of the study was to evaluate the PSAT predictivity for prostate cancer compared to the PSAD. Sixteen out of 104 patients (15.4%) had histologically confirmed prostate cancer, and 88 (84.6%) had benign prostatic hyperplasia. When cut-off for PSAD was 0.15 ng/ml/cc, specificity and sensitivity were respectively 75% and 68% with positive and negative predictive values of 54% and 17%; when cut-off for PSAT was 0.34% ng/ml/cc, sensitivity and specificity were respectively 100% and 68% with positive and negative predictive values of 60% and 18%. Our results, according to the literature data, suggest that PSAT seems to have a higher predictivity for prostate cancer than PSAD, providing an optimization for the employ of prostatic biopsy, especially for those patients with PSA values between 4 and 10 ng/ml.

  4. Effects of work zone configurations and traffic density on performance variables and subjective workload.

    PubMed

    Shakouri, Mahmoud; Ikuma, Laura H; Aghazadeh, Fereydoun; Punniaraj, Karthy; Ishak, Sherif

    2014-10-01

    This paper investigates the effect of changing work zone configurations and traffic density on performance variables and subjective workload. Data regarding travel time, average speed, maximum percent braking force and location of lane changes were collected by using a full size driving simulator. The NASA-TLX was used to measure self-reported workload ratings during the driving task. Conventional lane merge (CLM) and joint lane merge (JLM) were modeled in a driving simulator, and thirty participants (seven female and 23 male), navigated through the two configurations with two levels of traffic density. The mean maximum braking forces was 34% lower in the JLM configuration, and drivers going through the JLM configuration remained in the closed lane longer. However, no significant differences in speed were found between the two merge configurations. The analysis of self-reported workload ratings show that participants reported 15.3% lower total workload when driving through the JLM. In conclusion, the implemented changes in the JLM make it a more favorable merge configuration in both high and low traffic densities in terms of optimizing traffic flow by increasing the time and distance cars use both lanes, and in terms of improving safety due to lower braking forces and lower reported workload.

  5. LAR, liprin alpha and the regulation of active zone morphogenesis.

    PubMed

    Stryker, Emily; Johnson, Karl G

    2007-11-01

    Active zones are protein-rich regions of neurons that act as sites of synaptic vesicle fusion and neurotransmitter release at the pre-synaptic terminus. Although the discovery that the receptor protein tyrosine phosphatase LAR and its cytoplasmic binding partner liprin alpha are essential for proper active zone formation is nearly a decade old, the underlying mechanisms are still poorly understood. Recent studies have identified a number of binding partners for both LAR and liprin alpha, several of which play key roles in active zone assembly. These include nidogen, dallylike and syndecan--extracellular ligands for LAR that regulate synapse morphogenesis. In addition, liprin-alpha-interacting proteins such as ERC2, RIM and the MALS/Veli-Cask-Mint1 complex cooperate to form a dense molecular scaffold at the active zone that is crucial for proper synaptic function. These studies allow us to propose testable models of LAR and liprin alpha function, and provide insights into the fundamental molecular mechanisms of synapse formation and stabilization.

  6. The Proteome of the Murine Presynaptic Active Zone

    PubMed Central

    Laßek, Melanie; Weingarten, Jens; Volknandt, Walter

    2014-01-01

    The proteome of the presynaptic active zone controls neurotransmitter release and the short- and long-term structural and functional dynamics of the nerve terminal. The proteinaceous inventory of the presynaptic active zone has recently been reported. This review will evaluate the subcellular fractionation protocols and the proteomic approaches employed. A breakthrough for the identification of the proteome of the presynaptic active zone was the successful employment of antibodies directed against a cytosolic epitope of membrane integral synaptic vesicle proteins for the immunopurification of synaptic vesicles docked to the presynaptic plasma membrane. Combining immunopurification and subsequent analytical mass spectrometry, hundreds of proteins, including synaptic vesicle proteins, components of the presynaptic fusion and retrieval machinery, proteins involved in intracellular and extracellular signaling and a large variety of adhesion molecules, were identified. Numerous proteins regulating the rearrangement of the cytoskeleton are indicative of the functional and structural dynamics of the presynapse. This review will critically discuss both the experimental approaches and prominent protein candidates identified. Many proteins have not previously been assigned to the presynaptic release sites and may be directly involved in the short- and long-term structural modulation of the presynaptic compartment. The identification of proteinaceous constituents of the presynaptic active zone provides the basis for further analyzing the interaction of presynaptic proteins with their targets and opens novel insights into the functional role of these proteins in neuronal communication. PMID:28250380

  7. On the problem of density diagnostics for the EUV spectrum of the solar transition zone

    NASA Technical Reports Server (NTRS)

    Doschek, G. A.; Feldman, U.

    1977-01-01

    Spectral-line ratios that may be used to determine the electron temperature and density in the solar transition zone and corona are identified. The problem of interpreting the intensity ratios of C III lines observed in Skylab EUV limb spectra is considered. It is shown that the intensity distribution with height above the solar limb of the 1176-A C III lines is different from that of the 1909-A C III lines in the Skylab spectra, suggesting that model atmospheres must be folded into the C III calculations for proper interpretation of the data. Possible reasons for the differences in the intensity distributions and widths of the 1176-A and 1909-A lines are discussed along with an application to the analogous lines of Si III.

  8. Structural Analysis of Active North Bozgush Fault Zone (NW Iran)

    NASA Astrophysics Data System (ADS)

    Saber, R.; Isik, V.; Caglayan, A.

    2013-12-01

    NW Iran is one of the seismically active regions between Zagros Thrust Belt at the south and Caucasus at the north. Not only large magnitude historical earthquakes (Ms>7), but also 1987 Bozgush, 1997 Ardebil (Mw 6.1) and 2012 Ahar-Varzagan (Mw 6.4) earthquakes reveal that the region is seismically active. The North Bozgush Fault Zone (NBFZ) in this region has tens of kilometers in length and hundreds of meters in width. The zone has produced some large and destructive earthquakes (1593 M:6.1 and 1883 M:6.2). The NBFZ affects the Cenozoic units and along this zone Eocene units thrusted over Miocene and/or Plio-Quaternary sedimentary units. Together with morphologic features (stream offsets and alluvial fan movements) affecting the young unites reveal that the zone is active. The zone is mainly characterized by strike-slip faults with reverse component and reverse faults. Reverse faults striking N55°-85°E and dip of 40°-50° to the SW while strike-slip faults show right lateral slip with N60°-85°W and N60°-80°E directions. Our structural data analysis in NBFZ indicates that the axis direction of σ2 principal stress is vertical and the stress ratio (R) is 0.12. These results suggest that the tectonic regime along the North Bozgush Fault Zone is transpressive. Obtained other principal stresses (σ1, σ3) results are compatible with stress directions and GPS velocity suggested for NW Iran.

  9. Declining densities and reproductive activities of the queen conch Strombus gigas (Mesogastropoda: Strombidae) in Banco Chinchorro, eastern Caribbean, Mexico.

    PubMed

    De Jesús-Navarrete, Alberto; Valencia-Hernández, Adriana

    2013-12-01

    Queen conch is a gastropod inhabiting the Caribbean Sea, it represents the second largest fishery after the spiny lobster, but it has been extensively captured in the area. In order to know its population status in Chinchorro Bank, we determined conch density changes and its effects on reproductive activities, between July and November 2009. For this, data on conch density, morphology and reproductive activities were obtained from 15 sites within three fishing zones, and compared with previously collected data (1990, 1992, 1994, and 1997). Data showed that adult density decreased with time, from 10,700 ind./ha in 1990, to 198 ind./h in 2009. Neither egg masses nor spawns were found and mating was only observed once in July 2009. In July, adult (lip>4 mm) density in the Southern zone was 23 ind./ha whereas in the Northern zone and Central zone densities were 15 and 9ind./ha respectively. In November, density was somewhat higher: Southern zone 96 ind./ha; Central zone 39 ind./ha and Northern zone had 38ind./ha. In July, mean shell length was 170.80 +/- 46.28 mm, with a higher median abundance at 180-189 mm. In November, higher frequency was 187.63 +/- 45.14 mm, maximumat 210-219 mm interval. For the last 10 years period, mean adult conch densities have diminished in each zone, which might be the main cause of decreased reproductive activities of the conch at Banco Chinchorro. It is therefore an immediate need to analyse the management plan for this species in this Reserve and perhaps to promote a re-population of queen conch and culture activities.

  10. The energy balance and pressure in the solar transition zone for network and active region features

    NASA Technical Reports Server (NTRS)

    Nicolas, K. R.; Bartoe, J.-D. F.; Brueckner, G. E.; Vanhoosier, M. E.

    1979-01-01

    The electron pressure and energy balance in the solar transition zone are determined for about 125 network and active region features on the basis of high spectral and spatial resolution extreme ultraviolet spectra. Si III line intensity ratios obtained from the Naval Research Laboratory high-resolution telescope and spectrograph during a rocket flight are used as diagnostics of electron density and pressure for solar features near 3.5 x 10 to the 4th K. Observed ratios are compared with the calculated dependence of the 1301 A/1312 A and 1301 A/1296 A line intensity ratios on electron density, temperature and pressure. Electron densities ranging from 2 x 10 to the 10th/cu cm to 10 to the 12th/cu cm and active region pressures from 3 x 10 to the 15th to 10 to the 16th/cu cm K are obtained. Energy balance calculations reveal the balance of the divergence of the conductive flux and turbulent energy dissipation by radiative energy losses in a plane-parallel homogeneous transition zone (fill factor of 1), and an energy source requirement for a cylindrical zone geometry (fill factor less than 0.04).

  11. Linking Plagioclase Zoning Patterns to Active Magma Processes

    NASA Astrophysics Data System (ADS)

    Izbekov, P. E.; Nicolaysen, K. P.; Neill, O. K.; Shcherbakov, V.; Plechov, P.; Eichelberger, J. C.

    2015-12-01

    Plagioclase, one of the most common and abundant mineral phases in volcanic products, will vary in composition in response to changes in temperature, pressure, composition of the ambient silicate melt, and melt H2O concentration. Changes in these parameters may cause dissolution or growth of plagioclase crystals, forming characteristic textural and compositional variations (zoning patterns), the complete core-to-rim sequence of which describes events experienced by an individual crystal from its nucleation to the last moments of its growth. Plagioclase crystals in a typical volcanic rock may look drastically dissimilar despite their spatial proximity and the fact that they have erupted together. Although they shared last moments of their growth during magma ascent and eruption, their prior experiences could be very different, as plagioclase crystals often come from different domains of the same magma system. Distinguishing similar zoning patterns, correlating them across the entire population of plagioclase crystals, and linking these patterns to specific perturbations in the magmatic system may provide additional perspective on the variety, extent, and timing of magma processes at active volcanic systems. Examples of magma processes, which may be distinguished based on plagioclase zoning patterns, include (1) cooling due to heat loss, (2) heating and/or pressure build up due to an input of new magmatic material, (3) pressure drop in response to magma system depressurization, and (4) crystal transfer between different magma domains/bodies. This review will include contrasting examples of zoning patters from recent eruptions of Karymsky, Bezymianny, and Tolbachik Volcanoes in Kamchatka, Augustine and Cleveland Volcanoes in Alaska, as well as from the drilling into an active magma body at Krafla, Iceland.

  12. 77 FR 71167 - Foreign-Trade Zone 59-Lincoln, Nebraska, Authorization of Production Activity, Novartis Consumer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-29

    ... Foreign-Trade Zones Board Foreign-Trade Zone 59--Lincoln, Nebraska, Authorization of Production Activity, Novartis Consumer Health, Inc. (Pharmaceutical and Related Preparations Production), Lincoln, Nebraska Novartis Consumer Health, Inc. submitted a notification of proposed production activity for the...

  13. 78 FR 28801 - Foreign-Trade Zone 117-Orange, TX, Authorization of Production Activity, Signal International...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-16

    ... Foreign-Trade Zones Board Foreign-Trade Zone 117--Orange, TX, Authorization of Production Activity, Signal International Texas GP, LLC (Shipbuilding), Orange, TX On January 10, 2013, the Foreign Trade Zone of Southeast...-Trade Zones (FTZ) Board on behalf of Signal International Texas GP, LLC, in Orange, Texas....

  14. Velocity and Density Models Incorporating the Cascadia Subduction Zone for 3D Earthquake Ground Motion Simulations

    USGS Publications Warehouse

    Stephenson, William J.

    2007-01-01

    INTRODUCTION In support of earthquake hazards and ground motion studies in the Pacific Northwest, three-dimensional P- and S-wave velocity (3D Vp and Vs) and density (3D rho) models incorporating the Cascadia subduction zone have been developed for the region encompassed from about 40.2?N to 50?N latitude, and from about -122?W to -129?W longitude. The model volume includes elevations from 0 km to 60 km (elevation is opposite of depth in model coordinates). Stephenson and Frankel (2003) presented preliminary ground motion simulations valid up to 0.1 Hz using an earlier version of these models. The version of the model volume described here includes more structural and geophysical detail, particularly in the Puget Lowland as required for scenario earthquake simulations in the development of the Seattle Urban Hazards Maps (Frankel and others, 2007). Olsen and others (in press) used the model volume discussed here to perform a Cascadia simulation up to 0.5 Hz using a Sumatra-Andaman Islands rupture history. As research from the EarthScope Program (http://www.earthscope.org) is published, a wealth of important detail can be added to these model volumes, particularly to depths of the upper-mantle. However, at the time of development for this model version, no EarthScope-specific results were incorporated. This report is intended to be a reference for colleagues and associates who have used or are planning to use this preliminary model in their research. To this end, it is intended that these models will be considered a beginning template for a community velocity model of the Cascadia region as more data and results become available.

  15. The active zone T-bar--a plasticity module?

    PubMed

    Wichmann, Carolin; Sigrist, Stephan J

    2010-09-01

    The synaptic active zone, the site where Ca(2+)-triggered fusion of synaptic vesicles takes place, is commonly associated with protein-rich, electron-dense cytomatrices. The molecular composition and functional role of active zones, especially in the context of vesicular exo- and endocytosis, are under intense investigation. Per se, Drosophila synapses, which display so-called T-bars as electron-dense specializations, should be a highly suitable model system, as they allow for a combination of efficient genetics with ultrastructural and electrophysiological analyses. However, it needed a biochemical approach of the Buchner laboratory to "molecularly" access the T-bar by identification of the CAST/ERC-family member Bruchpilot as the first T-bar-residing protein. Genetic elimination of Bruchpilot revealed that the protein is essential for T-bar formation, calcium channel clustering, and hence proper vesicle fusion and patterned synaptic plasticity. Recently, Bruchpilot was shown to directly shape the T-bar, likely by adopting an elongated conformation. Moreover, first mechanisms that control the availability of Bruchpilot for T-bar assembly were described. This review seeks to summarize the information on T-bar structure, as well as on functional aspects, formulating the hypothesis that T-bars are genuine "plasticity modules."

  16. Solar wind control of auroral zone geomagnetic activity

    NASA Technical Reports Server (NTRS)

    Clauer, C. R.; Mcpherron, R. L.; Searls, C.; Kivelson, M. G.

    1981-01-01

    Solar wind magnetosphere energy coupling functions are analyzed using linear prediction filtering with 2.5 minute data. The relationship of auroral zone geomagnetic activity to solar wind power input functions are examined, and a least squares prediction filter, or impulse response function is designed from the data. Computed impulse response functions are observed to have characteristics of a low pass filter with time delay. The AL index is found well related to solar wind energy functions, although the AU index shows a poor relationship. High frequency variations of auroral indices and substorm expansions are not predictable with solar wind information alone, suggesting influence by internal magnetospheric processes. Finally, the epsilon parameter shows a poorer relationship with auroral geomagnetic activity than a power parameter, having a VBs solar wind dependency.

  17. 33 CFR 3.70-20 - Activities Far East Marine Inspection Zone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Activities Far East Marine... SECURITY GENERAL COAST GUARD AREAS, DISTRICTS, SECTORS, MARINE INSPECTION ZONES, AND CAPTAIN OF THE PORT ZONES Fourteenth Coast Guard District § 3.70-20 Activities Far East Marine Inspection Zone....

  18. 33 CFR 3.70-20 - Activities Far East Marine Inspection Zone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Activities Far East Marine... SECURITY GENERAL COAST GUARD AREAS, DISTRICTS, SECTORS, MARINE INSPECTION ZONES, AND CAPTAIN OF THE PORT ZONES Fourteenth Coast Guard District § 3.70-20 Activities Far East Marine Inspection Zone....

  19. 33 CFR 3.70-20 - Activities Far East Marine Inspection Zone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Activities Far East Marine... SECURITY GENERAL COAST GUARD AREAS, DISTRICTS, SECTORS, MARINE INSPECTION ZONES, AND CAPTAIN OF THE PORT ZONES Fourteenth Coast Guard District § 3.70-20 Activities Far East Marine Inspection Zone....

  20. 78 FR 55057 - Foreign-Trade Zone 134-Chattanooga, Tennessee; Authorization of Production Activity; Komatsu...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-09

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 134--Chattanooga, Tennessee; Authorization of Production Activity; Komatsu America Corporation, (Construction and Forestry Equipment), Chattanooga, Tennessee On...

  1. 77 FR 61381 - Foreign-Trade Zone 7-Mayaguez, Puerto Rico, Authorization of Production Activity, Baxter...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-09

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 7--Mayaguez, Puerto Rico, Authorization of Production Activity, Baxter Healthcare of Puerto Rico, (Pharmaceutical and Nutritional Intravenous Bags...

  2. 78 FR 36523 - Foreign-Trade Zone 84-Houston, Texas; Authorization of Production Activity; Toshiba International...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-18

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 84--Houston, Texas; Authorization of Production Activity; Toshiba International Corporation; (Hybrid Electric Vehicle Motors and Generators Production);...

  3. Super-resolution microscopy of the synaptic active zone

    PubMed Central

    Ehmann, Nadine; Sauer, Markus; Kittel, Robert J.

    2015-01-01

    Brain function relies on accurate information transfer at chemical synapses. At the presynaptic active zone (AZ) a variety of specialized proteins are assembled to complex architectures, which set the basis for speed, precision and plasticity of synaptic transmission. Calcium channels are pivotal for the initiation of excitation-secretion coupling and, correspondingly, capture a central position at the AZ. Combining quantitative functional studies with modeling approaches has provided predictions of channel properties, numbers and even positions on the nanometer scale. However, elucidating the nanoscopic organization of the surrounding protein network requires direct ultrastructural access. Without this information, knowledge of molecular synaptic structure-function relationships remains incomplete. Recently, super-resolution microscopy (SRM) techniques have begun to enter the neurosciences. These approaches combine high spatial resolution with the molecular specificity of fluorescence microscopy. Here, we discuss how SRM can be used to obtain information on the organization of AZ proteins. PMID:25688186

  4. Magnetic fields over active tectonic zones in ocean

    USGS Publications Warehouse

    Kopytenko, Yu. A.; Serebrianaya, P.M.; Nikitina, L.V.; Green, A.W.

    2002-01-01

    The aim of our work is to estimate the electromagnetic effects that can be detected in the submarine zones with hydrothermal activity. It is known that meso-scale flows appear in the regions over underwater volcanoes or hot rocks. Their origin is connected with heat flux and hot jets released from underwater volcanoes or faults in a sea bottom. Values of mean velocities and turbulent velocities in plumes were estimated. Quasiconstant magnetic fields induced by a hot jet and a vortex over a plume top are about 1-40 nT. Variable magnetic fields are about 0.1-1 nT. These magnetic disturbances in the sea medium create an additional natural electromagnetic background that must be considered when making detailed magnetic surveys. ?? 2002 Elsevier Science Ltd. All rights reserved.

  5. Criticality evaluation of control component credited mixed zone spent and fresh fuel storage in high density PWR racks

    SciTech Connect

    Bilovsky, V.; Redmond, E.; Walker, C.; Ivanov, K.

    2006-07-01

    To expand the set of assemblies that qualify for storage in high-density racks, a mixed zone analysis may be performed where repeating pattern configurations within the rack are prescribed. In a mixed zone analysis, assemblies that are more reactive (low burnup) are stored adjacent to less reactive (highly burned) assemblies, thereby meeting the same overall criticality requirements as with the uniform burnup/enrichment analysis. The Arkansas Nuclear One (ANO) Plant has faced several challenges with respect to their spent fuel storage that reach beyond simply the number of spent fuel assemblies and available storage cells. These issues have resulted in the need for ANO to use an advanced storage strategy. In addition to using the mixed zone burnup approach in the high-density racks, ANO also proposed a new solution involving credit for control components in the spent fuel pool. ANO submitted an amendment of their spent fuel pool technical specifications to the Nuclear Regulatory Commission (NRC) based on the evaluation performed by Holtec International that was subsequently approved. This paper presents a description of the overall methodology used for supporting the submittal, and provides further discussion regarding the reactivity effect of control rods in a PWR spent fuel pool. (authors)

  6. The Dynamic Density Bottle: A Make-and-Take, Guided Inquiry Activity on Density

    ERIC Educational Resources Information Center

    Kuntzleman, Thomas S.

    2015-01-01

    An activity is described wherein students observe dynamic floating and sinking behavior of plastic pieces in various liquids. The liquids and solids are all contained within a plastic bottle; the entire assembly is called a "density bottle". After completing a series of experiments that guides students to think about the relative…

  7. Evaluation of Seismicity Using Density Analysis of 2000-2015 Earthquakes in The West Coastal Zone of Anatolia (Turkey) And Its Correlation with Geothermal Areas

    NASA Astrophysics Data System (ADS)

    Bakak, Özde

    2016-10-01

    The purpose of the study is to evaluate the seismic activity using the density analysis methods (point density and Kernel density analysis) for 2000-2015 earthquake catalogue belonging to the study area surrounded by Qanakkale to the north, Fethiye to the south and Denizli (Buharkent) to the east, and also to apply its correlation with geothermal regions. The earthquake data, in total 6.675 earthquakes with M>3 magnitudes were obtained from DDA Catalogue of Prime Ministry Disaster & Emergency Management Authority (AFAD) official website. In this survey, data analysis and maps were prepared using ArcGIS (version_10.1) program. The analysis maps present (1) the intensity clustered earthquakes dominant in Sigacik and Gokova Gulfs, (2) regions which have high seismic risk were determined according to Buffer analysis for 2 km distance, (3) geothermal areas (21.4-153°C) in the west coastal zone of Anatolia were mapped, (4) regions the most affected by seismic activity for the last 15 years were detected from 2015 population data, and as latest (5) Seferihisar, Urla, Gulbahge, Demircili, Bodrum, and Datga provinces are identified as areas having high seismic activity for the last 15 years. Consequently, all analysis results were compared with the geothermal areas, and the review made that earthquake catalogue has not the relationship with hot regions and also these shocks triggered by active faults in this region using ArcGIS program. the author recommends that these regions should be investigated the earthquake sensitivity analysis in the near future.

  8. Structural and functional maturation of active zones in large synapses.

    PubMed

    Cano, Raquel; Torres-Benito, Laura; Tejero, Rocío; Biea, Anca I; Ruiz, Rocío; Betz, William J; Tabares, Lucía

    2013-02-01

    Virtually all functions of the nervous system rely upon synapses, the sites of communication between neurons and between neurons and other cells. Synapses are complex structures, each one comprising hundreds of different types of molecules working in concert. They are organized by adhesive and scaffolding molecules that align presynaptic vesicular release sites, namely, active zones, with postsynaptic neurotransmitter receptors, thereby allowing rapid and reliable intercellular communication. Most synapses are relatively small, and acting alone exerts little effect on their postsynaptic partners. Some, however, are much larger and stronger, reliably driving the postsynaptic cell to its action potential threshold, acting essentially as electrical relays of excitation. These large synapses are among the best understood, and two of these are the subject of this review, namely, the vertebrate neuromuscular junction and the calyx of Held synapse in the mammalian auditory pathway of the brain stem. Both synapses undergo through a complex and well-coordinated maturation process, during which time the molecular elements and the biophysical properties of the secretory machinery are continuously adjusted to the synapse size and to the functional requirements. We here review the morphological and functional changes occurring during postnatal maturation, noting particular similarities and differences between these two large synapses.

  9. Photospheric Magnetic Free Energy Density of Solar Active Regions

    NASA Astrophysics Data System (ADS)

    Zhang, Hongqi

    2016-12-01

    We present the photospheric energy density of magnetic fields in two solar active regions (one of them recurrent) inferred from observational vector magnetograms, and compare it with other available differently defined energy parameters of magnetic fields in the photosphere. We analyze the magnetic fields in Active Regions NOAA 6580-6619-6659 and 11158. The quantity 1/4π{B}n\\cdot{B}p is an important energy parameter that reflects the contribution of magnetic shear to the difference between the potential (Bp) and the non-potential magnetic field (Bn), and also the contribution to the free magnetic energy near the magnetic neutral lines in the active regions. It is found that the photospheric mean magnetic energy density shows clear changes before the powerful solar flares in Active Region NOAA 11158, which is consistent with the change in magnetic fields in the flaring lower atmosphere.

  10. Density of Plutonium Turnings Generated from Machining Activities

    SciTech Connect

    Gonzales, John Robert; Vigil, Duane M.; Jachimowski, Thomas A.; Archuleta, Alonso; Arellano, Gerald Joseph; Melton, Vince Lee

    2016-10-20

    The purpose of this project was to determine the density of plutonium (Pu) turnings generated from the range of machining activities, using both surrogate material and machined Pu turnings. Verify that 500 grams (g) of plutonium will fit in a one quart container using a surrogate equivalent volume and that 100 grams of Pu will fit in a one quart Savy container.

  11. Density and Temperature Measurements in a Solar Active Region

    NASA Astrophysics Data System (ADS)

    Warren, Harry P.; Winebarger, Amy R.

    2003-10-01

    We present electron density and temperature measurements from an active region observed above the limb with the Solar Ultraviolet Measurements of Emitted Radiation spectrometer on the Solar and Heliospheric Observatory. Density-sensitive line ratios from Si VIII and S X indicate densities greater than 108 cm-3 as high as 200" (or 145 Mm) above the limb. At these heights, static, uniformly heated loop models predict densities close to 107 cm-3. Differential emission measure analysis shows that the observed plasma is nearly isothermal with a mean temperature of about 1.5 MK and a dispersion of about 0.2 MK. Both the differential emission measure and the Si XI/Si VIII line ratios indicate only small variations in the temperature at the heights observed. These measurements confirm recent observations from the Transition Region and Coronal Explorer of ``overdense'' plasma at temperatures near 1 MK in solar active regions. Time-dependent hydrodynamic simulations suggest that impulsive heating models can account for the large densities, but they have a difficult time reproducing the narrow range of observed temperatures. The observations of overdense, nearly isothermal plasma in the solar corona provide a significant challenge to theories of coronal heating.

  12. Structure and seismic activity of the Lesser Antilles subduction zone

    NASA Astrophysics Data System (ADS)

    Evain, M.; Galve, A.; Charvis, P.; Laigle, M.; Ruiz Fernandez, M.; Kopp, H.; Hirn, A.; Flueh, E. R.; Thales Scientific Party

    2011-12-01

    Several active and passive seismic experiments conducted in 2007 in the framework of the European program "Thales Was Right" and of the French ANR program "Subsismanti" provided a unique set of geophysical data highlighting the deep structure of the central part of the Lesser Antilles subduction zone, offshore Dominica and Martinique, and its seismic activity during a period of 8 months. The region is characterized by a relatively low rate of seismicity that is often attributed to the slow (2 cm/yr) subduction of the old, 90 My, Atlantic lithosphere beneath the Caribbean Plate. Based on tomographic inversion of wide-angle seismic data, the forearc can clearly be divided into an inner forearc, characterised by a high vertical velocity gradient in the igneous crust, and an outer forearc with lower crustal velocity gradient. The thick, high velocity, inner forearc is possibly the extension at depth of the Mesozoic Caribbean crust outcropping in La Désirade Island. The outer forearc, up to 70 km wide in the northern part of the study area, is getting narrower to the south and disappears offshore Martinique. Based on its seismic velocity structure with velocities higher than 6 km/s the backstop consists, at least partly, of magmatic rocks. The outer forearc is also highly deformed and faulted within the subducting trend of the Tiburon Ridge. With respect to the inner forearc velocity structure the outer forearc basement could either correspond to an accreted oceanic terrane or made of highly fractured rocks. The inner forearc is a dense, poorly deformable crustal block, tilted southward as a whole. It acts as a rigid buttress increasing the strain within both the overriding and subducting plates. This appears clearly in the current local seismicity affecting the subducting and the overriding plates that is located beneath the inner forearc. We detected earthquakes beneath the Caribbean forearc and in the Atlantic oceanic plate as well. The main seismic activity is

  13. 77 FR 55182 - Foreign-Trade Zone 45-Portland, OR, Authorization of Production Activity, Shimadzu USA...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-07

    ... Foreign-Trade Zones Board Foreign-Trade Zone 45--Portland, OR, Authorization of Production Activity... Production), Canby, OR The Port of Portland, grantee of FTZ 45, submitted a notification of proposed production activity within Subzone 45G, at the facility of Shimadzu USA Manufacturing, Inc....

  14. 78 FR 13857 - Foreign-Trade Zone 84-Houston, TX; Notification of Proposed Production Activity; Toshiba...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-01

    ... Foreign-Trade Zones Board Foreign-Trade Zone 84--Houston, TX; Notification of Proposed Production Activity; Toshiba International Corporation (Hybrid Electric Vehicle Motors and Generators Production) The Port of Houston Authority, grantee of FTZ 84, submitted a notification of proposed production activity on...

  15. Numerical density and biomass of macrobenthic animals living in the intertidal zone of Surinam, South America

    NASA Astrophysics Data System (ADS)

    Swennen, C.; Duiven, P.; Spaans, A. L.

    The macrobenthic fauna of all types of intertidal area of the Surinam coast, mainly mud flats, were briefly studied by coring. Crustaceans dominated; polychaetes and molluscs were poorly represented. The highest biomass values (32 to 37 g · m -2 ADW, mainly contributed by Uca maracoani) were found around high tide level, at the border of the mangrove forest. Just outside the Uca zone, on sheltered places also high values ( ca 20 g · m -2 ADW, mainly contributed by Tanaidacea) were found. In the middle and lower parts of the flats biomass was low (only a few g · m -2 or less), probably a result of the instability of the sediment. The following crustaceans not recorded previously for Surinam were found living in the intertidal clay and mud: Hexapanopeus schmitti, Cycloplax pinnotheroides, Pinnixa sayana (Brachyura), and Upogebia brasiliensis (Macrura).

  16. A comparison of food pattern, macro- and some micronutrients density of the diet across different socio-economic zones of Tehran

    PubMed Central

    Abdollahi, Morteza; Salehi, Forouzan; Kalantari, Naser; Asadilari, Mohsen; Khoshfetrat, Mohammad Reza; Ajami, Marjan

    2016-01-01

    Background: The consumption of low quality foods is common in low socioeconomic areas; and according to epidemiological studies, the density of nutrients often proves the quality of diet. This study aimed to compare the density of macronutrients and micronutrients in various parts of Tehran. Methods: This was a cross-sectional study performed from September to December 2007 in all the 22 districts of the municipality of Tehran including 1,807 households. Experienced interviewers completed a 24-hour recall questionnaire. To estimate the nutrient densities, nutrient intake (grams or milligrams) was calculated per 1,000 kcal energy intake. To calculate the density of energy intake, energy intake (kcal) was divided by 100 g of foodstuff. The 22 districts of Tehran were divided into five zones of north, center, east, west and south. ANOVA and Tukey tests were used. Results: The highest density of protein and fat intake was observed in the north of Tehran, while carbohydrate density was highest in the west, east and south zones, and energy density was highest in the south zone (p<0.05). Calcium and vitamin C had the highest density in the north of Tehran, and vitamin A and riboflavin had the highest density in the north and center of Tehran, and the lowest level in the south of Tehran (p<0.05). Conclusion: Despite the high density of energy in the south of Tehran, a deficiency of micronutrient intake was obvious, reflecting the importance of the impact of socioeconomic factors. PMID:27390710

  17. The hydrometeorological implications of zoning laws: Can land use regulations of urban density and sprawl improve a city's resilience?

    NASA Astrophysics Data System (ADS)

    Bou-Zeid, E.; Ryu, Y. H.; Smith, J. A.; Newburn, D. A.

    2015-12-01

    The intensification of heat waves and of the hydrological cycle due to global climate change pose particularly high risks to urban residents. Cities are already hotter than their surroundings due to the urban heat island effect and are known to result in local intensification of rainfall and flooding due to their coupled impacts on the surface and the lower atmosphere. These interacting local and global changes can adversely affect the health and well being of urban residents, and city administrators are increasing efforts to mitigate and adapt to the potential disruptions though various infrastructure and preparedness programs. However, as cities worldwide continue to expand, a key decision is how to manage that urban sprawl and regulate its spatial features to aid in the mitigation and adaptation effort. This study assesses whether alternative zoning regulations that modify the density and extent of a metropolitan region, but have a minimal impact on total population and demographic growth, have an appreciable impact on its response to extreme weather events, and as such, whether they can be used to increase urban resilience. We consider Baltimore (the city and its surrounding suburbs), which in 1967 adopted one of the first urban growth boundaries (UGBs) in the United States, as our test case. Departing from the urban extent circa 1900, we create alternative land use patterns that, compared to the actual current land use baseline, would have resulted from drastically different policy scenarios and approaches to zoning that the city would have undertaken. We consider various alternatives where the city is smaller and denser, due to stricter regulation, versus larger and less dense than the actual baseline, while maintaining the same total population. Our findings indicate that lower densities have significant benefits: compared to the current landscape and to denser patterns, they reduce both extreme temperatures during heat waves and spatio-temporal rainfall

  18. BDNF Enhances Quantal Neurotransmitter Release and Increases the Number of Docked Vesicles at the Active Zones of Hippocampal Excitatory Synapses

    PubMed Central

    Tyler, William J.; Pozzo-Miller, Lucas D.

    2009-01-01

    Brain-derived neurotrophic factor (BDNF) is emerging as a key mediator of activity-dependent modifications of synaptic strength in the CNS. We investigated the hypothesis that BDNF enhances quantal neurotransmitter release by modulating the distribution of synaptic vesicles within presynaptic terminals using organotypic slice cultures of postnatal rat hippocampus. BDNF specifically increased the number of docked vesicles at the active zone of excitatory synapses on CA1 dendritic spines, with only a small increase in active zone size. In agreement with the hypothesis that an increased docked vesicle density enhances quantal neurotransmitter release, BDNF increased the frequency, but not the amplitude, of AMPA receptor-mediated miniature EPSCs (mEPSCs) recorded from CA1 pyramidal neurons in hippocampal slices. Synapse number, independently estimated from dendritic spine density and electron microscopy measurements, was also increased after BDNF treatment, indicating that the actions of BNDF on mEPSC frequency can be partially attributed to an increased synaptic density. Our results further suggest that all these actions were mediated via tyrosine kinase B (TrkB) receptor activation, established by inhibition of plasma membrane tyrosine kinases with K-252a. These results provide additional evidence of a fundamental role of the BDNF–TrkB signaling cascade in synaptic transmission, as well as in cellular models of hippocampus-dependent learning and memory. PMID:11404410

  19. Separation of arginase isoforms by capillary zone electrophoresis and isoelectric focusing in density gradient column.

    PubMed

    Pedrosa, M M; Legaz, M E

    1995-04-01

    Four major arginase isoforms, I, II, III and IV, have been detected in Evernia prunastri thallus. They differ in terms of both physical and biochemical properties. The isoelectric point (pI) of these proteins has been determined by both isoelectric focusing in density gradient column and high-performance capillary electrophoresis (HPCE). Isoelectric focusing revealed charge microheterogeneity for isoforms II and IV whereas arginases I and II had the same pI value of 5.8. HPCE separation confirmed this charge microheterogeneity for isoform IV but not for isoform III, and provided evidence of microheterogeneity for isoforms I and II. The effect of various electrolyte buffers and running conditions on the HPCE separation of arginase isoform were investigated. Addition of 0.5 mM spermidine (SPD) to the running buffer reduced the electroosmotic flow (EOF) and permitted discriminating between the native proteins and protein fragments.

  20. Active zone proteins are transported via distinct mechanisms regulated by Par-1 kinase

    PubMed Central

    Barber, Kara R.; Sherman, Michael

    2017-01-01

    Disruption of synapses underlies a plethora of neurodevelopmental and neurodegenerative disease. Presynaptic specialization called the active zone plays a critical role in the communication with postsynaptic neuron. While the role of many proteins at the active zones in synaptic communication is relatively well studied, very little is known about how these proteins are transported to the synapses. For example, are there distinct mechanisms for the transport of active zone components or are they all transported in the same transport vesicle? Is active zone protein transport regulated? In this report we show that overexpression of Par-1/MARK kinase, a protein whose misregulation has been implicated in Autism spectrum disorders (ASDs) and neurodegenerative disorders, lead to a specific block in the transport of an active zone protein component- Bruchpilot at Drosophila neuromuscular junctions. Consistent with a block in axonal transport, we find a decrease in number of active zones and reduced neurotransmission in flies overexpressing Par-1 kinase. Interestingly, we find that Par-1 acts independently of Tau-one of the most well studied substrates of Par-1, revealing a presynaptic function for Par-1 that is independent of Tau. Thus, our study strongly suggests that there are distinct mechanisms that transport components of active zones and that they are tightly regulated. PMID:28222093

  1. Rapid structural alterations of the active zone lead to sustained changes in neurotransmitter release.

    PubMed

    Matz, Jacob; Gilyan, Andrew; Kolar, Annette; McCarvill, Terrence; Krueger, Stefan R

    2010-05-11

    The likelihood with which an action potential elicits neurotransmitter release, the release probability (p(r)), is an important component of synaptic strength. Regulatory mechanisms controlling several steps of synaptic vesicle (SV) exocytosis may affect p(r), yet their relative importance in determining p(r) and eliciting temporal changes in neurotransmitter release at individual synapses is largely unknown. We have investigated whether the size of the active zone cytomatrix is a major determinant of p(r) and whether changes in its size lead to corresponding alterations in neurotransmitter release. We have used a fluorescent sensor of SV exocytosis, synaptophysin-pHluorin, to measure p(r) at individual synapses with high accuracy and employed a fluorescently labeled cytomatrix protein, Bassoon, to quantify the amount of active zone cytomatrix present at these synapses. We find that, for synapses made by a visually identified presynaptic neuron, p(r) is indeed strongly correlated with the amount of active zone cytomatrix present at the presynaptic specialization. Intriguingly, active zone cytomatrices are frequently subject to synapse-specific changes in size on a time scale of minutes. These spontaneous alterations in active zone size are associated with corresponding changes in neurotransmitter release. Our results suggest that the size of the active zone cytomatrix has a large influence on the reliability of synaptic transmission. Furthermore, they implicate mechanisms leading to rapid structural alterations at active zones in synapse-specific forms of plasticity.

  2. Release probability of hippocampal glutamatergic terminals scales with the size of the active zone

    PubMed Central

    Holderith, Noemi; Lorincz, Andrea; Katona, Gergely; Rózsa, Balázs; Kulik, Akos; Watanabe, Masahiko; Nusser, Zoltan

    2012-01-01

    Cortical synapses display remarkable structural, molecular and functional heterogeneity. Our knowledge regarding the relationship between the ultrastructural and functional parameters is still fragmented. Here we asked how the release probability and presynaptic [Ca2+] transients relate to the ultrastructure of rat hippocampal glutamatergic axon terminals. Two-photon Ca2+ imaging-derived optical quantal analysis and correlated electron microscopic reconstructions revealed a tight correlation between the release probability and the active zone area. The peak amplitude of [Ca2+] transients in single boutons also positively correlated with the active zone area. Freeze-fracture immunogold labeling revealed that the voltage-gated Ca2+ 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 for Cav2.1 showed a nonrandom distribution within the active zones. Our results demonstrate that the number of several active zone proteins, including presynaptic Ca2+ channels, docked vesicles and the release probability scales linearly with the active zone area. PMID:22683683

  3. Comparison study between coherent echoes at VHF range and electron density estimated by Ionosphere Model for Auroral Zone

    NASA Astrophysics Data System (ADS)

    Nishiyama, Takanori; Nakamura, Takuji; Tsutsumi, Masaki; Tanaka, Yoshi; Nishimura, Koji; Sato, Kaoru; Tomikawa, Yoshihiro; Kohma, Masashi

    2016-07-01

    Polar Mesosphere Winter Echo (PMWE) is known as back scatter echo from 55 to 85 km in the mesosphere, and it has been observed by MST and IS radar in polar region during non-summer period. Since density of free electrons as scatterer is low in the dark mesosphere during winter, it is suggested that PMWE requires strong ionization of neutral atmosphere associated with Energetic Particles Precipitations (EPPs) during Solar Proton Events [Kirkwood et al., 2002] or during geomagnetically disturbed periods [Nishiyama et al., 2015]. However, studies on relationship between occurrence of PMWE and background electron density has been limited yet [Lübken et al., 2006], partly because the PMWE occurrence rate is known to be quite low (2.9%) [Zeller et al., 2006]. The PANSY (Program of the Antarctic Syowa MST/IS) radar, which is the largest MST radar in Antarctica, observed many PMWE events since it has started mesosphere observations in June 2012. We established an application method of the PANSY radar as riometer, which makes it possible to estimate Cosmic Noise Absorptions (CNA) as proxy of relative variations on background electron density. In addition, electron density profiles from 60 to 150 km altitude are calculated by Ionospheric Model for the Auroral Zone (IMAZ) [McKinnell and Friedrich, 2007] and CNA estimated by the PANSY radar. In this presentation, we would like to focus on strong PMWE during two big geomagnetic storm events, St. Patrick's Day and the Summer Solstice 2015 Event, in order to compare observed PMWE characteristics to model background electron density. On March 19 and 22, recovery phase of St. Patrick's Day Storm, sudden PMWE intensification was detected near 60 km by the PANSY radar. At the same time, strong Cosmic Noise Absorptions (CNA) of 0.8 dB and 1.0 dB were measured, respectively. However, calculated electron density profiles did not show high electron density at the altitude where the PMWE intensification were observed. On June 22, the

  4. 77 FR 75610 - Foreign-Trade Zone 22-Chicago, IL, Notification of Proposed Production Activity, Abbott...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-21

    ... Foreign-Trade Zones Board Foreign-Trade Zone 22--Chicago, IL, Notification of Proposed Production Activity, Abbott Laboratories, Inc., AbbVie, Inc. (Pharmaceutical Production), North Chicago, IL, Area Abbott... authority within Subzones 22F and 22S, at sites located in the North Chicago and Lake County, Illinois,...

  5. 78 FR 23220 - Foreign-Trade Zone 22-Chicago, Illinois, Authorization of Production Activity, Abbott...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-18

    ... Foreign-Trade Zones Board Foreign-Trade Zone 22--Chicago, Illinois, Authorization of Production Activity, Abbott Laboratories, Inc., AbbVie, Inc. (Pharmaceutical Production), North Chicago, Illinois, Area On... production authority within Subzones 22F and 22S, respectively, at sites located in the North Chicago...

  6. 77 FR 70139 - Foreign-Trade Zone 8-Toledo, OH; Authorization of Production Activity; Whirlpool Corporation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-23

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 8--Toledo, OH; Authorization of Production Activity; Whirlpool Corporation (Washing Machines); Clyde and Green Springs, OH On July 20, 2012 the...

  7. 33 CFR 3.70-20 - Activities Far East Marine Inspection Zone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Activities Far East Marine Inspection Zone. 3.70-20 Section 3.70-20 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY GENERAL COAST GUARD AREAS, DISTRICTS, SECTORS, MARINE INSPECTION ZONES, AND CAPTAIN OF THE...

  8. 33 CFR 3.70-20 - Activities Far East Marine Inspection Zone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Activities Far East Marine Inspection Zone. 3.70-20 Section 3.70-20 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY GENERAL COAST GUARD AREAS, DISTRICTS, SECTORS, MARINE INSPECTION ZONES, AND CAPTAIN OF THE...

  9. 78 FR 56859 - Foreign-Trade Zone 75-Phoenix, Arizona, Authorization of Limited Production Activity, Honeywell...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-16

    ... Foreign-Trade Zones Board Foreign-Trade Zone 75--Phoenix, Arizona, Authorization of Limited Production Activity, Honeywell Aerospace, Inc. (Aircraft Engines, Systems and Components), Phoenix and Tempe, Arizona On May 3, 2013, the City of Phoenix, grantee of FTZ 75, submitted a notification of...

  10. 78 FR 66330 - Foreign-Trade Zone 196-Fort Worth, Texas, Authorization of Production Activity, Flextronics...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-05

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 196--Fort Worth, Texas, Authorization of Production Activity, Flextronics International USA, Inc. (Mobile Phone Assembly and Kitting), Fort Worth, Texas On June 14,...

  11. 78 FR 30862 - Foreign-Trade Zone 41-Milwaukee, Wisconsin; Authorization of Production Activity; CNH America...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-23

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 41--Milwaukee, Wisconsin; Authorization of Production Activity; CNH America, LLC; Subzone 41I (Tractors and Tractor/Combine Components); Racine, Wisconsin...

  12. 77 FR 72816 - Foreign-Trade Zone 20-Suffolk, VA; Authorization of Production Activity; Usui International...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-06

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 20--Suffolk, VA; Authorization of Production Activity; Usui International Corporation (Diesel Engine Fuel Lines); Chesapeake, VA On June 28, 2012, the Virginia...

  13. 78 FR 41911 - Foreign-Trade Zone 161-Sedgwick County, Kansas; Authorization of Production Activity; Siemens...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 161--Sedgwick County, Kansas; Authorization of Production Activity; Siemens Energy, Inc. (Wind Turbine Nacelles and Hubs); Hutchinson, Kansas On March 7,...

  14. 78 FR 48413 - Foreign-Trade Zone 75-Phoenix, Arizona, Authorization of Production Activity, Orbital Sciences...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-08

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 75--Phoenix, Arizona, Authorization of Production Activity, Orbital Sciences Corporation, (Satellites and Spacecraft Launch Vehicles); Gilbert, Arizona On April...

  15. 78 FR 33808 - Foreign-Trade Zone 50-Long Beach, California; Authorization of Production Activity; Panasonic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-05

    ... [Federal Register Volume 78, Number 108 (Wednesday, June 5, 2013)] [Notices] [Page 33808] [FR Doc No: 2013-13314] DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-13-2013] Foreign-Trade Zone 50--Long Beach, California; Authorization of Production Activity; Panasonic Corporation of North America (Kitting of Consumer Electronics);...

  16. 78 FR 7394 - Foreign-Trade Zone 121-Albany, NY; Authorization of Production Activity; Albany Molecular...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-01

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 121--Albany, NY; Authorization of Production Activity; Albany Molecular Research, Inc.; Subzone 121A (Pharmaceutical Chemicals Production); Rensselaer, NY On September...

  17. 78 FR 68814 - Foreign-Trade Zone 32-Miami, Florida, Authorization of Production Activity, Brightstar...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-15

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 32--Miami, Florida, Authorization of Production Activity, Brightstar Corporation (Cell Phone Kitting), Miami, Florida On June 26, 2013, The Greater Miami Chamber...

  18. 77 FR 55455 - Foreign-Trade Zone 235-Lakewood, NJ, Authorization of Production Activity, Cosmetic Essence...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-10

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 235--Lakewood, NJ, Authorization of Production Activity, Cosmetic Essence Innovations, LLC, (Fragrance Bottling), Holmdel, NJ Cosmetic Essence Innovations, LLC...

  19. 77 FR 48127 - Foreign-Trade Zone 20-Suffolk, VA; Notification of Proposed Production Activity, Usui...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-13

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 20--Suffolk, VA; Notification of Proposed Production Activity, Usui International Corporation, (Diesel Engine Fuel Lines), Chesapeake, VA The Virginia Port Authority, grantee of FTZ 20, submitted a...

  20. 78 FR 28801 - Foreign-Trade Zone 22-Chicago, Illinois; Authorization of Production Activity Panasonic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-16

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 22--Chicago, Illinois; Authorization of Production Activity Panasonic Corporation of North America (Kitting of Consumer Electronics) Aurora, Illinois On January...

  1. Associations between active living-oriented zoning and no adult leisure-time physical activity in the U.S.

    PubMed

    Leider, Julien; Chriqui, Jamie F; Thrun, Emily

    2017-02-01

    Nearly one-third of adults report no leisure-time physical activity (LTPA). Governmental and authoritative bodies recognize the role that community design through zoning code changes can play in enabling LTPA. This study examined the association between zoning and no adult LTPA in the U.S. This study was conducted between 2012 and 2016, with analyses occurring in 2015-2016. Zoning codes effective as of 2010 were compiled for jurisdictions located in the 495 most populous U.S. counties and were evaluated for pedestrian-oriented code reform zoning, 11 active living-oriented provisions (e.g., sidewalks, bike-pedestrian connectivity, mixed use, bike lanes) and a summated zoning scale (max=12). Individual-level LTPA data were obtained from the 2012 CDC Behavioral Risk Factor Surveillance System (BRFSS). County-aggregated, population-weighted zoning variables were constructed for linking to BRFSS. Log-log multivariate regressions (N=147,517 adults), controlling for individual and county characteristics and with robust standard errors clustered on county, were conducted to examine associations between zoning and no LTPA. Relative risks (RR) compared predicted lack of LTPA at 0% and 100% county-level population exposure to each zoning predictor. Zoning code reforms were associated with a 13% lower probability of no LTPA (RR: 0.87, 95% CI: 0.82-0.92). Except for crosswalks, all zoning provisions were associated with an 11-16% lower probability of no LTPA. Having all 12 zoning provisions was associated with a 22% lower probability of no LTPA (RR: 0.78, 95% CI: 0.72-0.83). The results suggest that active living-oriented zoning is a policy lever available to communities seeking to reduce rates of no LTPA.

  2. Density, distribution, and activity of the ocelot Leopardus pardalis (Carnivora: Felidae) in Southeast Mexican rainforests.

    PubMed

    Pérez-Irineo, Gabriela; Santos-Moreno, Antonio

    2014-12-01

    The ocelot Leopardus pardalis is of particular significance in terrestrial communities due to its ecological role within the group of small-sized felids and as a mesopredator. However, despite the reduction of ocelot habitat in Southeast Mexico, there are still very few ecological studies. This research aimed to contribute with some ecological aspects of the species in this region. For this, 29 camera trap stations were established in a rain forest in Los Chimalapas (an area of 22 km2) during a two years period (March 2011-June, 2013), in Oaxaca state, Southeast Mexico. Data allowed the estimation of the population density, activity pattern, sex ratio, residence time, and spatial distribution. Population density was calculated using Capture-Recapture Models for demographically open populations; besides, circular techniques were used to determine if nocturnal and diurnal activity varied significantly over the seasons, and Multiple Discriminant Analysis was used to determine which of the selected environmental variables best explained ocelot abundance in the region. A total of 103 ocelot records were obtained, with a total sampling effort of 8,529 trap-days. Density of 22-38 individuals/100 km2 was estimated. Ocelot population had a high proportion of transient individuals in the zone (55%), and the sex ratio was statistically equal to 1:1. Ocelot activity was more frequent at night (1:00-6:00h), but it also exhibited diurnal activity throughout the study period. Ocelot spatial distribution was positively affected by the proximity to the village as well as by the amount of prey. The ocelot population here appears to be stable, with a density similar to other regions in Central and South America, which could be attributed to the diversity of prey species and a low degree of disturbance in Los Chimalapas.

  3. Exploring the Linkage between Activity-Friendly Zoning, Inactivity, and Cancer Incidence in the United States.

    PubMed

    Nicholson, Lisa M; Leider, Julien; Chriqui, Jamie F

    2017-03-07

    Background: Physical activity (PA) protects against cancer and enhances cancer survivorship. Given high inactivity rates nationwide, population-level physical activity facilitators are needed. Several authoritative bodies have recognized that zoning and planning helps create activity-friendly environments. This study examined the association between activity-friendly zoning, inactivity, and cancer in 478 of the most populous U.S. counties.Methods: County geocodes linked county-level data: cancer incidence and smoking (State Cancer Profiles), inactivity (Behavioral Risk Factor Surveillance System), 11 zoning measures (compiled by the study team), and covariates (from the American Community Survey and NAVTEQ). For each zoning measure, single mediation regression models and Sobel tests examined whether activity-friendly zoning was associated with reduced cancer incidence, and whether inactivity mediated those associations. All models were clustered on state with robust SEs and significance at the P < 0.05 level.Results: Zoning for crosswalks, bike-pedestrian connectivity, and bike-pedestrian trails/paths were associated with reduced cancer incidence (β between -0.71 and -1.27, P < 0.05), about 1 case per 100,000 for each 10 percentage-point increase in county population exposure to zoning. Except for crosswalks, each association was mediated by inactivity. However, county smoking attenuated these results, with only crosswalks remaining significant. Results were similar for males (with zoning for bike-pedestrian connectivity, street connectivity, and bike-pedestrian trails/paths), but not females, alone.Conclusions: Zoning can help to create activity-friendly environments that support decreased inactivity, and possibly reduced cancer incidence.Impact: Given low physical activity levels nationwide, cross-sectoral collaborations with urban planning can inform cancer prevention and public health efforts to decrease inactivity and cancer. Cancer Epidemiol Biomarkers Prev

  4. Presynaptic spinophilin tunes neurexin signalling to control active zone architecture and function

    PubMed Central

    Muhammad, Karzan; Reddy-Alla, Suneel; Driller, Jan H; Schreiner, Dietmar; Rey, Ulises; Böhme, Mathias A.; Hollmann, Christina; Ramesh, Niraja; Depner, Harald; Lützkendorf, Janine; Matkovic, Tanja; Götz, Torsten; Bergeron, Dominique D.; Schmoranzer, Jan; Goettfert, Fabian; Holt, Mathew; Wahl, Markus C.; Hell, Stefan W.; Scheiffele, Peter; Walter, Alexander M.; Loll, Bernhard; Sigrist, Stephan J.

    2015-01-01

    Assembly and maturation of synapses at the Drosophila neuromuscular junction (NMJ) depend on trans-synaptic neurexin/neuroligin signalling, which is promoted by the scaffolding protein Syd-1 binding to neurexin. Here we report that the scaffold protein spinophilin binds to the C-terminal portion of neurexin and is needed to limit neurexin/neuroligin signalling by acting antagonistic to Syd-1. Loss of presynaptic spinophilin results in the formation of excess, but atypically small active zones. Neuroligin-1/neurexin-1/Syd-1 levels are increased at spinophilin mutant NMJs, and removal of single copies of the neurexin-1, Syd-1 or neuroligin-1 genes suppresses the spinophilin-active zone phenotype. Evoked transmission is strongly reduced at spinophilin terminals, owing to a severely reduced release probability at individual active zones. We conclude that presynaptic spinophilin fine-tunes neurexin/neuroligin signalling to control active zone number and functionality, thereby optimizing them for action potential-induced exocytosis. PMID:26471740

  5. Cytokinin activity increases stomatal density and transpiration rate in tomato

    PubMed Central

    Farber, Mika; Attia, Ziv; Weiss, David

    2016-01-01

    Previous studies on cytokinin (CK) and drought have suggested that the hormone has positive and negative effects on plant adaptation to restrictive conditions. This study examined the effect of CK on transpiration, stomatal activity, and response to drought in tomato (Solanum lycopersicum) plants. Transgenic tomato plants overexpressing the Arabidopsis thaliana CK-degrading enzyme CK oxidase/dehydrogenase 3 (CKX3) maintained higher leaf water status under drought conditions due to reduced whole-plant transpiration. The reduced transpiration could be attributed to smaller leaf area and reduced stomatal density. CKX3-overexpressing plants contained fewer and larger pavement cells and fewer stomata per leaf area than wild-type plants. In addition, wild-type leaves treated with CK exhibited enhanced transpiration and had more pavement cells and increased numbers of stomata per leaf area than untreated leaves. Manipulation of CK levels did not affect stomatal movement or abscisic acid-induced stomatal closure. Moreover, we found no correlation between stomatal aperture and the activity of the CK-induced promoter Two-Component Signaling Sensor (TCS) in guard cells. Previous studies have shown that drought reduces CK levels, and we propose this to be a mechanism of adaptation to water deficiency: the reduced CK levels suppress growth and reduce stomatal density, both of which reduce transpiration, thereby increasing tolerance to prolonged drought conditions. PMID:27811005

  6. Cytokinin activity increases stomatal density and transpiration rate in tomato.

    PubMed

    Farber, Mika; Attia, Ziv; Weiss, David

    2016-12-01

    Previous studies on cytokinin (CK) and drought have suggested that the hormone has positive and negative effects on plant adaptation to restrictive conditions. This study examined the effect of CK on transpiration, stomatal activity, and response to drought in tomato (Solanum lycopersicum) plants. Transgenic tomato plants overexpressing the Arabidopsis thaliana CK-degrading enzyme CK oxidase/dehydrogenase 3 (CKX3) maintained higher leaf water status under drought conditions due to reduced whole-plant transpiration. The reduced transpiration could be attributed to smaller leaf area and reduced stomatal density. CKX3-overexpressing plants contained fewer and larger pavement cells and fewer stomata per leaf area than wild-type plants. In addition, wild-type leaves treated with CK exhibited enhanced transpiration and had more pavement cells and increased numbers of stomata per leaf area than untreated leaves. Manipulation of CK levels did not affect stomatal movement or abscisic acid-induced stomatal closure. Moreover, we found no correlation between stomatal aperture and the activity of the CK-induced promoter Two-Component Signaling Sensor (TCS) in guard cells. Previous studies have shown that drought reduces CK levels, and we propose this to be a mechanism of adaptation to water deficiency: the reduced CK levels suppress growth and reduce stomatal density, both of which reduce transpiration, thereby increasing tolerance to prolonged drought conditions.

  7. Group Problem Solving as a Zone of Proximal Development activity

    NASA Astrophysics Data System (ADS)

    Brewe, Eric

    2006-12-01

    Vygotsky described learning as a process, intertwined with development, which is strongly influenced by social interactions with others that are at differing developmental stages.i These interactions create a Zone of Proximal Development for each member of the interaction. Vygotsky’s notion of social constructivism is not only a theory of learning, but also of development. While teaching introductory physics in an interactive format, I have found manifestations of Vygotsky’s theory in my classroom. The source of evidence is a paired problem solution. A standard mechanics problem was solved by students in two classes as a homework assignment. Students handed in the homework and then solved the same problem in small groups. The solutions to both the group and individual problem were assessed by multiple reviewers. In many cases the group score was the same as the highest individual score in the group, but in some cases, the group score was higher than any individual score. For this poster, I will analyze the individual and group scores and focus on three groups solutions and video that provide evidence of learning through membership in a Zone of Proximal Development. Endnotes i L. Vygotsky -Mind and society: The development of higher mental processes. Cambridge, MA: Harvard University Press. (1978).

  8. PP2A and GSK-3beta act antagonistically to regulate active zone development.

    PubMed

    Viquez, Natasha M; Füger, Petra; Valakh, Vera; Daniels, Richard W; Rasse, Tobias M; DiAntonio, Aaron

    2009-09-16

    The synapse is composed of an active zone apposed to a postsynaptic cluster of neurotransmitter receptors. Each Drosophila neuromuscular junction comprises hundreds of such individual release sites apposed to clusters of glutamate receptors. Here, we show that protein phosphatase 2A (PP2A) is required for the development of structurally normal active zones opposite glutamate receptors. When PP2A is inhibited presynaptically, many glutamate receptor clusters are unapposed to Bruchpilot (Brp), an active zone protein required for normal transmitter release. These unapposed receptors are not due to presynaptic retraction of synaptic boutons, since other presynaptic components are still apposed to the entire postsynaptic specialization. Instead, these data suggest that Brp localization is regulated at the level of individual release sites. Live imaging of glutamate receptors demonstrates that this disruption to active zone development is accompanied by abnormal postsynaptic development, with decreased formation of glutamate receptor clusters. Remarkably, inhibition of the serine-threonine kinase GSK-3beta completely suppresses the active zone defect, as well as other synaptic morphology phenotypes associated with inhibition of PP2A. These data suggest that PP2A and GSK-3beta function antagonistically to control active zone development, providing a potential mechanism for regulating synaptic efficacy at a single release site.

  9. Activated platelets form protected zones of adhesion on fibrinogen and fibronectin-coated surfaces

    PubMed Central

    1993-01-01

    Leukocytes form zones of close apposition when they adhere to ligand- coated surfaces. Because plasma proteins are excluded from these contact zones, we have termed them protected zones of adhesion. To determine whether platelets form similar protected zones of adhesion, gel-filtered platelets stimulated with thrombin or ADP were allowed to adhere to fibrinogen- or fibronectin-coated surfaces. The protein- coated surfaces with platelets attached were stained with either fluorochrome-conjugated goat anti-human fibrinogen or anti-human fibronectin antibodies, or with rhodamine-conjugated polyethylene glycol polymers. Fluorescence microscopy revealed that F(ab')2 anti- fibrinogen (100 kD) did not penetrate into the contact zones between stimulated platelets and the underlying fibrinogen-coated surface, while Fab antifibrinogen (50 kD) and 10 kD polyethylene glycol readily penetrated and stained the substrate beneath the platelets. Thrombin- or ADP-stimulated platelets also formed protected zones of adhesion on fibronectin-coated surfaces. F(ab')2 anti-fibronectin and 10 kD polyethylene glycol were excluded from these adhesion zones, indicating that they are much less permeable than those formed by platelets on fibrinogen-coated surfaces. The permeability properties of protected zones of adhesion formed by stimulated platelets on surfaces coated with both fibrinogen and fibronectin were similar to the zones of adhesion formed on fibronectin alone. mAb 7E3, directed against the alpha IIb beta 3 integrin blocked the formation of protected adhesion zones between thrombin-stimulated platelets and fibrinogen or fibronectin coated surfaces. mAb C13 is directed against the alpha 5 beta 1 integrin on platelets. Stimulated platelets treated with this mAb formed protected zones of adhesion on surfaces coated with fibronectin. These protected zones were impermeable to F(ab')2 antifibronectin but were permeable to 10 kD polyethylene glycol. These results show that activated

  10. The South Tibetan Tadpole Zone: Ongoing density sorting at the Moho beneath the Indus-Tsangpo suture zone (and beneath volcanic arcs?)

    NASA Astrophysics Data System (ADS)

    Kelemen, Peter; Hacker, Bradley

    2016-04-01

    at less than 700°C (e.g. Jackson 02). We build on earlier studies (LePichon et al 92, 97; Schulte-Pelkum et al 05; Monsalve et al 08) to develop the hypothesis that there is rapid growth of garnet at 80 km and 1000°C within subducting Indian crust, causing increased rock densities. Dense eclogites founder into the mantle, while relatively buoyant lithologies accumulate in thickening lower crust. Mantle return flow plus radioactive heating in thick, felsic crust maintains high temperature, facilitating formation of hybrid magmas and pyroxenites. The crustal volume grows at 760 cubic m/yr/m of strike length. Moho-depth earthquakes may be due to localized deformation and thermal runaway in weak layers and along the margins of dense, foundering diapirs (e.g., Larsen & Yuen 97; Braeck & Podladchikov 07; Kelemen & Hirth 07; Lister et al 08; Kufner et al 16). A similar process may take place at some convergent margins, where forearc crust is thrust beneath hot, magmatic arc crust, leading to extensive, Moho-depth density sorting and hybrid crust-mantle magmatism in Arc Tadpole Zones.

  11. Factors affecting carbon-14 activity of unsaturated zone CO2 and implications for groundwater dating

    NASA Astrophysics Data System (ADS)

    Wood, Cameron; Cook, Peter G.; Harrington, Glenn A.; Meredith, Karina; Kipfer, Rolf

    2014-11-01

    Unsaturated zone processes may influence the carbon-14 (14C) activity of infiltrating groundwater and thus introduce error in derived groundwater residence times. However unsaturated zone 14C activities are rarely measured and there is little understanding of how they may vary spatially in a groundwater basin. In this study we measured 14C activity in unsaturated zone gas at five sites with different watertable depths (8.2-31.5 m) in the arid Ti Tree Basin, central Australia. We observed a relatively uniform decrease in 14C activity of unsaturated zone gas with depth at most sites, with variation in unsaturated zone depths leading to variation in 14C activities directly above the watertable at each site (ranging from 54 to 106 percent Modern Carbon (pMC)). Through modelling we show that the profiles are influenced by CO2 production at different depths from sources with different isotopic ratios, including production of ‘modern' CO2 in the root zone and production of ‘old' CO2 above the watertable. Scenario modelling showed that these processes are independent of recharge when recharge is low (0-10 mm y-1) but that higher recharge rates (>100 mm y-1) result in more advective transport of atmospheric CO2 to the watertable. The variation in 14C above the watertable was more sensitive to watertable depth and shallow and deep CO2 production rates. These findings offer insight into how unsaturated zone 14C activities may vary spatially and provide guidance as to when 14C depletion in unsaturated zone CO2 may become important for groundwater dating, particularly in arid settings.

  12. Transport of Carbon Tetrachloride in a Fractured Vadose Zone due to Atmospheric Pressure Fluctuations, Diffusion, and Vapor Density

    NASA Astrophysics Data System (ADS)

    McCray, J. E.; Downs, W.; Falta, R. W.; Housley, T.

    2005-12-01

    DNAPL sources of carbon tetrachloride (CT) vapors are of interest at the Radioactive Waste Management Complex (RWMC) at the Idaho National Engineering and Environmental Laboratory (INEEL). The site is underlain by thick fractured basalt that includes sedimentary interbeds, each are a few meters thick. Daily atmospheric pressure fluctuations serve as driving forces for CT vapor transport in the subsurface. Other important transport processes for vapor movement include gas-phase diffusion and density-driven transport. The objective of this research is to investigate the influence and relative importance of these processes on gaseous transport of CT. Gas pressure and vapor concentration measurements were conducted at various depths in two wells. A numerical multiphase flow model (TOUGH2), calibrated to field pressure data, is used to conduct sensitivity analyses to elucidate the importance of the different transport mechanisms. Results show that the basalt is highly permeable to vertical air flow. The pressure dampening occurs mainly in the sedimentary interbeds. Model-calibrated permeability values for the interbeds are similar to those obtained in a study by the U.S. Geological Survey for shallow sediments, and an order of magnitude higher than column-scale values obtained by previous studies conducted by INEEL scientists. The transport simulations indicate that considering the effect of barometric pressure changes is critical to simulating transport of pollutants in the vadose zone above the DNAPL source. Predicted concentrations can be orders of magnitude smaller than actual concentrations if the effect is not considered. Below the DNAPL vapor source, accounting for density and diffusion alone would yield acceptable results provided that a 20% error in concentrations are acceptable, and that simulating concentrations trends (and not actual concentrations) is the primary goal.

  13. 34 CFR 299.3 - What priority may the Secretary establish for activities in an Empowerment Zone or Enterprise...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... activities in an Empowerment Zone or Enterprise Community? 299.3 Section 299.3 Education Regulations of the... activities in an Empowerment Zone or Enterprise Community? For any ESEA discretionary grant program, the... significant portion of the program funds to address substantial problems in an Empowerment Zone, including...

  14. Geomorphic Indices in the Assessment of Tectonic Activity in Forearc of the Active Mexican Subduction Zone

    NASA Astrophysics Data System (ADS)

    Gaidzik, K.; Ramirez-Herrera, M. T.

    2015-12-01

    Rapid development of GIS techniques and constant advancement of digital elevation models significantly improved the accuracy of extraction of information on active tectonics from landscape features. Numerous attempts were made to quantitatively evaluate recent tectonic activity using GIS and DEMs, and a set of geomorphic indices (GI), however these studies focused mainly on sub-basins or small-scale areal units. In forearc regions where crustal deformation is usually large-scale and do not concentrate only along one specific fault, an assessment of the complete basin is more accurate. We present here the first attempt to implement thirteen GI in the assessment of active tectonics of a forearc region of an active convergent margin using the entire river basins. The GIs were divided into groups: BTAI - basin geomorphic indices (reflecting areal erosion vs. tectonics) and STAI - stream geomorphic indices (reflecting vertical erosion vs. tectonics). We calculated selected indices for 9 large (> 450 km2) drainage basins. Then we categorized the obtained results of each index into three classes of relative tectonic activity: 1 - high, 2 - moderate, and 3 - low. Finally we averaged these classes for each basin to determine the tectonic activity level (TAI). The analysis for the case study area, the Guerrero sector at the Mexican subduction zone, revealed high tectonic activity in this area, particularly in its central and, to a lesser degree, eastern part. This pattern agrees with and is supported by interpretation of satellite images and DEM, and field observations. The results proved that the proposed approach indeed allows identification and recognition of areas witnessing recent tectonic deformation. Moreover, our results indicated that, even though no large earthquake has been recorded in this sector for more than 100 years, the area is highly active and may represent a seismic hazard for the region.

  15. Concentric zones of active RhoA and Cdc42 around single cell wounds

    PubMed Central

    Benink, Hélène A.; Bement, William M.

    2005-01-01

    Rho GTPases control many cytoskeleton-dependent processes, but how they regulate spatially distinct features of cytoskeletal function within a single cell is poorly understood. Here, we studied active RhoA and Cdc42 in wounded Xenopus oocytes, which assemble and close a dynamic ring of actin filaments (F-actin) and myosin-2 around wound sites. RhoA and Cdc42 are rapidly activated around wound sites in a calcium-dependent manner and segregate into distinct, concentric zones around the wound, with active Cdc42 in the approximate middle of the F-actin array and active RhoA on the interior of the array. These zones form before F-actin accumulation, and then move in concert with the closing array. Microtubules and F-actin are required for normal zone organization and dynamics, as is crosstalk between RhoA and Cdc42. Each of the zones makes distinct contributions to the organization and function of the actomyosin wound array. We propose that similar rho activity zones control related processes such as cytokinesis. PMID:15684032

  16. Delineation of Active Basement Faults in the Eastern Tennessee and Charlevoix Intraplate Seismic Zones

    NASA Astrophysics Data System (ADS)

    Powell, C. A.; Langston, C. A.; Cooley, M.

    2013-12-01

    Recognition of distinct, seismogenic basement faults within the eastern Tennessee seismic zone (ETSZ) and the Charlevoix seismic zone (CSZ) is now possible using local earthquake tomography and datasets containing a sufficiently large number of earthquakes. Unlike the New Madrid seismic zone where seismicity clearly defines active fault segments, earthquake activity in the ETSZ and CSZ appears diffuse. New arrival time inversions for hypocenter relocations and 3-D velocity variations using datasets in excess of 1000 earthquakes suggest the presence of distinct basement faults in both seismic zones. In the ETSZ, relocated hypocenters align in near-vertical segments trending NE-SW, parallel to the long dimension of the seismic zone. Earthquakes in the most seismogenic portion of the ETSZ delineate another set of near-vertical faults trending roughly E-ESE. These apparent trends and steep dips are compatible with ETSZ focal mechanism solutions. The solutions are remarkably consistent and indicate strike-slip motion along the entire length of the seismic zone. Relocated hypocenter clusters in the CSZ define planes that trend and dip in directions that are compatible with known Iapitan rift faults. Seismicity defining the planes becomes disrupted where the rift faults encounter a major zone of deformation produced by a Devonian meteor impact. We will perform a joint statistical analysis of hypocenter alignments and focal mechanism nodal plane orientations in the ETSZ and the CSZ to determine the spatial orientations of dominant seismogenic basement faults. Quantifying the locations and dimensions of active basement faults will be important for seismic hazard assessment and for models addressing the driving mechanisms for these intraplate zones.

  17. Low resistivity and permeability in actively deforming shear zones on the San Andreas Fault at SAFOD

    USGS Publications Warehouse

    Morrow, Carolyn A.; Lockner, David A.; Hickman, Stephen H.

    2015-01-01

    The San Andreas Fault Observatory at Depth (SAFOD) scientific drillhole near Parkfield, California crosses the San Andreas Fault at a depth of 2.7 km. Downhole measurements and analysis of core retrieved from Phase 3 drilling reveal two narrow, actively deforming zones of smectite-clay gouge within a roughly 200 m-wide fault damage zone of sandstones, siltstones and mudstones. Here we report electrical resistivity and permeability measurements on core samples from all of these structural units at effective confining pressures up to 120 MPa. Electrical resistivity (~10 ohm-m) and permeability (10-21 to 10-22 m2) in the actively deforming zones were one to two orders of magnitude lower than the surrounding damage zone material, consistent with broader-scale observations from the downhole resistivity and seismic velocity logs. The higher porosity of the clay gouge, 2 to 8 times greater than that in the damage zone rocks, along with surface conduction were the principal factors contributing to the observed low resistivities. The high percentage of fine-grained clay in the deforming zones also greatly reduced permeability to values low enough to create a barrier to fluid flow across the fault. Together, resistivity and permeability data can be used to assess the hydrogeologic characteristics of the fault, key to understanding fault structure and strength. The low resistivities and strength measurements of the SAFOD core are consistent with observations of low resistivity clays that are often found in the principal slip zones of other active faults making resistivity logs a valuable tool for identifying these zones.

  18. Hyperoxia causes reduced density of retinal astrocytes in the central avascular zone in the mouse model of oxygen-induced retinopathy.

    PubMed

    Bucher, Felicitas; Stahl, Andreas; Agostini, Hansjürgen T; Martin, Gottfried

    2013-09-01

    The mouse model of oxygen-induced retinopathy (OIR) is commonly used to investigate various aspects of the pathogenesis of the retinopathy of prematurity (ROP) as well as angiogenesis in general. Retinal astrocytes were suggested to be involved in retinal angiogenesis. This study aimed to describe their localization and cell density during the course of physiological vascularization and pathological revascularization. Mice expressing H2B-GFP (green fluorescent protein fused to histone 2B) from the endogenous Pdgfra promoter were kept in 75% oxygen from P7 (post natal day 7) to P12 (mouse model of OIR). Retinal flatmounts or cryosections were immunostained for glial fibrillary acidic protein (Gfap), glutamine synthetase (Glul), collagen IV (Col IV), desmin (Des), caspase 3 (Casp3), paired box 2 (Pax2), or Ki67. Astrocytic nuclei were counted with the ImageJ macro AuTOCellQuant. The hypoxic state of the retina was investigated by Hypoxyprobe. The GFP signal of the Pdgfra reporter mice co-localized with Pax2, a nuclear marker for retinal astrocytes. This bright label was much easier to quantify than Gfap or Pax2 staining. Quantification of the cell density of astrocytes during physiological development specified the spreading of astrocytes in a concentrical wave from the optic nerve head towards the periphery. Astrocyte density was reduced during the remodelling of the primary vascular plexus into a hierarchical vascular tree (maximal astrocyte density at P1: 2800 astrocytes/mm2, final astrocyte density: 800 astrocytes/mm2). In the OIR model, cell density of astrocytes was elevated in the peripheral vascularized zone. In contrast, astrocyte density dropped to a half (400 astrocytes/mm2) of the normal value in the central avascular zone during the hyperoxic phase between P8 and P10 by apoptosis and rose only after P17 as the retinal network normalized. An additional drop of astrocyte density was observed within the angles between the large vessels of the central

  19. Platelet high-density lipoprotein activates transferrin-derived phagocytosis activators, MAPPs, following thrombin digestion.

    PubMed

    Sakamoto, Haruhiko; Wu, Bin; Nagai, Yumiko; Tanaka, Sumiko; Onodera, Masayuki; Ogawa, Takafumi; Ueno, Masaki

    2011-01-01

    Macromolecular activators of phagocytosis from platelets (MAPPs), transferrin-derived phagocytosis activators released from platelets, activate leukocytic phagocytosis via Fcγ receptors. It has been found that MAPPs can be prepared using stored platelets or their lysate. Using this artificial MAPP production system, it has been found that they can be produced from precursors (tetrameric and dimeric transferrins) following reaction with a low-molecular-weight (LMW) activator of MAPPs, which is liberated from a high-molecular-weight activator of MAPP (HMW activator) by reaction with thrombin. In this study, the HMW activator in platelet lysate was characterized by assaying phagocytosis of washed neutrophils. In an ultracentrifugation study of the platelet lysate, HMW activator activity was observed in the fraction corresponding to the density of high-density lipoprotein (HDL). The activity was observed in the apolipoproteins obtained from the HDL fraction. Among the apolipoproteins tested only apolipoprotein CIII showed the activity to produce MAPP in vitro. Affinity chromatography of the apolipoproteins from the HDL fraction of the platelet lysate using an anti-apolipoprotein CIII column revealed that the substance that binds with the antibody showed MAPP-forming activity. In a gel filtration study of thrombin-treated apolipoprotein CIII, a peak of LMW activator activity was observed for fractions with a molecular size smaller than that of apolipoprotein CIII. Finally, MAPP-forming activity of HDL obtained from the plasma was examined. MAPP was formed only when delipidized HDL was used. In conclusion, it is suggested that platelet HDL is the HMW activator and that this activation is achieved via apolipoprotein CIII after thrombin reaction in platelets.

  20. Postsynaptic actin regulates active zone spacing and glutamate receptor apposition at the Drosophila neuromuscular junction.

    PubMed

    Blunk, Aline D; Akbergenova, Yulia; Cho, Richard W; Lee, Jihye; Walldorf, Uwe; Xu, Ke; Zhong, Guisheng; Zhuang, Xiaowei; Littleton, J Troy

    2014-07-01

    Synaptic communication requires precise alignment of presynaptic active zones with postsynaptic receptors to enable rapid and efficient neurotransmitter release. How transsynaptic signaling between connected partners organizes this synaptic apparatus is poorly understood. To further define the mechanisms that mediate synapse assembly, we carried out a chemical mutagenesis screen in Drosophila to identify mutants defective in the alignment of active zones with postsynaptic glutamate receptor fields at the larval neuromuscular junction. From this screen we identified a mutation in Actin 57B that disrupted synaptic morphology and presynaptic active zone organization. Actin 57B, one of six actin genes in Drosophila, is expressed within the postsynaptic bodywall musculature. The isolated allele, act(E84K), harbors a point mutation in a highly conserved glutamate residue in subdomain 1 that binds members of the Calponin Homology protein family, including spectrin. Homozygous act(E84K) mutants show impaired alignment and spacing of presynaptic active zones, as well as defects in apposition of active zones to postsynaptic glutamate receptor fields. act(E84K) mutants have disrupted postsynaptic actin networks surrounding presynaptic boutons, with the formation of aberrant actin swirls previously observed following disruption of postsynaptic spectrin. Consistent with a disruption of the postsynaptic actin cytoskeleton, spectrin, adducin and the PSD-95 homolog Discs-Large are all mislocalized in act(E84K) mutants. Genetic interactions between act(E84K) and neurexin mutants suggest that the postsynaptic actin cytoskeleton may function together with the Neurexin-Neuroligin transsynaptic signaling complex to mediate normal synapse development and presynaptic active zone organization.

  1. Postsynaptic actin regulates active zone spacing and glutamate receptor apposition at the Drosophila neuromuscular junction

    PubMed Central

    Blunk, Aline D.; Akbergenova, Yulia; Cho, Richard W.; Lee, Jihye; Walldorf, Uwe; Xu, Ke; Zhong, Guisheng; Zhuang, Xiaowei; Littleton, J. Troy

    2014-01-01

    Synaptic communication requires precise alignment of presynaptic active zones with postsynaptic receptors to enable rapid and efficient neurotransmitter release. How transsynaptic signaling between connected partners organizes this synaptic apparatus is poorly understood. To further define the mechanisms that mediate synapse assembly, we carried out a chemical mutagenesis screen in Drosophila to identify mutants defective in the alignment of active zones with postsynaptic glutamate receptor fields at the larval neuromuscular junction. From this screen we identified a mutation in actin 57B that disrupted synaptic morphology and presynaptic active zone organization. Actin 57B, one of six actin genes in Drosophila, is expressed within the postsynaptic bodywall musculature. The isolated allele, actE84K, harbors a point mutation in a highly conserved glutamate residue in subdomain 1 that binds members of the Calponin Homology protein family, including spectrin. Homozygous actE84K mutants show impaired alignment and spacing of presynaptic active zones, as well as defects in apposition of active zones to postsynaptic glutamate receptor fields. actE84K mutants have disrupted postsynaptic actin networks surrounding presynaptic boutons, with the formation of aberrant actin swirls previously observed following disruption of postsynaptic spectrin. Consistent with a disruption of the postsynaptic actin cytoskeleton, spectrin, adducin and the PSD-95 homolog Disc-Large are all mislocalized in actE84K mutants. Genetic interactions between actE84K and neurexin mutants suggest that the postsynaptic actin cytoskeleton may function together with the Neurexin-Neuroligin transsynaptic signaling complex to mediate normal synapse development and presynaptic active zone organization. PMID:25066865

  2. 78 FR 25253 - Foreign-Trade Zone (FTZ) 26-Atlanta, Georgia; Notification of Proposed Production Activity; PBR...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-30

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone (FTZ) 26--Atlanta, Georgia; Notification of Proposed Production Activity; PBR, Inc. d/b/a SKAPS Industries (Polypropylene Geotextiles); Athens, Georgia Georgia Foreign-Trade Zone, Inc., grantee of FTZ...

  3. 78 FR 54234 - Foreign-Trade Zone 26-Atlanta, Georgia, Authorization of Production Activity PBR, Inc. d/b/a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-03

    ... Foreign-Trade Zones Board Foreign-Trade Zone 26--Atlanta, Georgia, Authorization of Production Activity PBR, Inc. d/b/a SKAPS Industries (Polypropylene Geotextiles), Athens, Georgia On April 8, 2013, Georgia Foreign-Trade Zone, Inc., grantee of FTZ 26, submitted a notification of proposed...

  4. 78 FR 65963 - Foreign-Trade Zone 44-Mt. Olive, New Jersey; Authorization of Production Activity; Givaudan...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-04

    ... Foreign-Trade Zones Board Foreign-Trade Zone 44--Mt. Olive, New Jersey; Authorization of Production Activity; Givaudan Fragrances Corporation (Fragrance and Flavor Products); Mt. Olive, New Jersey On June 11... Foreign-Trade Zones (FTZ) Board for its facility within Site 1 of FTZ 44 in Mt. Olive, New Jersey....

  5. [Characteristics of soil organic carbon and enzyme activities in soil aggregates under different vegetation zones on the Loess Plateau].

    PubMed

    Li, Xin; Ma, Rui-ping; An, Shao-shan; Zeng, Quan-chao; Li, Ya-yun

    2015-08-01

    In order to explore the distribution characteristics of organic carbon of different forms and the active enzymes in soil aggregates with different particle sizes, soil samples were chosen from forest zone, forest-grass zone and grass zone in the Yanhe watershed of Loess Plateau to study the content of organic carbon, easily oxidized carbon, and humus carbon, and the activities of cellulase, β-D-glucosidase, sucrose, urease and peroxidase, as well as the relations between the soil aggregates carbon and its components with the active soil enzymes were also analyzed. It was showed that the content of organic carbon and its components were in order of forest zone > grass zone > forest-grass zone, and the contents of three forms of organic carbon were the highest in the diameter group of 0.25-2 mm. The content of organic carbon and its components, as well as the activities of soil enzymes were higher in the soil layer of 0-10 cm than those in the 10-20 cm soil layer of different vegetation zones. The activities of cellulase, β-D-glucosidase, sucrose and urease were in order of forest zone > grass zone > forest-grass zone. The peroxidase activity was in order of forest zone > forest-grass zone > grass zone. The activities of various soil enzymes increased with the decreasing soil particle diameter in the three vegetation zones. The activities of cellulose, peroxidase, sucrose and urease had significant positive correlations with the contents of various forms of organic carbon in the soil aggregates.

  6. Inhibition of osteoclast bone resorption activity through osteoprotegerin-induced damage of the sealing zone.

    PubMed

    Song, Ruilong; Gu, Jianhong; Liu, Xuezhong; Zhu, Jiaqiao; Wang, Qichao; Gao, Qian; Zhang, Jiaming; Cheng, Laiyang; Tong, Xishuai; Qi, Xinyi; Yuan, Yan; Liu, Zongping

    2014-09-01

    Bone remodeling is dependent on the dynamic equilibrium between osteoclast-mediated bone resorption and osteoblast-mediated osteogenesis. The sealing zone is an osteoclast-specific cytoskeletal structure, the integrity of which is critical for osteoclast-mediated bone resorption. To date, studies have focused mainly on the osteoprotegerin (OPG)‑induced inhibition of osteoclast differentiation through the OPG/receptor activator of the nuclear factor kappa-B ligand (RANKL)/RANK system, which affects the bone resorption of osteoclasts. However, the effects of OPG on the sealing zone have not been reported to date. In this study, the formation of the sealing zone was observed by Hoffman modulation contrast (HMC) microscopy and confocal laser scanning microscopy. The effects of OPG on the existing sealing zone and osteoclast-mediated bone resorption activity, as well as the regulatory role of genes involved in the formation of the sealing zone were examined by immunofluorescence staining, HMC microscopy, quantitative reverse transcription polymerase chain reaction (RT-qPCR), western blot analysis and scanning electron microscopy. The sealing zone was formed on day 5, with belt-like protuberances at the cell edge and scattered distribution of cell nuclei, but no filopodia. The sealing zone was intact in the untreated control group. However, defects in the sealing zone were observed in the OPG-treated group (20 ng/ml) and the structure was absent in the groups treated with 40 and 80 ng/ml OPG. The podosomes showed a scattered or clustered distribution between the basal surface of the osteoclasts and the well surface. Furthermore, resorption lacunae were not detected in the 20 ng/ml OPG-treated group, indicating the loss of osteoclast-mediated bone resorption activity. Treatment with OPG resulted in a significant decrease in the expression of Arhgef8/Net1 and DOCK5 Rho guanine nucleotide exchange factors (RhoGEFs), 10 of 18 RhoGTPases (RhoA, RhoB, cdc42v1, cdc42v2

  7. Tsunamigenic potential of Mediterranean fault systems and active subduction zones

    NASA Astrophysics Data System (ADS)

    Petricca, Patrizio; Babeyko, Andrey

    2016-04-01

    Since the North East Atlantic and Mediterranean Tsunami Warning System (NEAMTWS) is under development by the European scientific community, it becomes necessary to define guidelines for the characterization of the numerous parameters must be taken into account in a fair assessment of the risk. Definition of possible tectonic sources and evaluation of their potential is one of the principal issues. In this study we systematically evaluate tsunamigenic potential of up-to-now known real fault systems and active subduction interfaces in the NEAMTWS region. The task is accomplished by means of numerical modeling of tsunami generation and propagation. We have simulated all possible uniform-slip ruptures populating fault and subduction interfaces with magnitudes ranging from 6.5 up to expected Mmax. A total of 15810 individual ruptures were processed. For each rupture, a tsunami propagation scenario was computed in linear shallow-water approximation on 1-arc minute bathymetric grid (Gebco_08) implying normal reflection boundary conditions. Maximum wave heights at coastal positions (totally - 23236 points of interest) were recorded for four hours of simulation and then classified according to currently adopted warning level thresholds. The resulting dataset allowed us to classify the sources in terms of their tsunamigenic potential as well as to estimate their minimum tsunamigenic magnitude. Our analysis shows that almost every source in the Mediterranean Sea is capable to produce local tsunami at the advisory level (i.e., wave height > 20 cm) starting from magnitude values of Mw=6.6. In respect to the watch level (wave height > 50 cm), the picture is less homogeneous: crustal sources in south-west Mediterranean as well as East-Hellenic arc need larger magnitudes (around Mw=7.0) to trigger watch levels even at the nearby coasts. In the context of the regional warning (i.e., source-to-coast distance > 100 km) faults also behave more heterogeneously in respect to the minimum

  8. A new perspective on the radio active zone at the Galactic center - feedback from nuclear activities

    NASA Astrophysics Data System (ADS)

    Zhao, J.-H.; Morris, M. R.; Goss, W. M.

    2014-05-01

    Based on our deep image of Sgr A using broadband data observed with the VLA† at 6 cm, we present a new perspective of the radio bright zone at the Galactic center. We further show the radio detection of the X-ray Cannonball, a candidate neutron star associated with the Galactic center SNR Sgr A East. The radio image is compared with the Chandra X-ray image to show the detailed structure of the radio counterparts of the bipolar X-ray lobes. The bipolar lobes are likely produced by the winds from the activities within Sgr A West, which could be collimated by the inertia of gas in the CND, or by the momentum driving of Sgr A*; and the poloidal magnetic fields likely play an important role in the collimation. The less-collimated SE lobe, in comparison to the NW one, is perhaps due to the fact that the Sgr A East SN might have locally reconfigured the magnetic field toward negative galactic latitudes. In agreement with the X-ray observations, the time-scale of ˜1 × 104 yr estimated for the outermost radio ring appears to be comparable to the inferred age of the Sgr A East SNR.

  9. Dynamical Organization of Syntaxin-1A at the Presynaptic Active Zone.

    PubMed

    Ullrich, Alexander; Böhme, Mathias A; Schöneberg, Johannes; Depner, Harald; Sigrist, Stephan J; Noé, Frank

    2015-09-01

    Synaptic vesicle fusion is mediated by SNARE proteins forming in between synaptic vesicle (v-SNARE) and plasma membrane (t-SNARE), one of which is Syntaxin-1A. Although exocytosis mainly occurs at active zones, Syntaxin-1A appears to cover the entire neuronal membrane. By using STED super-resolution light microscopy and image analysis of Drosophila neuro-muscular junctions, we show that Syntaxin-1A clusters are more abundant and have an increased size at active zones. A computational particle-based model of syntaxin cluster formation and dynamics is developed. The model is parametrized to reproduce Syntaxin cluster-size distributions found by STED analysis, and successfully reproduces existing FRAP results. The model shows that the neuronal membrane is adjusted in a way to strike a balance between having most syntaxins stored in large clusters, while still keeping a mobile fraction of syntaxins free or in small clusters that can efficiently search the membrane or be traded between clusters. This balance is subtle and can be shifted toward almost no clustering and almost complete clustering by modifying the syntaxin interaction energy on the order of only 1 kBT. This capability appears to be exploited at active zones. The larger active-zone syntaxin clusters are more stable and provide regions of high docking and fusion capability, whereas the smaller clusters outside may serve as flexible reserve pool or sites of spontaneous ectopic release.

  10. Reduced endogenous Ca2+ buffering speeds active zone Ca2+ signaling

    PubMed Central

    Delvendahl, Igor; Jablonski, Lukasz; Baade, Carolin; Matveev, Victor; Neher, Erwin; Hallermann, Stefan

    2015-01-01

    Fast synchronous neurotransmitter release at the presynaptic active zone is triggered by local Ca2+ signals, which are confined in their spatiotemporal extent by endogenous Ca2+ buffers. However, it remains elusive how rapid and reliable Ca2+ signaling can be sustained during repetitive release. Here, we established quantitative two-photon Ca2+ imaging in cerebellar mossy fiber boutons, which fire at exceptionally high rates. We show that endogenous fixed buffers have a surprisingly low Ca2+-binding ratio (∼15) and low affinity, whereas mobile buffers have high affinity. Experimentally constrained modeling revealed that the low endogenous buffering promotes fast clearance of Ca2+ from the active zone during repetitive firing. Measuring Ca2+ signals at different distances from active zones with ultra-high-resolution confirmed our model predictions. Our results lead to the concept that reduced Ca2+ buffering enables fast active zone Ca2+ signaling, suggesting that the strength of endogenous Ca2+ buffering limits the rate of synchronous synaptic transmission. PMID:26015575

  11. Dynamical Organization of Syntaxin-1A at the Presynaptic Active Zone

    PubMed Central

    Ullrich, Alexander; Böhme, Mathias A.; Schöneberg, Johannes; Depner, Harald; Sigrist, Stephan J.; Noé, Frank

    2015-01-01

    Synaptic vesicle fusion is mediated by SNARE proteins forming in between synaptic vesicle (v-SNARE) and plasma membrane (t-SNARE), one of which is Syntaxin-1A. Although exocytosis mainly occurs at active zones, Syntaxin-1A appears to cover the entire neuronal membrane. By using STED super-resolution light microscopy and image analysis of Drosophila neuro-muscular junctions, we show that Syntaxin-1A clusters are more abundant and have an increased size at active zones. A computational particle-based model of syntaxin cluster formation and dynamics is developed. The model is parametrized to reproduce Syntaxin cluster-size distributions found by STED analysis, and successfully reproduces existing FRAP results. The model shows that the neuronal membrane is adjusted in a way to strike a balance between having most syntaxins stored in large clusters, while still keeping a mobile fraction of syntaxins free or in small clusters that can efficiently search the membrane or be traded between clusters. This balance is subtle and can be shifted toward almost no clustering and almost complete clustering by modifying the syntaxin interaction energy on the order of only 1 kBT. This capability appears to be exploited at active zones. The larger active-zone syntaxin clusters are more stable and provide regions of high docking and fusion capability, whereas the smaller clusters outside may serve as flexible reserve pool or sites of spontaneous ectopic release. PMID:26367029

  12. Microbial respiration and extracellular enzyme activity in sediments from the Gulf of Mexico hypoxic zone

    EPA Science Inventory

    This study explores the relationship between sediment chemistry (TC, TN, TP) and microbial respiration (DHA) and extracellular enzyme activity (EEA) across the Gulf of Mexico (GOM) hypoxic zone. TC, TN, and TP were all positively correlated with each other (r=0.19-0.68). DHA was ...

  13. 77 FR 47429 - Agency Information Collection Activities; Petroleum Refineries in Foreign Trade Sub-zones

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-08

    ... SECURITY U.S. Customs and Border Protection Agency Information Collection Activities; Petroleum Refineries... concerning the Petroleum Refineries in Foreign Trade Sub-zones. This request for comment is being made... CBP is soliciting comments concerning the following information collection: Title:...

  14. Active and passive-source imaging of the Cascadia subduction zone using both onshore and offshore data

    NASA Astrophysics Data System (ADS)

    Janiszewski, H. A.; Abers, G. A.; Carton, H. D.; Webb, S. C.; Gaherty, J. B.; Trehu, A. M.

    2013-12-01

    The Cascadia subduction zone is characterized by the subduction of young lithosphere with relatively little seismicity, despite evidence of prehistoric earthquakes, and a thick incoming sediment section that feeds the plate interface. It has been suggested that the thrust zone forms a high-porosity channel of near-lithostatic pressure to 40 km depth, but stronger metasediments may also explain many observations. To test these hypotheses, we analyze new data and integrate results from both active and passive-source seismic studies of Cascadia that sample the interplate thrust zone. In June-July 2012, fifteen seismometers were deployed in Washington from the coast to 140 km inland to record airguns from the R/V Langseth along a linear trench-perpendicular profile. We also analyze broadband data from the coincident onshore CAFE (2006-08) broadband high-density array, which provided high-resolution receiver function images of the downgoing plate, and with the offshore Grays Harbor array of the Cascadia Initiative (CI). In the active-source data, arrivals are observed at up to 140 km offset from the stations, the farthest of which are likely turning waves that travel in the slab mantle. Signals from all but the farthest inland stations are dominated by strong reverberating signals at 20-90 km offset. Preliminary calculations indicate that some of these signals have apparent velocity and timing consistent with waves that reflect off the plate interface or just above it. Bounce points for these rays map a zone of high reflectivity extending ~15-20 km on either side of the coastline. Some aspects of the signals may indicate an origin on or near the plate boundary. In addition, these reflections directly underlie CAFE stations where receiver functions have been obtained on land and the CI broadband stations where receiver functions are being obtained offshore, allowing for direct comparison and integration of all three datasets. The CI stations present several challenges

  15. AHA! A Cool Salt Water/Density Activity--The Joy of Designing a Simple Experiment.

    ERIC Educational Resources Information Center

    Carlson, Gaylen R.

    1998-01-01

    Describes two science activities concerning water density and shares an idea for combining these activities into a third, completely new activity. Demonstrates the joy of rekindling the spirit of scientific thinking in a typical classroom. (PVD)

  16. Density increase due to active feedback in mirror machine

    NASA Astrophysics Data System (ADS)

    Seemann, Omri; Be'Ery, Ilan

    2014-10-01

    Mirror machines are one of the schemes for future fusion systems. Its main drawbacks are the flute instability and being open ended which results in plasma losses. A feedback system is used to stabilize the flute instability in a table top mirror machine with a continuous plasma source and RF heating. Under certain source density and temperature conditions, although the plasma was stabilized, plasma density increase was not measured. After decreasing the source density and increasing the temperature, Plasma density increase was achieved. It is theorized that these results are due to transition of the plasma main loss mechanism from collision dominated to instability dominated. In the former, the main density loss is through diffusion and In the latter, it is through flute instability which drives the plasma to the edge of the vacuum chamber. Future research directions are discussed for a planned machine which should achieve higher temperatures and better diagnostic capabilities. The research will focus on magnetic actuators and passive RF stabilization.

  17. Silicic volcanism in Iceland: Composition and distribution within the active volcanic zones

    NASA Astrophysics Data System (ADS)

    Jónasson, Kristján

    2007-01-01

    Silicic volcanic rocks within the active volcanic zones of Iceland are mainly confined to central volcanoes. The volcanic zones of Iceland can be divided into rift zones and flank zones. Each of these zones contains several central volcanoes, most of which have produced minor amounts of silicic rocks. The silicic rocks occur as lavas and domes or as tephra layers, welded tuffs and ignimbrites, formed both in effusive and explosive eruptions. They tend to be glassy or very fine-grained, containing small amounts of phenocrysts. Plagioclase (andesine-oligoclase), anorthoclase or occasionally sanidine coexist with minerals such as augite, fayalite, pigeonite, orthopyroxene and magnetite. Quartz phenocrysts are exceedingly rare. Zoning of phenocrysts is limited and the pattern is variable. A set of 90 samples representing all active central volcanoes that have erupted silicic rocks was analysed for major- and trace-elements. The silicic rocks can be classified as dacites, trachytes, low-alkali rhyolites and alkalic rhyolites. Some of the trachytes and alkalic rhyolites are peralkaline (mostly comenditic). Trachytes and alkalic rhyolites are only found within the flank zones, while dacites and low-alkali rhyolites are mostly confined to the rift zones. The Icelandic rhyolites plot close to the thermal minimum in the "granite" system, while dacites and trachytes plot within the plagioclase field and towards the alkali feldspar temperature minimum. The silicic rocks are relatively Fe-rich and Ca-poor indicating low water pressure in the source. Trace element concentrations follow similar patterns in most central volcanoes. Exceptions are Torfajökull where silicic rocks display a negative correlation of Ba to Th and unusually high Th-contents, and the western flank zone where Ba-concentrations are highly variable. The ratios of different high field-strength elements are generally similar within each central volcano or region, which probably reflects different ratios in the

  18. Population density and total biomass of microbial communities in chestnut soils and solonetzes of the dry steppe zone in the Lower Volga region

    NASA Astrophysics Data System (ADS)

    Kashirskaya, N. N.; Khomutova, T. E.; Chernysheva, E. V.; El'tsov, M. V.; Demkin, V. A.

    2015-03-01

    The population density and total biomass of microbial communities were determined in chestnut soils and solonetzes of the dry steppe zone in the Lower Volga region with the use of the methods of sequential fractionation of the soil and direct counting. The mean weighted values of the population density of the microbial communities in the soil profiles (A1 + B1 + B2 horizons) in the studied soils varied within 3.8-8.0 × 1011 cells/g of soil. The total microbial biomass in the soils of the Privolzhskaya Upland reached 0.9-2.4 mg C/g of soil; in the soils of the Ergeni Upland, it was 20 to 75% lower. The microbial cells in the soils of the Privolzhskaya Upland were larger than those in the soils of the Ergeni Upland. Sequential fractionation of the soil prior to direct counting contributed to the more complete assessment of the population density of the microbial communities.

  19. Hydrogen Gas Emissions from Active Faults and Identification of Flow Pathway in a Fault Zone

    NASA Astrophysics Data System (ADS)

    Ishimaru, T.; Niwa, M.; Kurosawa, H.; Shimada, K.

    2010-12-01

    It has been observed that hydrogen gas emissions from the subsurface along active faults exceed atmospheric concentrations (e.g. Sugisaki et. al., 1983). Experimental studies have shown that hydrogen gas is generated in a radical reaction of water with fractured silicate minerals due to rock fracturing caused by fault movement (e.g. Kita et al., 1982). Based on such research, we are studying an investigation method for an assessment of fault activity using hydrogen gas emissions from fracture zones. To start, we have devised portable equipment for rapid and simple in situ measurement of hydrogen gas emissions (Shimada et al., 2008). The key component of this equipment is a commercially available and compact hydrogen gas sensor with an integral data logger operable at atmospheric pressure. In the field, we have drilled shallow boreholes into incohesive fault rocks to depths ranging from 15 to 45 cm using a hand-operated drill with a 9mm drill-bit. Then, we have measured the hydrogen gas concentrations in emissions from active faults such as: the western part of the Atotsugawa fault zone, the Atera fault zone and the Neodani fault in central Japan; the Yamasaki fault zone in southwest Japan; and the Yamagata fault zone in northeast Japan. In addition, we have investigated the hydrogen gas concentrations in emissions from other major geological features such as tectonic lines: the Butsuzo Tectonic Line in the eastern Kii Peninsula and the Atokura Nappe in the Northeastern Kanto Mountains. As a result of the investigations, hydrogen gas concentration in emissions from the active faults was measured to be in the approximate range from 6,000 ppm to 26,000 ppm in two to three hours after drilling. A tendency for high concentrations of hydrogen gas in active faults was recognized, in contrast with low concentrations in emissions from tectonic lines that were observed to be in the range from 730 ppm to 2,000 ppm. It is inferred that the hydrogen gas migrates to ground

  20. 77 FR 39209 - Foreign-Trade Zone 74-Baltimore, MD, Notification of Proposed Production Activity, J.D. Neuhaus...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-02

    ... Foreign-Trade Zones Board Foreign-Trade Zone 74--Baltimore, MD, Notification of Proposed Production Activity, J.D. Neuhaus LP (Overhead Lifting Equipment Production) Sparks, MD The Baltimore Development Corporation, grantee of FTZ 74, submitted a notification of proposed production activity on behalf of...

  1. 77 FR 52680 - Foreign-Trade Zone 242-Boundary County, ID, Notification of Proposed Production Activity, AREVA...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-30

    ... Foreign-Trade Zones Board Foreign-Trade Zone 242--Boundary County, ID, Notification of Proposed Production Activity, AREVA Enrichment Services, LLC, (Gas Centrifuge Production Equipment), Bonneville County, ID Boundary County, grantee of FTZ 242, submitted a notification of proposed production activity on behalf...

  2. 77 FR 63290 - Foreign-Trade Zone 74-Baltimore, MD, Authorization of Production Activity, J.D. Neuhaus LP...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-16

    ... Foreign-Trade Zones Board Foreign-Trade Zone 74--Baltimore, MD, Authorization of Production Activity, J.D. Neuhaus LP, (Overhead Lifting Equipment Production), Sparks, MD On June 13, 2012, the Baltimore Development Corporation, grantee of FTZ 74, submitted a notification of proposed production activity on...

  3. Implementing an Inexpensive and Accurate Introductory Gas Density Activity with High School Students

    ERIC Educational Resources Information Center

    Cunningham, W. Patrick; Joseph, Christopher; Morey, Samantha; Santos Romo, Ana; Shope, Cullen; Strang, Jonathan; Yang, Kevin

    2015-01-01

    A simplified activity examined gas density while employing cost-efficient syringes in place of traditional glass bulbs. The exercise measured the density of methane, with very good accuracy and precision, in both first-year high school and AP chemistry settings. The participating students were tasked with finding the density of a gas. The…

  4. Transport critical current density of melt textured YBa2Cu3O7 - x rods prepared by zone melting using a high temperature gradient

    NASA Astrophysics Data System (ADS)

    Brand, M.; Elschner, S.; Gauss, S.; Assmus, W.

    1994-04-01

    We have developed a quasicontinuous crucible free zone melting method for texturing YBCO bulk material. Dense sintered rods with a length of 10 cm were partially molten in the hot zone of a 5 zone furnace and recrystallized in the large temperature gradient (140 °C/cm) limiting this zone. Suitable additions of Y2BaCuO5 (20 mol %) and PtO2 (1 wt %) to the starting material and a growth rate of not more than 1 mm/h were necessary to obtain stable growth conditions. After natural grain selection we obtained 8-cm-long rods with a uniform orientation of the crystallographic axes within 2°. The angle between c direction and rod axis typically was 55°. The critical current density at 77 K measured with continuous current over a length of 4.5 cm was 1.3×104 A/cm2 in zero field and 8×103 A/cm2 in 0.5 T. These values confirm the absence of grain boundaries.

  5. Holocene activity of the Rose Canyon fault zone in San Diego, California

    NASA Astrophysics Data System (ADS)

    Lindvall, Scott C.; Rockwell, Thomas K.

    1995-12-01

    The Rose Canyon fault zone in San Diego, California, has many well-expressed geomorphic characteristics of an active strike-slip fault, including scarps, offset and deflected drainages and channel walls, pressure ridges, a closed depression, and vegetation lineaments. Geomorphic expression of the fault zone from Mount Soledad south to Mission Bay indicates that the Mount Soledad strand is the most active. A network of trenches excavated across the Mount Soledad strand in Rose Creek demonstrate a minimum of 8.7 m of dextral slip in a distinctive early to middle Holocene gravel-filled channel that crosses the fault zone. The gravel-filled channel was preserved within and east of the fault but was removed west of the fault zone by erosion or possibly grading during development. Consequently, the actual displacement of the channel could be greater than 8.7 m. Radiocarbon dates on detrital charcoal recovered from the sediments beneath the channel yield a maximum calibrated age of about 8.1±0.2 kyr. The minimum amount of slip along with the maximum age yield a minimum slip rate of 1.07±0.03 mm/yr on this strand of the Rose Canyon fault zone for much of Holocene time. Other strands of the Rose Canyon fault zone, which are east and west of our site, may also have Holocene activity. Based on an analysis of the geomorphology of fault traces within the Rose Canyon fault zone, along with the results of our trenching study, we estimate the maximum likely slip rate at about 2 mm/yr and a best estimate of about 1.5 mm/yr. Stratigraphie evidence of at least three events is present during the past 8.1 kyr. The most recent surface rupture displaces the modern A horizon (topsoil), suggesting that this event probably occurred within the past 500 years. Stratigraphie and structural relationships also indicate the occurrence of a scarp-forming event at about 8.1 kyr, prior to deposition of the gravel-filled channel that was used as a piercing line. A third event is indicated by the

  6. A rod-type creepmeter for measurement of displacement in active fault zone

    NASA Astrophysics Data System (ADS)

    Lee, J.-C.; Jeng, F.-S.; Chu, H.-T.; Angelier, J.; Hu, J.-C.

    2000-05-01

    A creepmeter has been developed to monitor gradual displacements of near-surface movement in an active fault zone. This rod-type creepmeter is a robust, low-cost instrument that is simple to construct and install. This creepmeter consists of two 3-m invar rods attached to anchored steel piers at each end, straddling the surface traces of active fault. The invar rods are supported by a pair of U-shaped solid steel girders. A mechanical dial-gauge sensor in the middle of the creepmeter is adopted to record the displacement of fault creep, and has a precision of 0.01 mm. Because the creepmeter is installed on the surface, the temperature effect is important. To calibrate and correct for the temperature effect, we carried out hourly measurements over a period of 30 hours to calculate the thermal expansion coefficients for each creepmeter. Thermal corrections could thus be made when readings were taken. Five of these creepmeters have been installed in the Chihshang active fault zone of eastern Taiwan, in the present collision suture zone between the Philippine Sea plate and the Eurasian plate. Readings taken over one year have shown that this rod-type creepmeter is effective in providing a near-continuous record of active fault creep with a good precision.

  7. Readily releasable vesicles recycle at the active zone of hippocampal synapses.

    PubMed

    Schikorski, Thomas

    2014-04-08

    During the synaptic vesicle cycle, synaptic vesicles fuse with the plasma membrane and recycle for repeated exo/endocytic events. By using activity-dependent N-(3-triethylammoniumpropyl)-4-(4-(dibutylamino) styryl) pyridinium dibromide dye uptake combined with fast (<1 s) microwave-assisted fixation followed by photoconversion and ultrastructural 3D analysis, we tracked endocytic vesicles over time, "frame by frame." The first retrieved synaptic vesicles appeared 4 s after stimulation, and these endocytic vesicles were located just above the active zone. Second, the retrieved vesicles did not show any sign of a protein coat, and coated pits were not detected. Between 10 and 30 s, large labeled vesicles appeared that had up to 5 times the size of an individual synaptic vesicle. Starting at around 20 s, these large labeled vesicles decreased in number in favor of labeled synaptic vesicles, and after 30 s, labeled vesicles redocked at the active zone. The data suggest that readily releasable vesicles are retrieved as noncoated vesicles at the active zone.

  8. 78 FR 45181 - Foreign-Trade Zone 230-Piedmont Triad Area, North Carolina, Authorization of Production Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-26

    ... Production Activity, Oracle Flexible Packaging, Inc., (Foil-Backed Paperboard), Winston-Salem, North Carolina... proposed production activity to the Foreign-Trade Zones (FTZ) Board on behalf of Oracle Flexible...

  9. 78 FR 60826 - Foreign-Trade Zone 155-Calhoun/Victoria Counties, Texas; Authorization of Production Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-02

    ... Production Activity; Caterpillar, Inc. (Excavator and Frame Assembly Production); Victoria, Texas On May 29... proposed production activity to the Foreign-Trade Zones (FTZ) Board on behalf of Caterpillar, Inc.,...

  10. Earthquake swarm activity in the Oaxaca segment of Middle American Subduction Zone

    NASA Astrophysics Data System (ADS)

    Brudzinski, M. R.; Cabral, E.; Arciniega-Ceballos, A.

    2013-05-01

    An outstanding question in geophysics is the degree to which the newly discovered family of slow fault slip behaviors is related to more traditional earthquakes, especially since theoretical predictions indicate slip in the deeper transitional zone promotes failure in the shallower seismogenic zone. The Oaxacan segment of the Middle American Subduction zone is a natural region to pursue detailed studies of the spectrum of fault slip due to the unusually shallow subduction angle and short trench-to-coast distances that bring broad portions of the seismogenic and transitional zones of the plate interface inland. A deployment of broadband seismometers in this region has improved the network coverage to ~70 km station spacing since 2006, providing new opportunities to investigate smaller seismic phenomena. While characterization of tectonic tremor has been a prominent focus of this deployment, the improved network has also revealed productive earthquake swarms, whose sustained periods of similar magnitude earthquakes are also thought to be driven by slow slip. We identify a particularly productive earthquake swarm in July 2006 (~600 similar earthquakes detected), which occurred during a week-long episode of tectonic tremor and geodetically detected slow slip. Using a multi-station "template matching" waveform cross correlation technique, we have been able to detect and locate swarm earthquakes several orders of magnitude smaller than that of traditional processing, particularly during periods of increased background activity, because the detector is finely tuned to events with similar hypocentral location and focal mechanism. When we scan for repeats of the event families detected in the July 2006 sequence throughout the 6+ years since, we find these families were also activated during several other slow slip episodes, which indicates a link between slow slip in the transition zone and earthquakes at the downdip end of the seismogenic portion of the megathrust.

  11. Self-Polarizing Microswimmers in Active Density Waves

    NASA Astrophysics Data System (ADS)

    Geiseler, Alexander; Hänggi, Peter; Marchesoni, Fabio

    2017-02-01

    An artificial microswimmer drifts in response to spatio-temporal modulations of an activating suspension medium. We consider two competing mechanisms capable of influencing its tactic response: angular fluctuations, which help it explore its surroundings and thus diffuse faster toward more active regions, and self-polarization, a mechanism inherent to self-propulsion, which tends to orient the swimmer’s velocity parallel or antiparallel to the local activation gradients. We investigate, both numerically and analytically, the combined action of such two mechanisms. By determining their relative magnitude, we characterize the selective transport of artificial microswimmers in inhomogeneous activating media.

  12. Self-Polarizing Microswimmers in Active Density Waves.

    PubMed

    Geiseler, Alexander; Hänggi, Peter; Marchesoni, Fabio

    2017-02-09

    An artificial microswimmer drifts in response to spatio-temporal modulations of an activating suspension medium. We consider two competing mechanisms capable of influencing its tactic response: angular fluctuations, which help it explore its surroundings and thus diffuse faster toward more active regions, and self-polarization, a mechanism inherent to self-propulsion, which tends to orient the swimmer's velocity parallel or antiparallel to the local activation gradients. We investigate, both numerically and analytically, the combined action of such two mechanisms. By determining their relative magnitude, we characterize the selective transport of artificial microswimmers in inhomogeneous activating media.

  13. Self-Polarizing Microswimmers in Active Density Waves

    PubMed Central

    Geiseler, Alexander; Hänggi, Peter; Marchesoni, Fabio

    2017-01-01

    An artificial microswimmer drifts in response to spatio-temporal modulations of an activating suspension medium. We consider two competing mechanisms capable of influencing its tactic response: angular fluctuations, which help it explore its surroundings and thus diffuse faster toward more active regions, and self-polarization, a mechanism inherent to self-propulsion, which tends to orient the swimmer’s velocity parallel or antiparallel to the local activation gradients. We investigate, both numerically and analytically, the combined action of such two mechanisms. By determining their relative magnitude, we characterize the selective transport of artificial microswimmers in inhomogeneous activating media. PMID:28181504

  14. No Evidence for Activity Adjustment in Response to Increased Density in Daphnia magna

    PubMed Central

    Sereni, Laura; Einum, Sigurd

    2015-01-01

    Increased population density may lead to a decrease in energy available for growth and reproduction via effects on the activity level of individuals. Whilst this may be of particular importance for organisms that compete for defendable resources and/or have a high frequency of social interactions, it is less obvious how individual activity should covary with population density when food resources are not defendable or direct interactions among individuals are negligible. Based on observations that there is a general negative relationship between population density and metabolism it has been suggested that organisms actively reduce activity under increased density to accommodate an expected decrease in food availability. However, in the absence of direct activity measurements the validity of this hypothesis is unclear. Here we test for such anticipatory adjustments of activity levels in the planktonic cladoceran Daphnia magna Straus, a filter feeder whose food resources are not defendable, meaning that density responses can be evaluated in the absence of direct interactions. We tested for changes in activity in response to two separate density cues, one being the direct physical and visual stimuli resulting from being in the vicinity of conspecifics (‘direct density experiment’), and the other being the detection of olfactory cues in their environment (‘olfactory cue experiment’). Ten genetically distinct clones were used to evaluate the potential for genetic variation in these responses. Our measures of activity were highly repeatable, and there was significant variation in activity among clones. Furthermore, this clonal variation was consistent in the ‘direct density’ and ‘olfactory cue’ experiments. The estimated evolvability of the trait (1.3–3.2%) was within the range typically observed in behavioural traits. However, there was no indication that the activity level of individuals respond to population density, either directly to actual density

  15. High Fc Density Particles Result in Binary Complement Activation but Tunable Macrophage Phagocytosis

    NASA Astrophysics Data System (ADS)

    Sulchek, Todd; Pacheco, Patricia; White, David

    2014-03-01

    Macrophage phagocytosis and complement system activation represent two key components of the immune system and both can be activated through the presentation of multiple Fc domains of IgG antibodies. We have created functionalized micro- and nanoparticles with various densities of Fc domains to understand the modulation of the immune system for eventual use as a novel immunomodulation platform. Phagocytosis assays were carried out by adding functionalized particles to macrophage cells and quantitatively determined using fluorescent microscopy and flow cytometry. Complement system activation by the functionalized particles in human serum was quantified with an enzyme immunoassay. Our phagocytosis assay revealed a strong dependence on particle size and Fc density. For small particles, as the Fc density increased, the number of particles phagocytosed also increased. Large particles were phagocytosed at significantly lower levels and showed no dependency on Fc density. Complement was successfully activated at levels comparable to positive controls for small particles at high Fc densities. However at low Fc densities, there is a significant decrease in complement activation. This result suggests a binary response for complement system activation with a threshold density for successful activation. Therefore, varying the Fc density on micro/nanoparticles resulted in a tunable response in macrophage phagocytosis while a more binary response for complement activation.

  16. Can phosphatidylserine enhance atheroprotective activities of high-density lipoprotein?

    PubMed

    Darabi, Maryam; Kontush, Anatol

    2016-01-01

    Although high-density lipoprotein (HDL) is well known to be protective against atherosclerotic cardiovascular disease, therapeutic interventions to raise HDL-cholesterol levels do not translate into reduction in cardiovascular risk. Due to the compositional complexity of HDL particles, molecular determinants of their atheroprotective function still remain to be clarified. Recent structural and functional data identify phospholipid as a major bioactive component of HDL. Such a role has recently been specifically evidenced for phosphatidylserine (PS); indeed, HDL content of PS displayed positive correlations with all metrics of HDL functionality assessed. This review summarizes current knowledge about HDL-associated PS; possible mechanisms for its atheroprotective role are discussed and potential applications of PS to HDL-based therapies are highlighted.

  17. Micro 3D ERT tomography for data assimilation modelling of active root zone

    NASA Astrophysics Data System (ADS)

    Vanella, Daniela; Busato, Laura; Boaga, Jacopo; Cassiani, Giorgio; Binley, Andrew; Putti, Mario; Consoli, Simona

    2016-04-01

    Within the soil-plant-atmosphere system, root activity plays a fundamental role, as it connects different domains and allows a large part of the water and nutrient exchanges necessary for plant sustenance. The understanding of these processes is not only useful from an environmental point of view, making a fundamental contribution to the understanding of the critical zone dynamics, but also plays a pivotal role in precision agriculture, where the optimisation of water resources exploitation is mandatory and often carried out through deficit irrigation techniques. In this work, we present the results of non-invasive monitoring of the active root zone of two orange trees (Citrus sinensis, cv Tarocco Ippolito) located in an orange orchard in eastern Sicily (Italy) and drip irrigated with two different techniques: partial root drying and 100% crop evapotranspiration. The main goal of the monitoring activity is to assess possible differences between the developed root systems and the root water uptake between the two irrigation strategies. The monitoring is conducted using 3D micro-electrical resistivity tomography (ERT) based on an apparatus composed of a number of micro-boreholes (about 1.2 m deep) housing 12 electrodes each, plus a number of surface electrodes. Time-lapse measurements conducted both with long-term periodicity and short-term repetition before and after irrigation clearly highlight the presence and distribution of root water uptake zone both at shallow and larger depth, likely to correspond to zones utilized during the irrigation period (shallow) and during the time when the crop is not irrigated (deep). Subsidiary information is available in terms of precipitation, sap flow measurements and micrometeorological evapotranspiration estimates. This data ensemble lends itself to the assimilation into a variably saturated flow model, where both soil hydraulic parameters and root distribution shall be identified. Preliminary results in this directions show

  18. Micro 3D ERT tomography for data assimilation modelling of active root zone

    NASA Astrophysics Data System (ADS)

    Cassiani, G.; Boaga, J.; Busato, L.; Vanella, D.; Consoli, S.; Binley, A. M.

    2015-12-01

    Within the soil-plant-atmosphere system, root activity plays a fundamental role, as it connects different domains and allows a large part of the water and nutrient exchanges necessary for plant sustenance. The understanding of these processes is not only useful from an environmental point of view, making a fundamental contribution to the understanding of the critical zone dynamics, but also plays a pivotal role in precision agriculture, where the optimisation of water resources exploitation is mandatory and often carried out through deficit irrigation techniques. In this work, we present the results of non-invasive monitoring of the active root zone of two orange trees (Citrus sinensis, cv Tarocco Ippolito) located in an orange orchard in eastern Sicily (Italy) and drip irrigated with two different techniques: partial root drying and 100% crop evapotranspiration. The main goal of the monitoring activity is to assess possible differences between the developed root systems and the root water uptake between the two irrigation strategies. The monitoring is conducted using 3D micro-electrical resistivity tomography (ERT) based on an apparatus composed of a number of micro-boreholes (about 1.2 m deep) housing 12 electrodes each, plus a number of surface electrodes. Time-lapse measurements conducted both with long-term periodicity and short-term repetition before and after irrigation clearly highlight the presence and distribution of root water uptake zone both at shallow and larger depth, likely to correspond to zones utilized during the irrigation period (shallow) and during the time when the crop is not irrigated (deep). Subsidiary information is available in terms of precipitation, sap flow measurements and micrometeorological evapotranspiration estimates. This data ensemble lends itself to the assimilation into a variably saturated flow model, where both soil hydraulic parameters and root distribution shall be identified. Preliminary results in this directions show

  19. Fault zone structure and inferences on past activities of the active Shanchiao Fault in the Taipei metropolis, northern Taiwan

    NASA Astrophysics Data System (ADS)

    Chen, C.; Lee, J.; Chan, Y.; Lu, C.

    2010-12-01

    The Taipei Metropolis, home to around 10 million people, is subject to seismic hazard originated from not only distant faults or sources scattered throughout the Taiwan region, but also active fault lain directly underneath. Northern Taiwan including the Taipei region is currently affected by post-orogenic (Penglai arc-continent collision) processes related to backarc extension of the Ryukyu subduction system. The Shanchiao Fault, an active normal fault outcropping along the western boundary of the Taipei Basin and dipping to the east, is investigated here for its subsurface structure and activities. Boreholes records in the central portion of the fault were analyzed to document the stacking of post- Last Glacial Maximum growth sediments, and a tulip flower structure is illuminated with averaged vertical slip rate of about 3 mm/yr. Similar fault zone architecture and post-LGM tectonic subsidence rate is also found in the northern portion of the fault. A correlation between geomorphology and structural geology in the Shanchiao Fault zone demonstrates an array of subtle geomorphic scarps corresponds to the branch fault while the surface trace of the main fault seems to be completely erased by erosion and sedimentation. Such constraints and knowledge are crucial in earthquake hazard evaluation and mitigation in the Taipei Metropolis, and in understanding the kinematics of transtensional tectonics in northern Taiwan. Schematic 3D diagram of the fault zone in the central portion of the Shanchiao Fault, displaying regional subsurface geology and its relation to topographic features.

  20. Temperature and density structure of a recurring active region jet

    NASA Astrophysics Data System (ADS)

    Mulay, Sargam M.; Zanna, Giulio Del; Mason, Helen

    2017-01-01

    Aims: We present a study of a recurring jet observed on October 31, 2011 by the Atmosphereic Imaging Assembly (AIA) on board the Solar Dynamic Observatory, the X-ray Telescope (XRT) and EUV Imaging Spectrometer (EIS) on board Hinode. We discuss the physical parameters of the jet that are obtained using imaging and spectroscopic observations, such as density, differential emission measure, peak temperature, velocity, and filling factor. Methods: A differential emission measure (DEM) analysis was performed at the region of the jet spire and the footpoint using EIS observations and also by combining AIA and XRT observations. The resulting EIS DEM curves were compared to those obtained with AIA-XRT. The DEM curves were used to create synthetic spectra with the CHIANTI atomic database. The predicted total count rates for each AIA channel were compared with the observed count rates. The effects of varying elemental abundances and the temperature range for the DEM inversion were investigated. Spectroscopic diagnostics were used to obtain an electron number density distribution for the jet spire and the jet footpoint. Results: The plasma along the line of sight in the jet spire and jet footpoint was found to be peak at 2.0 MK (log T [K] = 6.3). We calculated electron densities using the Fe XII (λ186/λ195) line ratio in the region of the spire (Ne = 7.6 × 1010 cm-3) and the footpoint (1.1 × 1011 cm-3). The plane-of-sky velocity of the jet is found to be 524 km s-1. The resulting EIS DEM values are in good agreement with those obtained from AIA-XRT. The synthetic spectra contributing to each AIA channel confirms the multi-thermal nature of the AIA channels in both regions. There is no indication of high temperatures, such as emission from Fe XVII (λ254.87) (log T [K] = 6.75) seen in the jet spire. In the case of the jet footpoint, synthetic spectra predict weak contributions from Ca XVII (λ192.85) and Fe XVII (λ254.87). With further investigation, we confirmed

  1. Microearthquake activity on the Orozco Fracture Zone: Preliminary results from Project ROSE

    SciTech Connect

    Not Available

    1981-05-10

    We present preliminary hypocenter determinations for 52 earthquakes recorded by a large multiinstitutional network of ocean bottom seismometers and ocean bottom hydrophones in the Orozco Fracture Zone in the eastern Pacific during late February to mid-March 1979. The network was deployed as part of the Rivera Ocean Seismic Experiment, also known as Project ROSE. The Orozco Fracture Zone is Physiographically complex, and the pattern of microearthquake hypocenters at least partly reflects this complexity. All of the well-located epicenters lie within the active transform fault segment of the fracture zone. About half of the recorded earthquakes were aligned along a narrow trough that extends eastward from the northern rise crest intersection in the approximate direction of the Cocos-Pacific relative plate motion; these events appear to be characterized by strike-slip faulting. The second major group of activity occurred in the central portion of the transform fault; the microearthquakes in this group do not display a preferred alignment parallel to the direction of spreading, and several are not obviously associated with distinct topographic features. Hypocentral depth was well resolved for many of the earthquakes reported here. Nominal depths range from 0 to 17 km below the seafloor.

  2. 78 FR 13857 - Foreign-Trade Zone 93-Raleigh-Durham, NC; Authorization of Production Activity; Revlon Consumer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-01

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 93--Raleigh-Durham, NC; Authorization of Production Activity; Revlon Consumer Products Corporation (Hair Coloring Products); Oxford, NC On October 10, 2012,...

  3. 78 FR 58995 - Foreign-Trade Zone (FTZ) 138-Columbus, Ohio; Notification of Proposed Production Activity; Rolls...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-25

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone (FTZ) 138--Columbus, Ohio; Notification of Proposed Production Activity; Rolls Royce Energy Systems, Inc. (Industrial Gas Turbines, Power Generation Turbines, and Generator Sets); Mount Vernon, Ohio...

  4. 78 FR 16465 - Foreign-Trade Zone 7-Mayaguez, Puerto Rico, Authorization of Production Activity, Pepsi Cola...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-15

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 7--Mayaguez, Puerto Rico, Authorization of Production Activity, Pepsi Cola Puerto Rico Distributing, LLC (Soft Drink and Fruit Drink Beverages), Toa Baja,...

  5. 78 FR 62583 - Foreign-Trade Zone 39-Dallas-Fort Worth, Texas; Authorization of Production Activity; Lasko...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 39--Dallas-Fort Worth, Texas; Authorization of Production Activity; Lasko Products, Inc. (Household Electric Fans); Fort Worth, Texas On May 21, 2013, Lasko...

  6. 78 FR 40427 - Foreign-Trade Zone (FTZ) 183-Austin, Texas; Notification of Proposed Production Activity; Samsung...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-05

    ... Foreign-Trade Zones Board Foreign-Trade Zone (FTZ) 183--Austin, Texas; Notification of Proposed Production Activity; Samsung Austin Semiconductor, LLC (Semiconductors); Austin, Texas Samsung Austin Semiconductor... the FTZ Board for its facility in Austin, Texas. The notification conforming to the requirements...

  7. 77 FR 56611 - Foreign-Trade Zone 216-Olympia, WA; Authorization of Production Activity; Callisons, Inc. (Mint...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-13

    ... [Federal Register Volume 77, Number 178 (Thursday, September 13, 2012)] [Notices] [Page 56611] [FR Doc No: 2012-22601] DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [B-38-2012] Foreign-Trade Zone 216--Olympia, WA; Authorization of Production Activity; Callisons, Inc. (Mint Products); Lacey...

  8. 78 FR 29322 - Foreign-Trade Zone 41-Milwaukee, Wisconsin; Authorization of Production Activity; Subzone 41J...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 41--Milwaukee, Wisconsin; Authorization of Production Activity; Subzone 41J; Generac Power Systems, Inc. (Generators, Pressure Washers, Engines and Other...

  9. 78 FR 43141 - Foreign-Trade Zone 93-Raleigh-Durham, North Carolina, Authorization of Production Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-19

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 93--Raleigh-Durham, North Carolina, Authorization of Production Activity, Southern Lithoplate, Inc. (Aluminum Printing Plates), Youngsville, North Carolina...

  10. 77 FR 63290 - Foreign-Trade Zone 61-San Juan, Puerto Rico; Authorization of Production Activity, Pfizer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-16

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 61--San Juan, Puerto Rico; Authorization of Production Activity, Pfizer Pharmaceuticals, LLC (Subzone 61A), (Ibuprofen Pharmaceutical Products), Guayama,...

  11. 78 FR 79390 - Foreign-Trade Zone (FTZ) 265-Conroe, Texas, Notification of Proposed Production Activity, Bauer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-30

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone (FTZ) 265--Conroe, Texas, Notification of Proposed Production Activity, Bauer Manufacturing Inc., (Pile Drivers, Boring Machinery, and Foundation Construction Equipment), Conroe, Texas The City of Conroe,...

  12. 77 FR 71167 - Foreign-Trade Zone 37-Orange County, New York, Authorization of Production Activity, Takasago...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 37--Orange County, New York, Authorization of Production Activity, Takasago International Corporation (Fragrances), Harriman, New York On July 26, 2012,...

  13. 77 FR 75406 - Foreign-Trade Zone 26-Atlanta, GA; Notification of Proposed Production Activity; Perkins Shibaura...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE Foreign-Trade Zones Board Foreign-Trade Zone 26--Atlanta, GA; Notification of Proposed Production Activity; Perkins Shibaura Engines LLC, (Diesel Engines), Griffin, GA Perkins Shibaura Engines LLC (Perkins Shibaura), an operator of FTZ 26, submitted...

  14. Chemotaxis of artificial microswimmers in active density waves

    NASA Astrophysics Data System (ADS)

    Geiseler, Alexander; Hänggi, Peter; Marchesoni, Fabio; Mulhern, Colm; Savel'ev, Sergey

    2016-07-01

    Living microorganisms are capable of a tactic response to external stimuli by swimming toward or away from the stimulus source; they do so by adapting their tactic signal transduction pathways to the environment. Their self-motility thus allows them to swim against a traveling tactic wave, whereas a simple fore-rear asymmetry argument would suggest the opposite. Their biomimetic counterpart, the artificial microswimmers, also propel themselves by harvesting kinetic energy from an active medium, but, in contrast, lack the adaptive capacity. Here we investigate the transport of artificial swimmers subject to traveling active waves and show, by means of analytical and numerical methods, that self-propelled particles can actually diffuse in either direction with respect to the wave, depending on its speed and waveform. Moreover, chiral swimmers, which move along spiraling trajectories, may diffuse preferably in a direction perpendicular to the active wave. Such a variety of tactic responses is explained by the modulation of the swimmer's diffusion inside traveling active pulses.

  15. Earthquake source parameters at the sumatran fault zone: Identification of the activated fault plane

    NASA Astrophysics Data System (ADS)

    Kasmolan, Madlazim; Santosa, Bagus Jaya; Lees, Jonathan M.; Utama, Widya

    2010-12-01

    Fifteen earthquakes (Mw 4.1-6.4) occurring at ten major segments of the Sumatran Fault Zone (SFZ) were analyzed to identify their respective fault planes. The events were relocated in order to assess hypocenter uncertainty. Earthquake source parameters were determined from three-component local waveforms recorded by IRIS-DMC and GEOFON broadband lA networks. Epicentral distances of all stations were less than 10°. Moment tensor solutions of the events were calculated, along with simultaneous determination of centroid position. Joint analysis of hypocenter position, centroid position, and nodal planes produced clear outlines of the Sumatran fault planes. The preferable seismotectonic interpretation is that the events activated the SFZ at a depth of approximately 14-210 km, corresponding to the interplate Sumatran fault boundary. The identification of this seismic fault zone is significant to the investigation of seismic hazards in the region.

  16. More Active Living-oriented County and Municipal Zoning is Associated with Increased Adult Leisure Time Physical Activity-United States, 2011.

    PubMed

    Chriqui, Jamie F; Nicholson, Lisa M; Thrun, Emily; Leider, Julien; Slater, Sandy J

    2016-01-01

    Although zoning is recognized for its role in facilitating healthy communities, no study has examined whether active living-oriented zoning codes are associated with adult leisure time physical activity (PA). This study sought to fill this gap and hypothesized that adult leisure time PA would be greater in communities with more progressive zoning code reforms and more active living-oriented zoning. Zoning codes for 1,617 county and municipal jurisdictions located in 30 states (covering ~40% of the U.S. population) were evaluated for code reform zoning and 11 active living markers. County-aggregated zoning measures were created for linking with five adult PA behaviors obtained from the 2011 Behavioral Risk Factor Surveillance System controlling for individual and county sociodemographics. Zoning elements most associated with adult PA included requirements for mixed use, active and passive recreation, bike parking/street furniture, and bike-pedestrian trails/paths. This study provides new insights as to the role that zoning can play in facilitating adult PA.

  17. Landform development in a zone of active Gedi Fault, Eastern Kachchh rift basin, India

    NASA Astrophysics Data System (ADS)

    Kothyari, Girish Ch.; Rastogi, B. K.; Morthekai, P.; Dumka, Rakesh K.

    2016-02-01

    An earthquake of 2006 Mw 5.7 occurred along east-west trending Gedi Fault (GF) to the north of the Kachchh rift basin in western India which had the epicenter in the Wagad upland, which is approximately 60 km northeast of the 2001 Mw 7.7 earthquake site (or epicenter). Development of an active fault scarp, shifting of a river channel, offsetting of streams and uplift of the ground indicate that the terrain is undergoing active deformation. Based on detailed field investigations, three major faults that control uplifts have been identified in the GF zone. These uplifts were developed in a step-over zone of the GF, and formed due to compressive force generated by left-lateral motion within the segmented blocks. In the present research, a terrace sequence along the north flowing Karaswali river in a tectonically active GF zone has been investigated. Reconstructions based on geomorphology and terrace stratigraphy supported by optical chronology suggest that the fluvial aggradation in the Wagad area was initiated during the strengthening (at ~ 8 ka) and declining (~ 4 ka) of the Indian Summer Monsoon (ISM). The presence of younger valley fill sediments which are dated ~ 1 ka is ascribed to a short lived phase of renewed strengthening of ISM before present day aridity. Based on terrace morphology two major phases of enhanced uplift have been estimated. The older uplift event dated to 8 ka is represented by the Tertiary bedrock surfaces which accommodated the onset of valley-fill aggradation. The younger event of enhanced uplift dated to 4 ka was responsible for the incision of the older valley fill sediments and the Tertiary bedrock. These ages suggest that the average rate of uplift ranges from 0.3 to 1.1 mm/yr during the last 9 ka implying active nature of the area.

  18. Regulation of Synaptic Vesicle Docking by Different Classes of Macromolecules in Active Zone Material

    PubMed Central

    Szule, Joseph A.; Harlow, Mark L.; Jung, Jae Hoon; De-Miguel, Francisco F.; Marshall, Robert M.; McMahan, Uel J.

    2012-01-01

    The docking of synaptic vesicles at active zones on the presynaptic plasma membrane of axon terminals is essential for their fusion with the membrane and exocytosis of their neurotransmitter to mediate synaptic impulse transmission. Dense networks of macromolecules, called active zone material, (AZM) are attached to the presynaptic membrane next to docked vesicles. Electron tomography has shown that some AZM macromolecules are connected to docked vesicles, leading to the suggestion that AZM is somehow involved in the docking process. We used electron tomography on the simply arranged active zones at frog neuromuscular junctions to characterize the connections of AZM to docked synaptic vesicles and to search for the establishment of such connections during vesicle docking. We show that each docked vesicle is connected to 10–15 AZM macromolecules, which fall into four classes based on several criteria including their position relative to the presynaptic membrane. In activated axon terminals fixed during replacement of docked vesicles by previously undocked vesicles, undocked vesicles near vacated docking sites on the presynaptic membrane have connections to the same classes of AZM macromolecules that are connected to docked vesicles in resting terminals. The number of classes and the total number of macromolecules to which the undocked vesicles are connected are inversely proportional to the vesicles’ distance from the presynaptic membrane. We conclude that vesicle movement toward and maintenance at docking sites on the presynaptic membrane are directed by an orderly succession of stable interactions between the vesicles and distinct classes of AZM macromolecules positioned at different distances from the membrane. Establishing the number, arrangement and sequence of association of AZM macromolecules involved in vesicle docking provides an anatomical basis for testing and extending concepts of docking mechanisms provided by biochemistry. PMID:22438915

  19. Additivity, density fluctuations, and nonequilibrium thermodynamics for active Brownian particles

    NASA Astrophysics Data System (ADS)

    Chakraborti, Subhadip; Mishra, Shradha; Pradhan, Punyabrata

    2016-05-01

    Using an additivity property, we study particle-number fluctuations in a system of interacting self-propelled particles, called active Brownian particles (ABPs), which consists of repulsive disks with random self-propulsion velocities. From a fluctuation-response relation, a direct consequence of additivity, we formulate a thermodynamic theory which captures the previously observed features of nonequilibrium phase transition in the ABPs from a homogeneous fluid phase to an inhomogeneous phase of coexisting gas and liquid. We substantiate the predictions of additivity by analytically calculating the subsystem particle-number distributions in the homogeneous fluid phase away from criticality where analytically obtained distributions are compatible with simulations in the ABPs.

  20. Groundwater hydrochemistry in the active layer of the proglacial zone, Finsterwalderbreen, Svalbard

    USGS Publications Warehouse

    Cooper, R.J.; Wadham, J.L.; Tranter, M.; Hodgkins, R.; Peters, N.E.

    2002-01-01

    Glacial bulk meltwaters and active-layer groundwaters were sampled from the proglacial zone of Finsterwalderbreen during a single melt season in 1999, in order to determine the geochemical processes that maintain high chemical weathering rates in the proglacial zone of this glacier. Results demonstrate that the principle means of solute acquisition is the weathering of highly reactive moraine and fluvial active-layer sediments by supra-permafrost groundwaters. Active-layer groundwater derives from the thaw of the proglacial snowpack, buried ice and glacial bulk meltwaters. Groundwater evolves by sulphide oxidation and carbonate dissolution. Evaporation- and freeze-concentration of groundwater in summer and winter, respectively produce Mg-Ca-sulphate salts on the proglacial surface. Re-dissolution of these salts in early summer produces groundwaters that are supersaturated with respect to calcite. There is a pronounced spatial pattern to the geochemical evolution of groundwater. Close to the main proglacial channel, active layer sediments are flushed diurnally by bulk meltwaters. Here, Mg-Ca-sulphate deposits become exhausted in the early season and geochemical evolution proceeds by a combination of sulphide oxidation and carbonate dissolution. At greater distances from the channel, the dissolution of Mg-Ca-sulphate salts is a major influence and dilution by the bulk meltwaters is relatively minor. The influence of sulphate salt dissolution decreases during the sampling season, as these salts are exhausted and waters become increasingly routed by subsurface flowpaths. ?? 2002 Elsevier Science B.V. All rights reserved.

  1. Mineralogy and porosity transformation induced by normal fault activity, Pirgaki fault zone (Corinth rift, Greece).

    NASA Astrophysics Data System (ADS)

    Géraud, Y.; Diraison, M.

    2003-04-01

    The Pirgaki fault displays an average N095-100 strike direction and contributes to the south part of the Corinth graben. Several interconnected segments compose it and it forms a quite continuous fault scrap elevated up to 300 meters. The total length of outcropping fault zone is at least 30 km. The dip angle involves between 40° to 70° for the highest. The high angle part of the fault marks the contact between limestone and sediments of the rift series (Ghisetti et al. 2001). A large set of structural and sedimentological criteria are evidence of repeated activity of the Pirgaki fault during the whole Pliocene-Pleistocene period (Ghisetti et al., 2001). The studied part of the Pirgaki fault zone has low angle dip and affects limestones. These limestones, as well as in the hanging wall than in the footwall, are strongly affected by a previous neogene orogen with ductile (folds) and brittle (faults) structures. The sampling zone concerns the low dipping part of the fault. A set of 12 samples is analysed by Hg and water porosimetry, X-ray diffraction and SEM. Protolith is characterised by a very low porosity material, porous volume lower than 1% and threshold size lower 0.1µm. Clay fraction of the protolith material is formed by a set of interstratified illite-smectite and kaolinite minerals. The gouge zone is characterized by an important structural modification with formation of ductile strain part and a brittle strain part. Transformations of the clay content are important in this part of the fault zone. Interstratified phases disappear and are replaced by illite and chlorite phases. The highest illite content is measured for the brittle part of the gouge zone and the highest chlorite content is measured in the ductile part. These structural transformations are also associated with porosity modifications with an large increase of the porosity volume (10%) an of the threshold diameter (3µm) in the brittle part and a lower increase (porosity value, 2% and

  2. Active Crustal Faults in the Forearc Region, Guerrero Sector of the Mexican Subduction Zone

    NASA Astrophysics Data System (ADS)

    Gaidzik, Krzysztof; Ramírez-Herrera, Maria Teresa; Kostoglodov, Vladimir

    2016-10-01

    This work explores the characteristics and the seismogenic potential of crustal faults on the overriding plate in an area of high seismic hazard associated with the occurrence of subduction earthquakes and shallow earthquakes of the overriding plate. We present the results of geomorphic, structural, and fault kinematic analyses conducted on the convergent margin between the Cocos plate and the forearc region of the overriding North American plate, within the Guerrero sector of the Mexican subduction zone. We aim to determine the active tectonic processes in the forearc region of the subduction zone, using the river network pattern, topography, and structural data. We suggest that in the studied forearc region, both strike-slip and normal crustal faults sub-parallel to the subduction zone show evidence of activity. The left-lateral offsets of the main stream courses of the largest river basins, GPS measurements, and obliquity of plate convergence along the Cocos subduction zone in the Guerrero sector suggest the activity of sub-latitudinal left-lateral strike-slip faults. Notably, the regional left-lateral strike-slip fault that offsets the Papagayo River near the town of La Venta named "La Venta Fault" shows evidence of recent activity, corroborated also by GPS measurements (4-5 mm/year of sinistral motion). Assuming that during a probable earthquake the whole mapped length of this fault would rupture, it would produce an event of maximum moment magnitude Mw = 7.7. Even though only a few focal mechanism solutions indicate a stress regime relevant for reactivation of these strike-slip structures, we hypothesize that these faults are active and suggest two probable explanations: (1) these faults are characterized by long recurrence period, i.e., beyond the instrumental record, or (2) they experience slow slip events and/or associated fault creep. The analysis of focal mechanism solutions of small magnitude earthquakes in the upper plate, for the period between 1995

  3. Mutational Analysis of Rab3 Function for Controlling Active Zone Protein Composition at the Drosophila Neuromuscular Junction.

    PubMed

    Chen, Shirui; Gendelman, Hannah K; Roche, John P; Alsharif, Peter; Graf, Ethan R

    2015-01-01

    At synapses, the release of neurotransmitter is regulated by molecular machinery that aggregates at specialized presynaptic release sites termed active zones. The complement of active zone proteins at each site is a determinant of release efficacy and can be remodeled to alter synapse function. The small GTPase Rab3 was previously identified as playing a novel role that controls the distribution of active zone proteins to individual release sites at the Drosophila neuromuscular junction. Rab3 has been extensively studied for its role in the synaptic vesicle cycle; however, the mechanism by which Rab3 controls active zone development remains unknown. To explore this mechanism, we conducted a mutational analysis to determine the molecular and structural requirements of Rab3 function at Drosophila synapses. We find that GTP-binding is required for Rab3 to traffick to synapses and distribute active zone components across release sites. Conversely, the hydrolytic activity of Rab3 is unnecessary for this function. Through a structure-function analysis we identify specific residues within the effector-binding switch regions that are required for Rab3 function and determine that membrane attachment is essential. Our findings suggest that Rab3 controls the distribution of active zone components via a vesicle docking mechanism that is consistent with standard Rab protein function.

  4. 78 FR 11626 - Foreign-Trade Zone 181-Akron/Canton, OH, Authorization of Production Activity, Cimbar Performance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-19

    ..., Cimbar Performance Minerals, (Barium Sulfate Grinding), Wellsville, OH On October 10, 2012, the Northeast... activity to the Foreign-Trade Zones (FTZ) Board on behalf of Cimbar Performance Minerals, within FTZ...

  5. 78 FR 30269 - Foreign-Trade Zone 129-Bellingham, Washington; Authorization of Production Activity; T.C. Trading...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-22

    ... Activity; T.C. Trading Company, Inc. (Eyeglass Assembly and Kitting), Blaine, WA On January 17, 2013, the... Foreign-Trade Zones (FTZ) Board on behalf of T.C. Trading Company, Inc., within Subzone 129B, in...

  6. Influence of stretching and density contrasts on the chemical evolution of continental magmas: An example from the Ivrea-Verbano Zone

    USGS Publications Warehouse

    Sinigoi, S.; Quick, J.E.; Mayer, A.; Budahn, J.

    1996-01-01

    The southern Ivrea-Verbano Zone of the Italian Western Alps contains a huge mafic complex that intruded high-grade metamorphic rocks while they were resident in the lower crust. Geologic mapping and chemical variations of the igneous body were used to study the evolution of underplated crust. Slivers of crustal rocks (septa) interlayered with igneous mafic rocks are concentrated in a narrow zone deep in the complex (Paragneiss-bearing Belt) and show evidence of advanced degrees of partial melting. Variations of rare-earth-element patterns and Sr isotope composition of the igneous rocks across the sequence are consistent with increasing crustal contamination approaching the septa. Therefore, the Paragneiss-bearing Belt is considered representative of an "assimilation region" where in-situ interaction between mantle- and crust-derived magmas resulted in production of hybrid melts. Buoyancy caused upwards migration of the hybrid melts that incorporated the last septa and were stored at higher levels, feeding the Upper Mafic Complex. Synmagmatic stretching of the assimilation region facilitated mixing and homogenization of melts. Chemical variations of granitoids extracted from the septa show that deep septa are more depleted than shallow ones. This suggests that the first incorporated septa were denser than the later ones, as required by the high density of the first-injected mafic magmas. It is inferred that density contrasts between mafic melts and crustal rocks play a crucial role for the processes of contamination of continental magmas. In thick under- plated crust, the extraction of early felsic/hybrid melts from the lower crust may be required to increase the density of the lower crust and to allow the later mafic magmas to penetrate higher crustal levels.

  7. [Diurnal biting activity and seasonal density of Lutzomyia (C) orestes (Diptera: Psychodidae)].

    PubMed

    Lugo Mendoza, J; Aldecoa Gilí, T; Miqueli Negrín, E; Luis Pelegrino, J

    1991-01-01

    Daily bite activity and season density of Lutzomyia (C) orestes were recorded by means of the human bait technique in the Don Martin Cave, west of Havana Province, during one year. A correlation matrix test was carried out between density, temperature, relative humidity and rainfall.

  8. Role of Bassoon and Piccolo in Assembly and Molecular Organization of the Active Zone

    PubMed Central

    Gundelfinger, Eckart D.; Reissner, Carsten; Garner, Craig C.

    2016-01-01

    Bassoon and Piccolo are two very large scaffolding proteins of the cytomatrix assembled at the active zone (CAZ) where neurotransmitter is released. They share regions of high sequence similarity distributed along their entire length and seem to share both overlapping and distinct functions in organizing the CAZ. Here, we survey our present knowledge on protein-protein interactions and recent progress in understanding of molecular functions of these two giant proteins. These include roles in the assembly of active zones (AZ), the localization of voltage-gated Ca2+ channels (VGCCs) in the vicinity of release sites, synaptic vesicle (SV) priming and in the case of Piccolo, a role in the dynamic assembly of the actin cytoskeleton. Piccolo and Bassoon are also important for the maintenance of presynaptic structure and function, as well as for the assembly of CAZ specializations such as synaptic ribbons. Recent findings suggest that they are also involved in the regulation activity-dependent communication between presynaptic boutons and the neuronal nucleus. Together these observations suggest that Bassoon and Piccolo use their modular structure to organize super-molecular complexes essential for various aspects of presynaptic function. PMID:26793095

  9. Dissolved oxygen concentration profiles in the hyporheic zone through the use of a high density fiber optic measurement network

    NASA Astrophysics Data System (ADS)

    Reeder, W. J.; Quick, A. M.; Farrell, T. B.; Benner, S. G.; Feris, K. P.; Tonina, D.

    2013-12-01

    The hyporheic zone (HZ) is a potentially important source of the potent greenhouse gas, nitrous oxide (N2O); stream processes may account for up to 10% of global anthropogenic N2O emissions. However, mechanistic understanding and predictive quantification of this gas flux is hampered by complex temporally and spatially variable interactions between flow dynamics and biogeochemical processes. Reactive inorganic nitrogen (Nr) is typically present at low concentrations in natural stream waters, but many rural and urban streams suffer from an excess of Nr, typically in the form of ammonium (NH4+) and nitrate (NO3-). These reactive species are either assimilated by living biomass or transformed by microbial processes. The two primary microbial transformations of Nr are nitrification (NH4+ to NO3-) and denitrification (NO3- to N2). Denitrification, which occurs almost exclusively in the anoxic zone of the HZ, permanently removes between 30-70% of all Nr entering streams, other mechanisms may retain nitrogen. The mass transport of reactive species (i.e. O2, NO3- and N2O) by hyporheic flow strongly influences reaction rates, residence times, and subsequent N2O flux. By extension, stream flow and channel morphology presumably control, and may be effective predictors of, N2O generation rates. By recreating the stream processes in the University of Idaho flume, we are able to control the bed morphology, fluxes and residence times through the HZ and concentrations of Nr from exogenous (stream water) and endogenous (organic material in the streambed) sources. For the present experiment, the flume was divided into three streams, each with different morphologies (3, 6 and 9cm dunes) and all using the same source water. Stream water for this first experimental phase had no significant loading of Nr. As such, all reaction products were the result of endogenous sources of Nr. To measure dissolved oxygen (DO) concentrations we deployed 120 channels of a novel, fiber-optic optode

  10. Quantifying the density and utilization of active sites in non-precious metal oxygen electroreduction catalysts

    PubMed Central

    Sahraie, Nastaran Ranjbar; Kramm, Ulrike I.; Steinberg, Julian; Zhang, Yuanjian; Thomas, Arne; Reier, Tobias; Paraknowitsch, Jens-Peter; Strasser, Peter

    2015-01-01

    Carbon materials doped with transition metal and nitrogen are highly active, non-precious metal catalysts for the electrochemical conversion of molecular oxygen in fuel cells, metal air batteries, and electrolytic processes. However, accurate measurement of their intrinsic turn-over frequency and active-site density based on metal centres in bulk and surface has remained difficult to date, which has hampered a more rational catalyst design. Here we report a successful quantification of bulk and surface-based active-site density and associated turn-over frequency values of mono- and bimetallic Fe/N-doped carbons using a combination of chemisorption, desorption and 57Fe Mössbauer spectroscopy techniques. Our general approach yields an experimental descriptor for the intrinsic activity and the active-site utilization, aiding in the catalyst development process and enabling a previously unachieved level of understanding of reactivity trends owing to a deconvolution of site density and intrinsic activity. PMID:26486465

  11. Multiday thermospheric density oscillations associated with variations in solar radiation and geomagnetic activity

    NASA Astrophysics Data System (ADS)

    Xu, Jiyao; Wang, Wenbin; Zhang, Shunrong; Liu, Xiao; Yuan, Wei

    2015-05-01

    Thermospheric densities observed by Challenging Minisatellite Payload and Gravity Recovery and Climate Experiment satellites during 2002-2010 and the globally averaged thermospheric densities from 1967 to 2007 have been used to investigate latitudinal, longitudinal, and height dependences of the multiday oscillations of thermospheric densities. The data show that the main multiday oscillations in thermospheric densities are 27, 13.5, 9, and 7 day oscillations. The high-correlation coefficients between the density oscillations and the F10.7 or Ap index indicate that these oscillations are externally driven. The 27 day density oscillation, being the strongest, is induced by variations in solar radiation, as well as recurrent geomagnetic activity that is the result of corotating interaction regions (CIRs) and high-speed solar wind streams of coronal hole origin. Density oscillations at periods of 13.5, 9, and 7 days at solar minimum and during the declining phase are stronger than those at solar maximum. These oscillations are mainly associated with recurrent geomagnetic activity due to coronal hole high-speed streams and CIRs. The multiday, periodic oscillations of thermospheric density exhibit strong latitudinal and longitudinal variations in the geomagnetic coordinate and oscillate synchronously at different heights. Oscillations with zonal wave number 0 oscillate globally, whereas those with nonzero wave numbers are strong at high geomagnetic latitudes, and hemispherically asymmetric. They are stronger in the Southern Hemisphere. The spectral distributions of thermospheric densities at different heights have almost the same latitude and longitude structures, but the spectral magnitudes increase with height.

  12. An Integrated Geospatial System for earthquake precursors assessment in Vrancea tectonic active zone in Romania

    NASA Astrophysics Data System (ADS)

    Zoran, Maria A.; Savastru, Roxana S.; Savastru, Dan M.

    2015-10-01

    With the development of space-based technologies to measure surface geophysical parameters and deformation at the boundaries of tectonic plates and large faults, earthquake science has entered a new era. Using time series satellite data for earthquake prediction, it is possible to pursue the behaviors of earthquake precursors in the future and to announce early warnings when the differences between the predicted value and the observed value exceed the pre-define threshold value. Starting with almost one week prior to a moderate or strong earthquake a transient thermal infrared rise in LST of several Celsius degrees (oC) and the increased OLR values higher than the normal have been recorded around epicentral areas, function of the magnitude and focal depth, which disappeared after the main shock. Also are recorded associated geomagnetic and ionospheric distrurbances. Vrancea tectonic active zone in Romania is characterized by a high seismic hazard in European- Mediterranean region, being responsible of strong or moderate intermediate depth and normal earthquakes generation on a confined epicentral area. Based on recorded geophysical parameters anomalies was developed an integrated geospatial system for earthquake precursors assessment in Vrancea active seismic zone. This system integrates derived from time series MODIS Terra/Aqua, NOAA-AVHRR, ASTER, Landsat TM/ETM satellite data multi geophysical parameters (land surface temperature -LST, outgoing long-wave radiation- OLR, and mean air temperature- AT as well as geomagnetic and ionospheric data in synergy with in-situ data for surveillance and forecasting of seismic events.

  13. Fault displacement rates and recent activity on the Ierapetra Fault Zone, Crete, Greece

    NASA Astrophysics Data System (ADS)

    Veliz, V.

    2015-12-01

    Crete is an eastern Mediterranean island that includes the highest forearc topography of the Hellenic subduction margin, along which the African and Eurasian plates converge at rates of ~40 mm/yr. The island is currently experiencing regional uplift and is broken up by numerous active normal faults that contribute to the shaping of its topography. The largest of these onshore tectonic features is, the Ierapetra Fault Zone (IFZ), a normal fault that traverses the entire width of eastern Crete (>20 km) with a NNE strike and west diping. Here we use geomorphologic, structural and kinematic indicators to discuss fault segmentation along the IFZ and to provide quantitative constraints on the late Quaternary (~16.5 and 33 kyr) displacement rate on the fault, including evidence of Holocene earthquake activity on its central segment.

  14. Geophysical signature of hydration-dehydration processes in active subduction zones

    NASA Astrophysics Data System (ADS)

    Reynard, Bruno

    2013-04-01

    inclusions in arc lavas. High electrical conductivities up to 1 S/m in the hydrated wedge of the hot subductions (Ryukyu, Kyushu, Cascadia) reflect high fluid concentration, while low to moderate (<0.01 S/m) conductivities in the cold subductions (N-E Japan, Bolivia) reflect low fluid flow. This is consistent with the seismic observations of extensive shallow serpentinization in hot subduction zones, while serpentinization is sluggish in cold subduction zones. Bezacier, L., et al. 2010. Elasticity of antigorite, seismic detection of serpentinites, and anisotropy in subduction zones. Earth and Planetary Science Letters, 289, 198-208. Reynard, B., 2012. Serpentine in active subduction zones. Lithos, http://dx.doi.org/10.1016/j.lithos.2012.10.012. Reynard, B., Mibe, K. & Van de Moortele, B., 2011. Electrical conductivity of the serpentinised mantle and fluid flow in subduction zones. Earth and Planetary Science Letters, 307, 387-394. Reynard, B., Nakajima, J. & Kawakatsu, H., 2010. Earthquakes and plastic deformation of anhydrous slab mantle in double Wadati-Benioff zones. Geophysical Research Letters, 37, L24309.

  15. Density-Dependent Spacing Behaviour and Activity Budget in Pregnant, Domestic Goats (Capra hircus).

    PubMed

    Vas, Judit; Andersen, Inger Lise

    2015-01-01

    Very little is known about the spacing behaviour in social groups of domestic goats (Capra hircus) in the farm environment. In this experiment, we studied interindividual distances, movement patterns and activity budgets in pregnant goats housed at three different densities. Norwegian dairy goats were kept in stable social groups of six animals throughout pregnancy at 1, 2 or 3 m2 per individual and their spacing behaviours (i.e., distance travelled, nearest and furthest neighbour distance) and activity budgets (e.g., resting, feeding, social activities) were monitored. Observations were made in the first, second and last thirds of pregnancy in the mornings, at noon and in the afternoons of each of these phases (4.5 hours per observation period). The findings show that goats held at animal densities of 2 and 3 m2 moved longer distances when they had more space per animal and kept larger nearest and furthest neighbour distances when compared to the 1 m2 per animal density. Less feeding activity was observed at the high animal density compared to the medium and low density treatments. The phase of gestation also had an impact on almost all behavioural variables. Closer to parturition, animals moved further distances and the increase in nearest and furthest neighbour distance was more pronounced at the lower animal densities. During the last period of gestation, goats spent less time feeding and more on resting, social behaviours and engaging in other various activities. Our data suggest that more space per goat is needed for goats closer to parturition than in the early gestation phase. We concluded that in goats spacing behaviour is density-dependent and changes with stages of pregnancy and activities. Finally, the lower density allowed animals to express individual preferences regarding spacing behaviour which is important in ensuring good welfare in a farming situation.

  16. Density-Dependent Spacing Behaviour and Activity Budget in Pregnant, Domestic Goats (Capra hircus)

    PubMed Central

    Vas, Judit; Andersen, Inger Lise

    2015-01-01

    Very little is known about the spacing behaviour in social groups of domestic goats (Capra hircus) in the farm environment. In this experiment, we studied interindividual distances, movement patterns and activity budgets in pregnant goats housed at three different densities. Norwegian dairy goats were kept in stable social groups of six animals throughout pregnancy at 1, 2 or 3 m2 per individual and their spacing behaviours (i.e. distance travelled, nearest and furthest neighbour distance) and activity budgets (e.g. resting, feeding, social activities) were monitored. Observations were made in the first, second and last thirds of pregnancy in the mornings, at noon and in the afternoons of each of these phases (4.5 hours per observation period). The findings show that goats held at animal densities of 2 and 3 m2 moved longer distances when they had more space per animal and kept larger nearest and furthest neighbour distances when compared to the 1 m2 per animal density. Less feeding activity was observed at the high animal density compared to the medium and low density treatments. The phase of gestation also had an impact on almost all behavioural variables. Closer to parturition, animals moved further distances and the increase in nearest and furthest neighbour distance was more pronounced at the lower animal densities. During the last period of gestation, goats spent less time feeding and more on resting, social behaviours and engaging in other various activities. Our data suggest that more space per goat is needed for goats closer to parturition than in the early gestation phase. We concluded that in goats spacing behaviour is density-dependent and changes with stages of pregnancy and activities. Finally, the lower density allowed animals to express individual preferences regarding spacing behaviour which is important in ensuring good welfare in a farming situation. PMID:26657240

  17. Active faults in the deformation zone off Noto Peninsula, Japan, revealed by high- resolution seismic profiles

    NASA Astrophysics Data System (ADS)

    Inoue, T.; Okamura, Y.; Murakami, F.; Kimura, H.; Ikehara, K.

    2008-12-01

    Recently, a lot of earthquakes occur in Japan. The deformation zone which many faults and folds have concentrated exists on the Japan Sea side of Japan. The 2007 Noto Hanto Earthquake (MJMA 6.9) and 2007 Chuetsu-oki Earthquake (MJMA 6.8) were caused by activity of parts of faults in this deformation zone. The Noto Hanto Earthquake occurred on 25 March, 2007 under the northwestern coast of Noto Peninsula, Ishikawa Prefecture, Japan. This earthquake is located in Quaternary deformation zone that is continued from northern margin of Noto Peninsula to southeast direction (Okamura, 2007a). National Institute of Advanced Industrial Science and Technology (AIST) carried out high-resolution seismic survey using Boomer and 12 channels short streamer cable in the northern part off Noto Peninsula, in order to clarify distribution and activities of active faults in the deformation zone. A twelve channels short streamer cable with 2.5 meter channel spacing developed by AIST and private corporation is designed to get high resolution seismic profiles in shallow sea area. The multi-channel system is possible to equip on a small fishing boat, because the data acquisition system is based on PC and the length of the cable is short and easy to handle. Moreover, because the channel spacing is short, this cable is very effective for a high- resolution seismic profiling survey in the shallow sea, and seismic data obtained by multi-channel cable can be improved by velocity analysis and CDP stack. In the northern part off Noto Peninsula, seismic profiles depicting geologic structure up to 100 meters deep under sea floor were obtained. The most remarkable reflection surface recognized in the seismic profiles is erosion surface at the Last Glacial Maximum (LGM). In the western part, sediments about 30 meters (40 msec) thick cover the erosional surface that is distributed under the shelf shallower than 100m in depth and the sediments thin toward offshore and east. Flexures like deformation in

  18. Alignment of Synaptic Vesicle Macromolecules with the Macromolecules in Active Zone Material that Direct Vesicle Docking

    PubMed Central

    Xu, Jing; Jung, Jae Hoon; Marshall, Robert M.; McMahan, Uel J.

    2013-01-01

    Synaptic vesicles dock at active zones on the presynaptic plasma membrane of a neuron’s axon terminals as a precondition for fusing with the membrane and releasing their neurotransmitter to mediate synaptic impulse transmission. Typically, docked vesicles are next to aggregates of plasma membrane-bound macromolecules called active zone material (AZM). Electron tomography on tissue sections from fixed and stained axon terminals of active and resting frog neuromuscular junctions has led to the conclusion that undocked vesicles are directed to and held at the docking sites by the successive formation of stable connections between vesicle membrane proteins and proteins in different classes of AZM macromolecules. Using the same nanometer scale 3D imaging technology on appropriately stained frog neuromuscular junctions, we found that ∼10% of a vesicle’s luminal volume is occupied by a radial assembly of elongate macromolecules attached by narrow projections, nubs, to the vesicle membrane at ∼25 sites. The assembly’s chiral, bilateral shape is nearly the same vesicle to vesicle, and nubs, at their sites of connection to the vesicle membrane, are linked to macromolecules that span the membrane. For docked vesicles, the orientation of the assembly’s shape relative to the AZM and the presynaptic membrane is the same vesicle to vesicle, whereas for undocked vesicles it is not. The connection sites of most nubs on the membrane of docked vesicles are paired with the connection sites of the different classes of AZM macromolecules that regulate docking, and the membrane spanning macromolecules linked to these nubs are also attached to the AZM macromolecules. We conclude that the luminal assembly of macromolecules anchors in a particular arrangement vesicle membrane macromolecules, which contain the proteins that connect the vesicles to AZM macromolecules during docking. Undocked vesicles must move in a way that aligns this arrangement with the AZM macromolecules for

  19. Quantifying Leisure Physical Activity and Its Relation to Bone Density and Strength

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purpose: Compare three published methods of quantifying physical activity (total activity, peak strain, and bone loading exposure [BLE] scores) and identify their associations with areal bone mineral density (aBMD), volumetric BMD (vBMD), and bone strength. Methods: Postmenopausal women (N = 239; me...

  20. Exploiting the Magnetic Origin of Solar Activity in Forecasting Thermospheric Density Variations

    DTIC Science & Technology

    2014-09-01

    Exploiting the Magnetic Origin of Solar Activity in Forecasting Thermospheric Density Variations Harry Warren Naval Research Laboratory, Space...Science Division, Washington, DC John Emmert Naval Research Laboratory, Space Science Division, Washington, DC Abstract A detailed understanding of solar ...drag. Current operational models rely on forecasts of proxies for solar activity based on autoregression. The forecasts from these models generally

  1. Pharmacogenomic identification of small molecules for lineage specific manipulation of subventricular zone germinal activity

    PubMed Central

    Marcy, Guillaume; Pieropan, Francesca; Rivera, Andrea; Donega, Vanessa; Cantù, Claudio; Williams, Gareth; Berninger, Benedikt; Butt, Arthur M.; Raineteau, Olivier

    2017-01-01

    Strategies for promoting neural regeneration are hindered by the difficulty of manipulating desired neural fates in the brain without complex genetic methods. The subventricular zone (SVZ) is the largest germinal zone of the forebrain and is responsible for the lifelong generation of interneuron subtypes and oligodendrocytes. Here, we have performed a bioinformatics analysis of the transcriptome of dorsal and lateral SVZ in early postnatal mice, including neural stem cells (NSCs) and their immediate progenies, which generate distinct neural lineages. We identified multiple signaling pathways that trigger distinct downstream transcriptional networks to regulate the diversity of neural cells originating from the SVZ. Next, we used a novel in silico genomic analysis, searchable platform-independent expression database/connectivity map (SPIED/CMAP), to generate a catalogue of small molecules that can be used to manipulate SVZ microdomain-specific lineages. Finally, we demonstrate that compounds identified in this analysis promote the generation of specific cell lineages from NSCs in vivo, during postnatal life and adulthood, as well as in regenerative contexts. This study unravels new strategies for using small bioactive molecules to direct germinal activity in the SVZ, which has therapeutic potential in neurodegenerative diseases. PMID:28350803

  2. An attempt to monitor tectonic forces in the Vrancea active geodynamic zone: The Baspunar experiment

    NASA Astrophysics Data System (ADS)

    Besutiu, Lucian; Zlagnean, Luminita; Plopeanu, Marin

    2013-04-01

    (sparsely) run in the area, have provided inconsistent results on the PCF current dynamics. The Baspunar Geodynamic Observatory (BGO) has been designed and implemented by the Solid Earth Dynamics Department in the Institute of Geodynamics of the Romanian Academy in order to reveal and monitor eventual motions along PCF in the attempt to correlate variations in the slip rate with changes in the seismicity released within Vrancea zone. The first BGO records were strongly affected by changes in the atmospheric parameters. Consequently, technical measures and special corrections for the removal or at least mitigation of the effects created by changes in temperature, air pressure and humidity have been applied to the observations. In order to improve the signal to noise ratio, some mathematical filters have been applied too. The paper is aimed at revealing results of the geodetic observations along with preliminary geodynamic considerations. On the overall, after about two years of monitoring, PCF appears as an active tectonic contact. It mainly behaves as a left-lateral fault, but some short episodes with a reverse slip (dextral) were also pointed out. Correlations with crustal and intermediate-depth earthquakes occurring in both cases within the bending zone of East Carpathians are illustrated and discussed.

  3. 78 FR 22512 - Foreign-Trade Zone (FTZ) 225-Springfield, Missouri; Notification of Proposed Production Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-16

    ... Foreign-Trade Zones Board Foreign-Trade Zone (FTZ) 225--Springfield, Missouri; Notification of Proposed... available for public inspection at the Office of the Executive Secretary, Foreign-Trade Zones Board, Room...-free to 5.3%) for the foreign articles noted below. The articles sourced from abroad include:...

  4. Pedestrian-oriented zoning is associated with reduced income and poverty disparities in adult active travel to work, United States.

    PubMed

    Chriqui, Jamie F; Leider, Julien; Thrun, Emily; Nicholson, Lisa M; Slater, Sandy J

    2017-02-01

    Active travel to work can provide additional minutes of daily physical activity. While the literature points to the relationship between zoning, equity and socioeconomic status, and physical activity, no study has quantitatively explored these connections. This study examined whether zoning may help to moderate any income and poverty inequities in active travel and taking public transit to work. Research was conducted between May 2012 and June 2015. Zoning data were compiled for 3914 jurisdictions covering 45.45% of the U.S. population located in 471 of the most populous U.S. counties and 2 consolidated cities located in 48 states and the District of Columbia. (Sensitivity analyses also captured unincorporated areas which, with the municipalities, collectively covered ~72% of the U.S.

  5. EEG reactions of the human brain in the gradient magnetic field zone of the active geological fault (pilot study)

    NASA Astrophysics Data System (ADS)

    Pobachenko, S. V.; Shitov, A. V.; Grigorjev, P. E.; Sokolov, M. V.; Zubrilkin, A. I.; Vypiraylo, D. N.; Solovjev, A. V.

    2016-12-01

    This paper presents the results of experimental studies of the dynamics of the functional state of a person within the zone of an active geological fault characterized by abnormal spatial distribution of the magnetic- field vector values. It is shown that these geophysical modifications have a pronounced effect on the fluctuations of the electrical activity of the human brain. When the person gets into a zone with abnormal levels of gradient magnetic field in the absence of any subjective sensations, a nonspecific orientation activation reaction is observed, which is characterized by a significant increase in the levels of peak performance in key functional EEG frequency bands.

  6. Bioturbation effects of Corophium volutator: Importance of density and behavioural activity

    NASA Astrophysics Data System (ADS)

    De Backer, A.; Van Coillie, F.; Montserrat, F.; Provoost, P.; Van Colen, C.; Vincx, M.; Degraer, S.

    2011-01-01

    Bioturbation is one of the major processes influencing ecosystem functioning. Population parameters such as species density, burrow density and species-specific life modes, determine the impact of bioturbation on the ecosystem. A laboratory experiment was developed, using microcosms mimicking a marine intertidal sediment-water interface which allowed for quantification of different population parameters. The vertical redistribution, bioturbation rate and maximum penetration depth of two sizes (41 and 129 μm) of luminophores were measured in five treatments (control, low density of burrows with and without Corophium (1989 ind./m 2), and high density of burrows with and without Corophium (14,921 ind./m 2)) after 1, 7 and 14 days. Results indicate that the behavioural activities of Corophium are of the utmost importance in sediment reworking, since they contributed to a five-fold increase in bioturbation rate compared to the passive transport induced by the static structure of the burrows. Furthermore, density is an important parameter because only high densities play a prominent role in particle transport and hence in organic matter processing, while the role of low Corophium densities is limited in sediment reworking. No evidence for differentiation in sediment size fractions was observed. Finally, bioturbation rates in this study were low compared to other studies, and these results suggest an influence of the tidal rhythmicity in the behavioural activity of Corophium on the bioturbation rate.

  7. Effects of cell density, light intensity and mixing on Undaria pinnatifida gametophyte activity in a photobioreactor.

    PubMed

    Zou, Ning; Zhou, Baicheng; Li, Bingjun; Sun, Donghong; Zeng, Chengkui

    2003-07-01

    An on-line controlled 7 l sterilizable photobioreactor was used for the optimisation of a culture of gametophytes of Undaria pinnatifida. The gametophytes, which had been stored for three years in a culture cabinet at 16 degrees C, could rapidly grow in the photobioreactor under controlled conditions. The rate of increase of dissolved oxygen and pH were used to monitor the photosynthetic activity. Optimal gametophytes density changed varying the light intensity. The optimal cell densities were 3.24 and 3.45 g FW l(-1) when the cultures were exposed to 61.7 and 82.3 microE m(-2) s(-1), respectively. The optimal cell density was higher under a high photon flux density (PFD) than under low PFD. On the other hand, the optimal light intensities were different for different cell density cultures. The light saturation point was higher at high cell density cultures than at low cell density cultures. The optimal rotational speed was 150 rpm for high cell density culture in the photobioreactor.

  8. Global exospheric temperatures and densities under active solar conditions. [measured by OGO-6

    NASA Technical Reports Server (NTRS)

    Wydra, B. J.

    1975-01-01

    Temperatures measured by the OGO-6 satellite using the 6300 A airglow spectrum are compared with temperatures derived from total densities and N2 densities. It is shown that while the variation of the total densities with latitude and magnetic activity agree well with values used for CIRA (1972), the temperature behavior is very different. While the temperatures derived from the N2 density were in much better agreement there were several important differences which radically affect the pressure gradients. The variation of temperature with magnetic activity indicated a seasonal and local time effect and also a latitude and delay time variation different from previous density derived temperatures. A new magnetic index is proposed that is better correlated with the observed temperatures. The temperature variations at high latitudes were examined for three levels of magnetic activity for both solstices and equinox conditions. A temperature maximum in the pre-midnight sector and a minimum in the noon sector were noted and seasonal and geomagnetic time and latitude effects discussed. Neutral temperature, density, pressure and boundary oxygen variations for the great storm of March 8, 1970 are presented.

  9. Climatically-Active Gases in the Eastern Boundary Upwelling and Oxygen Minimum Zone (OMZ) Systems

    NASA Astrophysics Data System (ADS)

    Garbe, C.; Garçon, V.; Butz, A.; Yahia, H.; Sudre, J.; Illig, S.; Dewitte, B.; Paulmier, A.; Dadou, I.

    2012-04-01

    The EBUS (Eastern Boundary Upwelling Systems) and OMZs (Oxygen Minimum Zone) contribute very significantly to the gas exchange between the ocean and the atmosphere, notably with respect to the greenhouse gases (hereafter GHG). From in-situ ocean measurements, the uncertainty of the net global ocean-atmosphere CO2 fluxes is between 20 and 30%, and could be much higher in the EBUS-OMZ. Off Peru, very few in-situ data are available presently, which justifies alternative approaches for assessing these fluxes. GHG air-sea fluxes determination can be inferred from inverse modeling applied to Vertical Column Densities (VCDs) from GOSAT, using state of the art modeling, at low spatial resolution. For accurately linking sources of GHGs to EBUS and OMZs, the resolution of the source regions needs to be increased. This task develops on new non-linear and multiscale processing methods for complex signals to infer a higher spatial resolution mapping of the fluxes and the associated sinks and sources between the atmosphere and the ocean. The use of coupled satellite data (e.g. SST and/or Ocean colour) that carry turbulence information associated to ocean dynamics is taken into account at unprecedented detail level to incorporate turbulence effects in the evaluation of the air-sea fluxes. We will present a framework as described above for determining sources and sinks of GHG from satellite remote sensing with the Peru OMZ as a test bed.

  10. The Presynaptic Active Zone Protein RIM1α Is Critical for Normal Learning and Memory

    PubMed Central

    Powell, Craig M.; Schoch, Susanne; Monteggia, Lisa; Barrot, Michel; Matos, Maria F.; Feldmann, Nicole; Südhof, Thomas C.; Nestler, Eric J.

    2014-01-01

    Summary The active zone protein RIM1α is required both for maintaining normal probability of neurotransmitter release and for long-term presynaptic potentiation at brain synapses. We now demonstrate that RIM1α−/− mice exhibit normal coordination and anxiety-related behaviors but display severely impaired learning and memory. Mice with a synaptotagmin 1 mutation, which selectively lowers release probability, and mice with Rab3A deletion, which selectively abolishes presynaptic long-term potentiation, do not exhibit this abnormality. Our data suggest that a decrease in release probability or a loss of presynaptic LTP alone is not sufficient to cause major behavioral alterations, but the combination of presynaptic abnormalities in RIM1α−/− mice severely alters learning and memory. PMID:15066271

  11. Sustaining rapid vesicular release at active zones: potential roles for vesicle tethering

    PubMed Central

    Hallermann, Stefan; Silver, R. Angus

    2016-01-01

    Rapid information processing in our nervous system relies on high-frequency fusion of transmitter-filled vesicles at chemical synapses. Some sensory synapses possess prominent electron-dense ribbon structures that provide a scaffold for tethering synaptic vesicles at the active zone (AZ), enabling sustained vesicular release. Here, we review functional data indicating that some central and neuromuscular synapses can also sustain vesicle-fusion rates that are comparable to those of ribbon-type sensory synapses. Comparison of the ultrastructure across these different types of synapses, together with recent work showing that cytomatrix proteins can tether vesicles and speed vesicle reloading, suggests that filamentous structures may play a key role in vesicle supply. We discuss potential mechanisms by which vesicle tethering could contribute to sustained high rates of vesicle fusion across ribbon-type, central, and neuromuscular synapses. PMID:23164531

  12. Quantitative super-resolution imaging of Bruchpilot distinguishes active zone states

    NASA Astrophysics Data System (ADS)

    Ehmann, Nadine; van de Linde, Sebastian; Alon, Amit; Ljaschenko, Dmitrij; Keung, Xi Zhen; Holm, Thorge; Rings, Annika; Diantonio, Aaron; Hallermann, Stefan; Ashery, Uri; Heckmann, Manfred; Sauer, Markus; Kittel, Robert J.

    2014-08-01

    The precise molecular architecture of synaptic active zones (AZs) gives rise to different structural and functional AZ states that fundamentally shape chemical neurotransmission. However, elucidating the nanoscopic protein arrangement at AZs is impeded by the diffraction-limited resolution of conventional light microscopy. Here we introduce new approaches to quantify endogenous protein organization at single-molecule resolution in situ with super-resolution imaging by direct stochastic optical reconstruction microscopy (dSTORM). Focusing on the Drosophila neuromuscular junction (NMJ), we find that the AZ cytomatrix (CAZ) is composed of units containing ~137 Bruchpilot (Brp) proteins, three quarters of which are organized into about 15 heptameric clusters. We test for a quantitative relationship between CAZ ultrastructure and neurotransmitter release properties by engaging Drosophila mutants and electrophysiology. Our results indicate that the precise nanoscopic organization of Brp distinguishes different physiological AZ states and link functional diversification to a heretofore unrecognized neuronal gradient of the CAZ ultrastructure.

  13. Seismic evidence for active underplating below the megathrust earthquake zone in Japan.

    PubMed

    Kimura, Hisanori; Takeda, Tetsuya; Obara, Kazushige; Kasahara, Keiji

    2010-07-09

    Determining the structure of subduction zones is important for understanding mechanisms for the generation of interplate phenomena such as megathrust earthquakes. The peeling off of the uppermost part of a subducting slab and accretion to the bottom of an overlying plate (underplating) at deep regions has been inferred from exhumed metamorphic rocks and deep seismic imaging, but direct seismic evidence of this process is lacking. By comparing seismic reflection profiles with microearthquake distributions in central Japan, we show that repeating microearthquakes occur along the bottom interface of the layer peeling off from the subducting Philippine Sea plate. This region coincides with the location of slow-slip events that may serve as signals for monitoring active underplating.

  14. Ependymal stem cells divide asymmetrically and transfer progeny into the subventricular zone when activated by injury.

    PubMed

    Gleason, D; Fallon, J H; Guerra, M; Liu, J-C; Bryant, P J

    2008-09-22

    Evidence is presented to show that cells of the ependymal layer surrounding the ventricles of the mammalian (rat) forebrain act as neural stem cells (NSCs), and that these cells can be activated to divide by a combination of injury and growth factor stimulation. Several markers of asymmetric cell division (ACD), a characteristic of true stem cells, are expressed asymmetrically in the ependymal layer but not in the underlying subventricular zone (SVZ), and when the brain is treated with a combination of local 6-hydroxydopamine (6-OHDA) with systemic delivery of transforming growth factor-alpha (TGFalpha), ependymal cells divide asymmetrically and transfer progeny into the SVZ. The SVZ cells then divide as transit amplifying cells (TACs) and their progeny enter a differentiation pathway. The stem cells in the ependymal layer may have been missed in many previous studies because they are usually quiescent and divide only in response to strong stimuli.

  15. Hydrothermal quartz formation during fluctuations of brittle shear-zone activity and fluid flow: grain growth and deformation structures of the Pfahl shear zone (Germany)

    NASA Astrophysics Data System (ADS)

    Yilmaz, T.; Prosser, G.; Liotta, D.; Kruhl, J. H.

    2012-12-01

    The Bavarian Pfahl shear zone is a WNW-ESE trending dextral strike-slip shear zone at the SW margin of the Bohemian Massif (Central Europe). It was discontinuously active during decreasing PT-conditions, i.e. from ductile to brittle, from the late-Carboniferous to the late-Cretaceous - Paleocene times. Triassic hydrothermal activity produced a 150 km long and 30-100 m wide quartz dyke along the main fault, surrounded by sheared basement rocks. Within a zone of >10 m metasomatism transformed the wall rocks to mostly kaolinite, chlorite and phyllosilicates. The quartz dyke exhibits a layered to lenticular and partly symmetric structure with different types of quartz masses, transected by a complex quartz vein network. This already indicates pulses of fluid flux and fragmentation during the lifetime of the shear zone. Analyses by optical microscopy, cathodoluminescence (CL) and SEM-EDX reveal at least four subsequent stages of quartz crystallization and fragmentation. (i) The oldest generation of quartz is represented by a homogeneous dark grey to reddish quartz mass made up by ~10-20 μm-sized crystals. It contains mm- to cm-sized angular wall-rock fragments, completely altered to kaolinite, indicating intense wall-rock alteration prior to the earliest event of silica precipitation. This rules out the possibility that the quartz mass developed from silicification of the wall rocks. This first type of quartz occurs as cm- to dm-large angular fragments in (ii) a light grey to pink quartz mass formed by ~10-50 μm-sized crystals. The different colours result from variable types and amounts of inclusions. Quartz of both generations shows random crystallographic orientations and complex inclusion structures. It probably developed during two fragmentation events and possibly from a silica gel precursor that crystallized after precipitation. (iii) The third quartz generation formed as a set of mm- to dm-wide veins roughly parallel to the trend of the Pfahl zone

  16. Quaternary grabens in southernmost Illinois: deformation near an active intraplate seismic zone

    NASA Astrophysics Data System (ADS)

    Nelson, W. John; Denny, F. Brett; Follmer, Leon R.; Masters, John M.

    1999-05-01

    Narrow grabens displace Quaternary sediments near the northern edge of the Mississippi Embayment in extreme southern Illinois, east-central United States. Grabens are part of the Fluorspar Area Fault Complex (FAFC), which has been recurrently active throughout Phanerozoic time. The FAFC strikes directly toward the New Madrid Seismic Zone (NMSZ), scene of some of the largest intra-plate earthquakes in history. The NMSZ and FAFC share origin in a failed Cambrian rift (Reelfoot Rift). Every major fault zone of the FAFC in Illinois exhibits Quaternary displacement. The structures appear to be strike-slip pull-apart grabens, but the magnitude and direction of horizontal slip and their relationship to the current stress field are unknown. Upper Tertiary strata are vertically displaced more than 100 m, Illinoian and older Pleistocene strata 10 to 30 m, and Wisconsinan deposits 1 m or less. No Holocene deformation has been observed. Average vertical slip rates are estimated at 0.01 to 0.03 mm/year, and recurrence intervals for earthquakes of magnitude 6 to 7 are on the order of 10,000s of years for any given fault. Previous authors remarked that the small amount of surface deformation in the New Madrid area implies that the NMSZ is a young feature. Our findings show that tectonic activity has shifted around throughout the Quaternary in the central Mississippi Valley. In addition to the NMSZ and southern Illinois, the Wabash Valley (Illinois-Indiana), Benton Hills (Missouri), Crowley's Ridge (Arkansas-Missouri), and possibly other sites have experienced Quaternary tectonism. The NMSZ may be only the latest manifestation of seismicity in an intensely fractured intra-plate region.

  17. APP Is a Context-Sensitive Regulator of the Hippocampal Presynaptic Active Zone.

    PubMed

    Laßek, Melanie; Weingarten, Jens; Wegner, Martin; Mueller, Benjamin F; Rohmer, Marion; Baeumlisberger, Dominic; Arrey, Tabiwang N; Hick, Meike; Ackermann, Jörg; Acker-Palmer, Amparo; Koch, Ina; Müller, Ulrike; Karas, Michael; Volknandt, Walter

    2016-04-01

    The hallmarks of Alzheimer's disease (AD) are characterized by cognitive decline and behavioral changes. The most prominent brain region affected by the progression of AD is the hippocampal formation. The pathogenesis involves a successive loss of hippocampal neurons accompanied by a decline in learning and memory consolidation mainly attributed to an accumulation of senile plaques. The amyloid precursor protein (APP) has been identified as precursor of Aβ-peptides, the main constituents of senile plaques. Until now, little is known about the physiological function of APP within the central nervous system. The allocation of APP to the proteome of the highly dynamic presynaptic active zone (PAZ) highlights APP as a yet unknown player in neuronal communication and signaling. In this study, we analyze the impact of APP deletion on the hippocampal PAZ proteome. The native hippocampal PAZ derived from APP mouse mutants (APP-KOs and NexCreAPP/APLP2-cDKOs) was isolated by subcellular fractionation and immunopurification. Subsequently, an isobaric labeling was performed using TMT6 for protein identification and quantification by high-resolution mass spectrometry. We combine bioinformatics tools and biochemical approaches to address the proteomics dataset and to understand the role of individual proteins. The impact of APP deletion on the hippocampal PAZ proteome was visualized by creating protein-protein interaction (PPI) networks that incorporated APP into the synaptic vesicle cycle, cytoskeletal organization, and calcium-homeostasis. The combination of subcellular fractionation, immunopurification, proteomic analysis, and bioinformatics allowed us to identify APP as structural and functional regulator in a context-sensitive manner within the hippocampal active zone network.

  18. APP Is a Context-Sensitive Regulator of the Hippocampal Presynaptic Active Zone

    PubMed Central

    Mueller, Benjamin F.; Rohmer, Marion; Baeumlisberger, Dominic; Arrey, Tabiwang N.; Hick, Meike; Ackermann, Jörg; Acker-Palmer, Amparo; Koch, Ina; Müller, Ulrike; Karas, Michael; Volknandt, Walter

    2016-01-01

    The hallmarks of Alzheimer’s disease (AD) are characterized by cognitive decline and behavioral changes. The most prominent brain region affected by the progression of AD is the hippocampal formation. The pathogenesis involves a successive loss of hippocampal neurons accompanied by a decline in learning and memory consolidation mainly attributed to an accumulation of senile plaques. The amyloid precursor protein (APP) has been identified as precursor of Aβ-peptides, the main constituents of senile plaques. Until now, little is known about the physiological function of APP within the central nervous system. The allocation of APP to the proteome of the highly dynamic presynaptic active zone (PAZ) highlights APP as a yet unknown player in neuronal communication and signaling. In this study, we analyze the impact of APP deletion on the hippocampal PAZ proteome. The native hippocampal PAZ derived from APP mouse mutants (APP-KOs and NexCreAPP/APLP2-cDKOs) was isolated by subcellular fractionation and immunopurification. Subsequently, an isobaric labeling was performed using TMT6 for protein identification and quantification by high-resolution mass spectrometry. We combine bioinformatics tools and biochemical approaches to address the proteomics dataset and to understand the role of individual proteins. The impact of APP deletion on the hippocampal PAZ proteome was visualized by creating protein-protein interaction (PPI) networks that incorporated APP into the synaptic vesicle cycle, cytoskeletal organization, and calcium-homeostasis. The combination of subcellular fractionation, immunopurification, proteomic analysis, and bioinformatics allowed us to identify APP as structural and functional regulator in a context-sensitive manner within the hippocampal active zone network. PMID:27092780

  19. Quaternary grabens in southernmost Illinois: Deformation near an active intraplate seismic zone

    USGS Publications Warehouse

    Nelson, W.J.; Denny, F.B.; Follmer, L.R.; Masters, J.M.

    1999-01-01

    Narrow grabens displace Quaternary sediments near the northern edge of the Mississippi Embayment in extreme southern Illinois, east-central United States. Grabens are part of the Fluorspar Area Fault Complex (FAFC), which has been recurrently active throughout Phanerozoic time. The FAFC strikes directly toward the New Madrid Seismic Zone (NMSZ), scene of some of the largest intra-plate earthquakes in history. The NMSZ and FAFC share origin in a failed Cambrian rift (Reelfoot Rift). Every major fault zone of the FAFC in Illinois exhibits Quaternary displacement. The structures appear to be strike-slip pull-apart grabens, but the magnitude and direction of horizontal slip and their relationship to the current stress field are unknown. Upper Tertiary strata are vertically displaced more than 100 m, Illinoian and older Pleistocene strata 10 to 30 m, and Wisconsinan deposits 1 m or less. No Holocene deformation has been observed. Average vertical slip rates are estimated at 0.01 to 0.03 mm/year, and recurrence intervals for earthquakes of magnitude 6 to 7 are on the order of 10,000s of years for any given fault. Previous authors remarked that the small amount of surface deformation in the New Madrid area implies that the NMSZ is a young feature. Our findings show that tectonic activity has shifted around throughout the Quaternary in the central Mississippi Valley. In addition to the NMSZ and southern Illinois, the Wabash Valley (Illinois-Indiana), Benton Hills (Missouri), Crowley's Ridge (Arkansas-Missouri), and possibly other sites have experienced Quaternary tectonism. The NMSZ may be only the latest manifestation of seismicity in an intensely fractured intra-plate region.

  20. Significant foreshock activities of M>7.5 earthquakes in the Kuril subduction zone

    NASA Astrophysics Data System (ADS)

    Harada, T.; Yokoi, S.; Satake, K.

    2014-12-01

    In the Kuril subduction zone, some M>7.5 earthquakes are accompanied by significant foreshock activities, providing a good opportunity to understand the characteristics of foreshocks for large interplate events such as occur along the Japan Trench and Nankai Trough etc. Some preliminary results from our examination of the foreshock sequences are as follows. Relocated foreshocks tend to migrate with time toward the trench axis. Foreshock distributions of the interplate earthquakes do not overlap with the large coseismic slips (asperities) of the mainshocks. Foreshocks of the 2007 northern Kuril outer-rise event, however, were distributed on the entire rupture area. Foreshock sequences seem to be limited in the regions where the background seismicity rates are relatively high. The foreshock activities were found in the examination of the space-time pattern of M>7 events along the northern Japan to Kuril trench since 1913 (e.g. Harada, Satake, and Ishibashi, 2011:AGU, 2012:AOGS). The large earthquakes preceded by active foreshock sequences are: the 2006 (M8.3), 2007 (M8.1) offshore Simushir earthquakes, the 1963 (M8.5), 1991 (M7.6), 1995 (M7.9) offshore Urup events, the 1978 (M7.8) offshore Iturup events, the 1969 (M8.2) offshore Shikotan event. In contrast, M>7.5 interplate earthquakes offshore Hokkaido (1952 (M8.1), 1973 (M7.8), 2003 (M8.1)) and intraslab earthquakes (1958 (M8.3), 1978 (M7.8), 1993 (M7.6), 1994 (M8.3)) had few or no foreshocks. In the examination of the active foreshocks, we relocated foreshocks by the Modified JHD method (Hurukawa, 1995), compared relocated foreshock areas with mainshock coseismic slip distributions estimated by the teleseismic body-wave inversion (Kikuchi and Kanamori, 2003), and examined the relation between active foreshock sequences and regional background seismicity. This study was supported by the MEXT's "New disaster mitigation research project on Mega thrust earthquakes around Nankai/Ryukyu subduction zones".

  1. Impacts of stellar evolution and dynamics on the habitable zone: The role of rotation and magnetic activity

    NASA Astrophysics Data System (ADS)

    Gallet, F.; Charbonnel, C.; Amard, L.; Brun, S.; Palacios, A.; Mathis, S.

    2017-01-01

    Context. With the ever growing number of detected and confirmed exoplanets, the probability of finding a planet that looks like the Earth increases continuously. While it is clear that the presence of a planet in the habitable zone does not imply the planet is habitable, a systematic study of the evolution of the habitable zone is required to account for its dependence on stellar parameters. Aims: In this article, we aim to provide the community with the dependence of the habitable zone upon the stellar mass, metallicity, rotation, and for various prescriptions of the limits of the habitable zone. Methods: We use stellar evolution models computed with the code STAREVOL, which includes the most current physical mechanisms of internal transport of angular momentum and external wind braking, to study the evolution of the habitable zone and the continuously habitable zone limits. Results: The stellar parameters mass and metallicity affect the habitable zone limits most dramatically. Conversely, for a given stellar mass and metallicity, stellar rotation has only a marginal effect on these limits and does not modify the width of the habitable zone. Moreover, and as expected in the main-sequence phase and for a given stellar mass and metallicity, the habitable zone limits remain almost constant, and this confirms the usual assumptions of a relative constancy of these limits during that phase. The evolution of the habitable zone limits is also correlated to the evolution of the stellar activity (through the Rossby number), which depends on the stellar mass considered. While the magnetic activity has negligible consequence in the case of more massive stars, these effects may have a strong impact on the habitability of a planet around M-dwarf stars. Thus, stellar activity cannot be neglected and may have a strong impact on the development of life during the early stage of the continuously habitable zone phase of low-mass stars. Using observed trends of stellar magnetic field

  2. Underground Corrosion of Activated Metals in an Arid Vadose Zone Environment

    SciTech Connect

    Adler Flitton, M.K; Mizia, R.E.; Bishop, C.W.

    2001-10-24

    The subsurface radioactive disposal site located at the Idaho National Engineering and Environmental Laboratory contains neutron-activated metals from nonfuel nuclear-reactor- core components. A long-term corrosion test is being conducted to obtain site-specific corrosion rates to support efforts to more accurately estimate the transfer of activated elements in an arid vadose zone environment. The tests use nonradioactive metal coupons representing the prominent neutron-activated material buried at the disposal location, namely, Type 304L stainless steel, Type 315L stainless steel, nickel-chromium alloy (UNS NO7718), beryllium, aluminum 6061-T6, and a zirconium alloy, (UNS R60804). In addition, carbon steel (the material presently used in the cask disposal liners and other disposal containers) and a duplex stainless steel (UNS S32550) (the proposed material for the high- integrity disposal containers) are also included in the test program. This paper briefly describes the test program and presents the early corrosion rate results after 1 year and 3 years of underground exposure.

  3. Underground Corrosion of Activated Metals in an Arid Vadose Zone Environment

    SciTech Connect

    Adler Flitton, Mariana Kay; Mizia, Ronald Eugene; Bishop, Carolyn Wagoner

    2002-04-01

    The subsurface radioactive disposal site located at the Idaho National Engineering and Environmental Laboratory contains neutron-activated metals from nonfuel nuclear-reactor- core components. A long-term corrosion test is being conducted to obtain site-specific corrosion rates to support efforts to more accurately estimate the transfer of activated elements in an arid vadose zone environment. The tests use nonradioactive metal coupons representing the prominent neutron-activated material buried at the disposal location, namely, Type 304L stainless steel, Type 315L stainless steel, nickel-chromium alloy (UNS NO7718), beryllium, aluminum 6061-T6, and a zirconium alloy, (UNS R60804). In addition, carbon steel (the material presently used in the cask disposal liners and other disposal containers) and a duplex stainless steel (UNS S32550) (the proposed material for the high- integrity disposal containers) are also included in the test program. This paper briefly describes the test program and presents the early corrosion rate results after 1 year and 3 years of underground exposure.

  4. Probabilistic secretion of quanta and the synaptosecretosome hypothesis: evoked release at active zones of varicosities, boutons, and endplates.

    PubMed

    Bennett, M R; Gibson, W G; Robinson, J

    1997-10-01

    A quantum of transmitter may be released upon the arrival of a nerve impulse if the influx of calcium ions through a nearby voltage-dependent calcium channel is sufficient to activate the vesicle-associated calcium sensor protein that triggers exocytosis. A synaptic vesicle, together with its calcium sensor protein, is often found complexed with the calcium channel in active zones to form what will be called a "synaptosecretosome." In the present work, a stochastic analysis is given of the conditions under which a quantum is released from the synaptosecretosome by a nerve impulse. The theoretical treatment considers the rise of calcium at the synaptosecretosome after the stochastic opening of a calcium channel at some time during the impulse, followed by the stochastic binding of calcium to the vesicle-associated protein and the probability of this leading to exocytosis. This allows determination of the probabilities that an impulse will release 0, 1, 2,... quanta from an active zone, whether this is in a varicosity, a bouton, or a motor endplate. A number of experimental observations of the release of transmitter at the active zones of sympathetic varicosities and boutons as well as somatic motor endplates are described by this analysis. These include the likelihood of the secretion of only one quantum at an active zone of endplates and of more than one quantum at an active zone of a sympathetic varicosity. The fourth-power relationship between the probability of transmitter release at the active zones of sympathetic varicosities and motor endplates and the external calcium concentration is also explained by this approach. So, too, is the fact that the time course of the increased rate of quantal secretion from a somatic active zone after an impulse is invariant with changes in the amount of calcium that enters through its calcium channel, whether due to changes consequent on the actions of autoreceptor agents such as adenosine or to facilitation. The increased

  5. Probing Microbial Activity in a Perched Water Body Located in a Deep Vadose Zone

    NASA Astrophysics Data System (ADS)

    Fujita, Y.; Taylor, J. L.; Henriksen, J. R.; Delwiche, M.; Gebrehiwet, T.; Hubbard, S. S.; Spycher, N.; Weathers, T. S.; Ginn, T. R.; Pfiffner, S. M.; Smith, R. W.

    2011-12-01

    Waste releases to the vadose zone are a legacy of past activities at a number of Department of Energy (DOE) facilities. At the Idaho National Laboratory (INL), 90Sr has been detected in perched water bodies underlying the Idaho Nuclear Technology and Engineering Center (INTEC) facility. Microbially induced calcite precipitation (MICP) using urea-hydrolyzing microbes is one proposed approach for immobilization of 90Sr in the subsurface. The sequestration mechanism is co-precipitation in calcite, promoted by the production of carbonate alkalinity from ureolysis. In order to assess the potential efficacy of MICP at INTEC a field study was conducted at the INL Vadose Zone Research Park (VZRP). The VZRP is located approximately 3 km from INTEC and shares many of the same hydrologic and lithologic features but in a non-contaminated setting. We conducted experiments over two field seasons in a perched water body located approximately 15 meters below land surface, using a 5-spot wellfield design. During the first season amendments (molasses and urea) were injected into the central well and water was extracted from two wells on either side, located along a diagonal. Water samples were characterized for microbial abundance, ureolytic activity and ureC gene numbers, along with solution composition. Before, during and after the injections cross-borehole geophysical imaging was performed, using various combinations of the available wells. During the second field season in situ static experiments were conducted to specifically characterize attached and unattached microbial communities, using surrogate substrates colonized during a 12 week incubation. Based on the field data a first order in situ urea hydrolysis rate constant of 0.034 d-1 was estimated. This was more than an order of magnitude higher than rate constants estimated above-ground using water samples, suggesting that attached microorganisms were responsible for >90% of the observed urea hydrolysis activity. The

  6. Critical behavior of subcellular density organization during neutrophil activation and migration

    PubMed Central

    Baker-Groberg, Sandra M.; Phillips, Kevin G.; Healy, Laura D.; Itakura, Asako; Porter, Juliana E.; Newton, Paul K.; Nan, Xiaolin; McCarty, Owen J.T.

    2015-01-01

    Physical theories of active matter continue to provide a quantitative understanding of dynamic cellular phenomena, including cell locomotion. Although various investigations of the rheology of cells have identified important viscoelastic and traction force parameters for use in these theoretical approaches, a key variable has remained elusive both in theoretical and experimental approaches: the spatiotemporal behavior of the subcellular density. The evolution of the subcellular density has been qualitatively observed for decades as it provides the source of image contrast in label-free imaging modalities (e.g., differential interference contrast, phase contrast) used to investigate cellular specimens. While these modalities directly visualize cell structure, they do not provide quantitative access to the structures being visualized. We present an established quantitative imaging approach, non-interferometric quantitative phase microscopy, to elucidate the subcellular density dynamics in neutrophils undergoing chemokinesis following uniform bacterial peptide stimulation. Through this approach, we identify a power law dependence of the neutrophil mean density on time with a critical point, suggesting a critical density is required for motility on 2D substrates. Next we elucidate a continuum law relating mean cell density, area, and total mass that is conserved during neutrophil polarization and migration. Together, our approach and quantitative findings will enable investigators to define the physics coupling cytoskeletal dynamics with subcellular density dynamics during cell migration. PMID:26640599

  7. Observations of Seafloor Deformation and Methane Venting within an Active Fault Zone Offshore Southern California

    NASA Astrophysics Data System (ADS)

    Anderson, K.; Lundsten, E. M.; Paull, C. K.; Caress, D. W.; Thomas, H. J.; Brewer, P. G.; Vrijenhoek, R.; Lundsten, L.

    2013-12-01

    Detailed mapping surveys of the floor and flanks of the Santa Monica Basin, San Pedro Basin, and San Diego Trough were conducted during the past seven years using an Autonomous Underwater Vehicle (AUV) built and operated by MBARI specifically for seafloor mapping. The AUV collected data provide up to 1 m resolution multibeam bathymetric grids with a vertical precision of 0.15 m. Along with high-resolution multibeam, the AUV also collects chirp seismic reflection profiles. Structures within the uppermost 10-20 m of the seafloor, which in the surveys presented here is composed of recent sediment drape, can typically be resolved in the sub-bottom reflectors. Remotely operated vehicle (ROV) dives allowed for ground-truth observations and sampling within the surveyed areas. The objectives of these dives included finding evidence of recent seafloor deformation and locating areas where chemosynthetic biological communities are supported by fluid venting. Distinctive seafloor features within an active fault zone are revealed in unprecedented detail in the AUV generated maps and seismic reflection profiles. Evidence for recent fault displacements include linear scarps which can be as small as 20 cm high but traceable for several km, right lateral offsets within submarine channels and topographic ridges, and abrupt discontinuities in sub-bottom reflectors, which in places appear to displace seafloor sediments. Several topographic highs that occur within the fault zone appear to be anticlines related to step-overs in these faults. These topographic highs are, in places, topped with circular mounds that are up to 15 m high and have ~30° sloping sides. The crests of the topographic highs and the mounds both have distinctive rough morphologies produced by broken pavements of irregular blocks of methane-derived authigenic carbonates, and by topographic depressions, commonly more than 2 m deep. These areas of distinctive rough topography are commonly associated with living

  8. Seasonal and solar activity variability of D-region electron density at 69°N

    NASA Astrophysics Data System (ADS)

    Singer, Werner; Latteck, Ralph; Friedrich, Martin; Wakabayashi, Makato; Rapp, Markus

    2011-06-01

    A narrow beam Doppler radar operating at 3.17 MHz and installed close to the Andøya Rocket Range in Andenes, Norway, (69.3°N, 16.0°E) has been providing electron densities in the lower ionosphere since summer 2003. The experiment utilizes partial reflection of ordinary and extraordinary component waves from scatterers in the altitude range 50-95 km to estimate electron densities from differential absorption and differential phase measurements. These ground-based observations are in good agreement with concurrent rocket-borne radio wave propagation measurements at Andenes. Results of the diurnal and seasonal variability of electron densities and the response of D-region electron densities to solar activity storms are presented.

  9. Calculating in situ density and heat capacity of rocks with GMIN: new type of input data for thermomechanical modeling of subduction zones

    NASA Astrophysics Data System (ADS)

    Burchard, M.; Gerya, T.

    2003-04-01

    The technique of minimizing the Gibbs free energy of specified rock compositions by varying the amounts and compositions of coexisting phases has provided new insights and possibilities for petrological investigations. For thermomechanical modeling of subduction zone processes density, isobaric heat capacity, thermal expansion and compressibility can then be extracted as a function of the amounts and compositions of coexisting phases [1]. At present two programs offer the possibility of calculating phase diagrams with this technique, Holland and Powell's Thermocalc [2] and De Capitani's Theriac/Domino [3] package. The first one is a command line program producing a text output which can be converted to graphics with a user-written MathematicaTM program. It uses the Holland and Powell data base [2]. De Capitani's program is distributed as a Fortran 77 source code and uses the Berman database. Neither of these programs offers interfaces for use with geodynamic modeling programs. We have therefore enhanced our new Gibbs minimization program GMin [4] with an interface able to transfer density, entahalpy and volume values into databases or other programs. The minimization algorithm of our program is based on the de Capitani method [3], modified and adapted for the Holland and Powell database [2]. To achieve rapid convergence and stability of minimization we have optimized the computing strategy for models of solid solutions used in [2]. The standard program is divided in two parts, a front end and a calculation program controlled by the front end program. This construction opens the possibility of starting up several calculations in parallel on different computers and different operating systems. In this way large numbers of calculations can be performed on normal PC-networks (servers and clients) controlled by only one front end program. The front end is able to create pressure and temperature ordered databases containing density, enthalpy, volume and composition which

  10. Radiation activated CHK1/MEPE pathway may contribute to microgravity-induced bone density loss

    NASA Astrophysics Data System (ADS)

    Zhang, Xiangming; Wang, Ping; Wang, Ya

    2015-11-01

    Bone density loss in astronauts on long-term space missions is a chief medical concern. Microgravity in space is the major cause of bone density loss (osteopenia), and it is believed that high linear energy transfer (LET) radiation in space exacerbates microgravity-induced bone density loss; however, the mechanism remains unclear. It is known that acidic serine- and aspartate-rich motif (ASARM) as a small peptide released by matrix extracellular phosphoglycoprotein (MEPE) promotes osteopenia. We previously discovered that MEPE interacted with checkpoint kinase 1 (CHK1) to protect CHK1 from ionizing radiation promoted degradation. In this study, we addressed whether the CHK1-MEPE pathway activated by radiation contributes to the effects of microgravity on bone density loss. We examined the CHK1, MEPE and secreted MEPE/ASARM levels in irradiated (1 Gy of X-ray) and rotated cultured human osteoblast cells. The results showed that radiation activated CHK1, decreased the levels of CHK1 and MEPE in human osteoblast cells and increased the release of MEPE/ASARM. These results suggest that the radiation-activated CHK1/MEPE pathway exacerbates the effects of microgravity on bone density loss, which may provide a novel targeting factor/pathway for a future countermeasure design that could contribute to reducing osteopenia in astronauts.

  11. Radiation activated CHK1/MEPE pathway may contribute to microgravity-induced bone density loss

    PubMed Central

    Zhang, Xiangming; Wang, Ping; Wang, Ya

    2016-01-01

    Bone density loss in astronauts on long-term space missions is a chief medical concern. Microgravity in space is the major cause of bone density loss (osteopenia), and it is believed that high linear energy transfer (LET) radiation in space exacerbates microgravity-induced bone density loss; however, the mechanism remains unclear. It is known that acidic serine- and aspartate-rich motif (ASARM) as a small peptide released by matrix extracellular phosphoglycoprotein (MEPE) promotes osteopenia. We previously discovered that MEPE interacted with checkpoint kinase 1 (CHK1) to protect CHK1 from ionizing radiation promoted degradation. In this study, we addressed whether the CHK1-MEPE pathway activated by radiation contributes to the effects of microgravity on bone density loss. We examined the CHK1, MEPE and secreted MEPE/ASARM levels in irradiated (1 Gy of X-ray) and rotated cultured human osteoblast cells. The results showed that radiation activated CHK1, decreased the levels of CHK1 and MEPE in human osteoblast cells and increased the release of MEPE/ASARM. These results suggest that the radiation-activated CHK1/MEPE pathway exacerbates the effects of microgravity on bone density loss, which may provide a novel targeting factor/pathway for a future countermeasure design that could contribute to reducing osteopenia in astronauts. PMID:26553637

  12. Phosphodiesterase7 Inhibition Activates Adult Neurogenesis in Hippocampus and Subventricular Zone In Vitro and In Vivo.

    PubMed

    Morales-Garcia, Jose A; Echeverry-Alzate, Victor; Alonso-Gil, Sandra; Sanz-SanCristobal, Marina; Lopez-Moreno, Jose A; Gil, Carmen; Martinez, Ana; Santos, Angel; Perez-Castillo, Ana

    2017-02-01

    The phosphodiesterase 7 (PDE7) enzyme is one of the enzymes responsible for controlling intracellular levels of cyclic adenosine 3',5'-monophosphate in the immune and central nervous system. We have previously shown that inhibitors of this enzyme are potent neuroprotective and anti-inflammatory agents. In addition, we also demonstrated that PDE7 inhibition induces endogenous neuroregenerative processes toward a dopaminergic phenotype. Here, we show that PDE7 inhibition controls stem cell expansion in the subgranular zone of the dentate gyrus of the hippocampus (SGZ) and the subventricular zone (SVZ) in the adult rat brain. Neurospheres cultures obtained from SGZ and SVZ of adult rats treated with PDE7 inhibitors presented an increased proliferation and neuronal differentiation compared to control cultures. PDE7 inhibitors treatment of neurospheres cultures also resulted in an increase of the levels of phosphorylated cAMP response element binding protein, suggesting that their effects were indeed mediated through the activation of the cAMP/PKA signaling pathway. In addition, adult rats orally treated with S14, a specific inhibitor of PDE7, presented elevated numbers of proliferating progenitor cells, and migrating precursors in the SGZ and the SVZ. Moreover, long-term treatment with this PDE7 inhibitor shows a significant increase in newly generated neurons in the olfactory bulb and the hippocampus. Also a better performance in memory tests was observed in S14 treated rats, suggesting a functional relevance for the S14-induced increase in SGZ neurogenesis. Taken together, our results indicate for the first time that inhibition of PDE7 directly regulates proliferation, migration and differentiation of neural stem cells, improving spatial learning and memory tasks. Stem Cells 2017;35:458-472.

  13. Locating an active fault zone in Coso geothermal field by analyzing seismic guided waves from microearthquake data

    SciTech Connect

    SGP-TR-150-16

    1995-01-26

    Active fault systems usually provide high-permeability channels for hydrothermal outflow in geothermal fields. Locating such fault systems is of a vital importance to plan geothermal production and injection drilling, since an active fault zone often acts as a fracture-extensive low-velocity wave guide to seismic waves. We have located an active fault zone in the Coso geothermal field, California, by identifying and analyzing a fault-zone trapped Rayleigh-type guided wave from microearthquake data. The wavelet transform is employed to characterize guided-wave's velocity-frequency dispersion, and numerical methods are used to simulate the guided-wave propagation. The modeling calculation suggests that the fault zone is {approx} 200m wide, and has a P wave velocity of 4.80 km/s and a S wave velocity of 3.00 km/s, which is sandwiched between two half spaces with relatively higher velocities (P wave velocity 5.60 km/s, and S wave velocity 3.20 km/s). zones having vertical or nearly vertical dipping fault planes.

  14. Altitude variations in the thermosphere mass density response to geomagnetic activity during the recent solar minimum

    NASA Astrophysics Data System (ADS)

    Liu, X.; Thayer, J. P.; Burns, A.; Wang, W.; Sutton, E.

    2014-03-01

    Accelerometer data from coplanar orbits of Challenging Minisatellite Payload (CHAMP) and Gravity Recovery and Climate Experiment (GRACE) satellites were used to study the complex altitude and latitude variations of the thermosphere mass density response to geomagnetic activity during 1-10 December 2008 near 09 LT. Helium number densities near 500 km altitude were extracted from the CHAMP and GRACE measurements and clearly show the presence of a winter hemisphere helium bulge. This recent extreme solar minimum indicates that wintertime helium concentrations exceed NRLMSISE-00 model estimates by 30%-70% during quiet geomagnetic activity after adjusting F10.7 input into MSIS. The perturbation in mass density from quiet to active conditions is found to be less enhanced in the winter hemisphere at the higher GRACE altitudes (25%) than at the lower CHAMP altitudes (60%) and is attributed to dynamic behavior in the helium/oxygen transition. The investigation revealed the maximum storm time density perturbation to occur near the He/O transition region with a much weaker maximum near the O/N2 transition region. The altitude of maximum density perturbation occurs where the perturbation in the weighted pressure scale height is equal and opposite to the perturbation in the weighted mean molecular weight scale height. The altitude structure of density scale height perturbation is significantly influenced by the changes in the molecular weight scale height and can account for 50% of the change in mass density scale height in a region correspondingly close to the He/O transition during the 2008 solar minimum period.

  15. Distribution of dehalogenation activity in subseafloor sediments of the Nankai Trough subduction zone

    PubMed Central

    Futagami, Taiki; Morono, Yuki; Terada, Takeshi; Kaksonen, Anna H.; Inagaki, Fumio

    2013-01-01

    Halogenated organic matter buried in marine subsurface sediment may serve as a source of electron acceptors for anaerobic respiration of subseafloor microbes. Detection of a diverse array of reductive dehalogenase-homologous (rdhA) genes suggests that subseafloor organohalide-respiring microbial communities may play significant ecological roles in the biogeochemical carbon and halogen cycle in the subseafloor biosphere. We report here the spatial distribution of dehalogenation activity in the Nankai Trough plate-subduction zone of the northwest Pacific off the Kii Peninsula of Japan. Incubation experiments with slurries of sediment collected at various depths and locations showed that degradation of several organohalides tested only occurred in the shallow sedimentary basin, down to 4.7 metres below the seafloor, despite detection of rdhA in the deeper sediments. We studied the phylogenetic diversity of the metabolically active microbes in positive enrichment cultures by extracting RNA, and found that Desulfuromonadales bacteria predominate. In addition, for the isolation of genes involved in the dehalogenation reaction, we performed a substrate-induced gene expression screening on DNA extracted from the enrichment cultures. Diverse DNA fragments were obtained and some of them showed best BLAST hit to known organohalide respirers such as Dehalococcoides, whereas no functionally known dehalogenation-related genes such as rdhA were found, indicating the need to improve the molecular approach to assess functional genes for organohalide respiration. PMID:23479745

  16. Molecular Machines Regulating the Release Probability of Synaptic Vesicles at the Active Zone

    PubMed Central

    Körber, Christoph; Kuner, Thomas

    2016-01-01

    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 probabilistic 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 buffering 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 molecules and molecular machines taking part in the determination of vesicular Pr at the AZ. PMID:26973506

  17. Children who stutter show reduced action-related activity in the rostral cingulate zone.

    PubMed

    Harrewijn, A; Schel, M A; Boelens, H; Nater, C M; Haggard, P; Crone, E A

    2017-02-01

    Previous studies have indicated that children who stutter show not only speech-related problems, but also wider difficulties in self-control. In this study we test the novel hypothesis that children who stutter may experience difficulties with inhibitory control over voluntary actions. We used functional MRI to compare brain activity between children who stutter and children who do not stutter in a task that captures key cognitive aspects of voluntary action control. Participants performed a rolling marble task, in which they were instructed to press a key to stop a rolling marble from crashing on some of the trials (instructed action condition). They were also asked to choose voluntarily whether to execute or inhibit this prepotent response in other trials (volition condition). Children who stutter reported less motor and cognitive impulsivity and had shorter stop-signal reaction times when controlled for IQ, consistent with greater inhibition, compared to children who do not stutter. At the neural level, children who stutter showed decreased activation in the rostral cingulate zone during voluntary action selection compared to children who do not stutter. This effect was more pronounced for children who were rated as showing more stuttered syllables in the stutter screening, and was furthermore correlated with stop-signal reaction times and impulsivity ratings. These findings suggest that stuttering in childhood could reflect wider difficulties in self-control, also in the non-verbal domain. Understanding these neural mechanisms could potentially lead to more focused treatments of stuttering.

  18. An automatic continuous monitoring station for groundwater geochemistry at an active fault zone in SW Taiwan

    NASA Astrophysics Data System (ADS)

    Lai, Chun-Wei; Yang, Tsanyao F.; Fu, Ching-Chou; Hilton, David R.; Liu, Tsung-Kwei; Walia, Vivek; Lai, Tzu-Hua

    2015-04-01

    Previous studies have revealed that gas compositions of fluid samples collected from southwestern Taiwan where many hot springs and mud volcanoes are distributed along tectonic sutures show significant variation prior to and after some disaster seismic events. Such variations, including radon activity, CH4/CO2, CO2/3He and 3He/4He ratios of gas compositions, are considered to be precursors of earthquakes in this area. To validate the relationship between fluid compositions and local earthquakes, a continuous monitoring station has been established at Yun-Shui, which is an artesian well located at an active fault zone in SW Taiwan. It is equipped with a radon detector and a quadrupole mass spectrometer (QMS) for in-situ measurement of the dissolved gas composition. Data is telemetered to Taipei so we are able to monitor variations of gas composition in real time. Furthermore, we also installed a syringe pump apparatus for the retrieval and temporal analysis of helium (SPARTAH) at this station. From the SPARTAH samples, we can obtain detailed time series records of H-O isotopic compositions, DIC concentration and δ13C isotopic ratios, and anion concentration of the water samples at this station. After continuous monitoring for about one year, some anomalies occurred prior to some local earthquakes. It demonstrates that this automated system is feasible for long-term continuous seismo-geochemical research in this area. Keywords: monitoring; geochemistry; isotope; dissolved gases; pre-seismic signal.

  19. Quantitative control of active targeting of nanocarriers to tumor cells through optimization of folate ligand density.

    PubMed

    Tang, Zhaomin; Li, Dan; Sun, Huili; Guo, Xing; Chen, Yuping; Zhou, Shaobing

    2014-09-01

    The active targeting delivery system has been widely studied in cancer therapy by utilizing folate (FA) ligands to generate specific interaction between nanocarriers and folate receptors (FRs) on tumor cell. However, there is little work that has been published to investigate the influence of the definite density of the FA ligands on the active targeting of nanocarriers. In this study, we have combined magnetic-guided iron oxide nanoparticles with FA ligands, adjusted the FA ligand density and then studied the resulting effects on the active targeting ability of this dual-targeting drug delivery system to tumor cells. We have also optimized the FA ligand density of the drug delivery system for their active targeting to FR-overexpressing tumor cells in vitro. Prussian blue staining, semi-thin section of cells observed with transmission electron microscopy (TEM) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) have shown that the optimal FA density is from 2.3 × 10(18) to 2.5 × 10(18) per gram nanoparticles ((g·NPs)(-1)). We have further tried to qualitatively and quantitatively control the active targeting and delivering of drugs to tumors on 4T1-bearing BALB/c mice. As expected, the in vivo experimental results have also demonstrated that the FA density of the magnetic nanoparticles (MNPs) could be optimized for a more easily binding to tumor cells via the multivalent linkages and more readily internalization through the FR-mediated endocytosis. Our study can provide a strategy to quantitatively control the active targeting of nanocarriers to tumor cells for cancer therapy.

  20. [Correlation analysis between meteorological factors, biomass, and active components of Salvia miltiorrhiza in different climatic zones].

    PubMed

    Zhang, Chen-lu; Liang, Zong-suo; Guo, Hong-bo; Liu, Jing-ling; Liu, Yan; Liu, Feng-hua; Wei, Lang-zhu

    2015-02-01

    In this study, the growth and accumulation of active components of Salvia miltiorrhiza in twenty two experimental sites which crossing through three typical climate zones. The S. miltiorrhiza seedlings with the same genotype were planted in each site in spring, which were cultivated in fields with uniform management during their growing seasons till to harvest. The diterpene ketones (dihydrotanshinone, cryptotanshinone, tanshinone I and tanshinone II(A)) in S. miltiorrhiza root samples were determined by using high-performance liquid chromatography (HPLC) method. The biomass of root (root length, number of root branches, root width and dry weight) was also measured. The results showed that tanshinone II(A) in all samples of each site were higher than the standards required by China Pharmacopoeia. It has been found there is a relationship between root shape and climate change. The correlation analysis between active components and meteorological factors showed that the accumulation of tanshinones were effected by such meteorological factors as average relative humidity from April to October > average vapor pressure from April to October > average temperature difference day and night from April to October > annual average temperature and so on. The correlation analysis between root biomass and meteorological factors exhibited that root shape and accumulation of dry matter were affected by those factors, such as average annual aboveground (0-20 cm) temperature from April to October > annual average temperature > average vapor pressure from April to October > annual active accumulated temperature > annual average temperature > average vapor pressure from April to October. The accumulation of tanshinones and biomass was increased with the decrease of latitude. At the same time, the dry matter and diameter of root decreased if altitude rises. In addition, S. miltiorrhiza required sunlight is not sophisticated, when compared with humid and temperature. To sum up, S

  1. Slip Rates of Main Active Fault Zones Through Turkey Inferred From GPS Observations

    NASA Astrophysics Data System (ADS)

    Ozener, H.; Aktug, B.; Dogru, A.; Tasci, L.; Acar, M.; Emre, O.; Yilmaz, O.; Turgut, B.; Halicioglu, K.; Sabuncu, A.; Bal, O.; Eraslan, A.

    2015-12-01

    Active Fault Map of Turkey was revised and published by General Directorate of Mineral Research and Exploration in 2012. This map reveals that there are about 500 faults can generate earthquakes.In order to understand the earthquake potential of these faults, it is needed to determine the slip rates. Although many regional and local studies were performed in the past, the slip rates of the active faults in Turkey have not been determined. In this study, the block modelling, which is the most common method to produce slip rates, will be done. GPS velocities required for block modeling is being compiled from the published studies and the raw data provided then velocity field is combined. To form a homogeneous velocity field, different stochastic models will be used and the optimal velocity field will be achieved. In literature, GPS site velocities, which are computed for different purposes and published, are combined globally and this combined velocity field are used in the analysis of strain accumulation. It is also aimed to develop optimal stochastic models to combine the velocity data. Real time, survey mode and published GPS observations is being combined in this study. We also perform new GPS observations. Furthermore, micro blocks and main fault zones from Active Fault Map Turkey will be determined and homogeneous velocity field will be used to infer slip rates of these active faults. Here, we present the result of first year of the study. This study is being supported by THE SCIENTIFIC AND TECHNOLOGICAL RESEARCH COUNCIL OF TURKEY (TUBITAK)-CAYDAG with grant no. 113Y430.

  2. Direct effects of tillage on the activity density of ground beetle (Coleoptera: Carabidae) weed seed predators.

    PubMed

    Shearin, A F; Reberg-Horton, S C; Gallandt, E R

    2007-10-01

    Ground beetles are well known as beneficial organisms in agroecosystems, contributing to the predation of a wide range of animal pests and weed seeds. Tillage has generally been shown to have a negative effect on ground beetles, but it is not known whether this is because of direct mortality or the result of indirect losses resulting from dispersal caused by habitat deterioration. In 2005, field experiments measured direct, tillage-induced mortality, of four carabid weed seed predators, Harpalus rufipes DeGeer, Agonum muelleri Herbst, Anisodactylus merula Germar, and Amara cupreolata Putzeys, and one arthropod predator, Pterostichus melanarius Illiger, common to agroecosystems in the northeastern United States. Three tillage treatments (moldboard plow, chisel plow, and rotary tillage) were compared with undisturbed controls at two sites (Stillwater and Presque Isle) and at two dates (July and August) in Maine. Carabid activity density after disturbance was measured using fenced pitfall traps installed immediately after tillage to remove any effects of dispersal. Rotary tillage and moldboard plowing reduced weed seed predator activity density 52 and 54%, respectively. Carabid activity density after chisel plowing was similar to the undisturbed control. This trend was true for each of the weed seed predator species studied. However, activity density of the arthropod predator P. melanarius was reduced by all tillage types, indicating a greater sensitivity to tillage than the four weed seed predator species. These results confirm the need to consider both direct and indirect effects of management in studies of invertebrate seed predators.

  3. Electron-density descriptors as predictors in quantitative structure--activity/property relationships and drug design.

    PubMed

    Matta, Chérif F; Arabi, Alya A

    2011-06-01

    The use of electron density-based molecular descriptors in drug research, particularly in quantitative structure--activity relationships/quantitative structure--property relationships studies, is reviewed. The exposition starts by a discussion of molecular similarity and transferability in terms of the underlying electron density, which leads to a qualitative introduction to the quantum theory of atoms in molecules (QTAIM). The starting point of QTAIM is the topological analysis of the molecular electron-density distributions to extract atomic and bond properties that characterize every atom and bond in the molecule. These atomic and bond properties have considerable potential as bases for the construction of robust quantitative structure--activity/property relationships models as shown by selected examples in this review. QTAIM is applicable to the electron density calculated from quantum-chemical calculations and/or that obtained from ultra-high resolution x-ray diffraction experiments followed by nonspherical refinement. Atomic and bond properties are introduced followed by examples of application of each of these two families of descriptors. The review ends with a study whereby the molecular electrostatic potential, uniquely determined by the density, is used in conjunction with atomic properties to elucidate the reasons for the biological similarity of bioisosteres.

  4. Physical activity and lifestyle effects on bone mineral density among young adults: sociodemographic and biochemical analysis

    PubMed Central

    Alghadir, Ahmad H.; Gabr, Sami A.; Al-Eisa, Einas

    2015-01-01

    [Purpose] The purpose of this study was to assess the possible role of physical activities, calcium consumption and lifestyle factors in both bone mineral density and bone metabolism indices in 350 young adult volunteers. [Subjects and Methods] All volunteers were recruited for the assessment of lifestyle behaviors and physical activity traits using validated questioners, and bone mineral density (BMD), serum osteocalcin (s-OC), bone-specific alkaline phosphatase (BAP), and calcium were estimated using dual-energy X-ray absorptiometry analysis, and immunoassay techniques. [Results] Male participants showed a significant increase in BMD along with an increase in bone metabolism markers compared with females in all groups. However, younger subjects showed a significant increase in BMD, OC, BAP, and calcium compared with older subjects. Osteoporosis was more common in older subjects linked with abnormal body mass index and waist circumference. Bone metabolism markers correlated positively with BMD, physically activity and negatively with osteoporosis in all stages. Also, moderate to higher calcium and milk intake correlated positively with higher BMD. However, low calcium and milk intake along with higher caffeine, and carbonated beverage consumption, and heavy cigarette smoking showed a negative effect on the status of bone mineral density. Stepwise regression analysis showed that life style factors including physical activity and demographic parameters explained around 58–69.8% of the bone mineral density variation in young adults especially females. [Conclusion] body mass index, physical activity, low calcium consumption, and abnormal lifestyle have role in bone mineral density and prognosis of osteoporosis in young adults. PMID:26311965

  5. Dual-color STED microscopy reveals a sandwich structure of Bassoon and Piccolo in active zones of adult and aged mice

    PubMed Central

    Nishimune, Hiroshi; Badawi, Yomna; Mori, Shuuichi; Shigemoto, Kazuhiro

    2016-01-01

    Presynaptic active zones play a pivotal role as synaptic vesicle release sites for synaptic transmission, but the molecular architecture of active zones in mammalian neuromuscular junctions (NMJs) at sub-diffraction limited resolution remains unknown. Bassoon and Piccolo are active zone specific cytosolic proteins essential for active zone assembly in NMJs, ribbon synapses, and brain synapses. These proteins are thought to colocalize and share some functions at active zones. Here, we report an unexpected finding of non-overlapping localization of these two proteins in mouse NMJs revealed using dual-color stimulated emission depletion (STED) super resolution microscopy. Piccolo puncta sandwiched Bassoon puncta and aligned in a Piccolo-Bassoon-Piccolo structure in adult NMJs. P/Q-type voltage-gated calcium channel (VGCC) puncta colocalized with Bassoon puncta. The P/Q-type VGCC and Bassoon protein levels decreased significantly in NMJs from aged mouse. In contrast, the Piccolo levels in NMJs from aged mice were comparable to levels in adult mice. This study revealed the molecular architecture of active zones in mouse NMJs at sub-diffraction limited resolution, and described the selective degeneration mechanism of active zone proteins in NMJs from aged mice. Interestingly, the localization pattern of active zone proteins described herein is similar to active zone structures described using electron microscope tomography. PMID:27321892

  6. 78 FR 73824 - Foreign-Trade Zone (FTZ) 20-Suffolk, Virginia; Notification of Proposed Production Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-09

    ... Foreign-Trade Zones Board Foreign-Trade Zone (FTZ) 20--Suffolk, Virginia; Notification of Proposed... that apply to toner cartridges, bottles and cartridge parts (duty free) for the foreign-status inputs... are: duty-free, 10 cents/barrel or 6.5%). Public comment is invited from interested...

  7. Group Dynamics in the Language Classroom: Embodied Participation as Active Reception in the Collective Zone of Proximal Development

    ERIC Educational Resources Information Center

    van Compernolle, Rémi A.; Williams, Lawrence

    2013-01-01

    This article explores the notion of "active reception" during small-group collaborative interaction in the foreign language classroom, focusing on the embodied participation of a secondary (nonspeaking) interactant, Diane. Drawing on Vygotskian sociocultural theory, we argue that within small-group work, a Zone of Proximal Development…

  8. 77 FR 28569 - Foreign-Trade Zone 92-Gulfport, MS Notification of Proposed Production Activity; Gulf Ship, LLC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-15

    ...; Gulf Ship, LLC, (Shipbuilding), Gulfport, MS The Mississippi Coast Foreign-Trade Zone, Inc., grantee of FTZ 92, submitted a notification of proposed production activity on behalf of Gulf Ship, LLC (Gulf Ship), located in Gulfport, Mississippi. The Gulf Ship facility is located within Site 3 of FTZ 92....

  9. The Status of Secondary School Science Laboratory Activities for Quality Education in Case of Wolaita Zone, Southern Ethiopia

    ERIC Educational Resources Information Center

    Zengele, Ashebir Gogile; Alemayehu, Bereket

    2016-01-01

    A high quality science education in primary and secondary schools contributes to developing scientific literacy and would be expected to predispose students to study the enabling sciences at university. The major purpose of this study was to assess the practice and problems in science laboratory activities in the secondary school of Wolaita Zone,…

  10. APP—A Novel Player within the Presynaptic Active Zone Proteome

    PubMed Central

    Weingarten, Jens; Weingarten, Melanie; Wegner, Martin; Volknandt, Walter

    2017-01-01

    The amyloid precursor protein (APP) was discovered in the 1980s as the precursor protein of the amyloid A4 peptide. The amyloid A4 peptide, also known as A-beta (Aβ), is the main constituent of senile plaques implicated in Alzheimer’s disease (AD). In association with the amyloid deposits, increasing impairments in learning and memory as well as the degeneration of neurons especially in the hippocampus formation are hallmarks of the pathogenesis of AD. Within the last decades much effort has been expended into understanding the pathogenesis of AD. However, little is known about the physiological role of APP within the central nervous system (CNS). Allocating APP to the proteome of the highly dynamic presynaptic active zone (PAZ) identified APP as a novel player within this neuronal communication and signaling network. The analysis of the hippocampal PAZ proteome derived from APP-mutant mice demonstrates that APP is tightly embedded in the underlying protein network. Strikingly, APP deletion accounts for major dysregulation within the PAZ proteome network. Ca2+-homeostasis, neurotransmitter release and mitochondrial function are affected and resemble the outcome during the pathogenesis of AD. The observed changes in protein abundance that occur in the absence of APP as well as in AD suggest that APP is a structural and functional regulator within the hippocampal PAZ proteome. Within this review article, we intend to introduce APP as an important player within the hippocampal PAZ proteome and to outline the impact of APP deletion on individual PAZ proteome subcommunities. PMID:28265241

  11. Trio, a Rho Family GEF, Interacts with the Presynaptic Active Zone Proteins Piccolo and Bassoon

    PubMed Central

    Terry-Lorenzo, Ryan T.; Torres, Viviana I.; Wagh, Dhananjay; Galaz, Jose; Swanson, Selene K.; Florens, Laurence; Washburn, Michael P.; Waites, Clarissa L.; Gundelfinger, Eckart D.; Reimer, Richard J.; Garner, Craig C.

    2016-01-01

    Synaptic vesicles (SVs) fuse with the plasma membrane at a precise location called the presynaptic active zone (AZ). This fusion is coordinated by proteins embedded within a cytoskeletal matrix assembled at the AZ (CAZ). In the present study, we have identified a novel binding partner for the CAZ proteins Piccolo and Bassoon. This interacting protein, Trio, is a member of the Dbl family of guanine nucleotide exchange factors (GEFs) known to regulate the dynamic assembly of actin and growth factor dependent axon guidance and synaptic growth. Trio was found to interact with the C-terminal PBH 9/10 domains of Piccolo and Bassoon via its own N-terminal Spectrin repeats, a domain that is also critical for its localization to the CAZ. Moreover, our data suggest that regions within the C-terminus of Trio negatively regulate its interactions with Piccolo/Bassoon. These findings provide a mechanism for the presynaptic targeting of Trio and support a model in which Piccolo and Bassoon play a role in regulating neurotransmission through interactions with proteins, including Trio, that modulate the dynamic assembly of F-actin during cycles of synaptic vesicle exo- and endocytosis. PMID:27907191

  12. Modelling of cloud formation due to air-sea interactions in an energy-active zone

    NASA Astrophysics Data System (ADS)

    Kondratyev, K. Ya.; Khvorostyanov, V. I.

    1989-02-01

    A mesoscale 3D numerical model is described, with which detailed calculations have been made of turbulence and wind characteristics in the atmospheric boundary layer (ABL), as well as cloud particle size distribution, longwave and solar radiation fluxes and flux divergences, and atmosphere-ocean heat exchange. Based on numerical experiments simulating winter conditions of the Newfoundland energy-active zone of the ocean (EAZO), atmosphere-ocean energy exchange is investigated. It is shown that the basic mechanisms for the EAZO formation involve the following processes: (i) at the hydrological front between cold and warm ocean currents, the fluxes of sensible and latent heat grow significantly; (ii) at this front, in a particular synoptic situation, overcast low-level cloudiness forms, screening solar radiation so that in winter, the radiation budget at the front is reduced, and the radiative flux into the ocean is less than the energy release to the atmosphere; (iii) frequent occurrence of such synoptic situations with cloudiness decreases the oceanic enthalpy and creates negative SST anomalies. The transport of these anomalies by currents to the western coasts of the continents causes anomalies of weather and climate.

  13. Trio, a Rho Family GEF, Interacts with the Presynaptic Active Zone Proteins Piccolo and Bassoon.

    PubMed

    Terry-Lorenzo, Ryan T; Torres, Viviana I; Wagh, Dhananjay; Galaz, Jose; Swanson, Selene K; Florens, Laurence; Washburn, Michael P; Waites, Clarissa L; Gundelfinger, Eckart D; Reimer, Richard J; Garner, Craig C

    2016-01-01

    Synaptic vesicles (SVs) fuse with the plasma membrane at a precise location called the presynaptic active zone (AZ). This fusion is coordinated by proteins embedded within a cytoskeletal matrix assembled at the AZ (CAZ). In the present study, we have identified a novel binding partner for the CAZ proteins Piccolo and Bassoon. This interacting protein, Trio, is a member of the Dbl family of guanine nucleotide exchange factors (GEFs) known to regulate the dynamic assembly of actin and growth factor dependent axon guidance and synaptic growth. Trio was found to interact with the C-terminal PBH 9/10 domains of Piccolo and Bassoon via its own N-terminal Spectrin repeats, a domain that is also critical for its localization to the CAZ. Moreover, our data suggest that regions within the C-terminus of Trio negatively regulate its interactions with Piccolo/Bassoon. These findings provide a mechanism for the presynaptic targeting of Trio and support a model in which Piccolo and Bassoon play a role in regulating neurotransmission through interactions with proteins, including Trio, that modulate the dynamic assembly of F-actin during cycles of synaptic vesicle exo- and endocytosis.

  14. APP-A Novel Player within the Presynaptic Active Zone Proteome.

    PubMed

    Weingarten, Jens; Weingarten, Melanie; Wegner, Martin; Volknandt, Walter

    2017-01-01

    The amyloid precursor protein (APP) was discovered in the 1980s as the precursor protein of the amyloid A4 peptide. The amyloid A4 peptide, also known as A-beta (Aβ), is the main constituent of senile plaques implicated in Alzheimer's disease (AD). In association with the amyloid deposits, increasing impairments in learning and memory as well as the degeneration of neurons especially in the hippocampus formation are hallmarks of the pathogenesis of AD. Within the last decades much effort has been expended into understanding the pathogenesis of AD. However, little is known about the physiological role of APP within the central nervous system (CNS). Allocating APP to the proteome of the highly dynamic presynaptic active zone (PAZ) identified APP as a novel player within this neuronal communication and signaling network. The analysis of the hippocampal PAZ proteome derived from APP-mutant mice demonstrates that APP is tightly embedded in the underlying protein network. Strikingly, APP deletion accounts for major dysregulation within the PAZ proteome network. Ca(2+)-homeostasis, neurotransmitter release and mitochondrial function are affected and resemble the outcome during the pathogenesis of AD. The observed changes in protein abundance that occur in the absence of APP as well as in AD suggest that APP is a structural and functional regulator within the hippocampal PAZ proteome. Within this review article, we intend to introduce APP as an important player within the hippocampal PAZ proteome and to outline the impact of APP deletion on individual PAZ proteome subcommunities.

  15. Liparid and macrourid fishes of the hadal zone: in situ observations of activity and feeding behaviour

    PubMed Central

    Jamieson, A.J.; Fujii, T.; Solan, M.; Matsumoto, A.K.; Bagley, P.M.; Priede, I.G.

    2008-01-01

    Using baited camera landers, the first images of living fishes were recorded in the hadal zone (6000–11 000 m) in the Pacific Ocean. The widespread abyssal macrourid Coryphaenoides yaquinae was observed at a new depth record of approximately 7000 m in the Japan Trench. Two endemic species of liparid were observed at similar depths: Pseudoliparis amblystomopsis in the Japan Trench and Notoliparis kermadecensis in the Kermadec Trench. From these observations, we have documented swimming and feeding behaviour of these species and derived the first estimates of hadal fish abundance. The liparids intercepted bait within 100–200 min but were observed to preferentially feed on scavenging amphipods. Notoliparis kermadecensis act as top predators in the hadal food web, exhibiting up to nine suction-feeding events per minute. Both species showed distinctive swimming gaits: P. amblystomopsis (mean length 22.5 cm) displayed a mean tail-beat frequency of 0.47 Hz and mean caudal : pectoral frequency ratio of 0.76, whereas N. kermadecensis (mean length 31.5 cm) displayed respective values of 1.04 and 2.08 Hz. Despite living at extreme depths, these endemic liparids exhibit similar activity levels compared with shallow-water liparids. PMID:19129104

  16. Liparid and macrourid fishes of the hadal zone: in situ observations of activity and feeding behaviour.

    PubMed

    Jamieson, A J; Fujii, T; Solan, M; Matsumoto, A K; Bagley, P M; Priede, I G

    2009-03-22

    Using baited camera landers, the first images of living fishes were recorded in the hadal zone (6000-11000 m) in the Pacific Ocean. The widespread abyssal macrourid Coryphaenoides yaquinae was observed at a new depth record of approximately 7000 m in the Japan Trench. Two endemic species of liparid were observed at similar depths: Pseudoliparis amblystomopsis in the Japan Trench and Notoliparis kermadecensis in the Kermadec Trench. From these observations, we have documented swimming and feeding behaviour of these species and derived the first estimates of hadal fish abundance. The liparids intercepted bait within 100-200 min but were observed to preferentially feed on scavenging amphipods. Notoliparis kermadecensis act as top predators in the hadal food web, exhibiting up to nine suction-feeding events per minute. Both species showed distinctive swimming gaits: P. amblystomopsis (mean length 22.5 cm) displayed a mean tail-beat frequency of 0.47 Hz and mean caudal:pectoral frequency ratio of 0.76, whereas N. kermadecensis (mean length 31.5 cm) displayed respective values of 1.04 and 2.08 Hz. Despite living at extreme depths, these endemic liparids exhibit similar activity levels compared with shallow-water liparids.

  17. Synaptophysin 1 Clears Synaptobrevin 2 from the Presynaptic Active Zone to Prevent Short-Term Depression.

    PubMed

    Rajappa, Rajit; Gauthier-Kemper, Anne; Böning, Daniel; Hüve, Jana; Klingauf, Jürgen

    2016-02-16

    Release site clearance is an important process during synaptic vesicle (SV) recycling. However, little is known about its molecular mechanism. Here we identify self-assembly of exocytosed Synaptobrevin 2 (Syb2) and Synaptophysin 1 (Syp1) by homo- and hetero-oligomerization into clusters as key mechanisms mediating release site clearance for preventing cis-SNARE complex formation at the active zone (AZ). In hippocampal neurons from Syp1 knockout mice, neurons expressing a monomeric Syb2 mutant, or after acute block of the ATPase N-ethylmaleimide-sensitive factor (NSF), responsible for cis-SNARE complex disassembly, we found strong frequency-dependent short-term depression (STD), whereas retrieval of Syb2 by compensatory endocytosis was only affected weakly. Defects in Syb2 endocytosis were stimulus- and frequency-dependent, indicating that Syp1 is not essential for Syb2 retrieval, but for its efficient clearance upstream of endocytosis. Our findings identify an SV protein as a release site clearance factor.

  18. Establishment of Active Traces of Lower Tagus Valley Fault Zone through an Integrated Approach

    NASA Astrophysics Data System (ADS)

    Besana-Ostman, G. M.; Vilanova, S.; Flor, A.; Canora, C.; Heleno, S.; Domingues, A.; Narciso, J.; Pinheiro, P.; Pinto, L.; Fonseca, J. F.

    2013-05-01

    Despite the occurrence of at least two damaging earthquakes in historical times - the M~7 1531 and the M6 1909 earthquakes - the Lower Tagus Valley Fault Zone (LTVFZ) has only recently been mapped (Besana-Ostman et al., 2012). In addition, a new set of active traces has been identified to the east during recent analysis and field inspections. The major challenges to the identification of active traces within Lower Tagus Valley (LTV) are both the presence of the very dynamic Tagus River (LTR) and the extensive urban and agricultural modifications introduced in the landscape. The detailed reports on the geological effects of the 1909 earthquake, while documenting extensively the secondary, shaking-related effects, provide no indication of surface rupture. The active traces of the northeast-southwest trending left-lateral LTVFZ within the LTV were established through integrated approaches as follows: aerial photo analysis, drainage system and satellite images examination, geomorphic feature identification, field mapping, geomorphic index measurements and trenching. The mapped traces extend to about 80 kilometers long and transect Quaternary and Holocene deposits. The mapped length of the western splay is compatible with an M7.2 earthquake. On the other hand, the newly mapped eastern traces plot almost parallel with the western splay, which may extend southwards to a comparable length. Preliminary analysis of satellite data show some evidence of additional splays located further east and south relative to the LTV. The new active traces suggest that the LTVFZ is a left-stepping left-lateral fault system with a regional NNE-SSW trend. Moreover, its extent and kinematics suggest magnitudes higher than previously assessed for the region. The location of the active traces displays a better correlation with the damage distribution of the historical events. Given the significance and implications of these findings for earthquake hazards assessment in Portugal, further studies

  19. Communication: Active space decomposition with multiple sites: Density matrix renormalization group algorithm

    SciTech Connect

    Parker, Shane M.; Shiozaki, Toru

    2014-12-07

    We extend the active space decomposition method, recently developed by us, to more than two active sites using the density matrix renormalization group algorithm. The fragment wave functions are described by complete or restricted active-space wave functions. Numerical results are shown on a benzene pentamer and a perylene diimide trimer. It is found that the truncation errors in our method decrease almost exponentially with respect to the number of renormalization states M, allowing for numerically exact calculations (to a few μE{sub h} or less) with M = 128 in both cases. This rapid convergence is because the renormalization steps are used only for the interfragment electron correlation.

  20. North-south asymmetry in activity on the Sun and cosmic ray density gradients

    NASA Technical Reports Server (NTRS)

    Swinson, D. B.; Shea, M. A.; Humble, J. E.

    1985-01-01

    The marked N-S asymmetry in solar activity (with predominant activity in the Sun's Northern Hemisphere) during the 1960's could certainly account for a S-pointing cosmic ray gradient. It is also clear from the data that the response to this change in solar activity asymmetry, and the related change in the perpendicular cosmic ray density gradient, is different for cosmic ray telescopes in the Earth's Northern and Southern Hemispheres. Northern Hemisphere detectors see a S-pointing gradient in the 60's and a N-pointing gradient after 1971, while Southern Hemisphere telescopes see a S-pointing gradient both before and after the reversal.

  1. The Salton Seismic Imaging Project (SSIP): Active Rift Processes in the Brawley Seismic Zone

    NASA Astrophysics Data System (ADS)

    Han, L.; Hole, J. A.; Stock, J. M.; Fuis, G. S.; Rymer, M. J.; Driscoll, N. W.; Kent, G.; Harding, A. J.; Gonzalez-Fernandez, A.; Lazaro-Mancilla, O.

    2011-12-01

    The Salton Seismic Imaging Project (SSIP), funded by NSF and USGS, acquired seismic data in and across the Salton Trough in southern California and northern Mexico in March 2011. The project addresses both rifting processes at the northern end of the Gulf of California extensional province and earthquake hazards at the southern end of the San Andreas Fault system. Seven lines of onshore refraction and low-fold reflection data were acquired in the Coachella, Imperial, and Mexicali Valleys, two lines and a grid of airgun and OBS data were acquired in the Salton Sea, and onshore-offshore data were recorded. Almost 2800 land seismometers and 50 OBS's were used in almost 5000 deployments at almost 4300 sites, in spacing as dense as 100 m. These instruments received seismic signals from 126 explosive shots up to 1400 kg and over 2300 airgun shots. In the central Salton Trough, North American lithosphere appears to have been rifted completely apart. Based primarily on a 1979 seismic refraction project, the 20-22 km thick crust is apparently composed entirely of new crust added by magmatism from below and sedimentation from above. Active rifting of this new crust is manifested by shallow (<10km depth) seismicity in the oblique Brawley Seismic Zone (BSZ), small Salton Buttes volcanoes aligned perpendicular to the transform faults, very high heat flow (~140 mW/m2), and geothermal energy production. This presentation is focused on an onshore-offshore line of densely sampled refraction and low-fold reflection data that crosses the Brawley Seismic Zone and Salton Buttes in the direction of plate motion. At the time of abstract submission, data analysis was very preliminary, consisting of first-arrival tomography of the onshore half of the line for upper crustal seismic velocity. Crystalline basement (>5 km/s), comprised of late-Pliocene to Quaternary sediment metamorphosed by the high heat flow, occurs at ~2 km depth beneath the Salton Buttes and geothermal field and ~4 km

  2. Correlation Between the Extent of Catalytic Activity and Charge Density of Montmorillonites

    NASA Astrophysics Data System (ADS)

    Ertem, Gözen; Steudel, Annett; Emmerich, Katja; Lagaly, Gerhard; Schuhmann, Rainer

    2010-09-01

    The clay mineral montmorillonite is a member of the phyllosilicate group of minerals, which has been detected on martian soil. Montmorillonite catalyzes the condensation of activated monomers to form RNA-like oligomers. Extent of catalysis, that is, the yield of oligomers, and the length of the longest oligomer formed in these reactions widely varies with the source of montmorillonite (i.e., the locality where the mineral is mined). This study was undertaken to establish whether there exists a correlation between the extent of catalytic property and the charge density of montmorillonites. Charge density was determined by saturating the montmorillonites with alkyl ammonium cations that contained increasing lengths of alkyl chains, [CH3-(CH2)n-NH3]+, where n = 3-16 and 18, and then measuring d(001), interlayer spacing of the resulting montmorillonite-alkyl ammonium-montmorillonite complex by X-ray diffractometry (XRD). Results demonstrate that catalytic activity of montmorillonites with lower charge density is superior to that of higher charge density montmorillonite. They produce longer oligomers that contain 9 to 10 monomer units, while montmorillonite with high charge density catalyzes the formation of oligomers that contain only 4 monomer units. The charge density of montmorillonites can also be calculated from the chemical composition if elemental analysis data of the pure mineral are available. In the next mission to Mars, CheMin (Chemistry and Mineralogy), a combined X-ray diffraction/X-ray fluorescence instrument, will provide information on the mineralogical and elemental analysis of the samples. Possible significance of these results for planning the future missions to Mars for the search of organic compounds and extinct or extant life is discussed.

  3. Correlation Between the Extent of Catalytic Activity and Charge Density of Montmorillonites

    PubMed Central

    Steudel, Annett; Emmerich, Katja; Lagaly, Gerhard; Schuhmann, Rainer

    2010-01-01

    Abstract The clay mineral montmorillonite is a member of the phyllosilicate group of minerals, which has been detected on martian soil. Montmorillonite catalyzes the condensation of activated monomers to form RNA-like oligomers. Extent of catalysis, that is, the yield of oligomers, and the length of the longest oligomer formed in these reactions widely varies with the source of montmorillonite (i.e., the locality where the mineral is mined). This study was undertaken to establish whether there exists a correlation between the extent of catalytic property and the charge density of montmorillonites. Charge density was determined by saturating the montmorillonites with alkyl ammonium cations that contained increasing lengths of alkyl chains, [CH3-(CH2)n-NH3]+, where n = 3–16 and 18, and then measuring d(001), interlayer spacing of the resulting montmorillonite-alkyl ammonium-montmorillonite complex by X-ray diffractometry (XRD). Results demonstrate that catalytic activity of montmorillonites with lower charge density is superior to that of higher charge density montmorillonite. They produce longer oligomers that contain 9 to 10 monomer units, while montmorillonite with high charge density catalyzes the formation of oligomers that contain only 4 monomer units. The charge density of montmorillonites can also be calculated from the chemical composition if elemental analysis data of the pure mineral are available. In the next mission to Mars, CheMin (Chemistry and Mineralogy), a combined X-ray diffraction/X-ray fluorescence instrument, will provide information on the mineralogical and elemental analysis of the samples. Possible significance of these results for planning the future missions to Mars for the search of organic compounds and extinct or extant life is discussed. Key Words: Mars—Origin of life—Montmorillonite—Mineral catalysis—Layer charge density—X–ray diffractometry. Astrobiology 10, 743–749. PMID:20854214

  4. Correlation between the extent of catalytic activity and charge density of montmorillonites.

    PubMed

    Ertem, Gözen; Steudel, Annett; Emmerich, Katja; Lagaly, Gerhard; Schuhmann, Rainer

    2010-09-01

    The clay mineral montmorillonite is a member of the phyllosilicate group of minerals, which has been detected on martian soil. Montmorillonite catalyzes the condensation of activated monomers to form RNA-like oligomers. Extent of catalysis, that is, the yield of oligomers, and the length of the longest oligomer formed in these reactions widely varies with the source of montmorillonite (i.e., the locality where the mineral is mined). This study was undertaken to establish whether there exists a correlation between the extent of catalytic property and the charge density of montmorillonites. Charge density was determined by saturating the montmorillonites with alkyl ammonium cations that contained increasing lengths of alkyl chains, [CH₃-(CH₂)(n)-NH₃](+), where n = 3-16 and 18, and then measuring d(₀₀₁), interlayer spacing of the resulting montmorillonite-alkyl ammonium-montmorillonite complex by X-ray diffractometry (XRD). Results demonstrate that catalytic activity of montmorillonites with lower charge density is superior to that of higher charge density montmorillonite. They produce longer oligomers that contain 9 to 10 monomer units, while montmorillonite with high charge density catalyzes the formation of oligomers that contain only 4 monomer units. The charge density of montmorillonites can also be calculated from the chemical composition if elemental analysis data of the pure mineral are available. In the next mission to Mars, CheMin (Chemistry and Mineralogy), a combined X-ray diffraction/X-ray fluorescence instrument, will provide information on the mineralogical and elemental analysis of the samples. Possible significance of these results for planning the future missions to Mars for the search of organic compounds and extinct or extant life is discussed.

  5. The Rhizosphere Zone: A Hot Spot of Microbial Activity and Methylmercury Production in Saltmarsh Sediments of San Francisco Bay, California

    NASA Astrophysics Data System (ADS)

    Windham-Myers, L.; Marvin-Dipasquale, M.; Voytek, M.; Kirshtein, J.; Krabbenhoft, D. P.; Agee, J. L.; Cox, M.; Kakouros, E.; Collins, J. N.; Yee, D.

    2008-12-01

    Tidal marshes of varying hydrology and salinity have been shown to have high rates of microbial methylmercury (MeHg) production, especially the periodically flooded, higher elevations which are densely vegetated with shallowly rooted plants. The specific influence of emergent wetland plants and their active rhizosphere (root zone) on mercury (Hg) biogeochemistry, however, is poorly understood. Seasonal and spatial patterns of Hg biogeochemistry were examined in 2005 and 2006 at three marshes along a salinity gradient of the Petaluma River, in Northern San Francisco Bay, California. In addition, to directly examine the influence of rhizosphere activity on MeHg production, a suite of devegetation experiments was conducted in 2006 within each marsh using paired vegetated and devegetated plots in two marsh subhabitats: poorly- drained interior sites and well-drained "edge" sites near slough channels. Surface sediment (0-2cm) was sampled in both April and August from these plots, as well as from 1st and 3rd order slough channels that were naturally free of vegetation. Vegetated marsh sites produced 3- to19-fold more MeHg than did slough sites, and MeHg production rates were greater in marsh interior sites compared to more oxic marsh "edge" sites. Microbial biomass (ng DNA gdrysed) was greater in vegetated marsh settings, compared to slough channels, and increased significantly between April and August at all marsh sites. Despite this seasonal increase in microbial biomass, MeHg concentrations and production rates decreased from April to August in vegetated surface sediments. Microbial indicators of methylation also decreased from April to August, including rates of microbial sulfate reduction and the abundance of iron- and sulfate- reducing bacterial DNA. Results from the devegetated plots suggest that root exudation of fermentative labile carbon to surface soils is responsible for the higher microbial biomass, and the higher relative abundance of iron- and sulfate

  6. The role of sexual vs. asexual recruitment of Artemisia wudanica in transition zone habitats between inter-dune lowlands and active dunes in Inner Mongolia, China

    NASA Astrophysics Data System (ADS)

    Wang, Yongcui; Alberto, Busso Carlos; Jiang, Deming; Ala, Musa; Li, Xuehua; Zhou, Quanlai; Lin, Jixiang; Ren, Guohua; Jia, Lian

    2016-04-01

    Artemisia wudanica is an endemic, perennial, pioneering psammophyte species in the sand dune ecosystems of western Horqin Sand Land in northern China. However, no studies have addressed how sexual and asexual reproduction modes of A. wudanica perform at the transitional zones between active dune inter-dune lowlands and active dunes. In early spring, quadrats were randomly set up in the study area to monitor surviving seedling and/or ramet density and frequency coming from sexual/asexual reproduction of A. wudanica. Iron sticks were inserted near each quadrat to determine wind erosion intensity (WE). Additionally, soil samples were collected nearby each quadrat to test for soil moisture (SM), organic matter (OM) and pH. Surviving seedlings of A. wudanica showed an inverse response in comparison with ramets to SM, OM and WE. Soil moisture showed the most positive effect, and WE the negative effect, on surviving, sexual reproduction seedlings. Contrarily, WE had the most positive effect, and SM the negative effect, on asexual reproduction ramets. This suggests that increases in SM and decreases in WE should benefit recruitment of A. wudanica seedlings. On the contrary, ramets coming from asexual reproduction showed a different response to environmental factors in transition zone habitats. While SM was not a key constraint for the survival of seedlings, they showed a better, positive response to wind erosion environments. Overall, various study environmental parameters could be improved to foster A. wudanica invasion and settlement in the plant community through different reproductive modes, thereby promoting vegetation restoration and rehabilitation.

  7. Activated Microporous Carbon Derived from Almond Shells for High Energy Density Asymmetric Supercapacitors.

    PubMed

    Wu, Chun; Yang, Shaoran; Cai, Junjie; Zhang, Qiaobao; Zhu, Ying; Zhang, Kaili

    2016-06-22

    Via the activation treatment of carbonized almond shells with HNO3 and KOH, activated microporous carbon (AMC-3 and AMC-2) was successfully synthesized. These two AMC electrodes demonstrate remarkable electrochemical behaviors such as high rate capability, high specific capacitance, and excellent cycle stability when serving as electrodes for supercapacitors. More importantly, through the use of a Zn-Ni-Co ternary oxide (ZNCO) positive electrode and the AMC negative electrode, asymmetric supercapacitors (ASC) were assembled that deliver superior energy density (53.3 Wh kg(-1) at a power density of 1126.1 W kg(-1) for ASC-2 and 53.6 Wh kg(-1) at a power density of 1124.5 W kg(-1) for ASC-3) and excellent stability (82.7% and 83.4% specific capacitance retention for ZNCO//AMC ASC-2 and ZNCO//AMC ASC-3, respectively, after 5000 cycles). Through these two methods, low-cost, renewable, and environmentally friendly electrode materials can be provided for high energy density supercapacitors.

  8. [Characteristics of soil denitrifying enzyme activity in riparian zones with different land use types in Chongming Island, Shanghai of China].

    PubMed

    Chen, Gang-Liang; Li, Jian-Hua; Yang, Chang-Ming

    2013-10-01

    By using acetylene inhibition method, this paper studied the soil denitrifying enzyme activity (DEA) and its affecting factors in the riparian zone with different land use types (cropland riparian, forested riparian, and grassy riparian zones) in Chongming Island, Shanghai of China. The riparian soil DEA was (0.69 +/- 0.11)--(134.93 +/- 33.72) microg N x kg(-1) x h(-1), which differed obviously among different land types, with a decreasing trend of forested riparian zone > cropland riparian zone > grassy riparian zone. The soil DEA was significantly (P < 0.05) higher in 0-10 cm in 10-30, 30-50, and 50-70 cm layers. There were significant positive relationships between soil DEA and soil TOC, TN, and NO(3-)-N (P < 0.01). Land use change mainly altered the soil natural structure and soil physical and chemical properties, decreased the accumulation of soil organic carbon, and affected the soil nitrogen transformation, and thus, inhibited the occurrence of riparian soil denitrification.

  9. 78 FR 20091 - Foreign-Trade Zone 26-Atlanta, Georgia, Authorization of Production Activity, Perkins Shibaura...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-03

    ..., Perkins Shibaura Engines, LLC (Diesel Engines), Griffin, Georgia On November 29, 2012, Georgia Foreign... Foreign-Trade Zones (FTZ) Board on behalf of Perkins Shibaura Engines, LLC, submitted a notification...

  10. Present-day submarine hydrothermal activity in the Taupo-Rotorua Zone (Bay of Plenty, New Zealand)

    SciTech Connect

    Osipenko, A.B.; Egorov, Yu.O.; Fazlullin, S.M.; Gavrilenko, G.M.; Shul`kin, V.I.; Chertkova, L.V.

    1994-09-01

    We made detailed descriptions of the structure and material composition of sedimentary and water columns in the vicinity of active submarine hydrothermal activity in the southern part of the Bay of Plenty (North Island, New Zealand). Geophysical methods revealed that the hydrothermal system is confined to a tectonically distinct zone with a sedimentary cover characterized by complex structure. Chemical and mineralogical investigations confirmed that the activity of underwater vents exerts no substantial regional influence on the composition and features of ore mineralization in these formations. It is shown that essentially hydrothermal formations distinguishable within areas of otherwise monotypic sediments directly coincide with zones of hydrothermal discharge in the ocean floor. The absence of pronounced hydrothermal anomalies, together with the presence of {open_quotes}tongues{close_quotes} of anomalous concentrations of water-soluble gases suggests that the discharges are primarily hydrothermal in character.

  11. Exoplanet detection. Stellar activity masquerading as planets in the habitable zone of the M dwarf Gliese 581.

    PubMed

    Robertson, Paul; Mahadevan, Suvrath; Endl, Michael; Roy, Arpita

    2014-07-25

    The M dwarf star Gliese 581 is believed to host four planets, including one (GJ 581d) near the habitable zone that could possibly support liquid water on its surface if it is a rocky planet. The detection of another habitable-zone planet--GJ 581g--is disputed, as its significance depends on the eccentricity assumed for d. Analyzing stellar activity using the Hα line, we measure a stellar rotation period of 130 ± 2 days and a correlation for Hα modulation with radial velocity. Correcting for activity greatly diminishes the signal of GJ 581d (to 1.5 standard deviations) while significantly boosting the signals of the other known super-Earth planets. GJ 581d does not exist, but is an artifact of stellar activity which, when incompletely corrected, causes the false detection of planet g.

  12. Shoreline changes and its impact on activities in the coastal zone in Greenland

    NASA Astrophysics Data System (ADS)

    Kroon, A.; Bendixen, M.; Elberling, B.

    2015-12-01

    shorelines. The shoreline changes were estimated using the digital shoreline analysis system (DSAS) of the USGS. The spatial variability of accumulation and erosion patterns was detected and shows a surprising thread for ancient settlements and present-day activities in the coastal zone. The same patterns are finally discussed in terms of coastal risk assessment.

  13. Activated Carbon Fiber Paper Based Electrodes with High Electrocatalytic Activity for Vanadium Flow Batteries with Improved Power Density.

    PubMed

    Liu, Tao; Li, Xianfeng; Xu, Chi; Zhang, Huamin

    2017-02-08

    Vanadium flow batteries (VFBs) have received high attention for large-scale energy storage due to their advantages of flexibility design, long cycle life, high efficiency, and high safety. However, commercial progress of VFBs has so far been limited by its high cost induced by its low power density. Ultrathin carbon paper is believed to be a very promising electrode for VFB because it illustrates super-low ohmic polarization, however, is limited by its low electrocatalytic activity. In this paper, a kind of carbon paper (CP) with super-high electrocatalytic activity was fabricated via a universal and simple CO2 activation method. The porosity and oxygen functional groups can be easily tuned via this method. The charge transfer resistance (denoting the electrochemical polarization) of a VFB with CP electrode after CO2 activation decreased dramatically from 970 to 120 mΩcm(2). Accordingly, the energy efficiency of a VFB with activated carbon paper as the electrode increased by 13% as compared to one without activation and reaches nearly 80% when the current density is 140 mAcm(-2). This paper provides an effective way to prepare high-performance porous carbon electrodes for VFBs and even for other battery systems.

  14. Local and Landscape Correlates of Spider Activity Density and Species Richness in Urban Gardens.

    PubMed

    Otoshi, Michelle D; Bichier, Peter; Philpott, Stacy M

    2015-08-01

    Urbanization is a major threat to arthropod biodiversity and abundance due to reduction and loss of suitable natural habitat. Green spaces and small-scale agricultural areas may provide habitat and resources for arthropods within densely developed cities. We studied spider activity density (a measure of both abundance and degree of movement) and diversity in urban gardens in Santa Cruz, Santa Clara, and Monterey counties in central California, USA. We sampled for spiders with pitfall traps and sampled 38 local site characteristics for 5 mo in 19 garden sites to determine the relative importance of individual local factors. We also analyzed 16 landscape variables at 500-m and 1-km buffers surrounding each garden to determine the significance of landscape factors. We identified individuals from the most common families to species and identified individuals from other families to morphospecies. Species from the families Lycosidae and Gnaphosidae composed 81% of total adult spider individuals. Most of the significant factors that correlated with spider activity density and richness were local rather than landscape factors. Spider activity density and richness increased with mulch cover and flowering plant species, and decreased with bare soil. Thus, changes in local garden management have the potential to promote diversity of functionally important spiders in urban environments.

  15. Selective regulation of current densities underlies spontaneous changes in the activity of cultured neurons.

    PubMed

    Turrigiano, G; LeMasson, G; Marder, E

    1995-05-01

    We study the electrical activity patterns and the expression of conductances in adult stomatogastric ganglion (STG) neurons as a function of time in primary cell culture. When first plated in culture, these neurons had few active properties. After 1 d in culture they produced small action potentials that rapidly inactivated during maintained depolarization. After 2 d in culture they fired large action potentials tonically when depolarized, and their properties resembled very closely the properties of STG neurons pharmacologically isolated in the ganglion. After 3-4 d in culture, however, their electrical properties changed and they fired in bursts when depolarized. We characterized the currents expressed by these neurons in culture. They included two TTX-sensitive sodium currents, a calcium current, a delayed-rectifier-like current, a calcium-dependent potassium current, and two A-type currents. The changes in firing properties with time in culture were accompanied by an increase in inward and decrease in outward current densities. A single-compartment conductance-based model of an STG neuron was constructed by fitting the currents measured in the biological neurons. When the current densities in the model neuron were matched to those measured for the biological neurons in each activity state, the model neuron closely reproduced each state, indicating that the changes in current densities are sufficient to account for the changes in intrinsic properties. These data indicate that STG neurons isolated in culture change their intrinsic electrical properties by selectively adjusting the magnitudes of their ionic conductances.

  16. Tectonic Activity and Processes Preceding the Formation of the Dead Sea Fault Zone

    NASA Astrophysics Data System (ADS)

    Eppelbaum, L. V.; Pilchin, A. N.

    2007-12-01

    Analysis of geological-geophysical data indicates that at the end of the Proterozoic, blocks of the Arabian Shield (AS) were thrust to the north-west onto the crust of the proto-Mediterranean (PM). This was caused by the pushing of oceanic crust from the south-east forming the Najd faults system (NF). This thrusting took place between 630 and 590 Ma, and is confirmed by the offsets between the Yanbu suture of the AS and Allaqi-Sol Hamid suture of the Nubian Shield (NS), the Bi'r Umq suture of AS and Nakasib suture of NS, and parts of the Yanbu and Nabitah sutures of AS. This caused the separation of AS from NS, and AS from the continental crust to north-east of it with its north-western displacement, resulting in opening of the Persian Gulf. This caused the start of deposition of huge amounts of Vendian-Cambrian evaporites in Saudi Arabia, Oman, Persian Gulf, Zagros, central Iran and other regions. The fact of the formation and preservation of the evaporites, and the common similarities in Vendian-Triassic sedimentary cover of Central Iran, Zagros, Taurus, and Arabian Plate (AP) and common Late Proterozoic-Early Paleozioc magmatic activity, show that these regions did not change their position significantly since then. Results of the DESERT project show that the lowermost part of the crust is present east of the Dead Sea Fault Zone (DSFZ), but it is absent west of it. This could be explained by detachment of the bottom part of the crust west of DSFZ during AP thrusting onto the crust of PM. The lithospheric slice discovered by seismic data between Moho and depth of about 55 km in S. Israel could be a remnant of that crust. During the thrusting, the AP overrode the detached slice. The slice was later remelted during formation of the postorogenic magmatic rocks of 590-530 Ma widespread in Jordan. The formation of three dyke swarms in S. Israel (600-540 Ma), widespread dykes in Sinai (590-530 Ma) and AP (590-530 Ma), as well as high-T-low-P metamorphism between 600

  17. Factors in Daily Physical Activity Related to Calcaneal Mineral Density in Men

    NASA Technical Reports Server (NTRS)

    Hutchinson, Teresa M.; Whalen, Robert T.; Cleek, Tammy M.; Vogel, John M.; Arnaud, Sara B.

    1995-01-01

    To determine the factors in daily physical activity that influence the mineral density of the calcaneus, we recorded walking steps and the type and duration of exercise in 43 healthy 26-to 51-yr-old men. Areal (g/sq cm) calcaneal bone mineral density (CBMD) was measured by single energy x-ray densitometry. Subjects walked a mean (+/- SD) of 7902(+/-2534) steps per day or approximately 3.9(+/-1.2) miles daily. Eight subjects reported no exercise activities. The remaining 35 subjects spent 143(2-772) (median and range) min/wk exercising. Twenty-eight men engaged in exercise activities that generate single leg peak vertical ground reaction forces (GRF(sub z)) of 2 or more body weights (high loaders, HL), and 15 reported exercise or daily activities that typically generate GRF(sub z) less than 1.5 body weights (low loaders, LL). CBMD was 12% higher in HL than LL (0.668 +/- 0.074 g/sq cm vs 0.597 +/- 0.062 g/sq cm, P less than 0.004). In the HL group, CBMD correlated to reported minutes of high load exercise (r = 0.41, P less than 0.03). CBMD was not related to the number of daily walking steps (N = 43, r = 0.03, NS). The results of this study support the concept that the dominant factor in daily physical activity relating to bone mineral density is the participation in site specific high loading activities, i.e., for the calcaneus, high calcaneal loads.

  18. The Active and Periactive Zone Organization and the Functional Properties of Small and Large Synapses

    PubMed Central

    Cano, Raquel; Tabares, Lucia

    2016-01-01

    The arrival of an action potential (AP) at a synaptic terminal elicits highly synchronized quanta release. Repetitive APs produce successive synaptic vesicle (SV) fusions that require management of spent SV components in the presynaptic membrane with minimum disturbance of the secretory apparatus. To this end, the synaptic machinery is structured accordingly to the strength and the range of frequencies at which each particular synapse operates. This results in variations in the number and dimension of Active Zones (AZs), amount and distribution of SVs, and probably, in the primary endocytic mechanisms they use. Understanding better how these structural differences determine the functional response in each case has been a matter of long-term interest. Here we review the structural and functional properties of three distinct types of synapses: the neuromuscular junction (NMJ; a giant, highly reliable synapse that must exocytose a large number of quanta with each stimulus to guarantee excitation of the postsynaptic cell), the hippocampal excitatory small synapse (which most often has a single release site and a relatively small pool of vesicles), and the cerebellar mossy fiber-granule cell synapse (which possesses hundreds of release sites and is able to translocate, dock and prime vesicles at high speed). We will focus on how the release apparatus is organized in each case, the relative amount of vesicular membrane that needs to be accommodated within the periAZ upon stimulation, the different mechanisms for retrieving the excess of membrane and finally, how these factors may influence the functioning of the release sites. PMID:27252645

  19. Simultaneous Segmentation of Prostatic Zones Using Active Appearance Models With Multiple Coupled Levelsets.

    PubMed

    Toth, Robert; Ribault, Justin; Gentile, John; Sperling, Dan; Madabhushi, Anant

    2013-09-01

    In this work we present an improvement to the popular Active Appearance Model (AAM) algorithm, that we call the Multiple-Levelset AAM (MLA). The MLA can simultaneously segment multiple objects, and makes use of multiple levelsets, rather than anatomical landmarks, to define the shapes. AAMs traditionally define the shape of each object using a set of anatomical landmarks. However, landmarks can be difficult to identify, and AAMs traditionally only allow for segmentation of a single object of interest. The MLA, which is a landmark independent AAM, allows for levelsets of multiple objects to be determined and allows for them to be coupled with image intensities. This gives the MLA the flexibility to simulataneously segmentation multiple objects of interest in a new image. In this work we apply the MLA to segment the prostate capsule, the prostate peripheral zone (PZ), and the prostate central gland (CG), from a set of 40 endorectal, T2-weighted MRI images. The MLA system we employ in this work leverages a hierarchical segmentation framework, so constructed as to exploit domain specific attributes, by utilizing a given prostate segmentation to help drive the segmentations of the CG and PZ, which are embedded within the prostate. Our coupled MLA scheme yielded mean Dice accuracy values of .81, .79 and .68 for the prostate, CG, and PZ, respectively using a leave-one-out cross validation scheme over 40 patient studies. When only considering the midgland of the prostate, the mean DSC values were .89, .84, and .76 for the prostate, CG, and PZ respectively.

  20. Simultaneous Segmentation of Prostatic Zones Using Active Appearance Models With Multiple Coupled Levelsets

    PubMed Central

    Toth, Robert; Ribault, Justin; Gentile, John; Sperling, Dan; Madabhushi, Anant

    2013-01-01

    In this work we present an improvement to the popular Active Appearance Model (AAM) algorithm, that we call the Multiple-Levelset AAM (MLA). The MLA can simultaneously segment multiple objects, and makes use of multiple levelsets, rather than anatomical landmarks, to define the shapes. AAMs traditionally define the shape of each object using a set of anatomical landmarks. However, landmarks can be difficult to identify, and AAMs traditionally only allow for segmentation of a single object of interest. The MLA, which is a landmark independent AAM, allows for levelsets of multiple objects to be determined and allows for them to be coupled with image intensities. This gives the MLA the flexibility to simulataneously segmentation multiple objects of interest in a new image. In this work we apply the MLA to segment the prostate capsule, the prostate peripheral zone (PZ), and the prostate central gland (CG), from a set of 40 endorectal, T2-weighted MRI images. The MLA system we employ in this work leverages a hierarchical segmentation framework, so constructed as to exploit domain specific attributes, by utilizing a given prostate segmentation to help drive the segmentations of the CG and PZ, which are embedded within the prostate. Our coupled MLA scheme yielded mean Dice accuracy values of .81, .79 and .68 for the prostate, CG, and PZ, respectively using a leave-one-out cross validation scheme over 40 patient studies. When only considering the midgland of the prostate, the mean DSC values were .89, .84, and .76 for the prostate, CG, and PZ respectively. PMID:23997571

  1. Circadian expression of the presynaptic active zone protein Bruchpilot in the lamina of Drosophila melanogaster.

    PubMed

    Górska-Andrzejak, Jolanta; Makuch, Renata; Stefan, Joanna; Görlich, Alicja; Semik, Danuta; Pyza, Elzbieta

    2013-01-01

    In the fly's visual system, the morphology of cells and the number of synapses change during the day. In the present study we show that in the first optic neuropil (lamina) of Drosophila melanogaster, a presynaptic active zone protein Bruchpilot (BRP) exhibits a circadian rhythm in abundance. In day/night (or light/dark, LD) conditions the level of BRP increases two times, in the morning and in the evening. The same pattern of changes in the BRP level was detected in whole brain homogenates, thus indicating that the majority of synapses in the brain peaks twice during the day. However, these two peaks in BRP abundance, measured as the fluorescence intensity of immunolabeling, seem to be regulated differently. The peak in the morning is predominantly regulated by light and involves the transduction pathway in the retina photoreceptors. This peak is present neither in wild-type Canton-S flies in constant darkness (DD), nor in norpA(7) phototransduction mutant in LD. However, it also depends on the clock gene per, because it is abolished in the per(0) arrhythmic mutant. In turn, the peak of BRP in the evening is endogenously regulated by an input from the pacemaker located in the brain. This peak is present in Canton-S flies in DD, as well as in the norpA(7) mutant in LD, but is absent in per(01), tim,(01) and cry(01) mutants in LD. In addition both peaks seem to depend on clock gene-expressing photoreceptors and glial cells of the visual system.

  2. Anti-hierarchical evolution of the active galactic nucleus space density in a hierarchical universe

    SciTech Connect

    Enoki, Motohiro; Ishiyama, Tomoaki; Kobayashi, Masakazu A. R.; Nagashima, Masahiro

    2014-10-10

    Recent observations show that the space density of luminous active galactic nuclei (AGNs) peaks at higher redshifts than that of faint AGNs. This downsizing trend in the AGN evolution seems to be contradictory to the hierarchical structure formation scenario. In this study, we present the AGN space density evolution predicted by a semi-analytic model of galaxy and AGN formation based on the hierarchical structure formation scenario. We demonstrate that our model can reproduce the downsizing trend of the AGN space density evolution. The reason for the downsizing trend in our model is a combination of the cold gas depletion as a consequence of star formation, the gas cooling suppression in massive halos, and the AGN lifetime scaling with the dynamical timescale. We assume that a major merger of galaxies causes a starburst, spheroid formation, and cold gas accretion onto a supermassive black hole (SMBH). We also assume that this cold gas accretion triggers AGN activity. Since the cold gas is mainly depleted by star formation and gas cooling is suppressed in massive dark halos, the amount of cold gas accreted onto SMBHs decreases with cosmic time. Moreover, AGN lifetime increases with cosmic time. Thus, at low redshifts, major mergers do not always lead to luminous AGNs. Because the luminosity of AGNs is correlated with the mass of accreted gas onto SMBHs, the space density of luminous AGNs decreases more quickly than that of faint AGNs. We conclude that the anti-hierarchical evolution of the AGN space density is not contradictory to the hierarchical structure formation scenario.

  3. Aftershocks illuminate the 2011 Mineral, Virginia, earthquake causative fault zone and nearby active faults

    USGS Publications Warehouse

    Horton, Jr., J. Wright; Shah, Anjana K.; McNamara, Daniel E.; Snyder, Stephen L.; Carter, Aina M

    2015-01-01

    Deployment of temporary seismic stations after the 2011 Mineral, Virginia (USA), earthquake produced a well-recorded aftershock sequence. The majority of aftershocks are in a tabular cluster that delineates the previously unknown Quail fault zone. Quail fault zone aftershocks range from ~3 to 8 km in depth and are in a 1-km-thick zone striking ~036° and dipping ~50°SE, consistent with a 028°, 50°SE main-shock nodal plane having mostly reverse slip. This cluster extends ~10 km along strike. The Quail fault zone projects to the surface in gneiss of the Ordovician Chopawamsic Formation just southeast of the Ordovician–Silurian Ellisville Granodiorite pluton tail. The following three clusters of shallow (<3 km) aftershocks illuminate other faults. (1) An elongate cluster of early aftershocks, ~10 km east of the Quail fault zone, extends 8 km from Fredericks Hall, strikes ~035°–039°, and appears to be roughly vertical. The Fredericks Hall fault may be a strand or splay of the older Lakeside fault zone, which to the south spans a width of several kilometers. (2) A cluster of later aftershocks ~3 km northeast of Cuckoo delineates a fault near the eastern contact of the Ordovician Quantico Formation. (3) An elongate cluster of late aftershocks ~1 km northwest of the Quail fault zone aftershock cluster delineates the northwest fault (described herein), which is temporally distinct, dips more steeply, and has a more northeastward strike. Some aftershock-illuminated faults coincide with preexisting units or structures evident from radiometric anomalies, suggesting tectonic inheritance or reactivation.

  4. Enhanced detection of lipid transfer inhibitor protein activity by an assay involving only low density lipoprotein.

    PubMed

    Morton, R E; Greene, D J

    1994-11-01

    Lipid transfer inhibitor protein (LTIP) activity has been typically quantitated by its ability to suppress lipid transfer protein-mediated lipid movement between low density lipoprotein (LDL) and high density lipoprotein (HDL). In an attempt to establish an LTIP activity assay that is more sensitive, we have exploited the reported preference of the inhibitor protein to interact with LDL. A lipid transfer assay was established that involves LDL as both the donor and the acceptor; LDL in one of these two pools was biotinylated to facilitate its removal with immobilized avidin. Compared to the standard LDL to HDL assay, LTIP inhibited lipid transfer from radiolabeled LDL to biotin-LDL 7-fold more. In the absence of LTIP, lipid transfer activity was the same in both assays. An added benefit of this assay was the near linearity (up to 85%) of the inhibitory response, in contrast to the highly curvilinear response of LTIP in LDL to HDL transfer assays. The high sensitivity of the LDL to biotin-LDL transfer assay in measuring LTIP activity could not be duplicated by other transfer assays including assays containing only HDL (HDL to biotin-HDL), assays between liposomes and LDL, or assays between LDL and HDL where the concentration of lipoproteins was reduced 10-fold. Thus, LTIP activity is most effectively measured in homologous lipid transfer assays involving only LDL (and its biotin derivative). This increased sensitivity to LTIP suggests that the inhibitor binds more avidly to the LDL surface than does lipid transfer protein.

  5. More Active Living–oriented County and Municipal Zoning is Associated with Increased Adult Leisure Time Physical Activity—United States, 2011

    PubMed Central

    Chriqui, Jamie F.; Nicholson, Lisa M.; Thrun, Emily; Leider, Julien; Slater, Sandy J.

    2016-01-01

    Although zoning is recognized for its role in facilitating healthy communities, no study has examined whether active living-oriented zoning codes are associated with adult leisure time physical activity (PA). This study sought to fill this gap and hypothesized that adult leisure time PA would be greater in communities with more progressive zoning code reforms and more active living-oriented zoning. Zoning codes for 1,617 county and municipal jurisdictions located in 30 states (covering ~40% of the U.S. population) were evaluated for code reform zoning and 11 active living markers. County-aggregated zoning measures were created for linking with five adult PA behaviors obtained from the 2011 Behavioral Risk Factor Surveillance System controlling for individual and county sociodemographics. Zoning elements most associated with adult PA included requirements for mixed use, active and passive recreation, bike parking/street furniture, and bike-pedestrian trails/paths. This study provides new insights as to the role that zoning can play in facilitating adult PA. PMID:27587898

  6. Screening of active metals for reactive adsorption desulfurization adsorbent using density functional theory

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Zhao, Liang; Xu, Chunming; Wang, Yuxian; Gao, Jinsen

    2017-03-01

    To explore characteristics of active metals for reactive adsorption desulfurization (RADS) technology, the adsorption of thiophene on M (100) (M = Cr, Mo, Co, Ni, Cu, Au, and Ag) surfaces was systematically studied by density functional theory with vdW correction (DFT + D3). We found that, in all case, the most stable molecular adsorption site was the hollow site and adsorptive capabilities of thiophene followed the order: Cr > Mo > Co ≈ Ni > Cu > Au ≈ Ag. By analyzing the nature of binding between thiophene and corresponding metals and the electronic structure of metals, the excessive activities of Cr and Mo were found to have a negative regeneration, the passive activities of Au and Ag were found to have an inactive adsorption for RADS adsorbent alone, while Ni and Co have appropriate characteristics as the active metals for RADS, followed by Cu.

  7. Living Clusters and Crystals from Low-Density Suspensions of Active Colloids

    NASA Astrophysics Data System (ADS)

    Mognetti, B. M.; Šarić, A.; Angioletti-Uberti, S.; Cacciuto, A.; Valeriani, C.; Frenkel, D.

    2013-12-01

    Recent studies aimed at investigating artificial analogs of bacterial colonies have shown that low-density suspensions of self-propelled particles confined in two dimensions can assemble into finite aggregates that merge and split, but have a typical size that remains constant (living clusters). In this Letter, we address the problem of the formation of living clusters and crystals of active particles in three dimensions. We study two systems: self-propelled particles interacting via a generic attractive potential and colloids that can move toward each other as a result of active agents (e.g., by molecular motors). In both cases, fluidlike “living” clusters form. We explain this general feature in terms of the balance between active forces and regression to thermodynamic equilibrium. This balance can be quantified in terms of a dimensionless number that allows us to collapse the observed clustering behavior onto a universal curve. We also discuss how active motion affects the kinetics of crystal formation.

  8. Experimental characterization of active acoustic metamaterial cell with controllable dynamic density

    NASA Astrophysics Data System (ADS)

    Akl, Wael; Baz, Amr

    2012-10-01

    Controlling wave propagation pattern within acoustic fluid domains has been the motivation for the acoustic metamaterials developments to target applications ranging from acoustic cloaking to passive noise control techniques. Currently, various numerical and analytical approaches exist to predict the fluid domain material properties necessary for specific propagation pattern. Physical attempts to realize such material properties have revealed engineered material constructions that are focused on predefined wave propagation patterns. In the current paper, coupled fluid-structure one-dimensional metamaterial cell, in which piezoelectric active ingredient has been introduced, is manufactured to achieve controllable dynamic density. The density-controllable cell has been manufactured by coupling a water-filled cavity with piezoelectric elements in a cell of 4.5 cm length and 4.1 cm diameter subject to impulse excitation. A finite element model of the cell has been developed and its predictions are validated against the experimental results. The validated model is utilized to predict the changes in the pressure gradient inside the developed cell which is a direct measure of the changes introduced to the dynamic density of the acoustic metamaterial domain. With such predictions, it is demonstrated that densities as high as 3.2 gm/cm3 and as low as 0.72 gm/cm3 can be achieved experimentally for excitation frequencies ranging between 100 Hz and 500 Hz.

  9. [Impacts of root-zone hypoxia stress on muskmelon growth, its root respiratory metabolism, and antioxidative enzyme activities].

    PubMed

    Liu, Yi-Ling; Li, Tian-Lai; Sun, Zhou-Ping; Chen, Ya-Dong

    2010-06-01

    By using aeroponics culture system, this paper studied the impacts of root-zone hypoxia (10% O2 and 5% O2) stress on the plant growth, root respiratory metabolism, and antioxidative enzyme activities of muskmelon at its fruit development stage. Root-zone hypoxia stress inhibited the plant growth of muskmelon, resulting in the decrease of plant height, root length, and fresh and dry biomass. Comparing with the control (21% O2), hypoxia stress reduced the root respiration rate and malate dehydrogenase (MDH) activity significantly, and the impact of 5% O2 stress was more serious than that of 10% O2 stress. Under hypoxic conditions, the lactate dehydrogenase (LDH), alcohol dehydrogenase (ADH), pyruvate decarboxylase (PDC), superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities and the malondialdehyde (MDA) content were significantly higher than the control. The increment of antioxidative enzyme activities under 10% O2 stress was significantly higher than that under 5% O2 stress, while the MDA content was higher under 5% O2 stress than under 10% O2 stress, suggesting that when the root-zone oxygen concentration was below 10%, the aerobic respiration of muskmelon at its fruit development stage was obviously inhibited while the anaerobic respiration was accelerated, and the root antioxidative enzymes induced defense reaction. With the increasing duration of hypoxic stress, the lipid peroxidation would be aggravated, resulting in the damages on muskmelon roots, inhibition of plant growth, and decrease of fruit yield and quality.

  10. Quantitative analysis of axonal fiber activation evoked by deep brain stimulation via activation density heat maps

    PubMed Central

    Hartmann, Christian J.; Chaturvedi, Ashutosh; Lujan, J. Luis

    2015-01-01

    Background: Cortical modulation is likely to be involved in the various therapeutic effects of deep brain stimulation (DBS). However, it is currently difficult to predict the changes of cortical modulation during clinical adjustment of DBS. Therefore, we present a novel quantitative approach to estimate anatomical regions of DBS-evoked cortical modulation. Methods: Four different models of the subthalamic nucleus (STN) DBS were created to represent variable electrode placements (model I: dorsal border of the posterolateral STN; model II: central posterolateral STN; model III: central anteromedial STN; model IV: dorsal border of the anteromedial STN). Axonal fibers of passage near each electrode location were reconstructed using probabilistic tractography and modeled using multi-compartment cable models. Stimulation-evoked activation of local axon fibers and corresponding cortical projections were modeled and quantified. Results: Stimulation at the border of the STN (models I and IV) led to a higher degree of fiber activation and associated cortical modulation than stimulation deeply inside the STN (models II and III). A posterolateral target (models I and II) was highly connected to cortical areas representing motor function. Additionally, model I was also associated with strong activation of fibers projecting to the cerebellum. Finally, models III and IV showed a dorsoventral difference of preferentially targeted prefrontal areas (models III: middle frontal gyrus; model IV: inferior frontal gyrus). Discussion: The method described herein allows characterization of cortical modulation across different electrode placements and stimulation parameters. Furthermore, knowledge of anatomical distribution of stimulation-evoked activation targeting cortical regions may help predict efficacy and potential side effects, and therefore can be used to improve the therapeutic effectiveness of individual adjustments in DBS patients. PMID:25713510

  11. Controlling activation site density by low-energy far-field stimulation in cardiac tissue.

    PubMed

    Hörning, Marcel; Takagi, Seiji; Yoshikawa, Kenichi

    2012-06-01

    Tachycardia and fibrillation are potentially fatal arrhythmias associated with the formation of rotating spiral waves in the heart. Presently, the termination of these types of arrhythmia is achieved by use of antitachycardia pacing or cardioversion. However, these techniques have serious drawbacks, in that they either have limited application or produce undesirable side effects. Low-energy far-field stimulation has recently been proposed as a superior therapy. This proposed therapeutic method would exploit the phenomenon in which the application of low-energy far-field shocks induces a large number of activation sites ("virtual electrodes") in tissue. It has been found that the formation of such sites can lead to the termination of undesired states in the heart and the restoration of normal beating. In this study we investigate a particular aspect of this method. Here we seek to determine how the activation site density depends on the applied electric field through in vitro experiments carried out on neonatal rat cardiac tissue cultures. The results indicate that the activation site density increases exponentially as a function of the intracellular conductivity and the level of cell isotropy. Additionally, we report numerical results obtained from bidomain simulations of the Beeler-Reuter model that are quantitatively consistent with our experimental results. Also, we derive an intuitive analytical framework that describes the activation site density and provides useful information for determining the ratio of longitudinal to transverse conductivity in a cardiac tissue culture. The results obtained here should be useful in the development of an actual therapeutic method based on low-energy far-field pacing. In addition, they provide a deeper understanding of the intrinsic properties of cardiac cells.

  12. Controlling activation site density by low-energy far-field stimulation in cardiac tissue

    NASA Astrophysics Data System (ADS)

    Hörning, Marcel; Takagi, Seiji; Yoshikawa, Kenichi

    2012-06-01

    Tachycardia and fibrillation are potentially fatal arrhythmias associated with the formation of rotating spiral waves in the heart. Presently, the termination of these types of arrhythmia is achieved by use of antitachycardia pacing or cardioversion. However, these techniques have serious drawbacks, in that they either have limited application or produce undesirable side effects. Low-energy far-field stimulation has recently been proposed as a superior therapy. This proposed therapeutic method would exploit the phenomenon in which the application of low-energy far-field shocks induces a large number of activation sites (“virtual electrodes”) in tissue. It has been found that the formation of such sites can lead to the termination of undesired states in the heart and the restoration of normal beating. In this study we investigate a particular aspect of this method. Here we seek to determine how the activation site density depends on the applied electric field through in vitro experiments carried out on neonatal rat cardiac tissue cultures. The results indicate that the activation site density increases exponentially as a function of the intracellular conductivity and the level of cell isotropy. Additionally, we report numerical results obtained from bidomain simulations of the Beeler-Reuter model that are quantitatively consistent with our experimental results. Also, we derive an intuitive analytical framework that describes the activation site density and provides useful information for determining the ratio of longitudinal to transverse conductivity in a cardiac tissue culture. The results obtained here should be useful in the development of an actual therapeutic method based on low-energy far-field pacing. In addition, they provide a deeper understanding of the intrinsic properties of cardiac cells.

  13. Thermospheric topside neutral density, ionospheric anomalous electric field and resistivity measurements by active experiment at EISCAT

    NASA Astrophysics Data System (ADS)

    Kosch, Michael; Ogawa, Yasunobu; Rietveld, Michael; Blagoveshchenskaya, Nataly; Yamazaki, Yosuke

    2016-07-01

    We have developed an active ground-based technique to estimate the topside thermospheric neutral density as well as topside ionospheric anomalous electric field and resistivity at EISCAT, combining the EISCAT UHF radar, HF heater and optics. When pumping the ionosphere the F-region electron temperature is significantly raised, increasing the upward plasma pressure gradient in the topside ionosphere, resulting in observed ion up-flow along the magnetic field line. Simultaneously, pump-induced suprathermal electrons produce artificial optical emissions. Using the modified ion-momentum equation, the thermospheric neutral density is estimated. Alternatively, using the MSIS model the field-aligned anomalous electric field is estimated. From the optical data the suprathermal electron flux is estimated, giving an estimate of the anomalous resistivity. Results from recent observations at EISCAT are presented.

  14. A High Power Density Single-Phase PWM Rectifier With Active Ripple Energy Storage

    SciTech Connect

    Wang, Ruxi; Wang, Fei; Boroyevich, Dushan; Burgos, Rolando; Lai, Rixin; Ning, Puqi; Rajashekara, Kaushik

    2011-01-01

    It is well known that single-phase pulse width modulation rectifiers have second-order harmonic currents and corresponding ripple voltages on the dc bus. The low-frequency harmonic current is normally filtered using a bulk capacitor in the bus, which results in low power density. However, pursuing high power density in converter design is a very important goal in the aerospace applications. This paper studies methods for reducing the energy storage capacitor for single-phase rectifiers. The minimum ripple energy storage requirement is derived independently of a specific topology. Based on theminimum ripple energy requirement, the feasibility of the active capacitor s reduction schemes is verified. Then, we propose a bidirectional buck boost converter as the ripple energy storage circuit, which can effectively reduce the energy storage capacitance. The analysis and design are validated by simulation and experimental results.

  15. An empirical model to estimate density of sodium hydroxide solution: An activator of geopolymer concretes

    NASA Astrophysics Data System (ADS)

    Rajamane, N. P.; Nataraja, M. C.; Jeyalakshmi, R.; Nithiyanantham, S.

    2016-02-01

    Geopolymer concrete is zero-Portland cement concrete containing alumino-silicate based inorganic polymer as binder. The polymer is obtained by chemical activation of alumina and silica bearing materials, blast furnace slag by highly alkaline solutions such as hydroxide and silicates of alkali metals. Sodium hydroxide solutions of different concentrations are commonly used in making GPC mixes. Often, it is seen that sodium hydroxide solution of very high concentration is diluted with water to obtain SHS of desired concentration. While doing so it was observed that the solute particles of NaOH in SHS tend to occupy lower volumes as the degree of dilution increases. This aspect is discussed in this paper. The observed phenomenon needs to be understood while formulating the GPC mixes since this influences considerably the relationship between concentration and density of SHS. This paper suggests an empirical formula to relate density of SHS directly to concentration expressed by w/w.

  16. The active zone protein family ELKS supports Ca2+ influx at nerve terminals of inhibitory hippocampal neurons.

    PubMed

    Liu, Changliang; Bickford, Lydia S; Held, Richard G; Nyitrai, Hajnalka; Südhof, Thomas C; Kaeser, Pascal S

    2014-09-10

    In a presynaptic nerve terminal, synaptic vesicle exocytosis is restricted to specialized sites called active zones. At these sites, neurotransmitter release is determined by the number of releasable vesicles and their probability of release. Proteins at the active zone set these parameters by controlling the presynaptic Ca(2+) signal, and through docking and priming of synaptic vesicles. Vertebrate ELKS proteins are enriched at presynaptic active zones, but their functions are not well understood. ELKS proteins are produced by two genes in vertebrates, and each gene contributes ∼50% to total brain ELKS. We generated knock-out mice for ELKS1 and found that its constitutive removal causes lethality. To bypass lethality, and to circumvent redundancy between ELKS1 and ELKS2 in synaptic transmission, we used a conditional genetic approach to remove both genes in cultured hippocampal neurons after synapses are established. Simultaneous removal of ELKS1 and ELKS2 resulted in a 50% decrease of neurotransmitter release at inhibitory synapses, paralleled by a reduction in release probability. Removal of ELKS did not affect synapse numbers or their electron microscopic appearance. Using Ca(2+) imaging, we found that loss of ELKS caused a 30% reduction in single action potential-triggered Ca(2+) influx in inhibitory nerve terminals, consistent with the deficits in synaptic transmission and release probability. Unlike deletion of the active zone proteins RIM, RIM-BP, or bruchpilot, ELKS removal did not lead to a measurable reduction in presynaptic Ca(2+) channel levels. Our results reveal that ELKS is required for normal Ca(2+) influx at nerve terminals of inhibitory hippocampal neurons.

  17. Tissue-type plasminogen activator suppresses activated stellate cells through low-density lipoprotein receptor-related protein 1

    PubMed Central

    Kang, Liang-I; Isse, Kumiko; Koral, Kelly; Bowen, William C; Muratoglu, Selen; Strickland, Dudley K; Michalopoulos, George K; Mars, Wendy M

    2015-01-01

    Hepatic stellate cell (HSC) activation and trans-differentiation into myofibroblast (MFB)-like cells is key for fibrogenesis after liver injury and a potential therapeutic target. Recent studies demonstrated that low-density lipoprotein receptor-related protein 1 (LRP1)-dependent signaling by tissue-type plasminogen activator (t-PA) is a pro-fibrotic regulator of the MFB phenotype in kidney. This study investigated whether LRP1 signaling by t-PA is also relevant to HSC activation following injury. Primary and immortalized rat HSCs were treated with t-PA and assayed by western blot, MTT, and TUNEL. In vitro results were then verified using an in vivo, acute carbon tetrachloride (CCl4) injury model that examined the phenotype and recovery kinetics of MFBs from wild-type animals vs mice with a global (t-PA) or HSC-targeted (LRP1) deletion. In vitro, in contrast to kidney MFBs, exogenous, proteolytically inactive t-PA suppressed, rather than induced, activation markers in HSCs following phosphorylation of LRP1. This process was mediated by LRP1 as inhibition of t-PA binding to LRP1 blocked the effects of t-PA. In vivo, following acute injury, phosphorylation of LRP1 on activated HSCs occurred immediately prior to their disappearance. Mice lacking t-PA or LRP1 retained higher densities of activated HSCs for a longer time period compared with control mice after injury cessation. Hence, t-PA, an FDA-approved drug, contributes to the suppression of activated HSCs following injury repair via signaling through LRP1. This renders t-PA a potential target for exploitation in treating patients with fibrosis. PMID:26237273

  18. The fate and transport of nitroglycerin in the unsaturated zone at active and legacy anti-tank firing positions.

    PubMed

    Bordeleau, Geneviève; Martel, Richard; Ampleman, Guy; Thiboutot, Sonia; Poulin, Isabelle

    2012-11-01

    The environmental fate of nitroglycerin (NG) in the unsaturated zone was evaluated in the context of double-base propellant residue deposition at anti-tank training ranges. Fresh propellant residues were collected during live anti-tank training. Surface soils, sub-surface soils and water samples from the unsaturated zone were collected at an active anti-tank range, and at a legacy site where NG-based propellants have been used. Results show that the residues are composed of intact propellant particles, as well as small quantities of NG, dinitroglycerin (DNG) and nitrate which are rapidly dissolved by precipitation, resulting in sporadic pulses of those compounds in water from the unsaturated zone after rain/snow melt events. The dissolved NG and DNG can be progressively degraded in the unsaturated zone, releasing nitrate as an end-product. Over a period of several years, small propellant particles located at the soil surface can be carried downward through the soil pore system by infiltration water, which explains the presence of NG in sub-surface soils at the legacy site, more than 35 years after site closure. NG is no longer leached from these old particles, therefore the detection of NG in sub-surface soils does not signify that groundwater is at risk of contamination by NG.

  19. Lysine-poly(2-hydroxyethyl methacrylate) modified polyurethane surface with high lysine density and fibrinolytic activity.

    PubMed

    Li, Dan; Chen, Hong; Wang, Shasha; Wu, Zhaoqiang; Brash, John L

    2011-03-01

    We have developed a potentially fibrinolytic surface in which a bioinert polymer is used as a spacer to immobilize lysine such that the ε-amino group is free to capture plasminogen when in contact with blood. Adsorbed plasminogen can be activated to plasmin and potentially dissolve nascent clots formed on the surface. In previous work lysine was immobilized through a poly(ethylene glycol) (PEG) spacer; however, the graft density of PEG was limited and the resulting adsorbed quantity of plasminogen was insufficient to dissolve clots efficiently. The aim of the present work was to optimize the surface using graft-polymerized poly(2-hydroxyethyl methacrylate) (poly(HEMA)) as a spacer to increase the grafting density of lysine. Such a poly(HEMA)-lysine modified polyurethane (PU) surface is expected to have increased plasminogen binding capacity and clot lysing efficiency compared with PEG-lysine modified PU. A lysine density of 2.81 nmol cm(-2) was measured on the PU-poly(HEMA)-Lys surface vs. 0.76 nmol cm(-2) on a comparable PU-PEG-Lys surface reported previously. The poly(HEMA)-lysine-modified surface was shown to reduce non-specific (fibrinogen) adsorption while binding plasminogen from plasma with high affinity. With increased plasminogen binding capacity these surfaces showed more rapid clot lysis (20 min) in a standard in vitro assay than the corresponding PEG-lysine system (40 min). The data suggest that poly(HEMA) is superior to PEG when used as a spacer in the immobilization of bioactive molecules at high density. This method of modification may also provide a generic approach for preparing bioactive PU surfaces of high activity and low non-specific adsorption of proteins.

  20. Enabling High Energy Density Li-Ion Batteries through Li{sub 2}O Activation.

    SciTech Connect

    Abouimrane, Ali; Cui, Yanjie; Chen, Zonghai; Belharouak, Ilias; Yahia, Hamdi B.; Wu, Huiming; Assary, Rajeev; Curtiss, Larry A.; Amine, Khalil

    2016-09-01

    Lithium oxide (Li2O) is activated in the presence of a layered composite cathode material (HEM) significantly increasing the energy density of lithium-ion batteries. The degree of activation depends on the current rate, electrolyte salt, and anode type. In full-cell tests, the Li2O was used as a lithium source to counter the first-cycle irreversibility of high-capacity composite alloy anodes. When Li2O is mixed with HEM to serve as a cathode, the electrochemical performance was improved in a full cell having an SiO-SnCoC composite as an anode. The mechanism behind the Li2O activation could also explain the first charge plateau and the abnormal high capacity associated with these high energy cathode materials.

  1. Density relative change and interface zone mutual diffusion of BiFeO3 films prepared on Si (1 0 0), SiO2 and SiO2/Si (1 0 0)

    NASA Astrophysics Data System (ADS)

    Xiao, RenZheng; Wang, ZeSong; Yuan, XianBao; Zhou, JianJun; Mao, ZhangLiang; Su, HuaShan; Li, Bo; Fu, DeJun

    2016-10-01

    The mutual diffusion taken place in the interface zone between BiFeO3 (BFO) films and substrates (Si (1 0 0), SiO2 and SiO2/Si (1 0 0)) has been revealed by energy dispersive X-ray spectroscopy (EDS) and Rutherford Backscattering Spectrometry (RBS). RBS spectra provide the relative atomic concentrations of Bi, Fe, Si, and O elements changed with the samples' depth as analyzed by RBS spectra fitting SIMNRA software. A certain width of the intermixing layer is probably formed between BFO films and individual substrate which is attributed to mutual diffusion in the interface zone during annealing process. The mechanism of concerted exchange component can explain the interface zone mutual diffusion phenomenon between BFO films and substrates. The width of the interface zone between BFO film and Si (1 0 0), SiO2, and SiO2/Si (1 0 0) substrate is about 1.94 × 1017, 2.01 × 1017 and 3.05 × 1017 atoms/cm2, respectively, which are equivalent to 30.9, 36.7, and 52.9 nm, respectively. It has been declared that the effect on density relative to BFO film is loosen or attenuation is presented in the interface zone, which can be interpreted as a migration or diffusion of various atoms during the annealing. This can also provide an evidence of atomic dynamics and defect engineering on interface diffusion.

  2. Ceruloplasmin as low-density lipoprotein oxidase: activation by ascorbate and dehydroascorbate.

    PubMed

    Feichtenhofer, S; Fabjan, J S; Abuja, P M

    2001-07-13

    The ability of ceruloplasmin (Cp) to oxidize low-density lipoproteins (LDL) in the presence of water-soluble antioxidants was investigated and a reaction mechanism proposed. Ascorbate strongly enhanced LDL oxidation, but only after its rapid consumption. Dehydroascorbate enhanced Cp-mediated LDL oxidation even more strongly. Lipid-soluble antioxidants and water-soluble peroxides did not show noticeable activation. However, loading of LDL with lipid hydroperoxides increased the initial oxidation rate. We conclude that Cp mediates a localized redox cycle, where reduction of Cp-Cu2+ is effected by water-soluble reductants and reoxidation by liposoluble hydroperoxides.

  3. A High Power Density Single-Phase PWM Rectifier with Active Ripple Energy Storage

    SciTech Connect

    Ning, Puqi; Wang, Ruxi; Wang, Fei; Boroyevich, Dushan

    2010-01-01

    It is well known that there exist second-order harmonic current and corresponding ripple voltage on dc bus for single phase PWM rectifiers. The low frequency harmonic current is normally filtered using a bulk capacitor in the bus which results in low power density. This paper proposed an active ripple energy storage method that can effectively reduce the energy storage capacitance. The feed-forward control method and design considerations are provided. Simulation and 15 kW experimental results are provided for verification purposes.

  4. Joint Associations of Residential Density and Neighborhood Involvement with Physical Activity among a Multiethnic Sample of Urban Adults

    ERIC Educational Resources Information Center

    Johnson-Lawrence, Vicki; Schulz, Amy J.; Zenk, Shannon N.; Israel, Barbara A.; Wineman, Jean; Marans, Robert W.; Rowe, Zachary

    2015-01-01

    Regular physical activity is associated with improvements in overall health. Although resident involvement in neighborhood social activities is positively associated with physical activity, neighborhood design features, including residential density, have varied associations with physical activity. Using data from a multiethnic sample of 696…

  5. Serum Paraoxonase 1 Activity Is Associated with Fatty Acid Composition of High Density Lipoprotein

    PubMed Central

    Boshtam, Maryam; Pourfarzam, Morteza; Ani, Mohsen; Naderi, Gholam Ali; Basati, Gholam; Mansourian, Marjan; Dinani, Narges Jafari; Asgary, Seddigheh; Abdi, Soheila

    2013-01-01

    Introduction. Cardioprotective effect of high density lipoprotein (HDL) is, in part, dependent on its related enzyme, paraoxonase 1 (PON1). Fatty acid composition of HDL could affect its size and structure. On the other hand, PON1 activity is directly related to the structure of HDL. This study was designed to investigate the association between serum PON1 activity and fatty acid composition of HDL in healthy men. Methods. One hundred and forty healthy men participated in this research. HDL was separated by sequential ultracentrifugation, and its fatty acid composition was analyzed by gas chromatography. PON1 activity was measured spectrophotometrically using paraxon as substrate. Results. Serum PON1 activity was directly correlated with the amount of stearic acid and dihomo-gamma-linolenic acid (DGLA). PON1/HDL-C was directly correlated with the amount of miristic acid, stearic acid, and DGLA and was inversely correlated with total amount of ω6 fatty acids of HDL. Conclusion. The fatty acid composition of HDL could affect the activity of its associated enzyme, PON1. As dietary fats are the major determinants of serum lipids and lipoprotein composition, consuming some special dietary fatty acids may improve the activity of PON1 and thereby have beneficial effects on health. PMID:24167374

  6. Neonatal hemodynamic response to visual cortex activity: high-density near-infrared spectroscopy study

    NASA Astrophysics Data System (ADS)

    Liao, Steve M.; Gregg, Nick M.; White, Brian R.; Zeff, Benjamin W.; Bjerkaas, Katelin A.; Inder, Terrie E.; Culver, Joseph P.

    2010-03-01

    The neurodevelopmental outcome of neonatal intensive care unit (NICU) infants is a major clinical concern with many infants displaying neurobehavioral deficits in childhood. Functional neuroimaging may provide early recognition of neural deficits in high-risk infants. Near-infrared spectroscopy (NIRS) has the advantage of providing functional neuroimaging in infants at the bedside. However, limitations in traditional NIRS have included contamination from superficial vascular dynamics in the scalp. Furthermore, controversy exists over the nature of normal vascular, responses in infants. To address these issues, we extend the use of novel high-density NIRS arrays with multiple source-detector distances and a superficial signal regression technique to infants. Evaluations of healthy term-born infants within the first three days of life are performed without sedation using a visual stimulus. We find that the regression technique significantly improves brain activation signal quality. Furthermore, in six out of eight infants, both oxy- and total hemoglobin increases while deoxyhemoglobin decreases, suggesting that, at term, the neurovascular coupling in the visual cortex is similar to that found in healthy adults. These results demonstrate the feasibility of using high-density NIRS arrays in infants to improve signal quality through superficial signal regression, and provide a foundation for further development of high-density NIRS as a clinical tool.

  7. Preliminary assessment of the nuclide migration from the activation zone around the proposed Spallation Neutron Source facility

    SciTech Connect

    Dole, L.R.

    1998-09-01

    The purpose of this study is to investigate the potential impacts of migrating radionuclides from the activation zone around the proposed Spallation Neutron Source (SNS). Using conservatively high estimates of the potential inventory of radioactive activation products that could form in the proposed compacted-soil shield berm around an SNS facility on the Oak Ridge Reservation (ORR), a conservative, simplified transport model was used to estimate the potential worst-case concentrations of the 12 long-lived isotopes in the groundwater under a site with the hydrologic characteristics of the ORR.

  8. Association of sarcopenia and physical activity with femur bone mineral density in elderly women

    PubMed Central

    Lee, Inhwan; Ha, Changduk; Kang, Hyunsik

    2016-01-01

    [Purpose] This study examined the association of femur bone mineral density (BMD) with body composition and physical activity in elderly women. [Methods] This was a cross sectional study involving 119 women with mean age of 73.1±5.5 years. Body composition parameters including body mass index (BMI), percent of body fat (%BF), appendicular skeletal muscle mass (ASM) index and femur BMD was measured by dual-energy X-ray absorptiometry (DXA). Physical activity was assessed by the uniaxial accelerometer for 7 consecutive days including weekends. Based on femur BMD T-scores, subjects were classified as optimal group, osteopenia group, and osteoporosis group. Based on ASM index, subjects were classified as normal group and sarcopenia group. According to WHO recommendations of physical activity for elderly, the subjects were classified as active group or inactive group. Logistic regression analyses were used to determine the odds ratio (OR) for osteopenia and osteoporosis. [Results] There were linear decreases for body composition parameters including weight (P=.023), BMI (P=.039), lean mass (P=.032), ASM index (P=.007) and physical activity parameters including daily of step (P<.001), low intensity physical activity (P<.001), moderate intensity physical activity (P=.001) across femur BMD levels. Compared to the normal group (OR=1), the sarcopenia group had a significantly higher OR (OR=4.823; P=.042), and the inactive group had a significantly higher OR (OR=5.478; P=.005) having osteopenia and osteoporosis when compared to the active group (OR=1). [Conclusion] The findings of this study suggested that physical activity along with a healthy nutrition should be promoted as a preventive strategy against osteopenia and osteoporosis in elderly women. PMID:27298809

  9. Circadian Variability in Methane Oxidation Activity in the Root Zone of Rice Plants

    NASA Astrophysics Data System (ADS)

    Schroth, M. H.; Cho, R.; Zeyer, J.

    2009-12-01

    Methane is an important greenhouse gas with a warming potential about 20 times stronger than that of carbon dioxide. A main source of biogenic methane are rice-paddy soils. Methane is produced in flooded rice fields under anaerobic conditions. Conversely, methanotrophic microorganisms oxidize methane to carbon dioxide in the root zone of rice plants in the presence of molecular oxygen supplied to the roots through the plants’ aerenchyma, thus reducing overall methane emissions to the atmosphere. To quantify methane oxidation we adapted push-pull tests (PPTs), a technique originally developed for aquifer testing, in combination with a suitable microbial inhibitor for application in the root zone of rice plants. During a PPT, 70 ml of a test solution containing dissolved substrates (methane, oxygen), nonreactive tracers (argon, chloride) and the methanogenesis inhibitor 2-Bromoethane sulfonate was injected into the plant’s root zone, and after a rest period of two hours extracted from the same location. Reaction rate constants were calculated from extraction-phase breakthrough curves of substrates and tracers. We conducted a set of three different laboratory PPTs to quantify methane oxidation at day time, directly after dawn, and at night in the root zone of four different potted rice plants each. High diurnal methane oxidation rate constants (up to 23 h-1) were obtained for all rice plants. Methane oxidation potential decreased soon after nightfall. At night, rate constants were usually below 1 h-1. Methane oxidation rates were apparently independent of additional oxygen supplied via the injected test solutions, but strongly dependent on photosynthetically produced oxygen transported to the roots through the plants’ aerenchyma. Additional PPTs utilizing 13C-labeled methane are currently being conducted to corroborate these findings. Ultimately, this novel tool shall support efforts to quantitatively understand the controlling mechanisms of methane turnover in

  10. Ion density and temperature variations at altitude of 500 km during moderate seismic activity

    NASA Astrophysics Data System (ADS)

    Bardhan, Ananna; Khurana, M. S.; Bahal, B. M.; Aggarwal, Malini; Sharma, D. K.

    2017-02-01

    Ionospheric ions (O+ and H+) and temperature (Ti) as precursory parameters to seismic activity have been analysed from year 1995 till 1998, using SROSS-C2 (average altitude range of ∼500 km) satellite measurements for moderate magnitude earthquakes. The details of seismic events during this period are downloaded from United State Geological Survey (USGS) and National Earthquake Information Centre (NEIC) website. 13 seismic events of moderate magnitude (M = 4-5.5) from 1995 to 1998, using SROSS-C2 satellite measurements have been analysed. During seismic affected period, considerable decrease in the density of heavier ion - O+ and increase in the ion temperature (Ti) is observed during all the selected events. Lighter ion - H+ doesn't show any significant change. Electric field and electromagnetic emissions generated due to seismogenic activity could be the plausible initializing agents responsible for change in ion concentration and temperature values during these events.

  11. Geometry and faults tectonic activity of the Okavango Rift Zone, Botswana: Evidence from magnetotelluric and electrical resistivity tomography imaging

    NASA Astrophysics Data System (ADS)

    Bufford, Kelsey Mosley; Atekwana, Estella A.; Abdelsalam, Mohamed G.; Shemang, Elijah; Atekwana, Eliot A.; Mickus, Kevin; Moidaki, Moikwathai; Modisi, Motsoptse P.; Molwalefhe, Loago

    2012-04-01

    We used Magnetotelluric (MT) and Electrical Resistivity Tomography (ERT) to investigate the geometry and nature of faults activity of the Okavango Rift Zone (ORZ) in Botswana, an incipient rift at the southern tip of the Southwestern Branch of the East African Rift System. The ORZ forms a subtle topographic depression filled with Quaternary lacustrine and fluvio-deltaic sediments and is bounded by NE-trending normal faults that are more prominent in the southeastern portion of the rift basin. An MT model from a regional (˜140 km) NW-SE trending MT transect shows that much of the rift basin is underlain by a broad asymmetrical low resistivity anomaly that slopes gently (˜1°) from NW to SE reaching a depth of ˜300 m. This anomaly suggests that faults in the southeastern part of the rift form a NW-dipping border fault zone and that the lacustrine and fluvio-deltaic sediments contain brackish to saline water filling the broad half-graben structure. Furthermore, MT and ERT models from detailed (4-13 km long) MT transects and resistivity profiles show that one border fault (Thamalakane) and two within-basin faults (Lecha and Tsau) in the southeastern part of the ORZ are characterized by a localized high conductivity anomaly while another border fault (Kunyere) lacks such an anomaly. These localized anomalies are attributed to channelized fresh surface water and saline groundwater percolating through these faults forming "fault zone conductors" and suggest actively displacing faults. The lack of a "fault zone conductor" in the Kunyere fault is interpreted as indicating diminishing displacement on this fault, and that strain was transferred to the Thamalakane fault further to the east. The fluids provide lubricant for the ORZ faults, hence preventing infrequent large magnitude earthquakes, but favoring frequent micro-seismicity.

  12. Activation volume of selected liquid crystals in the density scaling regime

    NASA Astrophysics Data System (ADS)

    Grzybowski, A.; Urban, S.; Mroz, S.; Paluch, M.

    2017-02-01

    In this paper, we demonstrate and thoroughly analyze the activation volumetric properties of selected liquid crystals in the nematic and crystalline E phases in comparison with those reported for glass-forming liquids. In the analysis, we have employed and evaluated two entropic models (based on either total or configurational entropies) to describe the longitudinal relaxation times of the liquid crystals in the density scaling regime. In this study, we have also exploited two equations of state: volumetric and activation volumetric ones. As a result, we have established that the activation volumetric properties of the selected liquid crystals are quite opposite to such typical properties of glass-forming materials, i.e., the activation volume decreases and the isothermal bulk modulus increases when a liquid crystal is isothermally compressed. Using the model based on the configurational entropy, we suggest that the increasing pressure dependences of the activation volume in isothermal conditions and the negative curvature of the pressure dependences of isothermal longitudinal relaxation times can be related to the formation of antiparallel doublets in the examined liquid crystals. A similar pressure effect on relaxation dynamics may be also observed for other material groups in case of systems, the molecules of which form some supramolecular structures.

  13. A density functional theory model of mechanically activated silyl ester hydrolysis

    SciTech Connect

    Pill, Michael F.; Schmidt, Sebastian W.; Beyer, Martin K.; Clausen-Schaumann, Hauke; Kersch, Alfred

    2014-01-28

    To elucidate the mechanism of the mechanically activated dissociation of chemical bonds between carboxymethylated amylose (CMA) and silane functionalized silicon dioxide, we have investigated the dissociation kinetics of the bonds connecting CMA to silicon oxide surfaces with density functional calculations including the effects of force, solvent polarizability, and pH. We have determined the activation energies, the pre-exponential factors, and the reaction rate constants of candidate reactions. The weakest bond was found to be the silyl ester bond between the silicon and the alkoxy oxygen atom. Under acidic conditions, spontaneous proton addition occurs close to the silyl ester such that neutral reactions become insignificant. Upon proton addition at the most favored position, the activation energy for bond hydrolysis becomes 31 kJ mol{sup −1}, which agrees very well with experimental observation. Heterolytic bond scission in the protonated molecule has a much higher activation energy. The experimentally observed bi-exponential rupture kinetics can be explained by different side groups attached to the silicon atom of the silyl ester. The fact that different side groups lead to different dissociation kinetics provides an opportunity to deliberately modify and tune the kinetic parameters of mechanically activated bond dissociation of silyl esters.

  14. Activation volume of selected liquid crystals in the density scaling regime

    PubMed Central

    Grzybowski, A.; Urban, S.; Mroz, S.; Paluch, M.

    2017-01-01

    In this paper, we demonstrate and thoroughly analyze the activation volumetric properties of selected liquid crystals in the nematic and crystalline E phases in comparison with those reported for glass-forming liquids. In the analysis, we have employed and evaluated two entropic models (based on either total or configurational entropies) to describe the longitudinal relaxation times of the liquid crystals in the density scaling regime. In this study, we have also exploited two equations of state: volumetric and activation volumetric ones. As a result, we have established that the activation volumetric properties of the selected liquid crystals are quite opposite to such typical properties of glass-forming materials, i.e., the activation volume decreases and the isothermal bulk modulus increases when a liquid crystal is isothermally compressed. Using the model based on the configurational entropy, we suggest that the increasing pressure dependences of the activation volume in isothermal conditions and the negative curvature of the pressure dependences of isothermal longitudinal relaxation times can be related to the formation of antiparallel doublets in the examined liquid crystals. A similar pressure effect on relaxation dynamics may be also observed for other material groups in case of systems, the molecules of which form some supramolecular structures. PMID:28181530

  15. Overexpression of INFLORESCENCE DEFICIENT IN ABSCISSION activates cell separation in vestigial abscission zones in Arabidopsis.

    PubMed

    Stenvik, Grethe-Elisabeth; Butenko, Melinka A; Urbanowicz, Breeanna Rae; Rose, Jocelyn K C; Aalen, Reidunn B

    2006-06-01

    Plants may shed organs when they have been injured or served their purpose. The differential pattern of organ abscission in different species is most likely the result of evolutionary adaptation to a variety of life styles and environments. The final step of abscission-related cell separation in floral organs of wild-type Arabidopsis thaliana, which only abscises sepals, petals, and stamens, is controlled by INFLORESCENCE DEFICIENT IN ABSCISSION (IDA). Here, we demonstrate that Arabidopsis 35S:IDA lines constitutively overexpressing IDA exhibit earlier abscission of floral organs, showing that the abscission zones are responsive to IDA soon after the opening of the flowers. In addition, ectopic abscission was observed at the bases of the pedicel, branches of the inflorescence, and cauline leaves. The silique valves also dehisced prematurely. Scanning electron microscopy indicated a spread of middle lamella degradation from preformed abscission zone cells to neighboring cells. A transcript encoding an arabinogalactan protein (AGP) was upregulated in the 35S:IDA lines, and large amounts of AGP were secreted at the sites of abscission. AGP was shown to be a constituent of wild-type floral abscission zones during and soon after cell separation had been completed. We suggest that the restricted expression pattern of IDA precludes abscission of nonfloral organs in Arabidopsis.

  16. Extracting extensor digitorum communis activation patterns using high-density surface electromyography

    PubMed Central

    Hu, Xiaogang; Suresh, Nina L.; Xue, Cindy; Rymer, William Z.

    2015-01-01

    The extensor digitorum communis muscle plays an important role in hand dexterity during object manipulations. This multi-tendinous muscle is believed to be controlled through separate motoneuron pools, thereby forming different compartments that control individual digits. However, due to the complex anatomical variations across individuals and the flexibility of neural control strategies, the spatial activation patterns of the extensor digitorum communis compartments during individual finger extension have not been fully tracked under different task conditions. The objective of this study was to quantify the global spatial activation patterns of the extensor digitorum communis using high-density (7 × 9) surface electromyogram (EMG) recordings. The muscle activation map (based on the root mean square of the EMG) was constructed when subjects performed individual four finger extensions at the metacarpophalangeal joint, at different effort levels and under different finger constraints (static and dynamic). Our results revealed distinct activation patterns during individual finger extensions, especially between index and middle finger extensions, although the activation between ring and little finger extensions showed strong covariance. The activation map was relatively consistent at different muscle contraction levels and for different finger constraint conditions. We also found that distinct activation patterns were more discernible in the proximal–distal direction than in the radial–ulnar direction. The global spatial activation map utilizing surface grid EMG of the extensor digitorum communis muscle provides information for localizing individual compartments of the extensor muscle during finger extensions. This is of potential value for identifying more selective control input for assistive devices. Such information can also provide a basis for understanding hand impairment in individuals with neural disorders. PMID:26500558

  17. Protective effect of high density lipoprotein associated paraoxonase. Inhibition of the biological activity of minimally oxidized low density lipoprotein.

    PubMed Central

    Watson, A D; Berliner, J A; Hama, S Y; La Du, B N; Faull, K F; Fogelman, A M; Navab, M

    1995-01-01

    Our group has previously demonstrated that oxidized phospholipids in mildly oxidized LDL (MM-LDL) produced by oxidation with lipoxygenase, iron, or cocultures of artery wall cells increase monocyte-endothelial interactions and this sequence of events is blocked by HDL. To obtain further insight into the mechanism by which HDL abolishes the activity of MM-LDL we investigated the effect of the HDL-associated ester hydrolase paraoxonase (PON). Treatment of MM-LDL with purified PON significantly reduced the ability of MM-LDL to induce monocyte-endothelial interactions. Inactivation of PON by pretreating HDL with heat or EDTA reduced the ability of HDL to inhibit LDL modification. HPLC analysis of phospholipids isolated from MM-LDL before and after treatment with purified PON showed that the 270 nm absorbance of phospholipids was decreased, while no effect was observed on 235 nm absorbance. Oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine (Ox-PAPC) and specific fractions of Ox-PAPC isolated by HPLC induced the same monocyte-endothelial interactions as did MM-LDL. Biologically active and inactive HPLC fractions of Ox-PAPC were compared by fast atom bombardment-mass spectrometry which revealed that active fractions possessed ions with a mass to charge [correction of change] ratio greater than native PAPC by multiples of 16 D suggesting the addition of 3 and 4 oxygen atoms to PAPC. Comparison of Ox-PAPC by fast atom bombardment-mass spectrometry before and after PON treatment showed that PON destroyed these multi-oxygenated molecules found in biologically active fractions of Ox-PAPC. These results suggest that PON in HDL may protect against the induction of inflammatory responses in artery wall cells by destroying biologically active lipids in mildly oxidized LDL. Images PMID:8675659

  18. Mapping the polarity and stimulus density requirements for T-cell activation

    NASA Astrophysics Data System (ADS)

    Wei, Xunbin; Krasieva, Tatiana B.; Zhang, Zhanxiang; Negulescu, Paul A.; Sun, Chung-Ho; Berns, Michael W.; Cahalan, Michael D.; Tromberg, Bruce J.

    1998-08-01

    T-cell contact with antigen-presenting cells (APC) initiates an activation cascade which includes an increase in T-cell intracellular calcium [(Ca2+)i] and leads to T-cell proliferation and differentiation. Although T-cell/APC physical contact is required for an immune response, little is known about the patterns of cellular interaction and their relation to activation. We have combined fluorescence spectroscopy and imaging with optical manipulation to investigate the contact requirements for T-cell activation, using optical tweezers to control the orientation of T- cell/APC pairs and fluorescence microscopy to measure the subsequent (Ca2+)i response, detected as an emission shift from the combination of fura-red and oregon- green, two cytoplasmic (Ca2+) indicators. APCs or beads coated with antibodies to the T-cell receptor (TCR) are trapped with a near-infrared titanium-sapphire laser and placed at different locations along the T-cell, which has a polarized appearance defined by the shape and direction of crawling (2-5 micrometers /min). T cells contacted with antigen- presenting cells or antibody-coated beads entered a dynamic and reproducible program in the first 10 - 20 mins, including (Ca2+)i increase, changes in shape and motility, engulfment, and stable contact. T cells presented with antigen at the leading edge had a higher probability of responding (85%) and a shorter latency of response (50 secs) than those contacting APCs or beads with their trailing end (APCs: 30%, 150 secs; beads: 6%, 300 secs). Alterations in antibody density, quantified by FACS analysis, and bead size were used to determine the spatial requirements for T cell activation and the minimum number of receptors which must be engaged in order to transmit a positive signal. Preliminary data show that T cell responses [response percentage, latency and (Ca2+)i pattern] depend on both antibody density and bead size.

  19. Depth of the biologically active zone in upland habitats at the Hanford Site, Washington: Implications for remediation and ecological risk management.

    PubMed

    Sample, Bradley E; Lowe, John; Seeley, Paul; Markin, Melanie; McCarthy, Chris; Hansen, Jim; Aly, Alaa H

    2015-01-01

    active soil zone in the Hanford Central Plateau does not exceed 300 cm (9.8 ft), the maximum rooting depth for the deepest rooting plant. The maximum depth at which most other plant and animal species occur is substantially shallower. Spatial distribution and density of burrows and roots over depths were also evaluated. Although maximum excavation by harvester ants is 270 cm (8.9 ft), trivial volume of soil is excavated below 150 cm (∼5 ft). Maximum rooting depths for all grasses, forbs, and the most abundant and deepest rooting shrubs are 300 cm (9.8 ft) or less. Most root biomass (>50-80%) is concentrated in the top 100 cm (3.3 ft), whereas at the maximum depth (9.8 ft), only trace root biomass is present. Available data suggest a limited likelihood for significant transport of contaminants to the surface by plants at or below 244 cm (8 ft), and suggest that virtually all plants or animal species occurring on the Central Plateau have a negligible likelihood for transporting soil contaminants to the surface from depths at or below 305 cm (10 ft).

  20. Quantitative Proteomic Analysis Reveals Molecular Adaptations in the Hippocampal Synaptic Active Zone of Chronic Mild Stress-Unsusceptible Rats

    PubMed Central

    Zhou, Jian; Liu, Zhao; Yu, Jia; Han, Xin; Fan, Songhua; Shao, Weihua; Chen, Jianjun; Qiao, Rui

    2016-01-01

    Background: While stressful events are recognized as an important cause of major depressive disorder, some individuals exposed to life stressors maintain normal psychological functioning. The molecular mechanism(s) underlying this phenomenon remain unclear. Abnormal transmission and plasticity of hippocampal synapses have been implied to play a key role in the pathoetiology of major depressive disorder. Methods: A chronic mild stress protocol was applied to separate susceptible and unsusceptible rat subpopulations. Proteomic analysis using an isobaric tag for relative and absolute quantitation coupled with tandem mass spectrometry was performed to identify differential proteins in enriched hippocampal synaptic junction preparations. Results: A total of 4318 proteins were quantified, and 89 membrane proteins were present in differential amounts. Of these, SynaptomeDB identified 81 (91%) having a synapse-specific localization. The unbiased profiles identified several candidate proteins within the synaptic junction that may be associated with stress vulnerability or insusceptibility. Subsequent functional categorization revealed that protein systems particularly involved in membrane trafficking at the synaptic active zone exhibited a positive strain as potential molecular adaptations in the unsusceptible rats. Moreover, through STRING and immunoblotting analysis, membrane-associated GTP-bound Rab3a and Munc18-1 appear to coregulate syntaxin-1/SNAP25/VAMP2 assembly at the hippocampal presynaptic active zone of unsusceptible rats, facilitating SNARE-mediated membrane fusion and neurotransmitter release, and may be part of a stress-protection mechanism in actively maintaining an emotional homeostasis. Conclusions: The present results support the concept that there is a range of potential protein adaptations in the hippocampal synaptic active zone of unsusceptible rats, revealing new investigative targets that may contribute to a better understanding of stress

  1. Toll-like receptor stimulation in splenic marginal zone lymphoma can modulate cell signaling, activation and proliferation

    PubMed Central

    Fonte, Eleonora; Agathangelidis, Andreas; Reverberi, Daniele; Ntoufa, Stavroula; Scarfò, Lydia; Ranghetti, Pamela; Cutrona, Giovanna; Tedeschi, Alessandra; Xochelli, Aliki; Caligaris-Cappio, Federico; Ponzoni, Maurilio; Belessi, Chrysoula; Davis, Zadie; Piris, Miguel A.; Oscier, David; Ghia, Paolo; Stamatopoulos, Kostas; Muzio, Marta

    2015-01-01

    Recent studies on splenic marginal zone lymphoma identified distinct mutations in genes belonging to the B-cell receptor and Toll-like receptor signaling pathways, thus pointing to their potential implication in the biology of the disease. However, limited data is available regarding the exact role of TLRs. We aimed at characterizing the expression pattern of TLRs in splenic marginal zone lymphoma cells and their functional impact on the activation, proliferation and viability of malignant cells in vitro. Cells expressed significant levels of TLR1, TLR6, TLR7, TLR8, TLR9 and TLR10 mRNA; TLR2 and TLR4 showed a low, variable pattern of expression among patients whereas TLR3 and TLR5 mRNAs were undetectable; mRNA specific for TLR signaling molecules and adapters was also expressed. At the protein level, TLR1, TLR6, TLR7, TLR9 and TLR10 were detected. Stimulation of TLR1/2, TLR2/6 and TLR9 with their respective ligands triggered the activation of IRAK kinases, MAPK and NF-κB signaling pathways, and the induction of CD86 and CD25 activation molecules, although in a heterogeneous manner among different patient samples. TLR-induced activation and cell viability were also inhibited by a specific IRAK1/4 inhibitor, thus strongly supporting the specific role of TLR signaling in these processes. Furthermore, TLR2/6 and TLR9 stimulation also significantly increased cell proliferation. In conclusion, we demonstrate that splenic marginal zone lymphoma cells are equipped with functional TLR and signaling molecules and that the stimulation of TLR1/2, TLR2/6 and TLR9 may play a role in regulating disease pathobiology, likely promoting the expansion of the neoplastic clone. PMID:26294727

  2. Colony density and activity times of the ant Camponotus semitestaceus (Hymenoptera: formicidae) in a shrub steppe community

    SciTech Connect

    Gano, K.A.; Rogers, L.E.

    1983-11-01

    Colony densities and above-ground activity periods were determined for Camponotus semitestaceus colonies within a shrub-steppe community. Colony densities (anti-x +/- SD) averaged 0.088 +/- 0.032 per m/sup 2/ and 0.048 +/- 0.028 per m/sup 2/ on two sagebrush-bunchgrass sites an

  3. Density functional calculation of activation energies for lattice and grain boundary diffusion in alumina

    NASA Astrophysics Data System (ADS)

    Lei, Yinkai; Gong, Yu; Duan, Zhiyao; Wang, Guofeng

    2013-06-01

    To acquire knowledge on the lattice and grain boundary diffusion processes in alumina, we have determined the activation energies of elementary O and Al diffusive jumps in the bulk crystal, Σ3(0001) grain boundaries, and Σ3(101¯0) grain boundaries of α-Al2O3 using the first-principles density functional theory method. Specifically, we calculated the activation energies for four elementary jumps of both O and Al lattice diffusion in alumina. It was predicted that the activation energy of O lattice diffusion varied from 3.58 to 5.03 eV, while the activation energy of Al lattice diffusion ranged from 1.80 to 3.17 eV. As compared with experimental measurements, the theoretical predictions of the activation energy for lattice diffusion were lower and thus implied that there might be other high-energy diffusive jumps in the experimental alumina samples. Moreover, our results suggested that the Al lattice diffusion was faster than the O lattice diffusion in alumina, in agreement with experiment observations. Furthermore, it was found from our calculations for α-Al2O3 that the activation energies of O and Al grain boundary diffusion in the high-energy Σ3(0001) grain boundaries were significantly lower than those of the lattice diffusion. In contrast, the activation energies of O and Al grain boundary diffusion in the low-energy Σ3(101¯0) grain boundaries could be even higher than those of the lattice diffusion.

  4. Cholesteryl Ester Hydroperoxides Are Biologically Active Components of Minimally Oxidized Low Density Lipoprotein*S⃞

    PubMed Central

    Harkewicz, Richard; Hartvigsen, Karsten; Almazan, Felicidad; Dennis, Edward A.; Witztum, Joseph L.; Miller, Yury I.

    2008-01-01

    Oxidation of low density lipoprotein (LDL) occurs in vivo and significantly contributes to the development of atherosclerosis. An important mechanism of LDL oxidation in vivo is its modification with 12/15-lipoxygenase (LO). We have developed a model of minimally oxidized LDL (mmLDL) in which native LDL is modified by cells expressing 12/15LO. This mmLDL activates macrophages inducing membrane ruffling and cell spreading, activation of ERK1/2 and Akt signaling, and secretion of proinflammatory cytokines. In this study, we found that many of the biological activities of mmLDL were associated with cholesteryl ester (CE) hydroperoxides and were diminished by ebselen, a reducing agent. Liquid chromatography coupled with mass spectroscopy demonstrated the presence of many mono- and polyoxygenated CE species in mmLDL but not in native LDL. Nonpolar lipid extracts of mmLDL activated macrophages, although to a lesser degree than intact mmLDL. The macrophage responses were also induced by LDL directly modified with immobilized 12/15LO, and the nonpolar lipids extracted from 12/15LO-modified LDL contained a similar set of oxidized CE. Cholesteryl arachidonate modified with 12/15LO also activated macrophages and contained a similar collection of oxidized CE molecules. Remarkably, many of these oxidized CE were found in the extracts of atherosclerotic lesions isolated from hyperlipidemic apoE–/– mice. These results suggest that CE hydroperoxides constitute a class of biologically active components of mmLDL that may be relevant to proinflammatory activation of macrophages in atherosclerotic lesions. PMID:18263582

  5. The independent prospective associations of activity intensity and dietary energy density with adiposity in young adolescents.

    PubMed

    van Sluijs, Esther M F; Sharp, Stephen J; Ambrosini, Gina L; Cassidy, Aedin; Griffin, Simon J; Ekelund, Ulf

    2016-03-14

    There is limited evidence on the prospective association of time spent in activity intensity (sedentary (SED), moderate (MPA) or vigorous (VPA) physical activity) and dietary intake with adiposity indicators in young people. This study aimed to assess associations between (1) baseline objectively measured activity intensity, dietary energy density (DED) and 4-year change in adiposity and (2) 4-year change in activity intensity/DED and adiposity at follow-up. We conducted cohort analyses including 367 participants (10 years at baseline, 14 years at follow-up) with valid data for objectively measured activity (Actigraph), DED (4-d food diary), anthropometry (waist circumference (WC), %body fat (%BF), fat mass index (FMI), weight status) and covariates. Linear and logistic regression models were fit, including adjustment for DED and moderate-to-vigorous physical activity. Results showed that baseline DED was associated with change in WC (β for 1kJ/g difference: 0·71; 95% CI 0·26, 1·17), particularly in boys (1·26; 95% CI 0·41, 2·16 v. girls: 0·26; 95% CI -0·34, 0·87), but not with %BF, FMI or weight status. In contrast, baseline SED, MPA or VPA were not associated with any of the outcomes. Change in DED was negatively associated with FMI (β for 1kJ/g increase: -0·86; 95% CI -1·59, -0·12) and %BF (-0·86; 95% CI -1·25, -0·11) but not WC (-0·27; 95% CI -1·02, 0·48). Change in SED, MPA and VPA did not predict adiposity at follow-up. In conclusion, activity intensity was not prospectively associated with adiposity, whereas the directions of associations with DED were inconsistent. To inform public health efforts, future studies should continue to analyse longitudinal data to further understand the independent role of different energy-balance behaviours in changes in adiposity in early adolescence.

  6. Fuzzy electron density fragments in macromolecular quantum chemistry, combinatorial quantum chemistry, functional group analysis, and shape-activity relations.

    PubMed

    Mezey, Paul G

    2014-09-16

    Conspectus Just as complete molecules have no boundaries and have "fuzzy" electron density clouds approaching zero density exponentially at large distances from the nearest nucleus, a physically justified choice for electron density fragments exhibits similar behavior. Whereas fuzzy electron densities, just as any fuzzy object, such as a thicker cloud on a foggy day, do not lend themselves to easy visualization, one may partially overcome this by using isocontours. Whereas a faithful representation of the complete fuzzy density would need infinitely many such isocontours, nevertheless, by choosing a selected few, one can still obtain a limited pictorial representation. Clearly, such images are of limited value, and one better relies on more complete mathematical representations, using, for example, density matrices of fuzzy fragment densities. A fuzzy density fragmentation can be obtained in an exactly additive way, using the output from any of the common quantum chemical computational techniques, such as Hartree-Fock, MP2, and various density functional approaches. Such "fuzzy" electron density fragments properly represented have proven to be useful in a rather wide range of applications, for example, (a) using them as additive building blocks leading to efficient linear scaling macromolecular quantum chemistry computational techniques, (b) the study of quantum chemical functional groups, (c) using approximate fuzzy fragment information as allowed by the holographic electron density theorem, (d) the study of correlations between local shape and activity, including through-bond and through-space components of interactions between parts of molecules and relations between local molecular shape and substituent effects, (e) using them as tools of density matrix extrapolation in conformational changes, (f) physically valid averaging and statistical distribution of several local electron densities of common stoichiometry, useful in electron density databank mining, for

  7. Diversity and Dynamics of Active Small Microbial Eukaryotes in the Anoxic Zone of a Freshwater Meromictic Lake (Pavin, France)

    PubMed Central

    Lepère, Cécile; Domaizon, Isabelle; Hugoni, Mylène; Vellet, Agnès; Debroas, Didier

    2016-01-01

    Microbial eukaryotes play a crucial role in ecosystem functioning and oxygen is considered to be one of the strongest barriers against their local dispersal. However, diversity of microbial eukaryotes in freshwater habitats with oxygen gradients has previously received very little attention. We applied high-throughput sequencing (V4 region of the 18S rRNA gene) in conjunction with quantitative PCR (DNA and RNA) and fluorescent in situ hybridization (FISH) analyses, to provide an unique spatio-temporal analysis of microbial eukaryotes diversity and potential activity in a meromictic freshwater lake (lake Pavin). This study revealed a high genetic diversity of unicellular eukaryotes in the permanent anoxic zone of lake Pavin and allowed the discrimination of active vs. inactive components. Forty-two percent of the OTUs (Operational Taxonomic Units) are exclusively present in the monimolimnion, where Alveolata (Ciliophora and Dinophyceae) and Fungi (Dikarya and Chytrids) are the most active phyla and are probably represented by species capable of anaerobic metabolism. Pigmented eukaryotes (Haptophyceae and Chlorophyceae) are also present and active in this zone, which opens up questions regarding their metabolism. PMID:26904006

  8. Determination of active oxide trap density and 1/f noise mechanism in RESURF LDMOS transistors

    NASA Astrophysics Data System (ADS)

    Çelik-Butler, Z.; Mahmud, M. I.; Hao, P.; Hou, F.; Amey, B. L.; Pendharkar, S.

    2015-09-01

    The physical origin of majority charge carrier fluctuations in the SiO2 interface of Si at accumulation has been investigated and analyzed for differently processed and voltage-rated reduced surface field (RESURF), lateral-double-diffused MOS (LDMOS) transistors. Surface carrier mobility fluctuation due to remote Coulomb scattering by the trapped charge in the gate oxide is identified as the dominant physical mechanism for LDMOS 1/f noise irrespective of process technologies. A significant contribution to the measured noise has been noted from the surface majority carrier mobility fluctuation due to trapped charge at the accumulation region of the extended drain region, dominant over other sources including the surface minority charge carrier fluctuations in the channel. Active oxide trap density was characterized spatially and for the first time up to ∼0.4 eV above the conduction band-edge of Si. The interface trap density in the unstressed devices (∼8 × 106 cm-2) increased more than an order of magnitude (∼1 × 108 cm-2) after the devices were stressed for 10,000 sec at their individual worst drain current and on-resistance degradation conditions. The extracted Si/SiO2 interface trap density above the silicon conduction band edge was found to be several orders of magnitude lower than that reported for silicon mid-gap energies, even after stressing. Since the traps near the quasi-Fermi level for electrons are active in trapping-detrapping, and the Fermi level is energetically positioned above the conduction band edge of Si in the investigated devices as compared to the previously reported observations, the lower trap density obtained here is an indication for reversal of the well-known exponential trap energy distribution beyond the conduction band-edge of Si. These findings shift the focus from the channel to the gate overlap section of the extended drain and the quality of the Si/SiO2 interface in that region.

  9. A Comparison of Bone Mineral Density in Amateur Male Boxers and Active Non-boxers.

    PubMed

    Bolam, K A; Skinner, T L; Sax, A T; Adlard, K N; Taaffe, D R

    2016-08-01

    To examine the site-specific osteogenic effect of upper limb impact-loading activity we compared the forearm and arm bone mineral density (BMD) of male boxers to that of active controls. A cross-sectional study was performed with 30 amateur male boxers (aged 18-44 years) and 32 age-matched, non-boxing, active controls. Participants had their regional and whole body BMD and bone mineral content (BMC) assessed by dual-energy X-ray absorptiometry. Hand grip strength, testosterone, oestradiol, sex hormone-binding globulin, vitamin D, lean and fat mass, and past and current physical activity were also assessed. Forearm and arm BMD were 1.5-2.2% higher in boxers than the control group although this was not statistically significant (p>0.05), with no significant difference for BMC (p>0.05). There were no differences between groups for spine, hip, or whole body BMD or BMC, or for body composition or hormone status. Within the arms, lean mass was associated with BMD and BMC in both boxers and the control group (BMD, r=0.60-0.76, p<0.001; BMC, r=0.67-0.82, p<0.001). There were no significant differences between amateur boxers and the control group for upper limb BMD and BMC. However, muscle mass appears to be particularly important to bone health of the upper limbs.

  10. Characterization of ichthyocidal activity of Pfiesteria piscicida: dependence on the dinospore cell density.

    PubMed

    Drgon, Tomás; Saito, Keiko; Gillevet, Patrick M; Sikaroodi, Masoumeh; Whitaker, Brent; Krupatkina, Danara N; Argemi, Federico; Vasta, Gerardo R

    2005-01-01

    The ichthyocidal activity of Pfiesteria piscicida dinospores was examined in an aquarium bioassay format by exposing fish to either Pfiesteria-containing environmental sediments or clonal P. piscicida. The presence of Pfiesteria spp. and the complexity of the microbial assemblage in the bioassay were assessed by molecular approaches. Cell-free water from bioassays that yielded significant fish mortality failed to show ichthyocidal activity. Histopathological examination of moribund and dead fish failed to reveal the skin lesions reported elsewhere. Fish larvae within "cages" of variable mesh sizes were killed in those where the pore size exceeded that of Pfiesteria dinospores. In vitro exposure of fish larvae to clonal P. piscicida indicated that fish mortality was directly proportional to the dinospore cell density. Dinospores clustered around the mouth, eyes, and operculi, suggesting that fish health may be affected by their direct interaction with skin, gill epithelia, or mucous surfaces. Molecular fingerprinting revealed the presence of a very diverse microbial community of bacteria, protists, and fungi within bioassay aquaria containing environmental sediments. Some components of the microbial community were identified as potential fish pathogens, preventing the rigorous identification of Pfiesteria spp. as the only cause of fish death. In summary, our results strongly suggest (i) that this aquarium bioassay format, which has been extensively reported in the literature, is unsuitable to accurately assess the ichthyocidal activity of Pfiesteria spp. and (ii) that the ichthyocidal activity of Pfiesteria spp. is mostly due to direct interactions of the zoospores with fish skin and gill epithelia rather than to soluble factors.

  11. Accelerating wavefunction in density-functional-theory embedding by truncating the active basis set

    NASA Astrophysics Data System (ADS)

    Bennie, Simon J.; Stella, Martina; Miller, Thomas F.; Manby, Frederick R.

    2015-07-01

    Methods where an accurate wavefunction is embedded in a density-functional description of the surrounding environment have recently been simplified through the use of a projection operator to ensure orthogonality of orbital subspaces. Projector embedding already offers significant performance gains over conventional post-Hartree-Fock methods by reducing the number of correlated occupied orbitals. However, in our first applications of the method, we used the atomic-orbital basis for the full system, even for the correlated wavefunction calculation in a small, active subsystem. Here, we further develop our method for truncating the atomic-orbital basis to include only functions within or close to the active subsystem. The number of atomic orbitals in a calculation on a fixed active subsystem becomes asymptotically independent of the size of the environment, producing the required O ( N 0 ) scaling of cost of the calculation in the active subsystem, and accuracy is controlled by a single parameter. The applicability of this approach is demonstrated for the embedded many-body expansion of binding energies of water hexamers and calculation of reaction barriers of SN2 substitution of fluorine by chlorine in α-fluoroalkanes.

  12. Impact of dietary intake, education, and physical activity on bone mineral density among North Indian women.

    PubMed

    Kumar, Ashok; Mittal, Soniya; Orito, Seiya; Ishitani, Ken; Ohta, Hiroaki

    2010-03-01

    The aim of the study was to determine the relationship of dietary nutrients and bone mineral density (BMD) in North Indian women. This cross-sectional study was conducted from April 2006 to March 2008. Subjects included 255 healthy women, aged 20-69 years, who were relatives of patients being admitted in the hospital. Various demographic characteristics including socioeconomic status and serum parameters in relationship to BMD were evaluated. In addition, the daily dietary intake of energy, protein, fat, and calcium and the amount of physical activity were assessed. BMD at the lumbar spine, femoral neck, and Ward's triangle was measured by dual-energy X-ray absorptiometry (DXA). Body mass index (BMI), physical activity, and educational level were positively correlated with BMD. The daily intakes of energy (1563.4 +/- 267.2 kcal) and protein (48.7 +/- 8.7 g) were below the recommended dietary allowance. Daily dietary energy, protein, and calcium intakes were correlated with BMD at the lumbar spine. Stepwise multiple linear regression analyses showed that age, BMI, and physical activity were significant predictors for BMD at all sites. In addition, energy intake was also a predictor for BMD at the lumbar spine. The protein intake was associated with BMD at the spine (P = 0.02 and beta = 0.163) even after making adjustments for energy intake. Thus, dietary pattern coupled with higher education levels and greater physical activity favored bone health.

  13. Antibodies toward high-density lipoprotein components inhibit paraoxonase activity in patients with systemic lupus erythematosus.

    PubMed

    Batuca, J R; Ames, P R J; Isenberg, D A; Alves, J Delgado

    2007-06-01

    Patients with systemic lupus erythematosus (SLE) have an increased incidence of vascular disease, and oxidative stress is recognized as an important feature in this condition, despite the underlying mechanisms not being fully understood. In these patients, an interaction between lipoproteins and the immune system has been suggested, but most studies have only looked at antibodies against oxidized low-density lipoproteins. This study was undertaken to determine the presence of antibodies directed against high-density lipoproteins (HDL) and to identify a possible association between these antibodies and paraoxonase (PON), an antioxidant enzyme present in HDL. Plasma from 55 patients with SLE was collected and IgG aHDL and antiapolipoprotein A-I (aApo A-I) antibodies were assessed by enzyme-linked immunosorbent assay. Standardization of the method was performed in a control population of 150 healthy subjects. Plasma levels above 5 standard deviations of the mean of the control population were considered positive. PON activity was assessed by quantification of p-nitrophenol formation (micromol/mL/min). Patients with SLE had higher titers of aHDL (P < 0.0001) and aApo A-I (P < 0.0001) antibodies, and lower PON activity (P < 0.0001) than healthy controls. There was also a direct correlation between the titers of aHDL and aApo A-I antibodies (r = 0.61; P < 0.0001). PON activity was inversely correlated with aApo A-I (P = 0.0129) antibody levels. Anti-HDL and aApo A-I antibodies from patients with high titers were isolated and subsequently incubated with human HDL. These antibodies reduced PON activity up to a maximum of 70.2% and 78.4%, respectively. This study showed the presence of aHDL and aApo A-I antibodies in patients with SLE. These antibodies were associated with reduced PON activity in plasma, and the in vitro inhibition assay confirmed a direct inhibition of the enzyme activity.

  14. Effect of particle surface area on ice active site densities retrieved from droplet freezing spectra

    NASA Astrophysics Data System (ADS)

    Beydoun, Hassan; Polen, Michael; Sullivan, Ryan C.

    2016-10-01

    Heterogeneous ice nucleation remains one of the outstanding problems in cloud physics and atmospheric science. Experimental challenges in properly simulating particle-induced freezing processes under atmospherically relevant conditions have largely contributed to the absence of a well-established parameterization of immersion freezing properties. Here, we formulate an ice active, surface-site-based stochastic model of heterogeneous freezing with the unique feature of invoking a continuum assumption on the ice nucleating activity (contact angle) of an aerosol particle's surface that requires no assumptions about the size or number of active sites. The result is a particle-specific property g that defines a distribution of local ice nucleation rates. Upon integration, this yields a full freezing probability function for an ice nucleating particle. Current cold plate droplet freezing measurements provide a valuable and inexpensive resource for studying the freezing properties of many atmospheric aerosol systems. We apply our g framework to explain the observed dependence of the freezing temperature of droplets in a cold plate on the concentration of the particle species investigated. Normalizing to the total particle mass or surface area present to derive the commonly used ice nuclei active surface (INAS) density (ns) often cannot account for the effects of particle concentration, yet concentration is typically varied to span a wider measurable freezing temperature range. A method based on determining what is denoted an ice nucleating species' specific critical surface area is presented and explains the concentration dependence as a result of increasing the variability in ice nucleating active sites between droplets. By applying this method to experimental droplet freezing data from four different systems, we demonstrate its ability to interpret immersion freezing temperature spectra of droplets containing variable particle concentrations. It is shown that general

  15. Active deformation in Zagros-Makran transition zone inferred from GPS measurements

    NASA Astrophysics Data System (ADS)

    Bayer, R.; Chery, J.; Tatar, M.; Vernant, Ph.; Abbassi, M.; Masson, F.; Nilforoushan, F.; Doerflinger, E.; Regard, V.; Bellier, O.

    2006-04-01

    The Bandar Abbas-Strait of Hormuz zone is considered as a transition between the Zagros collision and the Makran oceanic subduction. We used GPS network measurements collected in 2000 and 2002 to better understand the distribution of the deformation between the collision zone and the Makran subduction. Analysing the GPS velocities, we show that transfer of the deformation is mainly accommodated along the NNW-SSE-trending reverse right-lateral Zendan-Minab-Palami (ZMP) fault system. The rate is estimated to 10 +/- 3 mm yr-1 near the faults. Assuming that the ZMP fault system transfers the motion between the Makran-Lut Block and the Arabian plate, we estimate to 15 mm yr-1 and 6 mm yr-1, respectively, the dextral strike-slip and shortening components of the long-term transpressive displacement. Our geodetic measurements suggest also a 10-15 km locking depth for the ZMP fault system. The radial velocity pattern and the orientation of compressive strain axes around the straight of Hormuz is probably the consequence of the subducting Musandam promontory. The N-S Jiroft-Sabzevaran (JS) fault system prolongates southwards the dextral shear motion of the Nayband-Gowk (NG) fault system at an apparent rate of 3.1 +/- 2.5 mm yr-1. The change from strong to weak coupling for underthrusting the Arabian plate beneath the Zagros (strong) and the Makran (weak) may explain the dextral motion along the ZMP, JS/NG and Neh-Zahedan fault systems which transfer the convergence from a broad zone in the western Iran (Zagros, Tabriz fault system, Alborz, Caucasus and Caspian sea surroundings) to Makran subduction.

  16. Cell Density-Dependent Increase in Tyrosine-Monophosphorylated ERK2 in MDCK Cells Expressing Active Ras or Raf

    PubMed Central

    Kawabata, Noriyuki; Matsuda, Michiyuki

    2016-01-01

    The extracellular signal-regulated kinase (ERK) is one of the principal hub proteins that transmit growth signals from upstream oncogene products including Ras and BRaf to downstream effector proteins. However, there are both reports supporting and refuting the increase in ERK activity in cancer tissues expressing the active Ras and BRaf proteins. We considered that the cell density might account for this discrepancy. To examine this possibility, we prepared Madin-Darby canine kidney (MDCK) cells that expressed an active HRas, NRas, KRas, or BRaf and an ERK biosensor based on the principle of Förster resonance energy transfer (FRET). As we anticipated, expression of the active Ras or BRaf increased ERK activity at low cell densities. However, the ERK activity was markedly suppressed at high cell densities irrespective of the expression of the active Ras or BRaf. Western blotting analysis with Phos-tag gel revealed the decrease of tyrosine and threonine-diphosphorylated active ERK and the increase of tyrosine-monophosphorylated inactive ERK at high cell density. In addition, we found that calyculin A, an inhibitor for PPP-subfamily protein serine/threonine phosphatases, decreased the tyrosine-monophosphorylated ERK. Our study suggests that PPP-subfamily phosphatases may be responsible for cell density-dependent ERK dephosphorylation in cancer cells expressing active Ras or BRaf protein. PMID:27936234

  17. Magnetized Accretion and Dead Zones in Protoplanetary disks

    NASA Astrophysics Data System (ADS)

    Dzyurkevich, Natalia; Turner, Neal J.; Henning, Thomas; Kley, Wilhelm

    2013-07-01

    The edges of magnetically-dead zones in protostellar disks have been proposed as locations where density bumps may arise, trapping planetesimals and helping form planets. Magneto-rotational turbulence in magnetically-active zones provides both accretion of gas on the star and transport of mass to the dead zone. We investigate the location of the magnetically-active regions in a protostellar disk around a solar-type star, varying the parameters like dust-to-gas ratio. The dead zone is in most cases defined by the ambipolar diffusion. In our maps, the dead zone takes a variety of shapes, including a fish-tail pointing away from the star and islands located on and off the midplane. The corresponding accretion rates vary with radius, indicating locations where the surface density will increase over time, and others where it will decrease. We show that density bumps do not readily grow near the dead zone's outer edge, independently of the disk parameters and the dust properties. Instead, the accretion rate peaks at the radius where the gas-phase metals freeze out. This could lead to clearing a valley in the surface density, and to a trap for pebbles located just outside the metal freeze-out line. Here, we provide the fitting formula for the metal line and consider the cojoint impact of metal ans snow lines on the shape of the dead zone.

  18. Control of biologically active degradation zones by vertical heterogeneity: Applications in fractured media. 1997 annual progress report

    SciTech Connect

    Colwell, F.S.; Smith, R.W.; McKinley, J.; Fredrickson, J.; Onstott, T.C.; Reysenbach, A.L.

    1997-11-01

    'The objective of this research is to determine the relationship between of biologically active contaminant degradation zones in a fractured, subsurface medium and vertical geological heterogeneities. The research is being performed on samples collected from the Test Area North (TAN) site at the Idaho National Engineering and Environmental Laboratory (INEEL) where a dissolved trichloroethylene (TCE) plume is migrating in the basalts and interbed sediments of the Eastern Snake River Plain (ESRP) aquifer. Research results are leading to an enhanced understanding of the constraints that the geochemical and hydrological environment place on the activities and distribution of TCE-degrading organisms in this fractured subsurface medium. Enhanced understanding allows better decisions to be made regarding the use of remedial technologies such as natural attenuation and in situ bioremediation at geologically complex waste sites. Through this research, investigations conducted by the Subsurface Science Program (SSP) at TAN are being extended in order to develop a mechanistic understanding of the coupled geomicrobial and hydrogeochemical processes that are necessary to predict the field-scale intrinsic degradation rates of TCE. The research objective is being accomplished by characterizing paired cores and water samples from boreholes located in differing geochemical and flow environments within the plume. Analysis of these samples will allow the determination of the spatial correlation and microbial characterization. The results presented in this report consist primarily of TAN-33 data as many of those analyses have been completed. Nearly all of the TAN-37 data has yet to be acquired. It should be noted that most of the cores were collected from zones that consist of relatively competent, massive basalt. This was because the authors were doubtful about the quality of samples obtained from rubble zones due to potential alteration by the drilling fluids. Thus, microbiological

  19. Charge density and optical properties of multicomponent crystals containing active pharmaceutical ingredients or their analogues.

    PubMed

    Gryl, Marlena

    2015-08-01

    Active pharmaceutical ingredients (APIs), through their favourable donor/acceptor spatial distribution and synthon formation flexibility, are attractive building blocks in modern materials crystallography. The optical properties of a crystal strongly depend on two factors, i.e. the spatial distribution of molecules in the crystal structure and the electronic properties of molecular building blocks (dipole moments, polarizabilities, hyperpolarizabilities). Although the latter are easy to predict through ab initio calculations, the former are not. Only a combination of experimental and theoretical charge density studies together with prediction and measurement of optical properties enable full analysis of the obtained functional material in terms of its usefulness in practical applications. This article presents design strategies of optical materials based on selected pharmaceutical molecules. Factors that contribute to molecular recognition in the four selected polar/chiral crystal phases (derived through charge density and Hirshfeld surfaces analysis) have been determined. Theoretically predicted optical properties of the molecular/ionic building blocks as well as bulk effects have been confirmed experimentally. This research is a first step in the design of novel optical materials based on push-pull molecules and APIs.

  20. Late Quaternary Activity and Seismogenic Potential of the Gonave Microplate: Plantain Garden Strike-Slip Fault Zone of Eastern Jamaica

    NASA Astrophysics Data System (ADS)

    Mann, P.; Prentice, C.; King, W.; Demets, C.; Wiggins-Grandison, M.; Benford, B.

    2008-12-01

    At the longitude of Jamaica, Caribbean (Carib)-North America (Noam) plate motion of 19 ± 2 mm/a is carried by two parallel, left-lateral strike-slip faults, the Oriente fault zone, immediately south of Cuba, and the Enriquillo-Plantain Garden fault zone (EPGFZ), which lies 100-150 km further south. It has been postulated that the lithosphere between these faults constitutes an independent Gonave microplate that has formed in response to the ongoing collision between the leading edge of Carib in Hispaniola and the Bahama carbonate platform. GPS measurements in Jamaica and Hispanola is supportive of the microplate hypothesis and indicates that roughly half of Carib-Noam plate motion (8-14 mm/a) is carried by the EPGFZ of southern Hispaniola and eastern Jamaica. This study applies geomorphic and paleoseismic methods as a direct test of the activity and amount of microplate motion carried on the Plantain Garden fault segment of eastern Hispaniola and how this motion is distributed across a large restraining bend that has formed the island of Jamaica since the late Miocene. The EPFZ curves gently to the northeast and forming a steep mountain front to the Blue Mountains restraining bend with elevations up to 2200 m. Geomorphic fault-related features along the mountain front fault zone include left-laterally deflected rivers and streams, but no small scale features indicative of Holocene activity. River and stream deflections range from 0.1 to 0.5 km. We identified and trenched the most active trace of the mountain front fault at the Morant River where the fault is characterized by a 1.5-m-wide sub-vertical fault zone juxtaposing sheared alluvium and fault Cretaceous basement rocks This section is overlain by a 6-m-thick fluvial terrace. Trenching in the unfaulted terrace immediately overlying the fault trace revealed radiocarbon and OSL ages ranging from 20 to 21 ka that are consistent with a prominent unfaulted alluvial fan along the projection of this fault 1.5 km to

  1. Regional and Detailed Survey for Radon Activities in Soil-Gas and Groundwater in the Okchon Zone, Korea

    NASA Astrophysics Data System (ADS)

    Je, H.-K.; Chon, H.-T.

    2012-04-01

    The Okchon zone in Korea provides a typical example of natural geological materials enriched in potentially toxic elements including uranium which is parent nuclide for radon gas. For the purpose of radon radioactivity risk assessment, making the map of radon risk grade from Okchon zone, regional and detailed field surveys were carried out during 3 years. The study area is located in the central part of Korea, called the Okchon zone (about 5,100 km2), which occur in a 80km wide, northeast-trending belt that extends across the Korean Peninsula. The Okchon zone is underlain by metasedimentary rocks of unknown age that are composed mainly of black slate, phyllite, shale, and limestone. The three research areas (defined as Boeun, Chungju, and Nonsan) for detailed survey were selected from the results of regional survey. Results of detailed radon survey indicated a wide range of radon activities for soil-gases (148-1,843 pCi/L) and ground waters (23-5,540 pCi/L). About 15 percent of soil-gas samples exceeded 1,000 pCi/L and 84 percent of ground water samples exceeded the MCL (maximum contaminant level) of drinking water, 300 pCi/L, which proposed by U.S. Environmental Protection Agency in 1999. For detailed survey, radon activities of soil-gas and ground water were classified as bedrock geology, based on 1/50,000 geological map and field research. For soil-gas measurements, mean values of radon activity from black slate-shale (789 pCi/L) were highest among the other base rocks. And for groundwater measurements, mean value of radon activities were decreased in the order of granite (1,345 pCi/L) > black shale-slate (915 pCi/L) > metasediments (617 pCi/L). Result of indoor radon measurement from detailed survey areas showed that about 50% of houses exceeded the indoor guideline, 4 pCi/L. For the radon risk assessment in indoor environment showed that probability of lung cancer risk from the houses located on the granite base rock (3.0×10-2) was highest among the other

  2. Determinants of bone density among athletes engaged in weight-bearing and non-weight-bearing activity

    NASA Technical Reports Server (NTRS)

    Block, Jon E.; Friedlander, Anne L.; Brooks, George A.; Steiger, Peter; Stubbs, Harrison A.

    1989-01-01

    The effect of weight bearing activity on the bone density was investigated in athletes by comparing the measures of bone density of athletes engaged in weight-training programs with those of polo players and nonexercising subjects. All subjects had measurements of spinal trabecular and integral bone density by quantitative tomography, as well as determinations of hip bone density by dual photon absorptiometry. Results confirmed previous findings by Block et al. (1987) of significantly greater bone density among highly trained athletes compared with nonexercising subjects of similar age. Results also indicated that athletes engaged in non-weight-bearing forms of rigorous exercise had greater levels of bone density. However, as the participants in this study were exceptional athletes, engaged in a strenuous sport with both aerobic and heavy resistance components, a confirmation of these data is needed, using larger samples of individuals.

  3. The active-zone protein Munc13 controls the use-dependence of presynaptic voltage-gated calcium channels

    PubMed Central

    Calloway, Nathaniel; Gouzer, Géraldine; Xue, Mingyu; Ryan, Timothy A

    2015-01-01

    Presynaptic calcium channel function is critical for converting electrical information into chemical communication but the molecules in the active zone that sculpt this function are poorly understood. We show that Munc13, an active-zone protein essential for exocytosis, also controls presynaptic voltage-gated calcium channel (VGCC) function dictating their behavior during various forms of activity. We demonstrate that in vitro Munc13 interacts with voltage-VGCCs via a pair of basic residues in Munc13's C2B domain. We show that elimination of this interaction by either removal of Munc13 or replacement of Munc13 with a Munc13 C2B mutant alters synaptic VGCC's response to and recovery from high-frequency action potential bursts and alters calcium influx from single action potential stimuli. These studies illustrate a novel form of synaptic modulation and show that Munc13 is poised to profoundly impact information transfer at nerve terminals by controlling both vesicle priming and the trigger for exocytosis. DOI: http://dx.doi.org/10.7554/eLife.07728.001 PMID:26196145

  4. High-resolution water column survey to identify active sublacustrine hydrothermal discharge zones within Lake Rotomahana, North Island, New Zealand

    NASA Astrophysics Data System (ADS)

    Walker, Sharon L.; de Ronde, Cornel E. J.; Fornari, Daniel; Tivey, Maurice A.; Stucker, Valerie K.

    2016-03-01

    Autonomous underwater vehicles were used to conduct a high-resolution water column survey of Lake Rotomahana using temperature, pH, turbidity, and oxidation-reduction potential (ORP) to identify active hydrothermal discharge zones within the lake. Five areas with active sublacustrine venting were identified: (1) the area of the historic Pink Terraces; (2) adjacent to the western shoreline subaerial "Steaming Cliffs," boiling springs and geyser; (3) along the northern shoreline to the east of the Pink Terrace site; (4) the newly discovered Patiti hydrothermal system along the south margin of the 1886 Tarawera eruption rift zone; and (5) a location in the east basin (northeast of Patiti Island). The Pink Terrace hydrothermal system was active prior to the 1886 eruption of Mount Tarawera, but venting along the western shoreline, in the east basin, and the Patiti hydrothermal system appear to have been initiated in the aftermath of the eruption, similar to Waimangu Valley to the southwest. Different combinations of turbidity, pH anomalies (both positive and negative), and ORP responses suggest vent fluid compositions vary over short distances within the lake. The seasonal period of stratification limits vertical transport of heat to the surface layer and the hypolimnion temperature of Lake Rotomahana consequently increases with an average warming rate of ~ 0.010 °C/day due to both convective hydrothermal discharge and conductive geothermal heating. A sudden temperature increase occurred during our 2011 survey and was likely the response to an earthquake swarm just 11 days prior.

  5. Adjacent positioning of cellular structures enabled by a Cdc42 GTPase-activating protein-mediated zone of inhibition.

    PubMed

    Tong, Zongtian; Gao, Xiang-Dong; Howell, Audrey S; Bose, Indrani; Lew, Daniel J; Bi, Erfei

    2007-12-31

    Cells of the budding yeast Saccharomyces cerevisiae are born carrying localized transmembrane landmark proteins that guide the subsequent establishment of a polarity axis and hence polarized growth to form a bud in the next cell cycle. In haploid cells, the relevant landmark proteins are concentrated at the site of the preceding cell division, to which they recruit Cdc24, the guanine nucleotide exchange factor for the conserved polarity regulator Cdc42. However, instead of polarizing at the division site, the new polarity axis is directed next to but not overlapping that site. Here, we show that the Cdc42 guanosine triphosphatase-activating protein (GAP) Rga1 establishes an exclusion zone at the division site that blocks subsequent polarization within that site. In the absence of localized Rga1 GAP activity, new buds do in fact form within the old division site. Thus, Cdc42 activators and GAPs establish concentric zones of action such that polarization is directed to occur adjacent to but not within the previous cell division site.

  6. Active part of Charlie--Gibbs fracture zone: A study using sonar and other geophysical techniques

    SciTech Connect

    Searle, R.

    1981-01-10

    A short survey with Gloria side-scan sonar and other geophysical instruments has revealed new information about Charlie--Gibbs fracture zone between 29/sup 0/ and 36 /sup 0/W. The traces of two transform faults have been clearly delineated. They fit small circles about the pole of rotation with an rms error of only about 1 km, but they do not always follow the deepest parts of the transform valleys. The transforms are joined by a short spreading center at 31 /sup 0/45 'W. The median transverse ridge appears to have been produced by normal seafloor spreading at this center and bears identifiable Vine-Matthews magnetic anomalies. A transverse ridge along the eastern inactive part of the northern transform may be an intrusive feature. Considerable thickness of sediment appear to have been deposited in the northern transform valley from Norwegian Sea overflow water passing through the fracture zone, but transverse ridges have prevented the sediment reaching the southern valley.

  7. Incipient Crustal Stretching across AN Active Collision Belt: the Case of the Siculo-Calabrian Rift Zone (central Mediterranean)

    NASA Astrophysics Data System (ADS)

    Catalano, S.; Tortorici, G.; Romagnoli, G.; Pavano, F.

    2012-12-01

    In the Central Mediterranean, the differential roll-back of the subducting Nubia Plate caused the Neogene-Quaternary extrusion of the Calabrian arc onto the oceanic Ionian slab, and the opening of the oceanic Tyrrhenian Basin, in the overriding Eurasia Plate. The differential motion at the edges of the arc was largely accommodated along transform faults that propagated across the orogenic belt. Since the Late Quaternary, the southern edge of the arc has been replaced by the roughly N-S oriented Siculo-Calabrian Rift Zone (SCRZ) that formed as the NNW-directed normal faults of NE Sicily, crossing the orogenic belt, have linked the NNE-oriented Tyrrhenian margin of southern Calabria with the NNW-trending Africa-Ionian boundary of southeastern Sicily. Our study focused on the Sicily shoulder of the SCRZ, where the transition zone between the extensional belt and the still active Nubia-Eurasia convergent margin is characterized by two distinct mobile crustal wedges, both lying on an upwarped Mantle, where a re-orientations of the σ1 is combined with volcanism (e.g. Etna, Aeolian islands) and a huge tectonic uplift. In southeastern Sicily, the Hyblean-Etnean region evolved, since about 0.85 Ma, as an indipendent crustal wedge, moving towards the NNW and pointing to the active Mt. Etna volcano. A local ENE crustal stretching accompanied the traslation of the block and pre-dated the ESE-oriented extension governing the propagation of the southernmost branch of the SCR, which started at about 330 ka B.P.. Similarly, the Peloritani-Aeolian region, flanked by the 125 ka-old NE-Sicily branch of the rift zone, represents a mostly submerged crustal wedge that migrates towards the NE, diverging from the rest of the Sicily collision zone and pointing to the Stromboli volcano. The Peloritani-Aeolian block is characterized by the occurrence of a wide central NE-oriented collapsed basin contoured by an actively uplifting region, whose tectonic boundaries are evidenced by a sharp

  8. CF₃I synthesis catalyzed by activated carbon: a density functional theory study.

    PubMed

    Hu, Yingjie; Wu, Taiping; Liu, Weizhou; Zhang, Liyang; Pan, Renming

    2014-03-13

    A revised reaction mechanism of CF3I synthesis catalyzed by activated carbon is investigated with quantum chemistry methods using density functional theory (DFT). The adsorption configurations of possible intermediates are carefully examined. The reaction pathway and related transition states are also analyzed. According to our calculations, first, the dehydrofluorination of CHF3 is catalyzed by -COOH groups, which possesses the highest barrier and is accordingly identified as the rate-determining step. Second, the difluorocarbene disproportionation over graphite (001) surface proceeds instead of dimerization. The next reaction steps involving the association of fluoromethine and trifluoromethyl, the fluorine abstractions between intermediates and the iodine abstractions by the desorbed CF3 and CF2CF3 from molecular iodine are also feasible over graphite (001) surfaces. It is also found that the coke deposition in experiments is due to the fluorine abstraction from fluoromethine. This revised mechanism is in agreement with available experimental data and our theoretical computations.

  9. Mechanistic considerations on contact-active antimicrobial surfaces with controlled functional group densities.

    PubMed

    Bieser, Arno M; Tiller, Joerg C

    2011-04-08

    A series of N-alkyl-N,N-dimethyldeoxyammonium celluloses is synthesized by converting tosyl celluloses with DBA and DDA, respectively. Surface coatings with these water-insoluble derivatives contain well-defined densities of quaternary ammonium functions and nonactive hydrophobic and hydrophilic groups. It is shown that the antimicrobial activity of such surfaces against S. aureus requires a delicate balance between DDA, BDA, and hydrophobic groups. A mechanism is proposed that involves the selective adhesion of anionic phospholipids from the bacterial cell membrane. This so-called phospholipid sponge effect is supported by the fact that all coatings could be deactivated by treatment with SDS or negatively charged phospholipids, but not with neutral phospholipids.

  10. High-density EMG E-textile systems for the control of active prostheses.

    PubMed

    Farina, Dario; Lorrain, Thomas; Negro, Francesco; Jiang, Ning

    2010-01-01

    Myoelectric control of active prostheses requires electrode systems that are easy to apply for daily repositioning of the electrodes by the user. In this study we propose the use of Smart Fabric and Interactive Textile (SFIT) systems as an alternative solution for recording high-density EMG signals for myoelectric control. A sleeve covering the upper and lower arm, which contains 100 electrodes arranged in four grids of 5 × 5 electrodes, was used to record EMG signals in 3 subjects during the execution of 9 tasks of the wrist and hand. The signals were analyzed by extracting wavelet coefficients which were classified with linear discriminant analysis. The average classification accuracy for the nine tasks was 89.1 ± 1.9 %. These results show that SFIT systems can be used as an effective way for muscle-machine interfacing.

  11. Density Functional Theory Calculations of Activation Energies for Carrier Capture by Defects in Semiconductors

    NASA Astrophysics Data System (ADS)

    Modine, N. A.; Wright, A. F.; Lee, S. R.

    The rate of defect-induced carrier recombination is determined by both defect levels and carrier capture cross-sections. Density functional theory (DFT) has been widely and successfully used to predict defect levels, but only recently has work begun to focus on using DFT to determine carrier capture cross-sections. Lang and Henry developed the theory of carrier-capture by multiphonon emission in the 1970s and showed that carrier-capture cross-sections differ between defects primarily due to differences in their carrier capture activation energies. We present an approach to using DFT to calculate carrier capture activation energies that does not depend on an assumed configuration coordinate and that fully accounts for anharmonic effects, which can substantially modify carrier activation energies. We demonstrate our approach for intrinisic defects in GaAs and GaN and discuss how our results depend on the choice of exchange-correlation functional and the treatment of spin polarization. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  12. Enhanced photocurrent density in graphene/Si based solar cell (GSSC) by optimizing active layer thickness

    SciTech Connect

    Rosikhin, Ahmad Hidayat, Aulia Fikri; Syuhada, Ibnu; Winata, Toto

    2015-12-29

    Thickness dependent photocurrent density in active layer of graphene/Si based solar cell has been investigated via analytical – simulation study. This report is a preliminary comparison of experimental and analytical investigation of graphene/Si based solar cell. Graphene sheet was interfaced with Si thin film forming heterojunction solar cell that was treated as a device model for photocurrent generator. Such current can be enhanced by optimizing active layer thickness and involving metal oxide as supporting layer to shift photons absorption. In this case there are two type of devices model with and without TiO{sub 2} in which the silicon thickness varied at 20 – 100 nm. All of them have examined and also compared with each other to obtain an optimum value. From this calculation it found that generated currents almost linear with thickness but there are saturated conditions that no more enhancements will be achieved. Furthermore TiO{sub 2} layer is effectively increases photon absorption but reducing device stability, maximum current is fluctuates enough. This may caused by the disturbance of excitons diffusion and resistivity inside each layer. Finally by controlling active layer thickness, it is quite useful to estimate optimization in order to develop the next solar cell devices.

  13. Ultrasound Current Source Density Imaging of the Cardiac Activation Wave Using a Clinical Cardiac Catheter

    PubMed Central

    Qin, Yexian; Li, Qian; Ingram, Pier; Barber, Christy; Liu, Zhonglin

    2015-01-01

    Ultrasound current source density imaging (UCSDI), based on the acoustoelectric (AE) effect, is a noninvasive method for mapping electrical current in 4-D (space + time). This technique potentially overcomes limitations with conventional electrical mapping procedures typically used during treatment of sustained arrhythmias. However, the weak AE signal associated with the electrocardiogram is a major challenge for advancing this technology. In this study, we examined the effects of the electrode configuration and ultrasound frequency on the magnitude of the AE signal and quality of UCSDI using a rabbit Langendorff heart preparation. The AE signal was much stronger at 0.5 MHz (2.99 μV/MPa) than 1.0 MHz (0.42 μV/MPa). Also, a clinical lasso catheter placed on the epicardium exhibited excellent sensitivity without penetrating the tissue. We also present, for the first time, 3-D cardiac activation maps of the live rabbit heart using only one pair of recording electrodes. Activation maps were used to calculate the cardiac conduction velocity for atrial (1.31 m/s) and apical (0.67 m/s) pacing. This study demonstrated that UCSDI is potentially capable of real-time 3-D cardiac activation wave mapping, which would greatly facilitate ablation procedures for treatment of arrhythmias. PMID:25122512

  14. 78 FR 7394 - Foreign-Trade Zone 41-Milwaukee, WI; Notification of Proposed Production Activity; CNH America...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-01

    ... Foreign-Trade Zones Board Foreign-Trade Zone 41--Milwaukee, WI; Notification of Proposed Production... conforming to the requirements of the regulations of the Foreign Trade-Zones Board (the Board) (15 CFR 400.22..., Foreign-Trade Zones Board, Room 21013, U.S. Department of Commerce, 1401 Constitution Avenue...

  15. Density Functional Theory Study of Oxygen Reduction Activity on Ultrathin Platinum Nanotubes

    SciTech Connect

    Matanovic, Ivana; Kent, Paul; Garzon, Fernando; Henson, Neil J.

    2012-07-13

    The structure, stability, and catalytic activity of a number of single- and double-wall platinum (n,m) nanotubes ranging in diameter from 0.3 to 2.0 nm were studied using plane-wave based density functional theory in the gas phase and water environment. The change in the catalytic activity toward the oxygen reduction reaction (ORR) with the size and chirality of the nanotube was studied by calculating equilibrium adsorption potentials for ORR intermediates and by constructing free energy diagrams in the ORR dissociative mechanism network. In addition, the stability of the platinum nanotubes is investigated in terms of electrochemical dissolution potentials and by determining the most stable state of the material as a function of pH and potential, as represented in Pourbaix diagrams. Our results show that the catalytic activity and the stability toward electrochemical dissolution depend greatly on the diameter and chirality of the nanotube. On the basis of the estimated overpotentials for ORR, we conclude that smaller, approximately 0.5 nm in diameter single-wall platinum nanotubes consistently show a huge, up to 400 mV larger overpotential than platinum, indicating very poor catalytic activity toward ORR. This is the result of substantial structural changes induced by the adsorption of any chemical species on these tubes. Single-wall n = m platinum nanotubes with a diameter larger than 1 nm have smaller ORR overpotentials than bulk platinum for up to 180 mV and thus show improved catalytic activity relative to bulk. We also predict that these nanotubes can endure the highest cell potentials but dissolution potentials are still for 110 mV lower than for the bulk, indicating a possible corrosion problem.

  16. San Jacinto Fault Zone guided waves: A discrimination for recently active fault strands near Anza, California

    NASA Astrophysics Data System (ADS)

    Li, Yong-Gang; Aki, Keiiti; Vernon, Frank L.

    1997-06-01

    We deployed three 350-m-long eight-element linear seismic arrays in the San Jacinto Fault Zone (SJFZ) near Anza, California, to record microearthquakes starting in August through December 1995. Two arrays were deployed 18 km northwest of Anza, across the Casa Loma fault (CLF) and the Hot Springs fault (HSF) strands of the SJFZ. The third array was deployed across the San Jacinto fault (SJF) in the Anza slip gap. We observed fault zone guided waves characterized by low-frequency, large amplitudes following S waves at the CLF array and the SJF array for earthquakes occurring within the fault zone. However, we did not observe guided waves at the HSF array for any events. The amplitude spectra of these guided waves showed peaks at 4 Hz at the CLF and 6 Hz at the SJF, which decreased sharply with the distance from the fault trace. In contrast, no spectral peaks at frequency lower than 6 Hz were registered at the HSF array. We used a finite difference method to simulate these guided modes as 5 waves trapped in a low-velocity waveguide sandwiched between high-velocity wall rocks. The guided mode data are adequately fit by a waveguide on the CLF with the average width of 120 m and S velocity of 2.5 km/s, about 25% reduced from the S velocity of the surrounding rock; this waveguide becomes 40 to 60 m wide with the 5 velocity of 2.8 km/s in the Anza slip gap. On the other hand, there is not a continuous waveguide on the HSF at depth. Locations of the events with guided modes suggest that the fault plane waveguide extends along the CLF between the towns of San Jacinto and Anza, dipping northeastward at 75°-80° to a depth of about 18 km; it becomes nearly vertical in the Anza gap. We speculate that the existence of a continuous low-velocity waveguide on the CLF can be caused by the rupture of the magnitude 6.9 earthquake on April 21, 1918, occurring near the towns of San Jacinto and Hemet. Further, the lack of a clear waveguide on the HSF suggests that it was not ruptured in

  17. Analysis of the activity pattern of volcanoes through self-organized crack networks: The effect of density barriers—An application to Vesuvius activity in the period 1631-1944

    NASA Astrophysics Data System (ADS)

    Piegari, E.; Di Maio, R.; Scandone, R.

    2013-06-01

    We simulated the pattern of activity of a strato-volcano by using a cellular automaton model where magma is allowed to ascend to the surface through self-organized crack networks. Magma rises toward the surface by filling connected paths of fractures until the magma's density is less than that of surrounding rocks. If magma enters a region with negative or neutral buoyancy, it cools and solidifies; as a result, the local density profile is modified, and magmatic dikes are formed. We simulated the temporal evolution of high-density pathways of dikes that magma may eventually utilize to reach the surface. We showed that if a shallow neutral-negative buoyancy zone is restored after eruptions, due to, for example, piecemeal or chaotic collapses, a characteristic timescale appears in the inter-event repose time distribution. Such characteristic repose time represents the average time that magma takes to form a high-density pathway through the less dense rock layer, and it may give a hint to predict possible eruptive scenarios. Even if the model includes many simplifying assumptions in the definition of magma-rock interaction, the results obtained from simulations are consistent with the eruptive behavior of the Mt. Somma-Vesuvius volcano for the 1631-1944 period.

  18. Photogrammetry surveys and mosaic: a useful tool to monitor active zones. Applications to the Indonesian Lusi eruption site.

    NASA Astrophysics Data System (ADS)

    Romeo, Giovanni; Di Stefano, Giuseppe; Mazzini, Adriano; Iarocci, Alessandro; Caramelli, Antonio

    2016-04-01

    Unmanned and remotely operated aircraft showed to be an efficient and cost effective way to explore remote or extreme environments. Comparative photogrammetry studies are an efficient way to study and monitor he evolution of geologically active areas and ongoing events and are able to highlight details that are typically lost during traditional field campaigns. The Lusi mud eruption in eastern Java (Indonesia) represents one of the most spectacular geological phenomena that is ongoing since May 2006. In the framework of the Lusi Lab project (ERC grant n° 308126) we designed and constructed a multipurpose drone to survey the eruption site. Among the numerous other payloads, the Lusi drone is equipped with Olympus EPM-2 and Go-Pro Hero3 cameras that allow the operator to collect video stills, high quality pictures and to complete photogrammetry surveys. Targeted areas have been selected for detailed studies in the 7 km2 region inside the embankment that was prevent the mud burial of the settlements in the Sidoarjo Regency. The region is characterized by the presence of the Watukosek fault zone. This strike slip system originates from the Arjuno-Welirang volcanic complex and extends to the north east of the Java Island intersecting the Lusi crater. Therefore of particular interest are the faulted surveyed areas present around the Lusi crater inside the embankment. Results reveal a surprising accuracy for the collected mosaic. Multiple surveys are able to reveal the changes and the evolution of the fault through time and to indicate more active zones. In particular this type of survey can highlight the weakness zones and is thus useful to prevent potential geohazards in the area. The poster shows the aerial survey results, including a 3d-printed slice of LuSi, obtained combining 2500 16 Mp photographs. A 3d zoomed detail is also shown, evidencing the resolution that this technique can offer.

  19. Traumatic Brain Injury Activation of the Adult Subventricular Zone Neurogenic Niche

    PubMed Central

    Chang, Eun Hyuk; Adorjan, Istvan; Mundim, Mayara V.; Sun, Bin; Dizon, Maria L. V.; Szele, Francis G.

    2016-01-01

    Traumatic brain injury (TBI) is common in both civilian and military life, placing a large burden on survivors and society. However, with the recognition of neural stem cells in adult mammals, including humans, came the possibility to harness these cells for repair of damaged brain, whereas previously this was thought to be impossible. In this review, we focus on the rodent adult subventricular zone (SVZ), an important neurogenic niche within the mature brain in which neural stem cells continue to reside. We review how the SVZ is perturbed following various animal TBI models with regards to cell proliferation, emigration, survival, and differentiation, and we review specific molecules involved in these processes. Together, this information suggests next steps in attempting to translate knowledge from TBI animal models into human therapies for TBI. PMID:27531972

  20. Mapping bathymetry in an active surf zone with the WorldView2 multispectral satellite

    NASA Astrophysics Data System (ADS)

    Trimble, S. M.; Houser, C.; Brander, R.; Chirico, P.

    2015-12-01

    Rip currents are strong, narrow seaward flows of water that originate in the surf zones of many global beaches. They are related to hundreds of international drownings each year, but exact numbers are difficult to calculate due to logistical difficulties in obtaining accurate incident reports. Annual average rip current fatalities are estimated to be ~100, 53 and 21 in the United States (US), Costa Rica, and Australia respectively. Current warning systems (e.g. National Weather Service) do not account for fine resolution nearshore bathymetry because it is difficult to capture. The method shown here could provide frequent, high resolution maps of nearshore bathymetry at a scale required for improved rip prediction and warning. This study demonstrates a method for mapping bathymetry in the surf zone (20m deep and less), specifically within rip channels, because rips form at topographically low spots in the bathymetry as a result of feedback amongst waves, substrate, and antecedent bathymetry. The methods employ the Digital Globe WorldView2 (WV2) multispectral satellite and field measurements of depth to generate maps of the changing bathymetry at two embayed, rip-prone beaches: Playa Cocles, Puerto Viejo de Talamanca, Costa Rica, and Bondi Beach, Sydney, Australia. WV2 has a 1.1 day pass-over rate with 1.84m ground pixel resolution of 8 bands, including 'yellow' (585-625 nm) and 'coastal blue' (400-450 nm). The data is used to classify bottom type and to map depth to the return in multiple bands. The methodology is tested at each site for algorithm consistency between dates, and again for applicability between sites.

  1. Transforming a Traditional Hands-On Activity into an Enquiry Activity to Foster More In-Depth Understanding of the Concept of Density

    ERIC Educational Resources Information Center

    Lee, Yeung Chung; Kwok, Ping Wai

    2010-01-01

    Traditional methods used to teach the concept of density that employ solid objects of different masses and volumes can be supplemented by enquiry activities in which students vary the mass-to-volume ratio of the same object to test ideas about density and flotation. A simple substance, Blu-Tack, is an ideal material to use in this case. The…

  2. Trace Hydrophobic Organic Chemicals Present in Pennsylvania Groundwater are Correlated with Geogenic Brines rather than Hydraulic Fracturing Active Zones

    NASA Astrophysics Data System (ADS)

    Drollette, B.; Shregglman, K.; D'Ambro, E.; Elsner, M.; Warner, N. R.; O'Connor, M.; Karatum, O.; Vengosh, A.; Jackson, R. B.; Darrah, T.; Plata, D.

    2014-12-01

    Recent studies demonstrated that deep Marcellus shale brines migrate into shallow groundwater aquifers, presumably via fractures in the subsurface that exist independent of any gas extraction activities. However, whereas many inorganic species are conservative tracers, hydrophobic organic compounds are both sorptive and reactive, and geogenic organic chemicals may not survive transport from deep shales to the subsurface. Here, 40 shallow groundwater samples from private wells in Northeastern Pennsylvania were analyzed for volatile organic compounds (VOCs) and gasoline range organic compounds (GRO), and 17 were analyzed for VOCs, GRO, and diesel range organic compounds (DRO). BTEX compounds (i.e., benzene, toluene, ethylbenzene, and xylenes) were detected in 6 of 40 samples at concentrations orders of magnitude below EPA maximum contaminant levels (e.g., << 5 ppb) and did not spatially correlate with distance to the nearest active hydraulic fracturing well. GRO was detected in 10 of 40 samples at concentrations as high as 8.8 ± 0.4 ppb and did not correlate with distance to the nearest hydraulic fracturing well (p = 0.24) nor in active fracturing zones, which we defined as sample locations less than 1 km from a well (p = 0.60). However, GRO was strongly correlated (p = 0.004) with shallow groundwater with Marcellus Shale inorganic chemical character, as delineated by inorganic chemical analysis. DRO was detected in all 17 samples up to 158 ± 4 ppb and did not spatially correlate with distance to the nearest hydraulic fracturing well (p = 0.74), nor active zones (p = 0.61). Similar to GRO, DRO did correlate with shallow groundwater containing Marcellus Shale character with moderate significance (p = 0.08). These results indicate that: (a) hydrophobic organic chemicals can survive transport from the deep subsurface to shallow groundwaters, and (b) transport of these compounds is not detectably enhanced by hydraulic fracturing activities in Northeastern PA as of the

  3. Characterization of Ichthyocidal Activity of Pfiesteria piscicida: Dependence on the Dinospore Cell Density

    PubMed Central

    Drgon, Tomás; Saito, Keiko; Gillevet, Patrick M.; Sikaroodi, Masoumeh; Whitaker, Brent; Krupatkina, Danara N.; Argemi, Federico; Vasta, Gerardo R.

    2005-01-01

    The ichthyocidal activity of Pfiesteria piscicida dinospores was examined in an aquarium bioassay format by exposing fish to either Pfiesteria-containing environmental sediments or clonal P. piscicida. The presence of Pfiesteria spp. and the complexity of the microbial assemblage in the bioassay were assessed by molecular approaches. Cell-free water from bioassays that yielded significant fish mortality failed to show ichthyocidal activity. Histopathological examination of moribund and dead fish failed to reveal the skin lesions reported elsewhere. Fish larvae within “cages” of variable mesh sizes were killed in those where the pore size exceeded that of Pfiesteria dinospores. In vitro exposure of fish larvae to clonal P. piscicida indicated that fish mortality was directly proportional to the dinospore cell density. Dinospores clustered around the mouth, eyes, and operculi, suggesting that fish health may be affected by their direct interaction with skin, gill epithelia, or mucous surfaces. Molecular fingerprinting revealed the presence of a very diverse microbial community of bacteria, protists, and fungi within bioassay aquaria containing environmental sediments. Some components of the microbial community were identified as potential fish pathogens, preventing the rigorous identification of Pfiesteria spp. as the only cause of fish death. In summary, our results strongly suggest (i) that this aquarium bioassay format, which has been extensively reported in the literature, is unsuitable to accurately assess the ichthyocidal activity of Pfiesteria spp. and (ii) that the ichthyocidal activity of Pfiesteria spp. is mostly due to direct interactions of the zoospores with fish skin and gill epithelia rather than to soluble factors. PMID:15640229

  4. Safety Zones

    EPA Pesticide Factsheets

    These are established primarily to reduce the accidental spread of hazardous substances by workers or equipment from contaminated areas to clean areas. They include the exclusion (hot) zone, contamination reduction (warm) zone, and support (cold) zone.

  5. A structured three-dimensional polymer electrolyte with enlarged active reaction zone for Li–O2 batteries

    PubMed Central

    Bonnet-Mercier, Nadège; Wong, Raymond A.; Thomas, Morgan L.; Dutta, Arghya; Yamanaka, Keisuke; Yogi, Chihiro; Ohta, Toshiaki; Byon, Hye Ryung

    2014-01-01

    The application of conventional solid polymer electrolyte (SPE) to lithium-oxygen (Li–O2) batteries has suffered from a limited active reaction zone due to thick SPE and subsequent lack of O2 gas diffusion route in the positive electrode. Here we present a new design for a three-dimensional (3-D) SPE structure, incorporating a carbon nanotube (CNT) electrode, adapted for a gas-based energy storage system. The void spaces in the porous CNT/SPE film allow an increased depth of diffusion of O2 gas, providing an enlarged active reaction zone where Li+ ions, O2 gas, and electrons can interact. Furthermore, the thin SPE layer along the CNT, forming the core/shell nanostructure, aids in the smooth electron transfer when O2 gas approaches the CNT surface. Therefore, the 3-D CNT/SPE electrode structure enhances the capacity in the SPE-based Li–O2 cell. However, intrinsic instability of poly(ethylene oxide) (PEO) of the SPE matrix to superoxide (O2·−) and high voltage gives rise to severe side reactions, convincing us of the need for development of a more stable electrolyte for use in this CNT/SPE design. PMID:25410536

  6. Presynaptic calcium channels and α3-integrins are complexed with synaptic cleft laminins, cytoskeletal elements and active zone components.

    PubMed

    Carlson, Steven S; Valdez, Gregorio; Sanes, Joshua R

    2010-11-01

    At chemical synapses, synaptic cleft components interact with elements of the nerve terminal membrane to promote differentiation and regulate function. Laminins containing the β2 subunit are key cleft components, and they act in part by binding the pore-forming subunit of a pre-synaptic voltage-gated calcium channel (Ca(v)α) (Nishimune et al. 2004). In this study, we identify Ca(v)α-associated intracellular proteins that may couple channel-anchoring to assembly or stabilization of neurotransmitter release sites called active zones. Using Ca(v)α-antibodies, we isolated a protein complex from Torpedo electric organ synapses, which resemble neuromuscular junctions but are easier to isolate in bulk. We identified 10 components of the complex: six cytoskeletal proteins (α2/β2 spectrins, plectin 1, AHNAK/desmoyokin, dystrophin, and myosin 1), two active zone components (bassoon and piccolo), synaptic laminin, and a calcium channel β subunit. Immunocytochemistry confirmed these proteins in electric organ synapses, and PCR analysis revealed their expression by developing mammalian motor neurons. Finally, we show that synaptic laminins also interact with pre-synaptic integrins containing the α3 subunit. Together with our previous finding that a distinct synaptic laminin interacts with SV2 on nerve terminals (Son et al. 2000), our results identify three paths by which synaptic cleft laminins can send developmentally important signals to nerve terminals.

  7. Bone mineral density and body composition in a myelomeningocele children population: effects of walking ability and sport activity.

    PubMed

    Ausili, E; Focarelli, B; Tabacco, F; Fortunelli, G; Caradonna, P; Massimi, L; Sigismondi, M; Salvaggio, E; Rendeli, C

    2008-01-01

    Myelomeningocele causes serious locomotor disability, osteoporosis and pathologic fractures. The aim of this study was to investigate the relationship between body composition, bone mineral density, walking ability and sport activity in myelomeningocele children. 60 patients aged between 5 and 14 yrs with myelomeningocele (22 ambulatory and 38 non-ambulatory), were studied. Fat mass and fat-free-mass were calculated by anthropometry. The bone mineral density at lumbar and femoral neck were evaluated. Bone mineral density at the lumbar and femoral neck was lower than in the normal population. In the non-ambulaty group, bone mineral density was approximately 1 SD lower than in the ambulatory one (p < 0.01). Fat mass was greater than expected but without significantly differences between walking group (mean 26%) and wheel-chair users (25%). Patients practised sport activity had a better bone mineral density and body fat compared with other patients with the same disability. Patients with myelomeningocele have decreased bone mineral density and are at higher risk of pathologic bone fractures. All subjects showed an excess of fat as percentage of body weight and are shorter than normal children. The measurement of bone mineral density may help to identify those patients at greatest risk of suffering of multiple fractures. Walk ability and sport activity, associated with the development of muscle mass, are important factors in promoting bone and body growth, to reduce the risk of obesity and of pathological fractures.

  8. Identifying active interplate and intraplate fault zones in the western Caribbean plate from seismic reflection data and the significance of the Pedro Bank fault zone in the tectonic history of the Nicaraguan Rise

    NASA Astrophysics Data System (ADS)

    Ott, B.; Mann, P.

    2015-12-01

    The offshore Nicaraguan Rise in the western Caribbean Sea is an approximately 500,000 km2 area of Precambrian to Late Cretaceous tectonic terranes that have been assembled during the Late Cretaceous formation of the Caribbean plate and include: 1) the Chortis block, a continental fragment; 2) the Great Arc of the Caribbean, a deformed Cretaceous arc, and 3) the Caribbean large igneous province formed in late Cretaceous time. Middle Eocene to Recent eastward motion of the Caribbean plate has been largely controlled by strike-slip faulting along the northern Caribbean plate boundary zone that bounds the northern margin of the Nicaraguan Rise. These faults reactivate older rift structures near the island of Jamaica and form the transtensional basins of the Honduran Borderlands near Honduras. Recent GPS studies suggest that small amount of intraplate motion within the current margin of error of GPS measurements (1-3 mm/yr) may occur within the center of the western Caribbean plate at the Pedro Bank fault zone and Hess Escarpment. This study uses a database of over 54,000 km of modern and vintage 2D seismic data, combined with earthquake data and results from previous GPS studies to define the active areas of inter- and intraplate fault zones in the western Caribbean. Intraplate deformation occurs along the 700-km-long Pedro Bank fault zone that traverses the center of the Nicaraguan Rise and reactivates the paleo suture zone between the Great Arc of the Caribbean and the Caribbean large igneous province. The Pedro Bank fault zone also drives active extension at the 200-km-long San Andres rift along the southwest margin of the Nicaraguan Rise. Influence of the Cocos Ridge indentor may be contributing to reactivation of faulting along the southwesternmost, active segment of the Hess Escarpment.

  9. Is the peptide bond formation activated by Cu(2+) interactions? Insights from density functional calculations.

    PubMed

    Rimola, A; Rodríguez-Santiago, L; Ugliengo, P; Sodupe, M

    2007-05-24

    The catalytic role that Cu(2+) cations play in the peptide bond formation has been addressed by means of density functional calculations. First, the Cu(2+)-(glycine)2 --> Cu(2+)-(glycylglycine) + H2O reaction was investigated since mass spectrometry low collision activated dissociation (CAD) spectra of Cu(2+)-(glycine)2 led to the elimination of a water molecule, which suggested that an intracomplex peptide bond formation might have occurred. Results show that this intracomplex condensation is associated to a very high free energy barrier (97 kcal mol(-1)) and reaction free energy (66 kcal mol(-1)) because of the loss of metal coordination during the reaction. Second, on the basis of the salt-induced peptide formation theory, the condensation reaction between two glycines was studied in aqueous solution using discrete water molecules and the conductor polarized continuum model (CPCM) continuous method. It is found that the synergy between the interaction of glycines with Cu(2+) and the presence of water molecules acting as proton-transfer helpers significantly lower the activation barrier (from 55 kcal/mol for the uncatalyzed system to 20 kcal/mol for the Cu(2+) solvated system) which largely favors the formation of the peptide bond.

  10. Absolute Power Spectral Density Changes in the Magnetoencephalographic Activity During the Transition from Childhood to Adulthood.

    PubMed

    Gómez, Carlos M; Rodríguez-Martínez, Elena I; Fernández, Alberto; Maestú, Fernando; Poza, Jesús; Gómez, Carlos

    2017-01-01

    The aim of this study was to define the pattern of reduction in absolute power spectral density (PSD) of magnetoencephalography (MEG) signals throughout development. Specifically, we wanted to explore whether the human skull's high permeability for electromagnetic fields would allow us to question whether the pattern of absolute PSD reduction observed in the human electroencephalogram is due to an increase in the skull's resistive properties with age. Furthermore, the topography of the MEG signals during maturation was explored, providing additional insights about the areas and brain rhythms related to late maturation in the human brain. To attain these goals, spontaneous MEG activity was recorded from 148 sensors in a sample of 59 subjects divided into three age groups: children/adolescents (7-14 years), young adults (17-20 years) and adults (21-26 years). Statistical testing was carried out by means of an analysis of variance (ANOVA), with "age group" as between-subject factor and "sensor group" as within-subject factor. Additionally, correlations of absolute PSD with age were computed to assess the influence of age on the spectral content of MEG signals. Results showed a broadband PSD decrease in frontal areas, which suggests the late maturation of this region, but also a mild increase in high frequency PSD with age in posterior areas. These findings suggest that the intensity of the neural sources during spontaneous brain activity decreases with age, which may be related to synaptic pruning.

  11. Muscle mitochondrial density after exhaustive exercise in dogs - Prolonged restricted activity and retraining

    NASA Technical Reports Server (NTRS)

    Nazar, K.; Greenleaf, J. E.; Philpott, D.; Pohoska, E.; Olszewska, K.; Kaciuba-Uscilko, H.

    1993-01-01

    The effect of exhaustive treadmill exercise on mitochondrial density (MD) and ultrastructural changes in quadriceps femoris muscle was studied in 7 normal, healthy, male mongrel dogs before and after restricted activity (RA) and following a subsequent 2-month exercise retraining period. Mean time to exhaustion in the 2-month group decreased from 177 +/- 11 min before to 90 +/- 16 min after RA; retraining increased tolerance to 219 +/- 36 min above the pre-RA and 143 percent above the post-RA time. Post-RA exhaustion time in the 5-months group was 25 and 45 min. Muscle samples taken after RA showed abnormalities indicative of degeneration, which were reversed by retraining. Resting MD decreased from a control level of 27.8 percent to 14.7 percent and 16.3 percent, and was restored to 27.1 percent after retraining. Exhaustive exercise caused an increase in MD under control conditions and after RA, but not following retraining. Disruption of mitochondria after exercise was evident after 5-month confinement. Factors causing mitochondrial changes and eventually their disruption during exercise after restricted activity are not related as much to the state of fatigue as to the pre-exercise quality of the muscle modified by disease or training.

  12. T-cell activation: A queuing theory analysis at low agonist density.

    PubMed

    Wedagedera, J R; Burroughs, N J

    2006-09-01

    We analyze a simple linear triggering model of the T-cell receptor (TCR) within the framework of queuing theory, in which TCRs enter the queue upon full activation and exit by downregulation. We fit our model to four experimentally characterized threshold activation criteria and analyze their specificity and sensitivity: the initial calcium spike, cytotoxicity, immunological synapse formation, and cytokine secretion. Specificity characteristics improve as the time window for detection increases, saturating for time periods on the timescale of downregulation; thus, the calcium spike (30 s) has low specificity but a sensitivity to single-peptide MHC ligands, while the cytokine threshold (1 h) can distinguish ligands with a 30% variation in the complex lifetime. However, a robustness analysis shows that these properties are degraded when the queue parameters are subject to variation-for example, under stochasticity in the ligand number in the cell-cell interface and population variation in the cellular threshold. A time integration of the queue over a period of hours is shown to be able to control parameter noise efficiently for realistic parameter values when integrated over sufficiently long time periods (hours), the discrimination characteristics being determined by the TCR signal cascade kinetics (a kinetic proofreading scheme). Therefore, through a combination of thresholds and signal integration, a T cell can be responsive to low ligand density and specific to agonist quality. We suggest that multiple threshold mechanisms are employed to establish the conditions for efficient signal integration, i.e., coordinate the formation of a stable contact interface.

  13. A new active Li-Mn-O compound for high energy density Li-ion batteries.

    PubMed

    Freire, M; Kosova, N V; Jordy, C; Chateigner, D; Lebedev, O I; Maignan, A; Pralong, V

    2016-02-01

    The search for new materials that could improve the energy density of Li-ion batteries is one of today's most challenging issues. Many families of transition metal oxides as well as transition metal polyanionic frameworks have been proposed during the past twenty years. Among them, manganese oxides, such as the LiMn2O4 spinel or the overlithiated oxide Li[Li1/3Mn2/3]O2, have been intensively studied owing to the low toxicity of manganese-based materials and the high redox potential of the Mn(3+)/Mn(4+) couple. In this work, we report on a new electrochemically active compound with the 'Li4Mn2O5' composition, prepared by direct mechanochemical synthesis at room temperature. This rock-salt-type nanostructured material shows a discharge capacity of 355 mAh g(-1), which is the highest yet reported among the known lithium manganese oxide electrode materials. According to the magnetic measurements, this exceptional capacity results from the electrochemical activity of the Mn(3+)/Mn(4+) and O(2-)/O(-) redox couples, and, importantly, of the Mn(4+)/Mn(5+) couple also.

  14. A new active Li-Mn-O compound for high energy density Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Freire, M.; Kosova, N. V.; Jordy, C.; Chateigner, D.; Lebedev, O. I.; Maignan, A.; Pralong, V.

    2016-02-01

    The search for new materials that could improve the energy density of Li-ion batteries is one of today’s most challenging issues. Many families of transition metal oxides as well as transition metal polyanionic frameworks have been proposed during the past twenty years. Among them, manganese oxides, such as the LiMn2O4 spinel or the overlithiated oxide Li[Li1/3Mn2/3]O2, have been intensively studied owing to the low toxicity of manganese-based materials and the high redox potential of the Mn3+/Mn4+ couple. In this work, we report on a new electrochemically active compound with the `Li4Mn2O5’ composition, prepared by direct mechanochemical synthesis at room temperature. This rock-salt-type nanostructured material shows a discharge capacity of 355 mAh g-1, which is the highest yet reported among the known lithium manganese oxide electrode materials. According to the magnetic measurements, this exceptional capacity results from the electrochemical activity of the Mn3+/Mn4+ and O2-/O- redox couples, and, importantly, of the Mn4+/Mn5+ couple also.

  15. Fmrp Interacts with Adar and Regulates RNA Editing, Synaptic Density and Locomotor Activity in Zebrafish

    PubMed Central

    Porath, Hagit T.; Barak, Michal; Pinto, Yishay; Wachtel, Chaim; Zilberberg, Alona; Lerer-Goldshtein, Tali; Efroni, Sol; Levanon, Erez Y.; Appelbaum, Lior

    2015-01-01

    Fragile X syndrome (FXS) is the most frequent inherited form of mental retardation. The cause for this X-linked disorder is the silencing of the fragile X mental retardation 1 (fmr1) gene and the absence of the fragile X mental retardation protein (Fmrp). The RNA-binding protein Fmrp represses protein translation, particularly in synapses. In Drosophila, Fmrp interacts with the adenosine deaminase acting on RNA (Adar) enzymes. Adar enzymes convert adenosine to inosine (A-to-I) and modify the sequence of RNA transcripts. Utilizing the fmr1 zebrafish mutant (fmr1-/-), we studied Fmrp-dependent neuronal circuit formation, behavior, and Adar-mediated RNA editing. By combining behavior analyses and live imaging of single axons and synapses, we showed hyperlocomotor activity, as well as increased axonal branching and synaptic density, in fmr1-/- larvae. We identified thousands of clustered RNA editing sites in the zebrafish transcriptome and showed that Fmrp biochemically interacts with the Adar2a protein. The expression levels of the adar genes and Adar2 protein increased in fmr1-/- zebrafish. Microfluidic-based multiplex PCR coupled with deep sequencing showed a mild increase in A-to-I RNA editing levels in evolutionarily conserved neuronal and synaptic Adar-targets in fmr1-/- larvae. These findings suggest that loss of Fmrp results in increased Adar-mediated RNA editing activity on target-specific RNAs, which, in turn, might alter neuronal circuit formation and behavior in FXS. PMID:26637167

  16. Neural Stem Cells in the Adult Subventricular Zone Oxidize Fatty Acids to Produce Energy and Support Neurogenic Activity.

    PubMed

    Stoll, Elizabeth A; Makin, Rebecca; Sweet, Ian R; Trevelyan, Andrew J; Miwa, Satomi; Horner, Philip J; Turnbull, Douglass M

    2015-07-01

    Neural activity is tightly coupled to energy consumption, particularly sugars such as glucose. However, we find that, unlike mature neurons and astrocytes, neural stem/progenitor cells (NSPCs) do not require glucose to sustain aerobic respiration. NSPCs within the adult subventricular zone (SVZ) express enzymes required for fatty acid oxidation and show sustained increases in oxygen consumption upon treatment with a polyunsaturated fatty acid. NSPCs also demonstrate sustained decreases in oxygen consumption upon treatment with etomoxir, an inhibitor of fatty acid oxidation. In addition, etomoxir decreases the proliferation of SVZ NSPCs without affecting cellular survival. Finally, higher levels of neurogenesis can be achieved in aged mice by ectopically expressing proliferator-activated receptor gamma coactivator 1 alpha (PGC1α), a factor that increases cellular aerobic capacity by promoting mitochondrial biogenesis and metabolic gene transcription. Regulation of metabolic fuel availability could prove a powerful tool in promoting or limiting cellular proliferation in the central nervous system. Stem Cells 2015;33:2306-2319.

  17. Kinetic Monte Carlo study of activated states and correlated shear-transformation-zone activity during the deformation of an amorphous metal

    NASA Astrophysics Data System (ADS)

    Homer, Eric R.; Rodney, David; Schuh, Christopher A.

    2010-02-01

    Shear transformation zone (STZ) dynamics simulations, which are based on the kinetic Monte Carlo algorithm, are used to model the mechanical response of amorphous metals and provide insight into the collective aspects of the microscopic events underlying deformation. The present analysis details the activated states of STZs in such a model, as well as the statistics of their activation and how these are affected by imposed conditions of stress and temperature. The analysis sheds light on the spatial and temporal correlations between the individual STZ activations that lead to different macroscopic modes of deformation. Three basic STZ correlation behaviors are observed: uncorrelated activity, nearest-neighbor correlation, and self-reactivating STZs. These three behaviors correspond well with the macroscopic deformation modes of homogeneous flow, inhomogeneous deformation, and elastic behavior, respectively. The effect of pre-existing stresses in the simulation cell is also studied and found to have a homogenizing effect on STZ correlations, suppressing the tendency for localization.

  18. 78 FR 48647 - Foreign-Trade Zone 225-Springfield, Missouri; Authorization of Production Activity; General...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-09

    ... Activity; General Dynamics Ordnance and Tactical Systems Munitions Services (Demilitarization of Munitions... Dynamics Ordnance and Tactical Systems Munitions Services, within Site 3 of FTZ 225, in Carthage,...

  19. Linking mantle dynamics, plate tectonics and surface processes in the active plate boundary zones of eastern New Guinea (Invited)

    NASA Astrophysics Data System (ADS)

    Baldwin, S.; Moucha, R.; Fitzgerald, P. G.; Hoke, G. D.; Bermudez, M. A.; Webb, L. E.; Braun, J.; Rowley, D. B.; Insel, N.; Abers, G. A.; Wallace, L. M.; Vervoort, J. D.

    2013-12-01

    Eastern New Guinea lies within the rapidly obliquely converging Australian (AUS)- Pacific (PAC) plate boundary zone and is characterized by transient plate boundaries, rapidly rotating microplates and a globally significant geoid high. As the AUS plate moved northward in the Cenozoic, its leading edge has been a zone of subduction and arc accretion. The variety of tectonic settings in this region permits assessment of the complex interplay among mantle dynamics, plate tectonics, and surface processes. Importantly, the timescale of tectonic events (e.g., subduction, (U)HP exhumation, seafloor spreading) are within the valid bounds of mantle convection models. A record of changes in bathymetry and topography are preserved in high standing mountain belts, exhumed extensional gneiss domes and core complexes, uplifted coral terraces, and marine sedimentary basins. Global seismic tomography models indicate accumulation of subducted slabs beneath eastern New Guinea at the bottom of the upper mantle (i.e., <660km depth). Some of the deeply subducted material may indeed be buoyant subducted AUS continental margin (to depths of ~250-300 km), as well as subducted continental material that has reached the point of no return (i.e., > 250-300 km). Preliminary global-scale backward advected mantle convection models, driven by density inferred from joint seismic-geodynamic tomography models, exhibit large-scale flow associated with these subducted slab remnants and predict the timing and magnitude (up to 1500 m) of dynamic topography change (both subsidence and uplift) since the Oligocene. In this talk we will explore the effects of large-scale background mantle flow and plate tectonics on the evolution of topography and bathymetry in eastern New Guinea, and discuss possible mechanisms to explain basin subsidence and surface uplift in the region.

  20. Methylcholine-activated eccrine sweat gland density and output as a function of age.

    PubMed

    Kenney, W L; Fowler, S R

    1988-09-01

    The purpose of this investigation was to examine eccrine sweat gland responsiveness to intradermal injections of methylcholine (MCh) across three age groups of men [young (Y) = 22-24; middle (M) = 33-40; older (O) = 58-67 yr old, n = 5 per group]. Subjects were matched with respect to maximum O2 consumption, body size, and body composition, and were thoroughly heat acclimated before participation. Randomly ordered concentrations of acetyl-beta-methylcholine chloride ranging from 0% (saline) to 0.1% (5 x 10(-3) M) were injected into the skin of the dorsal thigh in a thermoneutral environment, and activated sweat glands were photographed at 30-s intervals for the next 8 min. Density of MCh-activated glands was independent of both age and [MCh] (e.g., 2 min after injection of 5 x 10(-3) M [MCh]: Y = 45 +/- 7, M = 46 +/- 12, O = 42 +/- 5 glands/cm2). However, sweat gland output (SGO) per active gland was significantly lower for the O group and failed to increase with increasing [MCh] above 5 x 10(-4) M. When MCh (5 x 10(-3) M) was injected after 1 h of exercise in the heat, higher SGO's were elicited in each group; however, the SGO of the O group was again significantly lower than that of the Y group (91 +/- 11 vs. 39 +/- 4 ng/gland, P less than 0.02) with the M group intermediate (69 +/- 11 nl/gland; 2 min postinjection data).(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Carbon dioxide activation and dissociation on ceria (110): a density functional theory study.

    PubMed

    Cheng, Zhuo; Sherman, Brent J; Lo, Cynthia S

    2013-01-07

    Ceria (CeO(2)) is a promising catalyst for the reduction of carbon dioxide (CO(2)) to liquid fuels and commodity chemicals, in part because of its high oxygen storage capacity, yet the fundamentals of CO(2) adsorption, activation, and reduction on ceria surfaces remain largely unknown. We use density functional theory, corrected for onsite Coulombic interactions (GGA+U), to explore various adsorption sites and configurations for CO(2) on stoichiometric and reduced ceria (110), the latter with either an in-plane oxygen vacancy or a split oxygen vacancy. We find that CO(2) adsorption on both reduced ceria (110) surfaces is thermodynamically favored over the corresponding adsorption on stoichiometric ceria (110), but the most stable adsorption configuration consists of CO(2) adsorbed parallel to the reduced ceria (110) surface at a split oxygen vacancy. Structural changes in the CO(2) molecule are also observed upon adsorption. At the split vacancy, the molecule bends out of plane to form a unidentate carbonate with the remaining oxygen anion at the surface; this is in stark contrast to the bridged carbonate observed for CO(2) adsorption at the in-plane vacancy. Also, we analyze the pathways for CO(2) conversion to CO on reduced ceria (110). The subtle difference in the energies of activation for the elementary steps suggest that CO(2) dissociation is favored on the split vacancy, while the reverse process of CO oxidation may favor the formation of the in-plane vacancy. We thus show how the structure and properties of the ceria catalyst govern the mechanism of CO(2) activation and reduction.

  2. Structure of the active rift zone and margins of the northern Imperial Valley from Salton Seismic Imaging Project (SSIP) data

    NASA Astrophysics Data System (ADS)

    Livers, A.; Han, L.; Delph, J. R.; White-Gaynor, A. L.; Petit, R.; Hole, J. A.; Stock, J. M.; Fuis, G. S.

    2012-12-01

    First-arrival refraction data were used to create a seismic velocity model of the upper crust across the actively rifting northern Imperial Valley and its margins. The densely sampled seismic refraction data were acquired by the Salton Seismic Imaging Project (SSIP) , which is investigating rift processes in the northern-most rift segment of the Gulf of California extensional province and earthquake hazards at the southern end of the San Andreas Fault system. A 95-km long seismic line was acquired across the northern Imperial Valley, through the Salton Sea geothermal field, parallel to the five Salton Butte volcanoes and perpendicular to the Brawley Seismic Zone and major strike-slip faults. Nineteen explosive shots were recorded with 100 m seismometer spacing across the valley and with 300-500 m spacing into the adjacent ranges. First-arrival travel times were picked from shot gathers along this line and a seismic velocity model was produced using tomographic inversion. Sedimentary basement and seismic basement in the valley are interpreted to be sediment metamorphosed by the very high heat flow. The velocity model shows that this basement to the west of the Brawley Seismic Zone is at ~4-km depth. The basement shallows to ~2-km depth in the active geothermal field and Salton Buttes volcanic field which locally coincide with the Brawley Seismic Zone. At the eastern edge of the geothermal field, the basement drops off again to ~3.5-km depth. The eastern edge of the valley appears to be fault bounded by the along-strike extension of the Sand Hills Fault, an inactive strike-slip fault. The seismic velocities to the east of the fault correspond to metamorphic rock of the Chocolate Mountains, different from the metamorphosed basement in the valley. The western edge of the valley appears to be fault bounded by the active Superstition Hills Fault. To the west of the valley, >4-km deep valley basement extends to the active Superstition Hills Fault. Basement then shallows

  3. Defect recombination induced by density-activated carrier diffusion in nonpolar InGaN quantum wells

    NASA Astrophysics Data System (ADS)

    Yang, Fan; Zhang, Chunfeng; Shi, Chentian; Joo Park, Min; Seop Kwak, Joon; Jung, Sukkoo; Choi, Yoon-Ho; Wu, Xuewei; Wang, Xiaoyong; Xiao, Min

    2013-09-01

    We report on the observation of carrier-diffusion-induced defect emission at high excitation density in a-plane InGaN single quantum wells. When increasing excitation density in a relatively high regime, we observed the emergence of defect-related emission together with a significant efficiency reduction of bandedge emission. The experimental results can be well explained with the density-activated carrier diffusion from localized states to defect states. Such a scenario of density-activated defect recombination, as confirmed by the dependences of photoluminescence on the excitation photon energy and temperature, is a plausible origin of efficiency droop in a-plane InGaN quantum-well light-emitting diodes.

  4. Application of hybrid supercapacitor using granule Li4Ti5O12/activated carbon with variation of current density

    NASA Astrophysics Data System (ADS)

    Lee, Byung-Gwan; Lee, Seung-Hwan

    2017-03-01

    We report the electrochemical performance of asymmetric hybrid supercapacitors composed of granule Li4Ti5O12 as an anode and activated carbon as a cathode with different current densities. It is demonstrated that the hybrid supercapacitors show good initial discharge capacities were ranged from 39.8 to 46.4 F g-1 in the current densities range of 0.3-1 A g-1. The performance degradation is proportional to the current density due to quick gassing, resulting from H2O and HF formation. In particular, the hybrid supercapacitors show the pretty good cycling stability of 97.4%, even at the high current density of 0.8 A g-1, which are among most important performance in the real application for energy storage devices. Therefore, we believe that hybrid supercapacitors using granule Li4Ti5O12/activated carbon are eligible for the promising next generation energy devices.

  5. Online Asynchronous Threaded Discussions: Good Enough to Advance Students through the Proximal Zone of Activity Theory?

    ERIC Educational Resources Information Center

    Maurino, Paula San Millan

    2007-01-01

    This paper presents a study which involved researching student interaction and participation under the lens of Activity Theory and Social Computing. Activity Theory is a philosophical framework that integrates the objective, the sociocultural, and the ecological, while Social Computing describes any type of computing application in which software…

  6. 78 FR 22843 - Foreign-Trade Zone 33-Pittsburgh, Pennsylvania, Authorization of Export Production Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-17

    ... Production Activity, Tsudis Chocolate Company (Chocolate Confectionery Bars), Pittsburgh, Pennsylvania On December 4, 2012, Tsudis Chocolate Company, submitted a notification of proposed export production activity... liquid chocolate admitted to FTZ 33 must be re-exported. Dated: April 11, 2013. Andrew...

  7. 78 FR 79391 - Foreign-Trade Zone (FTZ) 22-Chicago, Illinois, Notification of Proposed Production Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-30

    ... Production Activity, Electrolux Home Care Products Inc., (Kitting of Home Care Products), Minooka, Illinois... production activity to the FTZ Board on behalf of Electrolux Home Care Products Inc. (Electrolux), located in... FTZ 22. The facility is used for the distribution and kitting of floor care and other small...

  8. 78 FR 39707 - Foreign-Trade Zone (FTZ) 32-Miami, Florida; Notification of Proposed Production Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-02

    ... Activity; Brightstar Corporation; (Cell Phone Kitting); Miami, Florida The Greater Miami Chamber of... cell phones and cell phone accessories. Pursuant to 15 CFR 400.14(b), FTZ activity would be limited to... during customs entry procedures that apply to cell phones (duty rate 0%) for the foreign status...

  9. The Activity of Deep Roots in Bedrock Fractures at the Susquehanna Shale Hills Critical Zone Observatory, USA

    NASA Astrophysics Data System (ADS)

    Hasenmueller, E. A.; Gu, X.; Weitzman, J. N.; Adams, T. S.; Stinchcomb, G. E.; Eissenstat, D. M.; Brantley, S. L.; Kaye, J. P.

    2015-12-01

    Many areas in the world are characterized by shallow soils underlain by weathered bedrock, but root-rock interactions and their implications for regolith weathering are poorly understood. To test the role of tree roots in weathering bedrock, we excavated four pits along a catena in a shale-hosted catchment near the Susquehanna Shale Hills Critical Zone Observatory, USA. We measured a variety of physical and chemical properties including: (1) root density, distribution, and respiration rates, (2) soil gas, and (3) soil, rock, and rock fracture sediment elemental compositions, mineralogy, and morphology. As expected, root density declined rapidly with depth; nevertheless, roots were present in rock fractures even in the deepest, least weathered shale sampled (~ 1.8 m). Root density in the shale fractures was highest at the ridge for all depths and decreased 23-fold downslope as soils thickened and in spite of increasing rock fracture density. Root respiration rates (per gram of root) in fractures were comparable to those in augerable soil, with the highest respiration rates for all depths observed at the ridge. We only observed roots in larger shale fractures (> 50 μm) that were coated with sediment. These sediments were mineralogically and geochemically similar to overlying B and C soil horizons with respect to clay composition, total C and N, and potentially mineralizable C. Such similarities indicate that the sediment coatings are likely the result of translocation of soil particles downward into the fractures. However, concentrations of extractable inorganic N were higher in fracture sediments than in surface soils. Shale in contact with deep roots resembled unweathered parent material geochemically. In the bulk soil, depletion profiles (K, Mg, Si, Fe, and Al) relative to unweathered shale reflected characteristic weathering of illite and chlorite to kaolinite. Approximately 50% of soil K and Mg was lost as eroding particles, supporting the idea that fracture

  10. Relative Ages of the Highlands, Lowlands, and Transition Zone Along a Portion of the Mars Crustal Dichotomy from Densities of Visible and Buried Impact Craters

    NASA Technical Reports Server (NTRS)

    DeSoto, G. E.; Frey, H. V.

    2005-01-01

    Understanding the fundamental age relationships of the different parts of the Mars Crustal Dichotomy is essential to fully understanding the events that shaped the early history and formation of the surface of Mars. A dominant question is what are the true relative ages of the Northern Lowlands and the Southern Highlands? Using MOLA data from the Mars Global Surveyor and Viking visual images, a dataset of both buried and visible crater diameters was created over a nine million sq km study area of a section of the dichotomy boundary stretching from Arabia Terra to Utopia Planitia. Cumulative frequency plots on a log-log scale were used to determine the relative ages for the Highlands, the Lowlands, and the Transition Zone, separately for the visible, the buried and the combined total (visible+ buried) populations. We find the overall Highland crater population in this area is slightly older than the Lowlands, consistent with previous global studies, but the Lowlands and Transition Zone are also very old and formed at roughly the same time. It appears that the formation of the Lowlands in this region formed contemporaneously with a large-scale resurfacing event in the Highlands, perhaps caused by the process responsible for the Lowland formation.

  11. Investigating Aquatic Dead Zones

    ERIC Educational Resources Information Center

    Testa, Jeremy; Gurbisz, Cassie; Murray, Laura; Gray, William; Bosch, Jennifer; Burrell, Chris; Kemp, Michael

    2010-01-01

    This article features two engaging high school activities that include current scientific information, data, and authentic case studies. The activities address the physical, biological, and chemical processes that are associated with oxygen-depleted areas, or "dead zones," in aquatic systems. Students can explore these dead zones through both…

  12. Mechanisms of Discoordination of Contractile Activity in the Gastroduodenal Zone during Psychogenic Stress in Rabbits.

    PubMed

    Ovsyannikov, V I; Berezina, T P; Shemerovskii, K A

    2015-08-01

    Inhibition of the contractile activity of the stomach induced by psychogenic stress persisted after blockade of muscarinic and nicotinic cholinergic receptors and α2 and β1/β2-adrenergic receptors. Stress-induced increase in contractile activity in the proximal part of the duodenum persisted during blockade of muscarinic and nicotinic cholinergic receptors, β1/β2-adrenergic receptors. At the same time, blockade of the above cholinergic and adrenergic receptors eliminated the stress-induced increase in contractive activity in the distal part of the duodenum.

  13. Active crustal deformation of the El Salvador Fault Zone (ESFZ) using GPS data: Implications in seismic hazard assessment

    NASA Astrophysics Data System (ADS)

    Staller, Alejandra; Benito, Belen; Jesús Martínez-Díaz, José; Hernández, Douglas; Hernández-Rey, Román; Alonso-Henar, Jorge

    2014-05-01

    El Salvador, Central America, is part of the Chortis block in the northwestern boundary of the Caribbean plate. This block is interacting with a diffuse triple junction point with the Cocos and North American plates. Among the structures that cut the Miocene to Pleistocene volcanic deposits stands out the El Salvador Fault Zone (ESFZ): It is oriented in N90º-100ºE direction, and it is composed of several structural segments that deform Quaternary deposits with right-lateral and oblique slip motions. The ESFZ is seismically active and capable of producing earthquakes such as the February 13, 2001 with Mw 6.6 (Martínez-Díaz et al., 2004), that seriously affected the population, leaving many casualties. This structure plays an important role in the tectonics of the Chortis block, since its motion is directly related to the drift of the Caribbean plate to the east and not with the partitioning of the deformation of the Cocos subduction (here not coupled) (Álvarez-Gómez et al., 2008). Together with the volcanic arc of El Salvador, this zone constitutes a weakness area that allows the motion of forearc block toward the NW. The geometry and the degree of activity of the ESFZ are not studied enough. However their knowledge is essential to understand the seismic hazard associated to this important seismogenic structure. For this reason, since 2007 a GPS dense network was established along the ESFZ (ZFESNet) in order to obtain GPS velocity measurements which are later used to explain the nature of strain accumulation on major faults along the ESFZ. The current work aims at understanding active crustal deformation of the ESFZ through kinematic model. The results provide significant information to be included in a new estimation of seismic hazard taking into account the major structures in ESFZ.

  14. Influence of season on daytime behavioral activities of donkeys in the Northern Guinea Savanna zone of Nigeria

    PubMed Central

    ZAKARI, Friday Ocheja; AYO, Joseph Olusegun; REKWOT, Peter Ibrahim; KAWU, Mohammed Umar

    2016-01-01

    ABSTRACT The present experiment was performed with the aim of investigating the effect of season on behavioral activities of donkeys during the rainy and harmattan seasons in the Northern Guinea zone of Nigeria. Sixteen apparently healthy donkeys were used as subjects and divided into four groups based on age. During each season, behavioral activities of each donkey were evaluated for three weeks using the focal animal sampling technique. The dry-bulb temperature (DBT), relative humidity (RH), and temperature-humidity index (THI) were obtained three times each day during the experimental period using standard procedures. In the rainy season, the mean DBT (31.65 ± 0.49°C), RH (73.63 ± 1.09%), and THI (84.39 ± 0.71) were significantly (P<0.0001) higher than the corresponding values of 24.00 ± 0.44°C, 36.80 ± 0.92%, and 64.80 ± 0.62 in the harmattan season. During the rainy season, the donkeys spent 60.00 ± 0.77%, 25.40 ± 0.69%, and 2.94 ± 0.21% on grazing, resting, and grooming, respectively. During the harmattan season, the donkeys spent the most time on grazing (76.76 ± 0.43%), less time on resting (11.97 ± 0.38%), and the least time on grooming (0.89 ± 0.05%). In conclusion, season and seasonal variations affect the daytime behavioral activities of donkeys in the zone, and this should be considered in husbandry practices for donkeys. PMID:26858575

  15. Influence of season on daytime behavioral activities of donkeys in the Northern Guinea Savanna zone of Nigeria.

    PubMed

    Zakari, Friday Ocheja; Ayo, Joseph Olusegun; Rekwot, Peter Ibrahim; Kawu, Mohammed Umar

    2015-01-01

    The present experiment was performed with the aim of investigating the effect of season on behavioral activities of donkeys during the rainy and harmattan seasons in the Northern Guinea zone of Nigeria. Sixteen apparently healthy donkeys were used as subjects and divided into four groups based on age. During each season, behavioral activities of each donkey were evaluated for three weeks using the focal animal sampling technique. The dry-bulb temperature (DBT), relative humidity (RH), and temperature-humidity index (THI) were obtained three times each day during the experimental period using standard procedures. In the rainy season, the mean DBT (31.65 ± 0.49°C), RH (73.63 ± 1.09%), and THI (84.39 ± 0.71) were significantly (P<0.0001) higher than the corresponding values of 24.00 ± 0.44°C, 36.80 ± 0.92%, and 64.80 ± 0.62 in the harmattan season. During the rainy season, the donkeys spent 60.00 ± 0.77%, 25.40 ± 0.69%, and 2.94 ± 0.21% on grazing, resting, and grooming, respectively. During the harmattan season, the donkeys spent the most time on grazing (76.76 ± 0.43%), less time on resting (11.97 ± 0.38%), and the least time on grooming (0.89 ± 0.05%). In conclusion, season and seasonal variations affect the daytime behavioral activities of donkeys in the zone, and this should be considered in husbandry practices for donkeys.

  16. 78 FR 72861 - Foreign-Trade Zone (FTZ) 20-Suffolk, Virginia, Notification of Proposed Production Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-04

    ... applications. Pursuant to 15 CFR 400.14(b), FTZ activity would be limited to the specific foreign-status...; tower masts; shaped springs; shaped pipes; brackets; mufflers; stabilizer legs; locks; top covers;...

  17. 78 FR 68026 - Foreign-Trade Zone (FTZ) 99-Wilmington, Delaware, Notification of Proposed Production Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-13

    ... Production Activity, Noramco, Inc., (Pharmaceutical Intermediate), Wilmington, Delaware The Delaware Economic... Section 400.38 of the FTZ Board's regulations. The facility is used for the production of a...

  18. 77 FR 63320 - Agency Information Collection Activities: Petroleum Refineries in Foreign Trade Sub-zones

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-16

    ... SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: Petroleum Refineries... review and approval in accordance with the Paperwork Reduction Act: Petroleum Refineries in Foreign Trade... soliciting comments concerning the following information collection: Title: Petroleum Refineries in...

  19. The Presence of a Stable Block bounded by Active Zones (Mobile Belts) in the southwestern North American Proterozoic craton

    NASA Astrophysics Data System (ADS)

    Goodell, P.; Martinez P, C.; Mahar, M. A.

    2014-12-01

    Bouguer gravity data, initial Sr isotope values, zircon U-Pb, and multiple occurrences of felsic Proterozoic rocks, have revealed an elevated, less deformed, felsic cratonic block in the northern Mexico. The block is situated in western Chihuahua and is bounded by active zones or mobile belts on three sides, and is here referred to as the Western Chihuahua Cratonic Block (WCCB). Bouguer gravity data clearly indicate a region of a highly negative anomaly (< -200 mgal) in contrast to adjoining areas. The region is large and the anomaly is relatively smooth over broad areas; the WCCB appears as a smaller version of the Colorado Plateau. The block is characterized by high initial Sr isotope ratios (<0.706). Several occurrences of Proterozoic rocks are located within or next to the WCCB, and they reveal the character of the Bouguer anomaly. On the east, at Los Filtros, Proterozoic rocks crop out in a basement cored uplift interpreted to having been derived from the WCCB during the Ouachita orogeny. At Sierra La Mojina boulders of 1.1 Ga granites are found in Permian conglomerates. And at Basasiachic, xenoliths of 1.1 Ga granites are present in ash flow tuffs. Establishment of the Precambrian character of the WCCB is of importance, and these multiple occurrences are evidence. Prior studies of the Sierra Madre Occidental suggest that the region was uplifted because of a vast Cenozoic batholith presumed to lie under the SLIP (Silicic Large Igneous Province), the Upper Volcanic Series. The present study challenges that conclusion and maintains the SMO is underlain by Proterozoic silicic crust. The geology of age dated samples supports this. The WCCB is surrounded on three sides by Active Zones or Mobile Belts, which have been active extensional and translational zones periodically over a long period of time. On the east are the Paleozoic Pedrogosa Basin, Mesozoic Chihuahua Trough and Cenozoic Rio Grande Rift, the first two of which also continue around the northern border

  20. Acceleration of sinter diagenesis in an active fumarole, Taupo volcanic zone, New Zealand

    NASA Astrophysics Data System (ADS)

    Lynne, Bridget Y.; Campbell, Kathleen A.; Perry, Randall S.; Browne, P. R. L.; Moore, J. N.

    2006-09-01

    Siliceous sinters form where nearly neutral pH, alkali chloride waters discharge at the surface (≤100 °C). They may preserve biogenic and abiogenic material and therefore archive paleoenvironmental settings. Freshly precipitated sinters undergo diagenesis through a five-step series of silica mineral phase changes, from opal-A to opal-A/CT to opal-CT to opal-C to quartz. Transformation rates vary among sinters because postdepositional conditions can accelerate or retard diagenesis, meanwhile preserving or destroying biosignals. We monitored alteration and diagenesis of newly precipitated, filamentous microbe-rich sinter during a two-year field experiment, where sinter was suspended inside a fumarole at Orakei Korako, Taupo volcanic zone, New Zealand. Patchy and complex diagenesis resulted from changes in environmental conditions, including variations in temperature, pH, and the intermittent deposition of sulfur. Throughout the experiment, opal-A was dissolved by acidic steam condensate, and reprecipitated locally. Quartz crystals grew on the sinter surface within 21 weeks. Previous reports of transformation rates from opal to quartz are on the order of thousands of years in duration. Thus, our results show that fumarolic overprinting accelerates diagenesis. Microbial preservation was not favorable because primary filamentous fabrics were obscured by deposition of opal-A microspheres, smooth silica infill, and sulfur. If ancient hydrothermal systems were among the likely places where early life flourished, it is necessary to distinguish between depositional features and those inherited during diagenesis. This near real time experiment enabled observations on environmental controls of diagenetic change in silica minerals and illustrated the variability of conditions that can occur in nature during this complex process.

  1. Runx1 Activities in Superficial Zone Chondrocytes, Osteoarthritic Chondrocyte Clones and Response to Mechanical Loading

    PubMed Central

    LeBlanc, Kimberly T.; Walcott, Marie E.; Gaur, Tripti; O’Connell, Shannon L.; Basil, Kirti; Tadiri, Christina P.; Mason-Savas, April; Silva, Jason A.; van Wijnen, Andre J.; Stein, Janet L.; Stein, Gary S; Ayers, David C.; Lian, Jane B.; Fanning, Paul J.

    2015-01-01

    Objective Runx1, the hematopoietic lineage determining transcription factor, is present in perichondrium and chondrocytes. Here we addressed Runx1 functions, by examining expression in cartilage during mouse and human osteoarthritis (OA) progression and in response to mechanical loading. Methods Spared and diseased compartments in knees of OA patients and in mice with surgical destabilization of the medial meniscus were examined for changes in expression of Runx1 mRNA (Q-PCR) and protein (immunoblot, immunohistochemistry). Runx1 levels were quantified in response to static mechanical compression of bovine articular cartilage. Runx1 function was assessed by cell proliferation (Ki67, PCNA) and cell type phenotypic markers. Results Runx1 is enriched in superficial zone (SZ) chondrocytes of normal bovine, mouse, and human tissues. Increasing loading conditions in bovine cartilage revealed a positive correlation with a significant elevation of Runx1. Runx1 becomes highly expressed at the periphery of mouse OA lesions and in human OA chondrocyte ‘clones’ where Runx1 co-localizes with Vcam1, the mesenchymal stem cell (MSC) marker and lubricin (Prg4), a cartilage chondroprotective protein. These OA induced cells represent a proliferative cell population, Runx1 depletion in MPCs decreases cell growth, supporting Runx1 contribution to cell expansion. Conclusion The highest Runx1 levels in SZC of normal cartilage suggest a function that supports the unique phenotype of articular chondrocytes, reflected by upregulation under conditions of compression. We propose Runx1 co-expression with Vcam1 and lubricin in murine cell clusters and human ‘clones’ of OA cartilage, participate in a cooperative mechanism for a compensatory anabolic function. PMID:25078095

  2. The micro-architecture of mitochondria at active zones: electron tomography reveals novel anchoring scaffolds and cristae structured for high-rate metabolism.

    PubMed

    Perkins, Guy A; Tjong, Jonathan; Brown, Joshua M; Poquiz, Patrick H; Scott, Raymond T; Kolson, Douglas R; Ellisman, Mark H; Spirou, George A

    2010-01-20

    Mitochondria are integral elements of many nerve terminals. They must be appropriately positioned to regulate microdomains of Ca(2+) concentration and metabolic demand, but structures that anchor them in place have not been described. By applying the high resolution of electron tomography (ET) to the study of a central terminal, the calyx of Held, we revealed an elaborate cytoskeletal superstructure that connected a subset of mitochondria to the presynaptic membrane near active zones. This cytoskeletal network extended laterally and was well integrated into the nerve terminal cytoskeleton, which included filamentous linkages among synaptic vesicles. ET revealed novel features of inner membrane for these mitochondria. Crista structure was polarized in that crista junctions, circular openings of the inner membrane under the outer membrane, were aligned with the cytoskeletal superstructure and occurred at higher density in mitochondrial membrane facing the presynaptic membrane. These characteristics represent the first instance where a subcomponent of an organelle is shown to have a specific orientation relative to the polarized structure of a cell. The ratio of cristae to outer membrane surface area is large in these mitochondria relative to other tissues, indicating a high metabolic capacity. These observations suggest general principles for cytoskeletal anchoring of mitochondria in all tissues, reveal potential routes for nonsynaptic communication between presynaptic and postsynaptic partners using this novel cytoskeletal framework, and indicate that crista structure can be specialized for particular functions within cellular microdomains.

  3. THE FIRST HARD X-RAY POWER SPECTRAL DENSITY FUNCTIONS OF ACTIVE GALACTIC NUCLEUS

    SciTech Connect

    Shimizu, T. Taro; Mushotzky, Richard F.

    2013-06-10

    We present results of our power spectral density (PSD) analysis of 30 active galactic nuclei (AGNs) using the 58 month light curves from Swift's Burst Alert Telescope (BAT) in the 14-150 keV band. PSDs were fit using a Monte Carlo based algorithm to take into account windowing effects and measurement error. All but one source were found to be fit very well using an unbroken power law with a slope of {approx} - 1, consistent at low frequencies with previous studies in the 2-10 keV band, with no evidence of a break in the PSD. For five of the highest signal-to-noise ratio sources, we tested the energy dependence of the PSD and found no significant difference in the PSD at different energies. Unlike previous studies of X-ray variability in AGNs, we do not find any significant correlations between the hard X-ray variability and different properties of the AGN including luminosity and black hole mass. The lack of break frequencies and correlations seem to indicate that AGNs are similar to the high state of Galactic black holes.

  4. Oxidized low density lipoprotein increases acetylcholinesterase activity correlating with reactive oxygen species production.

    PubMed

    Yamchuen, Panit; Aimjongjun, Sathid; Limpeanchob, Nanteetip

    2014-12-01

    Hyperlipidemia, low density lipoproteins (LDL) and their oxidized forms, and oxidative stress are suspected to be a key combination in the onset of AD and acetylcholinesterase (AChE) plays a part in this pathology. The present study aimed to link these parameters using differentiated SH-SY5Y human neuroblastoma cells in culture. Both mildly and fully oxidized human LDL (mox- and fox-LDL), but not native (non-oxidized) LDL were cytotoxic in dose- and time-dependent patterns and this was accompanied by an increased production of intracellular reactive oxygen species (ROS). Oxidized LDL (10-200 μg/mL) augmented AChE activity after 4 and 24h treatments, respectively while the native LDL was without effect. The increased AChE with oxidized LDLs was accompanied by a proportionate increase in intracellular ROS formation (R=0.904). These findings support the notion that oxidized LDLs are cytotoxic and that their action on AChE may reduce central cholinergic transmission in AD and affirm AChE as a continued rational for anticholinesterase therapy but in conjunction with antioxidant/antihyperlipidemic cotreatments.

  5. Investigation of the density wave activity in the thermosphere above 220 KM

    NASA Astrophysics Data System (ADS)

    Illés-Almár, E.; Almár, I.; Bencze, P.

    Based on CACTUS (Capteur Accélérométrique Capacitif Triaxial Ultra Sensible) microaccelerometer measurements it has been demonstrated that - after taking into account all effects included in the MSIS'86=CIRA'86 (COSPAR, 1988) model - there are residual fluctuations in the density of the upper atmosphere much larger than that the accuracy of the measurements can account for. These fluctuations are attributed to some kind of wave activity (Illés-Almár, 1993, Illés-Almár et al. 1996a). The average deviations from a model are considered as a measure of the amplitude of the waves in the atmosphere and are analysed as a function of geomagnetic coordinates, altitude and local solar time, in order to identify possible wave sources either in the lower lying atmosphere or in the thermosphere/ionosphere system. As a first step, the present investigation intends to make a map of the wave pattern by this method.

  6. Impact Ignition of Low Density Mechanically Activated and Multilayer Foil Ni/Al

    NASA Astrophysics Data System (ADS)

    Beason, Matthew; Mason, B.; Son, Steven; Groven, Lori

    2013-06-01

    Mechanical activation (MA) via milling of reactive materials provides a means of lowering the ignition threshold of shock initiated reactions. This treatment provides a finely mixed microstructure with wide variation in the resulting scales of the intraparticle microstructure that makes model validation difficult. In this work we consider nanofoils produced through vapor deposition with well defined periodicity and a similar degree of fine scale mixing. This allows experiments that may be easier to compare with computational models. To achieve this, both equimolar Ni/Al powder that has undergone MA using high energy ball milling and nanofoils milled into a powder using low energy ball milling were used. The Asay Shear impact experiment was conducted on both MA Ni/Al and Ni/Al nanofoil-based powders at low densities (<60%) to examine their impact response and reaction behavior. Scanning electron microscopy and energy-dispersive x-ray spectroscopy were used to verify the microstructure of the materials. The materials' mechanical properties were evaluated using nano-indentation. Onset temperatures were evaluated using differential thermal analysis/differential scanning calorimetry. Impact ignition thresholds, burning rates, temperature field, and ignition delays are reported. Funding from the Defense Threat Reduction Agency (DTRA) Grant Number HDTRA1-10-1-0119. Counter-WMD basic research program, Dr. Suhithi M. Peiris, program director is gratefully acknowledged.

  7. Strain energy density gradients in bone marrow predict osteoblast and osteoclast activity: a finite element study.

    PubMed

    Webster, Duncan; Schulte, Friederike A; Lambers, Floor M; Kuhn, Gisela; Müller, Ralph

    2015-03-18

    Huiskes et al. hypothesized that mechanical strains sensed by osteocytes residing in trabecular bone dictate the magnitude of load-induced bone formation. More recently, the mechanical environment in bone marrow has also been implicated in bone׳s response to mechanical stimulation. In this study, we hypothesize that trabecular load-induced bone formation can be predicted by mechanical signals derived from an integrative µFE model, incorporating a description of both the bone and marrow phase. Using the mouse tail loading model in combination with in vivo micro-computed tomography (µCT) we tracked load induced changes in the sixth caudal vertebrae of C57BL/6 mice to quantify the amount of newly mineralized and eroded bone volumes. To identify the mechanical signals responsible for adaptation, local morphometric changes were compared to micro-finite element (µFE) models of vertebrae prior to loading. The mechanical parameters calculated were strain energy density (SED) on trabeculae at bone forming and resorbing surfaces, SED in the marrow at the boundary between bone forming and resorbing surfaces, along with SED in the trabecular bone and marrow volumes. The gradients of each parameter were also calculated. Simple regression analysis showed mean SED gradients in the trabecular bone matrix to significantly correlate with newly mineralized and eroded bone volumes R(2)=0.57 and 0.41, respectively, p<0.001). Nevertheless, SED gradients in the marrow were shown to be the best predictor of osteoblastic and osteoclastic activity (R(2)=0.83 and 0.60, respectively, p<0.001). These data suggest that the mechanical environment of the bone marrow plays a significant role in determining osteoblast and osteoclast activity.

  8. 17beta-estradiol attenuates programmed cell death in cortical pericontusional zone following traumatic brain injury via upregulation of ERalpha and inhibition of caspase-3 activation.

    PubMed

    Li, Li-Zhuo; Bao, Yi-Jun; Zhao, Min

    2011-01-01

    Pericontusional zone (PCZ) of traumatic cerebral contusion is a target of pharmacological intervention. It is well studied that 17beta-estradiol has a protective role in ischemic brain injury, but its role in brain protection of traumatic brain damage deserves further investigation, especially in pericontusional zone. Here we show that 17beta-estradiol enhances the protein expression and mRNA induction of estrogen alpha receptor (ERalpha) and prevents from programmed cell death in cortical pericontusional zone. ERalpha specific antagonist blocks this protective effect of 17beta-estradiol. Caspase-3 activation occurs in cortical pericontusional zone of the oil-treated injured rat brain and its activation is inhibited by 17beta-estradiol treatment. Additionally, ERalpha specific antagonist reverses this inhibition. Pan-caspase inhibitor also protect cortical pericontusional zone from programmed cell death. Our present study indicates 17beta-estradiol protects from programmed cell death in cortical pericontusional zone via enhancement of ERalpha and decrease of caspase-3 activation.

  9. Strontium-90 activity concentration in soil samples from the exclusion zone of the Fukushima daiichi nuclear power plant

    PubMed Central

    Sahoo, Sarata Kumar; Kavasi, Norbert; Sorimachi, Atsuyuki; Arae, Hideki; Tokonami, Shinji; Mietelski, Jerzy Wojciech; Łokas, Edyta; Yoshida, Satoshi

    2016-01-01

    The radioactive fission product 90Sr has a long biological half-life (˜18 y) in the human body. Due to its chemical similarity to calcium it accumulates in bones and irradiates the bone marrow, causing its high radio-toxicity. Assessing 90Sr is therefore extremely important in case of a nuclear disaster. In this work 16 soil samples were collected from the exclusion zone (<30 km) of the earthquake-damaged Fukushima Daiichi nuclear power plant, to measure 90Sr activity concentration using liquid scintillation counting. 137Cs activity concentration was also measured with gamma-spectroscopy in order to investigate correlation with 90Sr. The 90Sr activity concentrations ranged from 3.0 ± 0.3 to 23.3 ± 1.5 Bq kg−1 while the 137Cs from 0.7 ± 0.1 to 110.8 ± 0.3 kBq kg−1. The fact that radioactive contamination originated from the Fukushima nuclear accident was obvious due to the presence of 134Cs. However, 90Sr contamination was not confirmed in all samples although detectable amounts of 90Sr can be expected in Japanese soils, as a background, stemming from global fallout due to the atmospheric nuclear weapon tests. Correlation analysis between 90Sr and 137Cs activity concentrations provides a potentially powerful tool to discriminate background 90Sr level from its Fukushima contribution. PMID:27048779

  10. Strontium-90 activity concentration in soil samples from the exclusion zone of the Fukushima daiichi nuclear power plant.

    PubMed

    Sahoo, Sarata Kumar; Kavasi, Norbert; Sorimachi, Atsuyuki; Arae, Hideki; Tokonami, Shinji; Mietelski, Jerzy Wojciech; Łokas, Edyta; Yoshida, Satoshi

    2016-04-06

    The radioactive fission product (90)Sr has a long biological half-life (˜18 y) in the human body. Due to its chemical similarity to calcium it accumulates in bones and irradiates the bone marrow, causing its high radio-toxicity. Assessing (90)Sr is therefore extremely important in case of a nuclear disaster. In this work 16 soil samples were collected from the exclusion zone (<30 km) of the earthquake-damaged Fukushima Daiichi nuclear power plant, to measure (90)Sr activity concentration using liquid scintillation counting. (137)Cs activity concentration was also measured with gamma-spectroscopy in order to investigate correlation with (90)Sr. The (90)Sr activity concentrations ranged from 3.0 ± 0.3 to 23.3 ± 1.5 Bq kg(-1) while the (137)Cs from 0.7 ± 0.1 to 110.8 ± 0.3 kBq kg(-1). The fact that radioactive contamination originated from the Fukushima nuclear accident was obvious due to the presence of (134)Cs. However, (90)Sr contamination was not confirmed in all samples although detectable amounts of (90)Sr can be expected in Japanese soils, as a background, stemming from global fallout due to the atmospheric nuclear weapon tests. Correlation analysis between (90)Sr and (137)Cs activity concentrations provides a potentially powerful tool to discriminate background (90)Sr level from its Fukushima contribution.

  11. Strontium-90 activity concentration in soil samples from the exclusion zone of the Fukushima daiichi nuclear power plant

    NASA Astrophysics Data System (ADS)

    Sahoo, Sarata Kumar; Kavasi, Norbert; Sorimachi, Atsuyuki; Arae, Hideki; Tokonami, Shinji; Mietelski, Jerzy Wojciech; Łokas, Edyta; Yoshida, Satoshi

    2016-04-01

    The radioactive fission product 90Sr has a long biological half-life (˜18 y) in the human body. Due to its chemical similarity to calcium it accumulates in bones and irradiates the bone marrow, causing its high radio-toxicity. Assessing 90Sr is therefore extremely important in case of a nuclear disaster. In this work 16 soil samples were collected from the exclusion zone (<30 km) of the earthquake-damaged Fukushima Daiichi nuclear power plant, to measure 90Sr activity concentration using liquid scintillation counting. 137Cs activity concentration was also measured with gamma-spectroscopy in order to investigate correlation with 90Sr. The 90Sr activity concentrations ranged from 3.0 ± 0.3 to 23.3 ± 1.5 Bq kg‑1 while the 137Cs from 0.7 ± 0.1 to 110.8 ± 0.3 kBq kg‑1. The fact that radioactive contamination originated from the Fukushima nuclear accident was obvious due to the presence of 134Cs. However, 90Sr contamination was not confirmed in all samples although detectable amounts of 90Sr can be expected in Japanese soils, as a background, stemming from global fallout due to the atmospheric nuclear weapon tests. Correlation analysis between 90Sr and 137Cs activity concentrations provides a potentially powerful tool to discriminate background 90Sr level from its Fukushima contribution.

  12. Hair cells use active zones with different voltage dependence of Ca2+ influx to decompose sounds into complementary neural codes

    PubMed Central

    Ohn, Tzu-Lun; Rutherford, Mark A.; Jing, Zhizi; Jung, Sangyong; Duque-Afonso, Carlos J.; Hoch, Gerhard; Picher, Maria Magdalena; Scharinger, Anja; Strenzke, Nicola; Moser, Tobias

    2016-01-01

    For sounds of a given frequency, spiral ganglion neurons (SGNs) with different thresholds and dynamic ranges collectively encode the wide range of audible sound pressures. Heterogeneity of synapses between inner hair cells (IHCs) and SGNs is an attractive candidate mechanism for generating complementary neural codes covering the entire dynamic range. Here, we quantified active zone (AZ) properties as a function of AZ position within mouse IHCs by combining patch clamp and imaging of presynaptic Ca2+ influx and by immunohistochemistry. We report substantial AZ heterogeneity whereby the voltage of half-maximal activation of Ca2+ influx ranged over ∼20 mV. Ca2+ influx at AZs facing away from the ganglion activated at weaker depolarizations. Estimates of AZ size and Ca2+ channel number were correlated and larger when AZs faced the ganglion. Disruption of the deafness gene GIPC3 in mice shifted the activation of presynaptic Ca2+ influx to more hyperpolarized potentials and increased the spontaneous SGN discharge. Moreover, Gipc3 disruption enhanced Ca2+ influx and exocytosis in IHCs, reversed the spatial gradient of maximal Ca2+ influx in IHCs, and increased the maximal firing rate of SGNs at sound onset. We propose that IHCs diversify Ca2+ channel properties among AZs and thereby contribute to decomposing auditory information into complementary representations in SGNs. PMID:27462107

  13. The enzymatic activities of the Escherichia coli basic aliphatic amino acid decarboxylases exhibit a pH zone of inhibition.

    PubMed

    Kanjee, Usheer; Gutsche, Irina; Ramachandran, Shaliny; Houry, Walid A

    2011-11-01

    The stringent response regulator ppGpp has recently been shown by our group to inhibit the Escherichia coli inducible lysine decarboxylase, LdcI. As a follow-up to this observation, we examined the mechanisms that regulate the activities of the other four E. coli enzymes paralogous to LdcI: the constitutive lysine decarboxylase LdcC, the inducible arginine decarboxylase AdiA, the inducible ornithine decarboxylase SpeF, and the constitutive ornithine decarboxylase SpeC. LdcC and SpeC are involved in cellular polyamine biosynthesis, while LdcI, AdiA, and SpeF are involved in the acid stress response. Multiple mechanisms of regulation were found for these enzymes. In addition to LdcI, LdcC and SpeC were found to be inhibited by ppGpp; AdiA activity was found to be regulated by changes in oligomerization, while SpeF and SpeC activities were regulated by GTP. These findings indicate the presence of multiple mechanisms regulating the activity of this important family of decarboxylases. When the enzyme inhibition profiles are analyzed in parallel, a "zone of inhibition" between pH 6 and pH 8 is observed. Hence, the data suggest that E. coli utilizes multiple mechanisms to ensure that these decarboxylases remain inactive around neutral pH possibly to reduce the consumption of amino acids at this pH.

  14. H ingestion into He-burning convection zones in super-AGB stellar models as a potential site for intermediate neutron-density nucleosynthesis

    DOE PAGES

    Jones, Sam; Ritter, Christian; Herwig, Falk; ...

    2015-12-03

    We investigate the evolution of super-AGB (SAGB) thermal pulse (TP) stars for a range of metallicities (Z) and explore the effect of convective boundary mixing (CBM). With decreasing metallicity and evolution along the TP phase, the He-shell flash and the third dredge-up (TDU) occur closer together in time. After some time (depending upon the CBM parametrization), efficient TDU begins while the pulse-driven convection zone (PDCZ) is still present, causing a convective exchange of material between the PDCZ and the convective envelope. This results in the ingestion of protons into the convective He-burning pulse. Even small amounts of CBM encourage themore » interaction of the convection zones leading to transport of protons from the convective envelope into the He layer. H-burning luminosities exceed 109 (in some cases 1010) L⊙. We also calculate models of dredge-out in the most massive SAGB stars and show that the dredge-out phenomenon is another likely site of convective-reactive H-12C combustion. We discuss the substantial uncertainties of stellar evolution models under these conditions. Nevertheless, the simulations suggest that in the convective-reactive H-combustion regime of H ingestion the star may encounter conditions for the intermediate neutron capture process (i-process). We speculate that some CEMP-s/r stars could originate in i-process conditions in the H ingestion phases of low-Z SAGB stars. This scenario would however suggest a very low electron-capture supernova rate from SAGB stars. Here, we also simulate potential outbursts triggered by such H ingestion events, present their light curves and briefly discuss their transient properties.« less

  15. H ingestion into He-burning convection zones in super-AGB stellar models as a potential site for intermediate neutron-density nucleosynthesis

    SciTech Connect

    Jones, Sam; Ritter, Christian; Herwig, Falk; Fryer, Christopher Lee; Pignatari, Marco; Bertolli, Michael G.; Paxton, Bill

    2015-12-03

    We investigate the evolution of super-AGB (SAGB) thermal pulse (TP) stars for a range of metallicities (Z) and explore the effect of convective boundary mixing (CBM). With decreasing metallicity and evolution along the TP phase, the He-shell flash and the third dredge-up (TDU) occur closer together in time. After some time (depending upon the CBM parametrization), efficient TDU begins while the pulse-driven convection zone (PDCZ) is still present, causing a convective exchange of material between the PDCZ and the convective envelope. This results in the ingestion of protons into the convective He-burning pulse. Even small amounts of CBM encourage the interaction of the convection zones leading to transport of protons from the convective envelope into the He layer. H-burning luminosities exceed 109 (in some cases 1010) L⊙. We also calculate models of dredge-out in the most massive SAGB stars and show that the dredge-out phenomenon is another likely site of convective-reactive H-12C combustion. We discuss the substantial uncertainties of stellar evolution models under these conditions. Nevertheless, the simulations suggest that in the convective-reactive H-combustion regime of H ingestion the star may encounter conditions for the intermediate neutron capture process (i-process). We speculate that some CEMP-s/r stars could originate in i-process conditions in the H ingestion phases of low-Z SAGB stars. This scenario would however suggest a very low electron-capture supernova rate from SAGB stars. Here, we also simulate potential outbursts triggered by such H ingestion events, present their light curves and briefly discuss their transient properties.

  16. H ingestion into He-burning convection zones in super-AGB stellar models as a potential site for intermediate neutron-density nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Jones, S.; Ritter, C.; Herwig, F.; Fryer, C.; Pignatari, M.; Bertolli, M. G.; Paxton, B.

    2016-02-01

    We investigate the evolution of super-AGB (SAGB) thermal pulse (TP) stars for a range of metallicities (Z) and explore the effect of convective boundary mixing (CBM). With decreasing metallicity and evolution along the TP phase, the He-shell flash and the third dredge-up (TDU) occur closer together in time. After some time (depending upon the CBM parametrization), efficient TDU begins while the pulse-driven convection zone (PDCZ) is still present, causing a convective exchange of material between the PDCZ and the convective envelope. This results in the ingestion of protons into the convective He-burning pulse. Even small amounts of CBM encourage the interaction of the convection zones leading to transport of protons from the convective envelope into the He layer. H-burning luminosities exceed 109 (in some cases 1010) L⊙. We also calculate models of dredge-out in the most massive SAGB stars and show that the dredge-out phenomenon is another likely site of convective-reactive H-12C combustion. We discuss the substantial uncertainties of stellar evolution models under these conditions. Nevertheless, the simulations suggest that in the convective-reactive H-combustion regime of H ingestion the star may encounter conditions for the intermediate neutron capture process (i-process). We speculate that some CEMP-s/r stars could originate in i-process conditions in the H ingestion phases of low-Z SAGB stars. This scenario would however suggest a very low electron-capture supernova rate from SAGB stars. We also simulate potential outbursts triggered by such H ingestion events, present their light curves and briefly discuss their transient properties.

  17. Density, activity, and diversity of bacteria indigenous to a karstic aquifer.

    PubMed

    Rusterholtz, K J; Mallory, L M

    1994-07-01

    The microbial ecology of karstic ground water is largely unknown. The density, activity, and diversity of bacteria indigenous to subsurface karstic material in Mammoth Cave National Park, Mammoth Cave, Kentucky were studied using minimally disruptive, on-site procedures. Two sites, located 100 m below the surface and consisting of saturated fine to coarse sand in pooled water, were examined. Samples were taken aseptically using modified, sterile 60-cc syringes. Total cell and total respiring cell densities were determined using an acridine orange/p-iodonitrotetrazolium violet (AO/INT) staining procedure. Cells in selected cores were stained with INT and incubated in the cave for 4 h prior to fixing with glutaraldehyde and subsequent transport to the laboratory. Cells were stained with AO in the laboratory. Low- and high-nutrient media were used to determine viable cell counts. Plates were incubated in the cave for 1 day at ambient temperature prior to transportation to the laboratory in an insulated cooler. Viable cell counts ranged from 1.0 × 106 to 8.1 × 106 cells wet g(-1) of sediment. Total direct counts were 3.9 × 106 and 1.4 × 107 cells wet g(-1) for the Olivia's Dome and the Catherine's Dome sites, respectively. Viable cell counts were highly similar to respiring cell counts at both sites. At the Olivia's Dome site, viable cell counts represented 26-31% of the direct cell counts, while 58% of the total cell count were actively respiring. At the Catherine's Dome site, viable cell counts represented 11-58% of the direct counts, while 53% of the cells were actively respiring. A total of 237 strains recovered from low- and high-nutrient media at both Olivia's and Catherine's Domes, and 10 reference strains were examined for 117 morphological, biochemical, and physiological characteristics. Results were coded in a binary fashion and analyzed using numerical taxonomic techniques. Similarity values were calculated using a simple matching coefficient. Fifty

  18. Active Deformation in the Zagros-Makran Transition Zone Inferred From GPS, Tectonic and Seismological Measurements

    NASA Astrophysics Data System (ADS)

    Bayer, R.; Shabanian, E.; Regard, V.; Yaminifard, F.; Vernant, P.; Nilforoushan, F.; Abbassi, M.; Chery, J.; Tatar, M.; Doerflinger, E.; Peyret, M.; Daignières, M.; Bellier, O.; Hatzfeld, D.; Mokhtari, M.

    2002-12-01

    The present-day N-S convergence between the Arabian and the Eurasian plates is accommodated in Southern Iran along the Zagros fold and thrust belt (with a shortening of ~8 mm/yr)and by the subduction of the Oman oceanic lithosphere beneath the Makran (with a rate of 18mm/yr). The Bandar Abbas-Strait of Hormuz zone is considered as a transition between the Zagros continental collision and the Makran oceanic subduction. In this area, the strain is mainly accommodated along the NNW-SSE trending reverse right lateral Minab-Zendan-Palami faults and along the N-S trending faults of Sarduiyeh, Jiroft and Sabzevaran. We used GPS network measurements (carried out in 2000 and 2002) to better understand how the deformation is distributed between between the Zagros continental collision and the Makran oceanic subduction. The analysis of the velocities (together with the measurements of the global network of Iran) leads to the following conclusions : - The rate of shortening in the Eastern Zagros is < 8mm/yr. It is < 5 mm/yr between the coast and the Main Zagros Thrust. - The horizontal residual velocities of the coastal sites in Zagros relative to Musandan are < 3mm/yr, evidencing for a small deformation in the Persian Gulf. - Across the Minab-Zendan-Palami faults system GPS measurements are consistent with a N-S trending reverse right lateral motion at rate of ~ 10 mm/yr. - West of the Lut block at the latitude of Khanuj, the N-S trending Sarduiyeh-Jiroft-Sabzevaran fault system is characterized by a 2 mm/yr right strike slip motion. Local seismicity is located at an unusual depth down to 35 km. Little is associated with the Minab-Zendan-Palami faults strike slip faults. They rather suggest that they are associated with a complex transition between the Zagros collision and the Makran subduction. Times delays also suggest a large heterogeneity in the crust across the fault system. These measurements support the model that the convergence from the collision to the subduction is

  19. [Separation of water-soluble active components in Salvia miltiorrhiza bge. f. alba using capillary zone electrophoresis].

    PubMed

    Cui, Yingjie; Li, Yuqin; Shi, Weifeng; Yang, Mingfeng; Zhao, Xiaomin; Xia, Zuoli

    2007-09-01

    To establish a high performance capillary zone electrophoretic method for the separation of water-soluble active components, protocatechuic aldehyde (PAH), danshensu (DSS), and protocatechuic acid (PA), in Salvia miltiorrhiza bge. f. alba, many factors that can affect the resolution and the migration time, including the concentration of phosphate-borax buffer, pH value, separation voltage and detection wavelength were investigated. The optimized conditions were as follows: uncoated capillary column, 75 microm x 60.2 cm (effective length of 50 cm); column temperature, 25 degrees C; detection wavelength of the photo-diode-array detector, 210 nm; injection, 3.45 kPa x 4 s; separation voltage, 27.5 kV; running buffer, 5 mmol/L borax (pH 7.5). Under the optimized conditions, good separation of PAH, DSS and PA can be achieved in less than 8 min.

  20. Protein mutated in paroxysmal dyskinesia interacts with the active zone protein RIM and suppresses synaptic vesicle exocytosis

    PubMed Central

    Shen, Yiguo; Ge, Woo-Ping; Li, Yulong; Hirano, Arisa; Lee, Hsien-Yang; Rohlmann, Astrid; Missler, Markus; Tsien, Richard W.; Jan, Lily Yeh; Fu, Ying-Hui; Ptáček, Louis J.

    2015-01-01

    Paroxysmal nonkinesigenic dyskinesia (PNKD) is an autosomal dominant episodic movement disorder precipitated by coffee, alcohol, and stress. We previously identified the causative gene but the function of the encoded protein remains unknown. We also generated a PNKD mouse model that revealed dysregulated dopamine signaling in vivo. Here, we show that PNKD interacts with synaptic active zone proteins Rab3-interacting molecule (RIM)1 and RIM2, localizes to synapses, and modulates neurotransmitter release. Overexpressed PNKD protein suppresses release, and mutant PNKD protein is less effective than wild-type at inhibiting exocytosis. In PNKD KO mice, RIM1/2 protein levels are reduced and synaptic strength is impaired. Thus, PNKD is a novel synaptic protein with a regulatory role in neurotransmitter release. PMID:25730884

  1. Variation of D-region nitric-oxide density with solar activity and season at the dip equator

    NASA Technical Reports Server (NTRS)

    Chakrabarty, D. K.; Pakhomov, S. V.; Beig, G.

    1989-01-01

    To study the solar control on electron density (N sub e) in the equatorial D region, a program was initiated with Soviet collaboration in 1979. A total of 31 rockets were launched during the high solar activity period, and 47 rockets during the low solar activity period, from Thumba to measure the N sub e profiles. Analysis of the data shows that the average values of N sub e for the high solar activity period are higher by a factor of about 2 to 3 compared to the low solar activity values. It was found that a single nitric oxide density, (NO), profile cannot reproduce all the observed N sub e profiles. An attempt was made to reproduce theoretically the observed N sub e profiles by introducing variation in (NO) for the different solar activity periods and seasons.

  2. Analysis of radar images of the active volcanic zone at Krafla, Iceland: The effects of look azimuth biasing

    NASA Technical Reports Server (NTRS)

    Garvin, J. B.; Williams, R. S., Jr.

    1989-01-01

    The geomorphic expression of Mid-Ocean-Ridge (MOR) volcanism in a subaerial setting occurs uniquely on Earth in Iceland, and the most recent MOR eruptive activity has been concentrated in the Northeastern Volcanic Zone in an area known as Krafla. Within the Krafla region are many of the key morphologic elements of MOR-related basaltic volcanism, as well as volcanic explosion craters, subglacial lava shields, tectonic fissure swarms known as gjar, and basaltic-andesite flows with well developed ogives (pressure-ridges). The objective was to quantify the degree to which the basic volcanic and structural features can be mapped from directional SAR imagery as a function of the look azimuth. To accomplish this, the current expression of volcanic and tectonic constructs was independently mapped within the Krafla region on the E, W, and N-looking SAR images, as well as from SPOT Panchromatic imagery acquired in 1987. The initial observations of the E, W, and N images indicates that fresh a'a lava surfaces are extremely radar bright (rough at 3 cm to meter scales) independent of look direction; this suggests that these flows do not have strong flow direction related structures at meter and cm scales, which is consistent with typical Icelandic a'a lava surfaces in general. The basic impression from a preliminary analysis of the effects of look azimuth biasing on interpretation of the geology of an active MOR volcanic zone is that up to 30 percent of the diagnostic features can be missed at any given look direction, but that having two orthogonal look direction images is probably sufficient to prevent gross misinterpretation.

  3. Progressive failure during the 1596 Keicho earthquakes on the Median Tectonic Line active fault zone, southwest Japan

    NASA Astrophysics Data System (ADS)

    Ikeda, M.; Toda, S.; Nishizaka, N.; Onishi, K.; Suzuki, S.

    2015-12-01

    Rupture patterns of a long fault system are controlled by spatial heterogeneity of fault strength and stress associated with geometrical characteristics and stress perturbation history. Mechanical process for sequential ruptures and multiple simultaneous ruptures, one of the characteristics of a long fault such as the North Anatolian fault, governs the size and frequency of large earthquakes. Here we introduce one of the cases in southwest Japan and explore what controls rupture initiation, sequential ruptures and fault branching on a long fault system. The Median Tectonic Line active fault zone (hereinafter MTL) is the longest and most active fault in Japan. Based on historical accounts, a series of M ≥ 7 earthquakes occurred on at least a 300-km-long portion of the MTL in 1596. On September 1, the first event occurred on the Kawakami fault segment, in Central Shikoku, and the subsequent events occurred further west. Then on September 5, another rupture initiated from the Central to East Shikoku and then propagated toward the Rokko-Awaji fault zone to Kobe, a northern branch of the MTL, instead of the eastern main extent of the MTL. Another rupture eventually extended to near Kyoto. To reproduce this progressive failure, we applied two numerical models: one is a coulomb stress transfer; the other is a slip-tendency analysis under the tectonic stress. We found that Coulomb stress imparted from historical ruptures have triggered the subsequent ruptures nearby. However, stress transfer does not explain beginning of the sequence and rupture directivities. Instead, calculated slip-tendency values show highly variable along the MTL: high and low seismic potential in West and East Shikoku. The initiation point of the 1596 progressive failure locates near the boundary in the slip-tendency values. Furthermore, the slip-tendency on the Rokko-Awaji fault zone is far higher than that of the MTL in Wakayama, which may explain the rupture directivity toward Kobe-Kyoto.

  4. 78 FR 9667 - Foreign-Trade Zone 50-Long Beach, California; Notification of Proposed Production Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-11

    ... Production Activity; Panasonic Corporation of North America (Kitting of Consumer Electronics); Anaheim, CA... FTZ 50. The facility is used for the kitting of consumer electronics parts into retail packages... camera kits, digital cameras with lenses, digital cameras with memory cards, home theater systems...

  5. 78 FR 49254 - Foreign-Trade Zone 158-Vicksburg/Jackson, Mississippi; Authorization of Production Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-13

    ... Production Activity; Extension of Production Authority; Bauhaus USA, Inc. (Upholstered Furniture); Saltillo... Bauhaus USA, Inc., in Saltillo, Mississippi. The notification was processed in accordance with the... foreign status (19 CFR 146.42) is limited to 3.5 million square yards. 2. Bauhaus USA, Inc., must...

  6. 78 FR 16701 - Agency Information Collection Activities: Application for Foreign Trade Zone and/or Status...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-18

    ... SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: Application for... AGENCY: U.S. Customs and Border Protection (CBP), Department of Homeland Security ACTION: 30-Day Notice.... Customs and Border Protection (CBP) of the Department of Homeland Security will be submitting...

  7. Study and comparison of the maximum stress directions and main fault orientations in some active zones in Iran

    NASA Astrophysics Data System (ADS)

    Forouhid, Khatereh; Faraji, Atefeh; Ghorashi, Manouchehr

    2010-05-01

    Study and comparison of the maximum stress directions and main fault orientations in some active zones in Iran Khatereh Forouhid, Manouchehr Ghorashi, Atefeh Faraji Institute of Geophysics, Tehran University, Tehran, Iran kforouhid@yahoo.com Farajiatefeh@yahoo.com The Iranian plateau is the widest active zone in Alpine-Himalayan collision system that is located between two stable platforms, the Arabia in southwest and Eurasia in northeast. The convergence of these two platforms towards each other is the main reason for seismicity and different styles of deformation observed in Iran. In this study, the Iranian plateau is divided into 7 regions based on their seismotectonic characteristics. These regions are; Zagros, Makran, East Iran, Alborz, Kopeh Dagh, Central Iran and Azarbayejan (northwest of Iran). In each region, focal mechanism solutions of early and modern instrumental earthquakes (the only source of information suitable to use for stress distribution study in Iran) with magnitudes more than 5.0 and their relations to active faults are considered. By studying each maximum stress direction based on a group of earthquake focal mechanisms and considering main fault orientations, each region is studied individually. According to these data, some of these regions are divided into smaller parts. These sub-divided parts have some characters that make them different from their neighbors in the same region. In this regard, Zagros is studied in detail based on seismotectonic characteristics and divided into three parts, with N-S maximum stress direction (compressional) in one part and two different kind of NE-SW direction in two other. We use this information to investigate the style and distribution of active faulting in the Zagros and the relationships of this activity with shortening of the Arabia-Eurasia collision. It is worth to mention that as the fault slip will almost occur in the direction of maximum resolved shear stress on the fault plane, probably strain

  8. Discrimination and Assessment of Induced Seismicity in Active Tectonic Zones: A Case Study from Southern California

    NASA Astrophysics Data System (ADS)

    Bachmann, C. E.; Lindsey, N.; Foxall, W.; Robertson, M.

    2014-12-01

    Earthquakes induced by human activity have become a matter of heightened public concern during recent years. Of particular concern is seismicity associated with wastewater injection, which has included events having magnitudes greater than 5. The causes of the induced events are primarily changes in pore-pressure, fluid volume and perhaps temperature due to injection. Recent research in the US has focused on mid-continental regions having low rates of naturally-occurring seismicity, where induced events can be identified by relatively straightforward spatial and temporal correlation of seismicity with high-volume injection activities. Recent examples include events correlated with injection of wastewater in Oklahoma, Arkansas, Texas and Ohio, and long-term brine injection in the Paradox Valley in Colorado. Even in some of the cases where there appears at first sight to be a clear spatial correlation between seismicity and injection, it has been difficult to establish causality definitively. Here, we discuss methods to identify induced seismicity in active tectonic regions. We concentrate our study on Southern California, where large numbers of wastewater injection wells are located in oil-producing basins that experience moderate to high rates of naturally-occurring seismicity. Using the catalog of high-precision CISN relocations produced by Hauksson et al. (BSSA, 2012), we aim to discriminate induced from natural events based on spatio-temporal patterns of seismicity occurrence characteristics and their relationships to injection activities, known active faults and other faults favorably oriented for slip under the tectonic stress field. Since the vast majority of induced earthquakes are very small, it is crucial to include all events above the detection threshold of the CISN in each area studied. In addition to exploring the correlation of seismicity to injection activities in time and space, we analyze variations in frequency-magnitude distributions, which can

  9. A NEW PERSPECTIVE OF THE RADIO BRIGHT ZONE AT THE GALACTIC CENTER: FEEDBACK FROM NUCLEAR ACTIVITIES

    SciTech Connect

    Zhao, Jun-Hui; Morris, Mark R.; Goss, W. M.

    2016-02-01

    New observations of Sgr A have been carried out with the Jansky VLA in the B and C arrays using the broadband (2 GHz) continuum mode at 5.5 GHz. The field of view covers the central 13′ (30 pc) region of the radio-bright zone at the Galactic center. Using the multi-scale and multi-frequency-synthesis (MS-MFS) algorithms in CASA, we have imaged Sgr A with a resolution of 1″, achieving an rms noise of 8 μJy beam{sup −1}, and a dynamic range of 100,000:1. Both previously known and newly identified radio features in this region are revealed, including numerous filamentary sources. The radio continuum image is compared with Chandra X-ray images, with a CN emission-line image obtained with the Submillimeter Array and with detailed Paschen-α images obtained with Hubble Space Telescope/NICMOS. We discuss several prominent features in the radio image. The “Sgr A west Wings” extend 2′ (5 pc) from the NW and SE tips of the Sgr A west H ii region (the “Mini-spiral”) to positions located 2.9 and 2.4 arcmin to the northwest and southeast of Sgr A*, respectively. The NW wing, along with several other prominent features, including the previously identified “NW Streamers,” form an elongated radio lobe (NW lobe), oriented nearly perpendicular to the Galactic plane. This radio lobe, with a size of 6.′3 × 3.′2 (14.4 pc × 7.3 pc), has a known X-ray counterpart. In the outer region of the NW lobe, a row of three thermally emitting rings is observed. A field containing numerous amorphous radio blobs extends for a distance of ∼2 arcmin beyond the tip of the SE wing; these newly recognized features coincide with the SE X-ray lobe. Most of the amorphous radio blobs in the NW and SE lobes have Paschen-α counterparts. We propose that they have been produced by shock interaction of ambient gas concentrations with a collimated nuclear wind or an outflow that originated from within the circumnuclear disk (CND). We also discuss the possibility that the ionized

  10. A New Perspective of the Radio Bright Zone at The Galactic Center: Feedback from Nuclear Activities

    NASA Astrophysics Data System (ADS)

    Zhao, Jun-Hui; Morris, Mark R.; Goss, W. M.

    2016-02-01

    New observations of Sgr A have been carried out with the Jansky VLA in the B and C arrays using the broadband (2 GHz) continuum mode at 5.5 GHz. The field of view covers the central 13‧ (30 pc) region of the radio-bright zone at the Galactic center. Using the multi-scale and multi-frequency-synthesis (MS-MFS) algorithms in CASA, we have imaged Sgr A with a resolution of 1″, achieving an rms noise of 8 μJy beam-1, and a dynamic range of 100,000:1. Both previously known and newly identified radio features in this region are revealed, including numerous filamentary sources. The radio continuum image is compared with Chandra X-ray images, with a CN emission-line image obtained with the Submillimeter Array and with detailed Paschen-α images obtained with Hubble Space Telescope/NICMOS. We discuss several prominent features in the radio image. The “Sgr A west Wings” extend 2‧ (5 pc) from the NW and SE tips of the Sgr A west H ii region (the “Mini-spiral”) to positions located 2.9 and 2.4 arcmin to the northwest and southeast of Sgr A*, respectively. The NW wing, along with several other prominent features, including the previously identified “NW Streamers,” form an elongated radio lobe (NW lobe), oriented nearly perpendicular to the Galactic plane. This radio lobe, with a size of 6.‧3 × 3.‧2 (14.4 pc × 7.3 pc), has a known X-ray counterpart. In the outer region of the NW lobe, a row of three thermally emitting rings is observed. A field containing numerous amorphous radio blobs extends for a distance of ˜2 arcmin beyond the tip of the SE wing; these newly recognized features coincide with the SE X-ray lobe. Most of the amorphous radio blobs in the NW and SE lobes have Paschen-α counterparts. We propose that they have been produced by shock interaction of ambient gas concentrations with a collimated nuclear wind or an outflow that originated from within the circumnuclear disk (CND). We also discuss the possibility that the ionized wind or

  11. Military Activities in the Exclusive Economic Zone: Preventing Uncertainty and Defusing Conflict

    DTIC Science & Technology

    2002-03-01

    freedom of navigation." Id. (citing Edmund V. Carreno, America Latina y los Problems Contemporaneos del Derecho del Mar 27-28 (Santiago, 1973)). But see... fiscal , customs, immigration, and health laws.薯 As discussed above, however, despite this diplomatic and operational activity, while some States have...the coastal State may exercise the control necessary to.. prevent infringement of its customs, fiscal , inmnigration or sanitary laws and regulations

  12. Estimation of ground water residence times in the Critical zone: insight from U activity ratios

    NASA Astrophysics Data System (ADS)

    Chabaux, Francois; Ackerer, Julien; Lucas, Yann; viville, Daniel

    2016-04-01

    The use of radioactive disequilibria as tracers and chronometers of weathering processes and related mass transfers has been recognized since the 60'. The development, over the last two decades, of analytical methods for measuring very precisely U-series nuclides (especially, 234U, 230Th and 226Ra) in environmental samples has opened up new scientific applications in Earth Surface Sciences. Here, we propose to present the potential of U activity ratios in surface waters as chronometer of water transfers at a watershed scale. This will be illustrated from studies performed at different scales, with the analysis of U activity ratios in surface waters from small watersheds (Strengbach and Ringelbach watersheds in the Vosges Mountain, France) but also from watersheds of much more regional extension (e.g., the Upper Rhine basin or the Ganges basin). These various studies show that variations of U activity ratios in surface waters are mainly associated with 234U-238U fractionations occurring during the water transfer within the bedrock, which intensity depends on two main parameters: the petro-physical characteristics of the aquifer, principally the geometry of water-rock interfaces and the duration of the water-rock interactions. This readily explains why different U activity ratios (UAR) can be observed in the different aquifers of a continental hydrosystem and hence why UAR can be used to trace the source of river waters. For a hydrological system developed on a substratum marked by fairly homogeneous petro-physical characteristics, the main parameter controlling the UAR in waters draining such a system would be the duration of the water-rock interactions. Variations of UAR in stream or spring waters of such a system can therefore be modeled using simple reactive transport model, which allows the estimation of both the dissolution rate of the bedrock and the residence time of the waters within the aquifer.

  13. Quantal potential fields around individual active zones of amphibian motor-nerve terminals.

    PubMed Central

    Bennett, M R; Farnell, L; Gibson, W G; Macleod, G T; Dickens, P

    2000-01-01

    The release of a quantum from a nerve terminal is accompanied by the flow of extracellular current, which creates a field around the site of transmitter action. We provide a solution for the extent of this field for the case of a quantum released from a site on an amphibian motor-nerve terminal branch onto the receptor patch of a muscle fiber and compare this with measurements of the field using three extracellular electrodes. Numerical solution of the equations for the quantal potential field in cylindrical coordinates show that the density of the field at the peak of the quantal current gives rise to a peak extracellular potential, which declines approximately as the inverse of the distance from the source at distances greater than about 4 microm from the source along the length of the fiber. The peak extracellular potential declines to 20% of its initial value in a distance of about 6 microm, both along the length of the fiber and in the circumferential direction around the fiber. Simultaneous recordings of quantal potential fields, made with three electrodes placed in a line at right angles to an FM1-43 visualized branch, gave determinations of the field strengths in accord with the numerical solutions. In addition, the three electrodes were placed so as to straddle the visualized release sites of a branch. The positions of these sites were correctly predicted on the basis of the theory and independently ascertained by FM1-43 staining of the sites. It is concluded that quantal potential fields at the neuromuscular junction that can be measured with available recording techniques are restricted to regions within about 10 microm of the release site. PMID:10692301

  14. Unidirectional transfer in vivo of high-density lipoprotein cholesteryl esters to lower-density lipoproteins in the pig, an animal species without plasma cholesteryl ester transfer activity.

    PubMed

    Terpstra, A H; Stucchi, A F; Foxall, T L; Shwaery, G T; Vespa, D B; Nicolosi, R J

    1993-12-01

    The metabolism of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesteryl esters (CE) was studied in the pig, an animal species without plasma cholesteryl ester transfer activity (CETA). In the first series of experiments, LDL and HDL from normocholesterolemic pigs were radiolabeled with cholesteryl (1-14C)oleate and intravenously administered to two groups of four normocholesterolemic pigs. Radioactive tracer in LDL remained associated with the LDL fraction, and there was no transfer of LDL-CE to HDL. The transport rate (which represents the production and disposal rate) of LDL-CE in normocholesterolemic pigs was 39 mumol CE/h/L. However, radiolabeled HDL-CE were transferred to LDL (25%), and 36% of the LDL-CE mass was derived from the HDL. The transport rate of HDL-CE was 54 mumol CE/h/L, and the flux of HDL-CE to LDL was 14 mumol CE/h/L. There was no accumulation of radiolabeled HDL-CE in very-low-density lipoprotein (VLDL), which suggests that there was no transfer to VLDL. However, this does not rule out the possibility that either the very low levels of VLDL-CE (< 0.09 mmol/L) or the rapid turnover rate of the VLDL pool might have prevented the accumulation of substantial amounts of tracer in VLDL. Therefore, in a second set of experiments, the kinetics of HDL-CE were studied in high-fat-and high-cholesterol-fed pigs with elevated VLDL-CE concentrations (1.92 mmol/L). Hypercholesterolemia was associated with increased transport rates of LDL-CE (165 mumol/h/L) and HDL-CE (78 mumol/h/L) and with an increased flux of HDL-CE to LDL (78 mumol/h/L).(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Bacterial biomass and activity in the marginal ice zone of the northern Barents Sea

    NASA Astrophysics Data System (ADS)

    Tammert, Helen; Olli, Kalle; Sturluson, Maria; Hodal, Helene

    2008-10-01

    Bacteria in the Arctic Waters are well adapted to low temperatures and play a key role in the transformation of organic matter. However, the activity of planktonic bacteria at cellular level remains poorly understood. In this study, we use fluorescent markers (4',6'-diamidino-2-phenylindole (DAPI), 5-cyano-2,3-ditolyl tetrazolium chloride (CTC), Live/Dead BacLight viability kit) to discriminate between bacterial cells with a variety of physiological activities in the 0-200 m water column and sinking particles. During two field studies (July 2003 and 2004), we covered nine stations in the northern Barents Sea. The median bacterial abundance (DAPI staining) in the upper 50 m layer was 0.9×10 6 cells ml -1 (range 0.2-3.2×10 6 cells ml -1) in 2003 and 0.5×10 6 cells ml -1 (range 0.2-1.0×10 6 cells ml -1) in 2004. Bacteria with sufficient electron transport activity to be stained with CTC were on average 10% of the total count and ca. 20% of the total cells had intact cell membranes. In the water column, proxies of substrate availability (POC, PON, chlorophyll a, primary production) and bacterial production (thymidine and leucine uptake) correlated strongly with total bacterial count, CTC-stained cells and cells with 'leaky' membrane (stained with propidium iodine), but not with the concentration of cells with intact cell membrane. Contrary to expectations, the proportion of CTC-stained bacteria was not higher in the sinking particles (captured with sediment traps) compared to the ambient water. However, out of the bacteria with intact cell membranes, a higher proportion scored as CTC positive in the aggregates compared to the ambient water. Bacterial cells with 'leaky' cell membranes formed the largest part of total cell count in all samples, and accumulated in sites with high microbial activity (sinking aggregates, chlorophyll maxima, layers of high primary and bacterial production). We hypothesize that the source of the bacterial cells with 'leaky' cell membranes

  16. Preliminary Assessment of the Nuclide Migration from the Activation Zone Around the Proposed Spallation Neutron Source Facility

    SciTech Connect

    Dole, L.R.

    1998-09-01

    The purpose of this study is to investigate the potential impacts of migrating radionuclides from the activation zone around the proposed Spallation Neutron Source (SNS). Using conservatively high estimates of the potential inventory of radioactive activation products that could form in the proposed compacted-soil shield berm around an SNS facility on the Oak Ridge Reservation (ORR), a conservative, simplified transport model was used to estimate the potential worst-case concentrations of the 12 long-lived isotopes in the groundwater under a site with the hydrologic characteristics of the ORR. Of the 12, only 3 isotopes showed any potential to exceed the U.S. Nuclear Regulatory Commission (NRC) 10 Code of Federal Regulations (CFR) Part 20 Drinking Water Limits (DWLs). These isotopes were 14C, 22Na, and 54Mn. The latter two activation products have very short half-lives of 2.6 years and 0.854 year, respectively. Therefore, these will decay before reaching an off-site receptor, and they cannot pose off-site hazards. However, for this extremely conservative model, which overestimates the mobility of the contaminant, 14C, which has a 5,730-year half-life, was shown to represent a potential concern in the context of this study's conservative assumptions. This study examines alternative modifications to the SNS shield berm and makes recommendations.

  17. The impact of helium on thermosphere mass density response to geomagnetic activity during the recent solar minimum

    NASA Astrophysics Data System (ADS)

    Thayer, J. P.; Liu, X.; Lei, J.; Pilinski, M.; Burns, A. G.

    2012-07-01

    High-resolution mass density observations inferred from accelerometer measurements on the CHAMP and GRACE satellites are employed to investigate the thermosphere mass density response with latitude and altitude to geomagnetic activity during the recent solar minimum. Coplanar orbital periods in February 2007 and December 2008 revealed the altitude and latitude response in thermosphere mass density for their respective winter hemispheres was influenced by the relative amount of helium and oxygen present. The CHAMP-to-GRACE (C/G) mass density ratio depends on two terms; the first proportional to the ratio of the mean molecular weight to temperature and the second proportional to the vertical gradient of the logarithmic mean molecular weight. For the relative levels of helium and oxygen in February 2007, the winter hemisphere C/G mass density response to geomagnetic activity, although similar to the summer hemisphere, was caused predominantly by changes in the vertical gradient of the logarithmic mean molecular weight. In December 2008, the significant presence of helium caused the mean molecular weight changes to exceed temperature changes in the winter hemisphere leading to an increase in the C/G ratio with increasing geomagnetic activity, in opposition to the decrease observed in the summer hemisphere that was caused primarily by temperature changes. The observed behavior is indicative of composition effects influencing the mass density response and the dynamic action of the oxygen to helium transition region in both latitude and altitude will lead to complex behaviors in the mass density at GRACE altitudes throughout the extended solar minimum from 2007 to 2010.

  18. Tuning sensitivity of CAR to EGFR density limits recognition of normal tissue while maintaining potent anti-tumor activity

    PubMed Central

    Caruso, Hillary G.; Hurton, Lenka V.; Najjar, Amer; Rushworth, David; Ang, Sonny; Olivares, Simon; Mi, Tiejuan; Switzer, Kirsten; Singh, Harjeet; Huls, Helen; Lee, Dean A.; Heimberger, Amy B.; Champlin, Richard E.; Cooper, Laurence J. N.

    2015-01-01

    Many tumors over express tumor-associated antigens relative to normal tissue, such as epidermal growth factor receptor (EGFR). This limits targeting by human T cells modified to express chimeric antigen receptors (CARs) due to potential for deleterious recognition of normal cells. We sought to generate CAR+ T cells capable of distinguishing malignant from normal cells based on the disparate density of EGFR expression by generating two CARs from monoclonal antibodies which differ in affinity. T cells with low affinity Nimo-CAR selectively targeted cells over-expressing EGFR, but exhibited diminished effector function as the density of EGFR decreased. In contrast, the activation of T cells bearing high affinity Cetux-CAR was not impacted by the density of EGFR. In summary, we describe the generation of CARs able to tune T-cell activity to the level of EGFR expression in which a CAR with reduced affinity enabled T cells to distinguish malignant from non-malignant cells. PMID:26330164

  19. [Low density lipoprotein rich in triglycerides and hepatic lipase activity in insulin-dependent diabetic patients].

    PubMed

    Rosental, S B; Schreier, L E; Halperin, H; Berg, G; Paglione, A M; Ruiz, M; Wikinski, R L

    1995-01-01

    Genetic hepatic lipase (HL) deficiency is associated with low density lipoprotein (LDL) rich in triglycerides (TG), whose affinity for B:E receptors is decreased. In rats, experimental hypoinsulinemia produces HL deficiency. However, the relation between human insulin-dependent Diabetes Mellitus (IDDM), HL activity and the characteristics of LDL have not been studied. The objective of our study is to evaluate the relation between HL activity and the chemical composition of LDL in treated IDDM patients. Subjects were 15 IDDM patients and 15 controls (C), matched for sex and body mass index (BMI). The IDDM patients were classified by the WHO criteria, were free of nephropathy and hypothyroidism, and received no medication except insulin. Controls were clinically healthy and normolipidemic with no family history of diabetes. The IDDM group was divided into two subgroups: subgroup IDDM-A (n = 9) with HL values > or = 4.3 and IDDM-B (n = 6) with HL < or = than 4.2 mumoles glycerol/ml h. the HL in IDDM was lower than in C (p < 0.001). Table 1 shows clinical data. Blood samples were drawn after 12 h fasting. Percentage of HbA1c and plasma concentrations of glucose, total cholesterol, LDL-cholesterol, HDL-cholesterol and TG were assayed. LDL was separated by sequential ultracentrifugation at densities of 1.019-1.063 g/ml and its chemical composition was analyzed. The most relevant results were: plasma TG concentration was higher in IDDM than in C (p < 0.05) (Table 2), although average values DMID not exceed the reference values of 200 mg/dl. The TG-LDL were higher in IDDM than in C: 24.8 +/- 2.7 vs 17.5 +/- 1.1 mg/dl plasma, media +/- SE, (p < 0.02). This difference reflected the values of IDDM-B, whose plasma concentrations of TG-LDL were higher than in C: 32.3 +/- 3.6 vs 17.5 +/- 1.1 mg/dl (p < 0.001), and also higher than in IDDM-A (p < 0.02). (Table 3). The chemical composition of LDL in IDDM-B contained a higher percentage of TG than C: 8.5 +/- 0.7 vs 6.8 +/- 0.3% (p

  20. Quantifying fault-zone activity in arid environments with high-resolution topography

    NASA Astrophysics Data System (ADS)

    Oskin, Michael E.; Le, Kimberly; Strane, Michael D.

    2007-11-01

    High-resolution airborne laser swath-mapping (ALSM) topography illuminates active faulting with unprecedented clarity. We contrast ALSM topography of two dextral faults in arid regions of California with slip rates that differ by an order of magnitude: The Lenwood fault, with rate of ~1 mm/yr, and the Clark fault, a strand of the San Jacinto fault with net slip rate >10 mm/yr. Visualization of ALSM data reveals abundant fault scarps and deflected channels that when reconstructed can yield powerful slip constraints. Though many of these features may also be detected in existing aerial photography, these data are limited by stereo depth resolution and fixed illumination angle.

  1. Shh and ZRS enhancer colocalisation is specific to the zone of polarising activity

    PubMed Central

    Williamson, Iain; Lettice, Laura A.; Hill, Robert E.

    2016-01-01

    Limb-specific Shh expression is regulated by the (∼1 Mb distant) ZRS enhancer. In the mouse, limb bud-restricted spatiotemporal Shh expression occurs from ∼E10 to E11.5 at the distal posterior margin and is essential for correct autopod formation. Here, we have analysed the higher-order chromatin conformation of Shh in expressing and non-expressing tissues, both by fluorescence in situ hybridisation (FISH) and by chromosome conformation capture (5C). Conventional and super-resolution light microscopy identified significantly elevated frequencies of Shh/ZRS colocalisation only in the Shh-expressing regions of the limb bud, in a conformation consistent with enhancer-promoter loop formation. However, in all tissues and at all developmental stages analysed, Shh-ZRS spatial distances were still consistently shorter than those to a neural enhancer located between Shh and ZRS in the genome. 5C identified a topologically associating domain (TAD) over the Shh/ZRS genomic region and enriched interactions between Shh and ZRS throughout E11.5 embryos. Shh/ZRS colocalisation, therefore, correlates with the spatiotemporal domain of limb bud-specific Shh expression, but close Shh and ZRS proximity in the nucleus occurs regardless of whether the gene or enhancer is active. We suggest that this constrained chromatin configuration optimises the opportunity for the active enhancer to locate and instigate the expression of Shh. PMID:27402708

  2. Identification of active root zone by data assimilation techniques: monitoring and modelling of irrigation experiments

    NASA Astrophysics Data System (ADS)

    Busato, Laura; Vanella, Daniela; Boaga, Jacopo; Manoli, Gabriele; Marani, Marco; Putti, Mario; Consoli, Simona; Binley, Andrew M.; Cassiani, Giorgio

    2015-04-01

    The identification of active root distribution and the quantification of relevant water fluxes (root water uptake-RWU) are key elements in understanding the exchanges of mass and energy in soil-plant-atmosphere systems. In this contribution we present the assimilation of 3D time-lapse Electrical Resistivity Tomography (ERT) data, acquired around an orange tree during irrigation experiments, in a soil-plant model that accounts for soil moisture dynamics and root water uptake (RWU), whole plant transpiration, and leaf-level photosynthesis. The model is based on a numerical solution to the 3D Richards equation modified to account for a 3D RWU, trunk xylem, and stomatal conductances. The data assimilation procedure, assisted also by independent information concerning the soil properties, aims specifically at identifying the distribution and strength of active roots modelled as sinks in the unsaturated flow model. In addition the flow model is enhanced by a forward electrical current model in order to predict the electrical response measured by ERT in dependence of the soil water content distribution. Strengths and weaknesses of the proposed approach are discussed.

  3. The influence on arid zone oasis landscape eco-environment from human activities

    NASA Astrophysics Data System (ADS)

    Zhu, Honghui; Yin, Xiaojun; Shang, Yuxin

    2009-06-01

    Human activities are important factors leading to the change of regional land utilization/coverage. In order to reveal the influence of human activities on the oasis landscape ecosystem in arid area, in this article, the various landscapes of human acting regions in 2000 and 2005 were compared and analyzed for Xinjiang Manas County of West-China using remotely sensed data, which showed that there is a great increasing tendency in farmland and urban landscape area, however, a dramatically decreasing tendency in forest and grass areas and patch numbers. Meanwhile, the internal structure of forest and grass landscape also changes greatly. The main driving factors of this change are agricultural technology and innovation of agricultural organization system, which strengthen the replacement of forest and grass landscape by farmland. And at the same time, the quality and areas of some forests and grassland loom optimizing tendency with the policy of "change the farmland back to forest and grassland" implemented and ecological protecting forest constructed.

  4. Beyond Density: An Inquiry-Based Activity Involving Students Searching for Relationships.

    ERIC Educational Resources Information Center

    DeMeo, Stephen

    2001-01-01

    Explains the limitations of a traditional density experiment and presents an inquiry-based laboratory experiment which allows students to develop an understanding on the relationship between the object's properties and the volume of water the object displaces. (YDS)

  5. ERK1/2 Activation Is Necessary for BDNF to Increase Dendritic Spine Density in Hippocampal CA1 Pyramidal Neurons

    ERIC Educational Resources Information Center

    Alonso, Mariana; Medina, Jorge H.; Pozzo-Miller, Lucas

    2004-01-01

    Brain-derived neurotrophic factor (BDNF) is a potent modulator of synaptic transmission and plasticity in the CNS, acting both pre- and postsynaptically. We demonstrated recently that BDNF/TrkB signaling increases dendritic spine density in hippocampal CA1 pyramidal neurons. Here, we tested whether activation of the prominent ERK (MAPK) signaling…

  6. Bone Mineral Density Changes after Physical Training and Calcium Intake in Students with Attention Deficit and Hyper Activity Disorders

    ERIC Educational Resources Information Center

    Arab ameri, Elahe; Dehkhoda, Mohammad Reza; Hemayattalab, Rasool

    2012-01-01

    In this study we investigate the effects of weight bearing exercise and calcium intake on bone mineral density (BMD) of students with attention deficit and hyper activity (ADHD) disorder. For this reason 54 male students with ADHD (age 8-12 years old) were assigned to four groups with no differences in age, BMD, calcium intake, and physical…

  7. Signal Destruction Tunes the Zone of Activation in Spatially Distributed Signaling Networks.

    PubMed

    Silva, Kalinga Pavan; Chellamuthu, Prithiviraj; Boedicker, James Q

    2017-03-14

    Diverse microbial communities coordinate group behaviors through signal exchange, such as the exchange of acyl-homoserine lactones (AHLs) by Gram-negative bacteria. Cellular communication is prone to interference by neighboring microbes. One mechanism of interference is signal destruction through the production of an enzyme that cleaves the signaling molecule. Here we examine the ability of one such interference enzyme, AiiA, to modulate signal propagation in a spatially distributed system of bacteria. We have developed an experimental assay to measure signal transduction and implement a theoretical model of signaling dynamics to predict how the system responds to interference. We show that titration of an interfering strain into a signaling network tunes the spatial range of activation over the centimeter length scale, quantifying the robustness of the signaling network to signal destruction and demonstrating the ability to program systems-level responses of spatially heterogeneous cellular networks.

  8. Effect of long-term unilateral activity on bone mineral density of female junior tennis players.

    PubMed

    Haapasalo, H; Kannus, P; Sievänen, H; Pasanen, M; Uusi-Rasi, K; Heinonen, A; Oja, P; Vuori, I

    1998-02-01

    distal radius), no significant BMD differences were found between the players and controls in any Tanner stage. In the correlation analysis, the Tanner I and II players (mean ages 9.4 and 10.8 years) showed no significant associations between any of the predictive variables and the side-to-side BMD differences, while in Tanner stages III, IV, and V, such associations could be found; the total amount of training hours during the playing career and the number of training sessions per week showed a significant and systematic correlation (rs ranging from 0.43 to 0.80) with the side-to-side BMD differences in several measured bone sites. In conclusion, this study suggests that in a majority of female junior tennis players, the benefit of unilateral activity on bone density does not become clearly evident until the adolescent growth spurt or Tanner stage III. The total amount of training during the player's career and the current training frequency (sessions per week) seem to best explain the training effect on bone tissue, leaving, however, room for speculation on the still unknown factors that modulate the loading response of a growing bone.

  9. Endothelial NOS-dependent activation of c-Jun NH(2)- terminal kinase by oxidized low-density lipoprotein

    NASA Technical Reports Server (NTRS)

    Go, Y. M.; Levonen, A. L.; Moellering, D.; Ramachandran, A.; Patel, R. P.; Jo, H.; Darley-Usmar, V. M.

    2001-01-01

    Oxidized low-density lipoprotein (oxLDL) is known to activate a number of signal transduction pathways in endothelial cells. Among these are the c-Jun NH(2)-terminal kinase (JNK), also known as stress-activated protein kinase, and extracellular signal-regulated kinase (ERK). These mitogen-activated protein kinases (MAP kinase) determine cell survival in response to environmental stress. Interestingly, JNK signaling involves redox-sensitive mechanisms and is activated by reactive oxygen and nitrogen species derived from both NADPH oxidases, nitric oxide synthases (NOS), peroxides, and oxidized low-density lipoprotein (oxLDL). The role of endothelial NOS (eNOS) in the activation of JNK in response to oxLDL has not been examined. Herein, we show that on exposure of endothelial cells to oxLDL, both ERK and JNK are activated through independent signal transduction pathways. A key role of eNOS activation through a phosphatidylinositol-3-kinase-dependent mechanism leading to phosphorylation of eNOS is demonstrated for oxLDL-dependent activation of JNK. Moreover, we show that activation of ERK by oxLDL is critical in protection against the cytotoxicity of oxLDL.

  10. A combined methodology of multiplet and composite focal mechanism techniques for identifying seismologically active zones in Syria

    NASA Astrophysics Data System (ADS)

    Abdul-Wahed, Mohamad; Asfahani, Jamal; Al-Tahhan, Ibrahim

    2011-10-01

    This contribution is an attempt to enlarge the current knowledge about the focal mechanisms as well as the seismotectonic settings in Syria. The seismologically active zones have been identified by applying an appropriate methodology to the events recorded during the period 1995-2003 by the Syrian National Seismological Network (SNSN). The recorded events in Syria were classified as weak during the research period. It was extremely important to propose and apply an appropriate methodology to identify the focal mechanisms generating this seismic activity. The proposed methodology consists of applying a combination of two techniques: the multiplet and the composite focal mechanisms. The combination of many events in one composite focal mechanism was realized by a multiplet technique using the spectral coherence of the events as a measure of similarity. The application of the proposed methodology allows a data set of composite fault plane solutions to be obtained. Most of the composite fault plane solutions had strike-slip mechanisms which are in agreement with the configuration of seismogenic belts in Syria.

  11. An automated continuous system for seismo-geochemical research in an active fault zone in SW Taiwan

    NASA Astrophysics Data System (ADS)

    Yang, T. F.; Hilton, D. R.; Fu, C. C.; Lai, C. W.; Liu, T. K.; Walia, V.; Lai, T. H.

    2014-12-01

    Previous studies have revealed that gas compositions of fluid samples collected from southwestern Taiwan where many hot springs and mud volcanoes are distributed along tectonic sutures show significant variation prior to and after some disaster seismic events [1]. Such variations, including radon activity, CH4/CO2, CO2/3He and 3He/4He ratios of gas compositions, are considered to be precursors of earthquakes in this area. To validate the relationship between fluid compositions and local earthquakes, a continuous monitoring station has been established at Yun-Shuei, which is an artesian well located at an active fault zone in SW Taiwan. It is equipped with a radon detector and a quadrupole mass spectrometer (QMS) for in-situ measurement of the dissolved gas composition. Data is telemetered to Taipei so we are able to monitor variations of gas composition in real time. Furthermore, we also installed a syringe pump apparatus for the retrieval and temporal analysis of helium (SPARTAH) at this station [2]. From the SPARTAH samples, we can obtain detailed time series records of He and anion concentration of the water samples at this station. After continuous measurement for a few months, this automated system has been demonstrated to be feasible for long-term continuous seismo-geochemical research in this area. [1] Yang et al. (2006) PAGEOPH, 163(4), 693-709. [2] Barry et al. (2009) G3, 10(5), DOI: 10.1029/2009GC002422.

  12. Neural Stem Cells in the Adult Subventricular Zone Oxidize Fatty Acids to Produce Energy and Support Neurogenic Activity

    PubMed Central

    Makin, Rebecca; Sweet, Ian R.; Trevelyan, Andrew J.; Miwa, Satomi; Horner, Philip J.; Turnbull, Douglass M.

    2015-01-01

    Abstract Neural activity is tightly coupled to energy consumption, particularly sugars such as glucose. However, we find that, unlike mature neurons and astrocytes, neural stem/progenitor cells (NSPCs) do not require glucose to sustain aerobic respiration. NSPCs within the adult subventricular zone (SVZ) express enzymes required for fatty acid oxidation and show sustained increases in oxygen consumption upon treatment with a polyunsaturated fatty acid. NSPCs also demonstrate sustained decreases in oxygen consumption upon treatment with etomoxir, an inhibitor of fatty acid oxidation. In addition, etomoxir decreases the proliferation of SVZ NSPCs without affecting cellular survival. Finally, higher levels of neurogenesis can be achieved in aged mice by ectopically expressing proliferator‐activated receptor gamma coactivator 1 alpha (PGC1α), a factor that increases cellular aerobic capacity by promoting mitochondrial biogenesis and metabolic gene transcription. Regulation of metabolic fuel availability could prove a powerful tool in promoting or limiting cellular proliferation in the central nervous system. Stem Cells 2015;33:2306–2319 PMID:25919237

  13. Activation of type 1 cannabinoid receptor (CB1R) promotes neurogenesis in murine subventricular zone cell cultures.

    PubMed

    Xapelli, Sara; Agasse, Fabienne; Sardà-Arroyo, Laura; Bernardino, Liliana; Santos, Tiago; Ribeiro, Filipa F; Valero, Jorge; Bragança, José; Schitine, Clarissa; de Melo Reis, Ricardo A; Sebastião, Ana M; Malva, João O

    2013-01-01

    The endocannabinoid system has been implicated in the modulation of adult neurogenesis. Here, we describe the effect of type 1 cannabinoid receptor (CB1R) activation on self-renewal, proliferation and neuronal differentiation in mouse neonatal subventricular zone (SVZ) stem/progenitor cell cultures. Expression of CB1R was detected in SVZ-derived immature cells (Nestin-positive), neurons and astrocytes. Stimulation of the CB1R by (R)-(+)-Methanandamide (R-m-AEA) increased self-renewal of SVZ cells, as assessed by counting the number of secondary neurospheres and the number of Sox2+/+ cell pairs, an effect blocked by Notch pathway inhibition. Moreover, R-m-AEA treatment for 48 h, increased proliferation as assessed by BrdU incorporation assay, an effect mediated by activation of MAPK-ERK and AKT pathways. Surprisingly, stimulation of CB1R by R-m-AEA also promoted neuronal differentiation (without affecting glial differentiation), at 7 days, as shown by counting the number of NeuN-positive neurons in the cultures. Moreover, by monitoring intracellular calcium concentrations ([Ca(2+)]i) in single cells following KCl and histamine stimuli, a method that allows the functional evaluation of neuronal differentiation, we observed an increase in neuronal-like cells. This proneurogenic effect was blocked when SVZ cells were co-incubated with R-m-AEA and the CB1R antagonist AM 251, for 7 days, thus indicating that this effect involves CB1R activation. In accordance with an effect on neuronal differentiation and maturation, R-m-AEA also increased neurite growth, as evaluated by quantifying and measuring the number of MAP2-positive processes. Taken together, these results demonstrate that CB1R activation induces proliferation, self-renewal and neuronal differentiation from mouse neonatal SVZ cell cultures.

  14. Physical modeling of the formation and evolution of seismically active fault zones

    USGS Publications Warehouse

    Ponomarev, A.V.; Zavyalov, A.D.; Smirnov, V.B.; Lockner, D.A.

    1997-01-01

    Acoustic emission (AE) in rocks is studied as a model of natural seismicity. A special technique for rock loading has been used to help study the processes that control the development of AE during brittle deformation. This technique allows us to extend to hours fault growth which would normally occur very rapidly. In this way, the period of most intense interaction of acoustic events can be studied in detail. Characteristics of the acoustic regime (AR) include the Gutenberg-Richter b-value, spatial distribution of hypocenters with characteristic fractal (correlation) dimension d, Hurst exponent H, and crack concentration parameter Pc. The fractal structure of AR changes with the onset of the drop in differential stress during sample deformation. The change results from the active interaction of microcracks. This transition of the spatial distribution of AE hypocenters is accompanied by a corresponding change in the temporal correlation of events and in the distribution of event amplitudes as signified by a decrease of b-value. The characteristic structure that develops in the low-energy background AE is similar to the sequence of the strongest microfracture events. When the AR fractal structure develops, the variations of d and b are synchronous and d = 3b. This relation which occurs once the fractal structure is formed only holds for average values of d and b. Time variations of d and b are anticorrelated. The degree of temporal correlation of AR has time variations that are similar to d and b variations. The observed variations in laboratory AE experiments are compared with natural seismicity parameters. The close correspondence between laboratory-scale observations and naturally occurring seismicity suggests a possible new approach for understanding the evolution of complex seismicity patterns in nature. ?? 1997 Elsevier Science B.V. All rights reserved.

  15. Vadose zone microbial community structure and activity in metal/radionuclide contaminated sediments. Final technical report

    SciTech Connect

    Balkwill, David L.

    2002-08-17

    This final technical report describes the research carried out during the final two months of the no-cost extension ending 11/14/01. The primary goals of the project were (1) to determine the potential for transformation of Cr(VI) (oxidized, mobile) to Cr(III) (reduced, immobile) under unsaturated conditions as a function of different levels and combinations of (a) chromium, (b) nitrate (co-disposed with Cr), and (c) molasses (inexpensive bioremediation substrate), and (2) to determine population structure and activity in experimental treatments by characterization of the microbial community by signature biomarker analysis and by RT-PCR and terminal restriction fragment length polymorphism (T-RFLP) and 16S ribosomal RNA genes. It was determined early in the one-year no-cost extension period that the T-RFLP approach was problematic in regard to providing information on the identities of microorganisms in the samples examined. As a result, it could not provide the detailed information on microbial community structure that was needed to assess the effects of treatments with chromium, nitrate, and/or molasses. Therefore, we decided to obtain the desired information by amplifying (using TR-PCR, with the same primers used for T-RFLP) and cloning 16S rRNA gene sequences from the same RNA extracts that were used for T-RFLP analysis. We also decided to use a restriction enzyme digest procedure (fingerprinting procedure) to place the clones into types. The primary focus of the research carried out during this report period was twofold: (a) to complete the sequencing of the clones, and (b) to analyze the clone sequences phylogenetically in order to determine the relatedness of the bacteria detected in the samples to each other and to previously described genera and species.

  16. Differential structural and geomorphic mountain-front evolution in an active continental collision zone: the NW Pamir, southern Kyrgyzstan

    NASA Astrophysics Data System (ADS)

    Strecker, M. R.; Hilley, G. E.; Arrowsmith, J. R.; Coutand, I.

    2002-12-01

    Western, central, and eastern segments of the Trans Alai mountain front in the northern Pamir of Kyrgyzstan have accommodated varying degrees of approachment of the Pamir orogen with respect to the Tien Shan mountains to the north. Ongoing collision between the northwestern corner of the Indian indenter and Eurasia has resulted in closure of the intramontane Alai Valley, which separates the Tien Shan and Trans Alai (Pamir) ranges. The different segments highlight the processes of shaping tectonically active mountain fronts in a semi-arid environment. In this study, we have characterized this variation in processes with compilations of regional tectonic information, detailed geologic and geomorphic maps, topographic analyses, and interpretation of seismic reflection data. Along the sinuous western segment of the mountain front, dextrally oblique thrusting has created a wide (>500m) zone of highly erodible fault gouge. This fault zone impinges on the southern Tien Shan, but complete basin closure is prevented by erosion of the westward-flowing Kyzilsu River; the Kyzilsu valley forms the only outlet and is the vestige of a formerly contiguous sedimentary basin linking the Tarim Basin of China with the Tadjik Depression in the west. Numerous large landslides rooted in the fault zone have covered the trace of the active fault, which is partially undercut by the Kyzilsu River. Older, large landslides in this setting are associated with different levels of fluvial terraces of the former or present course of the Kyzilsu River, suggesting a causative relation between lateral fluvial scouring, failure of mechanically weak mountain fronts, ongoing faulting, and mass transfer. Along the linear central segment, deformation is confined to a narrow single south-dipping thrust fault that juxtaposes Pliocene/Pleistocene and Holocene conglomerates. In this sector, the mountain front has numerous Holocene offsets. This prevailing structural style and the long-term deformation are

  17. Differential structural and geomorphic mountain-front evolution in an active continental collision zone: the NW Pamir, southern Kyrgyzstan

    NASA Astrophysics Data System (ADS)

    Strecker, M. R.; Hilley, G. E.; Arrowsmith, J. R.; Coutand, I.

    2003-04-01

    Western, central, and eastern segments of the Trans Alai mountain front in the northern Pamir of Kyrgyzstan have accommodated varying degrees of approachment of the Pamir orogen with respect to the Tien Shan mountains to the north. Ongoing collision between the northwestern corner of the Indian indenter and Eurasia has resulted in closure of the intramontane Alai Valley, which separates the Tien Shan and Trans Alai (Pamir) ranges. The different segments highlight the processes of shaping tectonically active mountain fronts in a semi-arid environment. In this study, we have characterized this variation in processes with compilations of regional tectonic information, detailed geologic and geomorphic maps, topographic analyses, and interpretation of seismic reflection data. Along the sinuous western segment of the mountain front, dextrally oblique thrusting has created a wide (>500m) zone of highly erodible fault gouge. This fault zone impinges on the southern Tien Shan, but complete basin closure is prevented by erosion of the westward-flowing Kyzilsu River; the Kyzilsu valley forms the only outlet and is the vestige of a formerly contiguous sedimentary basin linking the Tarim Basin of China with the Tadjik Depression in the west. Numerous large landslides rooted in the fault zone have covered the trace of the active fault, which is partially undercut by the Kyzilsu River. Older, large landslides in this setting are associated with different levels of fluvial terraces of the former or present course of the Kyzilsu River, suggesting a causative relation between lateral fluvial scouring, failure of mechanically weak mountain fronts, ongoing faulting, and mass transfer. Along the linear central segment, deformation is confined to a narrow single south-dipping thrust fault that juxtaposes Pliocene/Pleistocene and Holocene conglomerates. In this sector, the mountain front has numerous Holocene offsets. This prevailing structural style and the long-term deformation are

  18. Pollution from organic contaminants in Greek marine areas, receiving anthropogenic pressures from intense activities in the coastal zone

    NASA Astrophysics Data System (ADS)

    Hatzianestis, Ioannis

    2014-05-01

    Polycyclic aromatic hydrocarbons (PAHs) are widespread pollutants in marine sediments, receiving the pressures from various anthropogenic activities in the coastal zone. Due to their mutagenic and carcinogenic behaviour, PAHs are classified as priority contaminants to be monitored in environmental quality control schemes. The purpose of this study was to determine the levels of PAHs in coastal areas of Greece directly influenced from the operation of major industrial units in the coastal zone, investigate their sources and evaluate their potential toxicity by comparison against effect - based sediment quality guidelines. Thirty two surface sediment samples were collected from three areas of the Hellenic coastline: a) Antikyra bay in Korinthiakos gulf, influenced from the operation of an alumina and aluminium production plant b) Larymna bay in Noth Evoikos gulf, influenced from the operation of a nickel production plant and c) Aliveri bay in South Evoikos Gulf, influenced from a cement production plant. In all the areas studied, aquaculture and fishing activities have been also developed in the coastal zone. PAH concentrations were determined by GC-MS, after soxhlet extraction and fractionation by silica column chromatography. PAH sources and origin were investigated by applying several isomeric ratio diagnostic criteria. The mean quotient Effect- Range Median (m-ERM) was used to evaluate the potential of adverse effects posed to benthic organisms. Three m-ERM-q values were used to differentiate the probability of observing toxicity and classify sites into four categories: sediments with m-ERM<0.1 have the lowest probability (9%) of being toxic, those with m-ERM from 0.11 to 0.5 have a 21% probability of toxicity, those with m-ERM from 0.51 to 1.5 a 49% probability of toxicity, while sediments with m-ERM >1.5 have the highest probability (76%) of toxicity. Extremely high PAH concentrations more than 100,000 ng/g were found in the close vicinity of the alumina

  19. A Quantitative Study on Packing Density and Pozzolanic Activity of Cementitious Materials Based on the Compaction Packing Model

    NASA Astrophysics Data System (ADS)

    Gong, Jianqing; Chou, Kai; Huang, Zheng Yu; Zhao, Minghua

    2014-08-01

    A brief introduction to the theoretical basis of compaction packing model (CPM) and an over-view of the principle of the specific strength method provided the starting point of this study. Then, research on quantitative relations was carried out to find the correlation between the contribution rate of the pozzolanic activity and the contribution value of packing density when CPM was applied to fine powder mixture systems. The concept of the contribution value of the packing density being in direct correspondence with the contribution rate was proved by the compressive strength results and SEM images. The results indicated that the variation rule of the contribution rate of the pozzolanic activity is similar to that of the contribution value of packing density as calculated by CPM. This means the contribution value of the packing density could approximately simulate the change tendency of the contribution rate of the pozzolanic activity, which is of significant value for the future of mix designs for high and ultra-high performance concrete.

  20. Ventilation rates and activity levels of juvenile jumbo squid under metabolic suppression in the oxygen minimum zone.

    PubMed

    Trübenbach, Katja; Pegado, Maria R; Seibel, Brad A; Rosa, Rui

    2013-02-01

    The Humboldt (jumbo) squid, Dosidicus gigas, is a part-time resident of the permanent oxygen minimum zone (OMZ) in the Eastern Tropical Pacific and, thereby, it encounters oxygen levels below its critical oxygen partial pressure. To better understand the ventilatory mechanisms that accompany the process of metabolic suppression in these top oceanic predators, we exposed juvenile D. gigas to the oxygen levels found in the OMZ (1% O(2), 1 kPa, 10 °C) and measured metabolic rate, activity cycling patterns, swimming mode, escape jet (burst) frequency, mantle contraction frequency and strength, stroke volume and oxygen extraction efficiency. In normoxia, metabolic rate varied between 14 and 29 μmol O(2) g(-1) wet mass h(-1), depending on the level of activity. The mantle contraction frequency and strength were linearly correlated and increased significantly with activity level. Additionally, an increase in stroke volume and ventilatory volume per minute was observed, followed by a mantle hyperinflation process during high activity periods. Squid metabolic rate dropped more than 75% during exposure to hypoxia. Maximum metabolic rate was not achieved under such conditions and the metabolic scope was significantly decreased. Hypoxia changed the relationship between mantle contraction strength and frequency from linear to polynomial with increasing activity, indicating that, under hypoxic conditions, the jumbo squid primarily increases the strength of mantle contraction and does not regulate its frequency. Under hypoxia, jumbo squid also showed a larger inflation period (reduced contraction frequency) and decreased relaxed mantle diameter (shortened diffusion pathway), which optimize oxygen extraction efficiency (up to 82%/34%, without/with consideration of 60% potential skin respiration). Additionally, they breathe 'deeply', with more powerful contractions and enhanced stroke volume. This deep-breathing behavior allows them to display a stable ventilatory volume per

  1. Activation of 15-lipoxygenase by low density lipoprotein in vascular endothelial cells. Relationship to the oxidative modification of low density lipoprotein.

    PubMed

    Derian, C K; Lewis, D F

    1992-01-01

    Oxidatively-modified low density lipoprotein (LDL) is thought to play a significant role in the formation of lipid-laden macrophages, the primary cellular component of atherosclerotic fatty lesions. Recently, lipoxygenases have been implicated as a major enzymatic pathway involved in rabbit endothelial cell-mediated LDL modification. We investigated the effect of LDL on porcine aortic endothelial cell (PAEC) and human umbilical vein (HUVEC) and aortic endothelial cell (HAEC) lipoxygenase activity. By thin layer chromatography, we observed that human LDL stimulated the metabolism of radiolabeled arachidonic acid to 12 + 15-hydroxyeicosatetraenoic acid (HETE) in indomethacin-treated PAEC. Furthermore, radiolabeled linoleic acid, a specific substrate for the 15-lipoxygenase, was metabolized to its respective product 13-hydroxyoctadecadienoic acid (13-HODE) in the presence of LDL. Increased product formation in both studies was inhibited by the lipoxygenase blockers nordihydroguaiaretic acid (NDGA) and RG 6866. 15-HETE was confirmed as the predominant HETE product in LDL-treated cells by high performance liquid chromatography. Both porcine- and human-derived LDL stimulated the CL release of 15-HETE from cells as determined by radioimmunoassay. Release of immunoreactive 15-HETE was inhibited by NDGA, RG 6866, and 5,8,11,14-eicosatetraynoic acid (ETYA) but not by the selective 5-lipoxygenase inhibitor RG 5901. These lipoxygenase inhibitors had similar effects on the modification of LDL. Our results suggest that the oxidative modification of LDL by endothelial cells may be mediated in part through activation of 15-lipoxygenase.

  2. Effect of Methionine Restriction on Bone Density and NK Cell Activity

    PubMed Central

    Dong, Jingming

    2016-01-01

    Methionine restriction (MR) is proven to increase the lifespan; and it also affects the bone density and the innate immune system. The aim of this study is to explore the effect of methionine restriction on bone density and natural killer (NK) cells. C57BL/6J mice were subjected to either basal diet (BD, containing 0.80% methionine) or methionine-restricted diet (containing 0.14% methionine). Mice with MR diet displayed reduced bone mass and decrease in the cytotoxicity of NK from the spleen, compared to BD animals. Also, mice with MR diet had an inferior body weight (P < 0.05) and higher plasma levels of adiponectin and FGF21 (P < 0.05) but lower concentrations of leptin and IGF-1 (P < 0.05). Overall, the investigation shows that methionine affects bone density and NK cell cytotoxicity. PMID:27882323

  3. Multiscale seismic imaging of active fault zones for hazard assessment: A case study of the Santa Monica fault zone, Los Angeles, California

    USGS Publications Warehouse

    Pratt, T.L.; Dolan, J.F.; Odum, J.K.; Stephenson, W.J.; Williams, R.A.; Templeton, M.E.

    1998-01-01

    High-resolution seismic reflection profiles at two different scales were acquired across the transpressional Santa Monica Fault of north Los Angeles as part of an integrated hazard assessment of the fault. The seismic data confirm the location of the fault and related shallow faulting seen in a trench to deeper structures known from regional studies. The trench shows a series of near-vertical strike-slip faults beneath a topographic scarp inferred to be caused by thrusting on the Santa Monica fault. Analysis of the disruption of soil horizons in the trench indicates multiple earthquakes have occurred on these strike-slip faults within the past 50 000 years, with the latest being 1000 to 3000 years ago. A 3.8-km-long, high-resolution seismic reflection profile shows reflector truncations that constrain the shallow portion of the Santa Monica Fault (upper 300 m) to dip northward between 30?? and 55??, most likely 30?? to 35??, in contrast to the 60?? to 70?? dip interpreted for the deeper portion of the fault. Prominent, nearly continuous reflectors on the profile are interpreted to be the erosional unconformity between the 1.2 Ma and older Pico Formation and the base of alluvial fan deposits. The unconformity lies at depths of 30-60 m north of the fault and 110-130 m south of the fault, with about 100 m of vertical displacement (180 m of dip-slip motion on a 30??-35?? dipping fault) across the fault since deposition of the upper Pico Formation. The continuity of the unconformity on the seismic profile constrains the fault to lie in a relatively narrow (50 m) zone, and to project to the surface beneath Ohio Avenue immediately south of the trench. A very high-resolution seismic profile adjacent to the trench images reflectors in the 15 to 60 m depth range that are arched slightly by folding just north of the fault. A disrupted zone on the profile beneath the south end of the trench is interpreted as being caused by the deeper portions of the trenched strike

  4. Spatial and temporal patterns of carabid activity-density in cereals do not explain levels of predation on weed seeds.

    PubMed

    Saska, P; van der Werf, W; de Vries, E; Westerman, P R

    2008-04-01

    Seed predation is an important component of seed mortality of weeds in agro-ecosystems, but the agronomic use and management of this natural weed suppression is hampered by a lack of insight in the underlying ecological processes. In this paper, we investigate whether and how spatial and temporal variation in activity-density of granivorous ground beetles (Coleoptera: Carabidae) results in a corresponding pattern of seed predation. Activity-density of carabids was measured by using pitfall traps in two organic winter wheat fields from March to July 2004. Predation of seeds (Capsella bursa-pastoris, Lamium amplexicaule, Poa annua and Stellaria media) was assessed using seed cards at the same sites and times. As measured by pitfall traps, carabids were the dominant group of insects that had access to the seed cards. In the field, predation of the four different species of seed was in the order: C. bursa-pastoris>P. annua>S. media>L. amplexicaule; and this order of preference was confirmed in the laboratory using the dominant species of carabid. On average, seed predation was higher in the field interior compared to the edge, whereas catches of carabids were highest near the edge. Weeks with elevated seed predation did not concur with high activity-density of carabids. Thus, patterns of spatial and temporal variation in seed predation were not matched by similar patterns in the abundance of granivorous carabid beetles. The lack of correspondence is ascribed to effects of confounding factors, such as weather, the background density of seeds, the composition of the carabid community, and the phenology and physiological state of the beetles. Our results show that differences in seed loss among weed species may be predicted from laboratory trials on preference. However, predator activity-density, as measured in pitfall traps, is an insufficient predictor of seed predation over time and space within a field.

  5. Magnetized Accretion and Dead Zones in Protostellar Disks

    NASA Astrophysics Data System (ADS)

    Dzyurkevich, Natalia; Turner, Neal J.; Henning, Thomas; Kley, Wilhelm

    2013-03-01

    The edges of magnetically dead zones in protostellar disks have been proposed as locations where density bumps may arise, trapping planetesimals and helping form planets. Magneto-rotational turbulence in magnetically active zones provides both accretion of gas on the star and transport of mass to the dead zone. We investigate the location of the magnetically active regions in a protostellar disk around a solar-type star, varying the disk temperature, surface density profile, and dust-to-gas ratio. We also consider stellar masses between 0.4 and 2 M ⊙, with corresponding adjustments in the disk mass and temperature. The dead zone's size and shape are found using the Elsasser number criterion with conductivities including the contributions from ions, electrons, and charged fractal dust aggregates. The charged species' abundances are found using the approach proposed by Okuzumi. The dead zone is in most cases defined by the ambipolar diffusion. In our maps, the dead zone takes a variety of shapes, including a fish tail pointing away from the star and islands located on and off the midplane. The corresponding accretion rates vary with radius, indicating locations where the surface density will increase over time, and others where it will decrease. We show that density bumps do not readily grow near the dead zone's outer edge, independently of the disk parameters and the dust properties. Instead, the accretion rate peaks at the radius where the gas-phase metals freeze out. This could lead to clearing a valley in the surface density, and to a trap for pebbles located just outside the metal freezeout line.

  6. MAGNETIZED ACCRETION AND DEAD ZONES IN PROTOSTELLAR DISKS

    SciTech Connect

    Dzyurkevich, Natalia; Henning, Thomas; Turner, Neal J.; Kley, Wilhelm

    2013-03-10

    The edges of magnetically dead zones in protostellar disks have been proposed as locations where density bumps may arise, trapping planetesimals and helping form planets. Magneto-rotational turbulence in magnetically active zones provides both accretion of gas on the star and transport of mass to the dead zone. We investigate the location of the magnetically active regions in a protostellar disk around a solar-type star, varying the disk temperature, surface density profile, and dust-to-gas ratio. We also consider stellar masses between 0.4 and 2 M{sub Sun }, with corresponding adjustments in the disk mass and temperature. The dead zone's size and shape are found using the Elsasser number criterion with conductivities including the contributions from ions, electrons, and charged fractal dust aggregates. The charged species' abundances are found using the approach proposed by Okuzumi. The dead zone is in most cases defined by the ambipolar diffusion. In our maps, the dead zone takes a variety of shapes, including a fish tail pointing away from the star and islands located on and off the midplane. The corresponding accretion rates vary with radius, indicating locations where the surface density will increase over time, and others where it will decrease. We show that density bumps do not readily grow near the dead zone's outer edge, independently of the disk parameters and the dust properties. Instead, the accretion rate peaks at the radius where the gas-phase metals freeze out. This could lead to clearing a valley in the surface density, and to a trap for pebbles located just outside the metal freezeout line.

  7. Late Cenozoic deformation of the Da'an-Dedu Fault Zone and its implications for the earthquake activities in the Songliao basin, NE China

    NASA Astrophysics Data System (ADS)

    Zhongyuan, Yu; Peizhen, Zhang; Wei, Min; Qinghai, Wei; Limei, Wang; Bin, Zhao; Shuang, Liu; Jian, Kang

    2015-08-01

    The Da'an-Dedu Fault Zone is a major tectonic feature cutting through the Songliao Basin from south to north in NE China. Five earthquakes with magnitudes over 5 that occurred during the past 30 years suggest the fault zone is a seismogenic structure with future seismic potential. The structural pattern, tectonic history, Quaternary activity and seismic potential have previously been unknown due to the Quaternary sedimentary coverage and lack of large historic earthquakes (M > 7). In this paper, we use seismic reflection profiles and drilling from petroleum explorations and shallow-depth seismic reflections to study those problems. The total length of the Da'an-Dedu Fault Zone is more than 400 km; modern seismicity delineates it into 4 segments each with a length of 90-100 km. In cross-section view, the folds and associated faults form a complex structural belt with a width of more than 10 km. Shallow-level seismic reflection across the Da'an-Dedu Fault Zone reveals that the Late Quaternary sediments were folded and faulted, indicating its present tectonic activity. The Da'an-Dedu Fault Zone and Songliao Basin have been subjected to three stages of tectonic evolution: a rifting stage characterized by normal faulting and extension (∼145-112 Ma), a prolonged stage of thermal subsidence (∼112-65 Ma), and a tectonic reversal that has been taking place since ∼65 Ma. Our shallow-level reflection profiles show that the folding and reverse faulting have influenced the Late Quaternary sediments. The seismicity and moderate earthquakes suggest that the tectonic activity persists today. The deformation rate across the Da'an-Dedu Fault Zone, however, is measured to be very slow. In conjunction with the inference that most deformation in NE China may be taken up by the Yilan-Yitong Fault Zone bounding the Songliao Basin to the east, we suggest moderate earthquake potential and thus moderate seismic hazards along the Da'an-Dedu Fault Zone. The geological structures, which

  8. Effects of watershed densities of animal feeding operations on nutrient concentrations and estrogenic activity in agricultural streams

    USGS Publications Warehouse

    Ciparis, S.; Iwanowicz, L.R.; Voshell, J.R.

    2012-01-01

    Application of manures from animal feeding operations (AFOs) as fertilizer on agricultural land can introduce nutrients and hormones (e.g. estrogens) to streams. A landscape-scale study was conducted in the Shenandoah River watershed (Virginia, USA) in order to assess the relationship between densities of AFOs in watersheds of agricultural streams and in-stream nutrient concentrations and estrogenic activity. The effect of wastewater treatment plants (WWTPs) on nutrients and estrogenic activity was also evaluated. During periods of high and low flow, dissolved inorganic nitrogen (DIN) and orthophosphate (PO 4-P) concentrations were analyzed and estrogens/estrogenic compounds were extracted and quantified as17??-estradiol equivalents (E2Eq) using a bioluminescent yeast estrogen screen. Estrogenic activity was measurable in the majority of collected samples, and 20% had E2Eq concentrations >1ng/L. Relatively high concentrations of DIN (>1000??g/L) were also frequently detected. During all sampling periods, there were strong relationships between watershed densities of AFOs and in-stream concentrations of DIN (R 2=0.56-0.81) and E2Eq (R 2=0.39-0.75). Relationships between watershed densities of AFOs and PO 4-P were weaker, but were also significant (R 2=0.27-0.57). When combined with the effect of watershed AFO density, streams receiving WWTP effluent had higher concentrations of PO 4-P than streams without WWTP discharges, and PO 4-P was the only analyte with a consistent relationship to WWTPs. The results of this study suggest that as the watershed density of AFOs increases, there is a proportional increase in the potential for nonpoint source pollution of agricultural streams and their receiving waters by nutrients, particularly DIN, and compounds that can cause endocrine disruption in aquatic organisms. ?? 2011 Elsevier B.V.

  9. Effects of watershed densities of animal feeding operations on nutrient concentrations and estrogenic activity in agricultural streams

    USGS Publications Warehouse

    Ciparis, Serena; Iwanowicz, Luke R.; Voshell, J. Reese

    2012-01-01

    Application of manures from animal feeding operations (AFOs) as fertilizer on agricultural land can introduce nutrients and hormones (e.g. estrogens) to streams. A landscape-scale study was conducted in the Shenandoah River watershed (Virginia, USA) in order to assess the relationship between densities of AFOs in watersheds of agricultural streams and in-stream nutrient concentrations and estrogenic activity. The effect of wastewater treatment plants (WWTPs) on nutrients and estrogenic activity was also evaluated. During periods of high and low flow, dissolved inorganic nitrogen (DIN) and orthophosphate (PO4-P) concentrations were analyzed and estrogens/estrogenic compounds were extracted and quantified as17β-estradiol equivalents (E2Eq) using a bioluminescent yeast estrogen screen. Estrogenic activity was measurable in the majority of collected samples, and 20% had E2Eq concentrations > 1 ng/L. Relatively high concentrations of DIN (> 1000 μg/L) were also frequently detected. During all sampling periods, there were strong relationships between watershed densities of AFOs and in-stream concentrations of DIN (R2 = 0.56–0.81) and E2Eq (R2 = 0.39–0.75). Relationships between watershed densities of AFOs and PO4-P were weaker, but were also significant (R2 = 0.27–0.57). When combined with the effect of watershed AFO density, streams receiving WWTP effluent had higher concentrations of PO4-P than streams without WWTP discharges, and PO4-P was the only analyte with a consistent relationship to WWTPs. The results of this study suggest that as the watershed density of AFOs increases, there is a proportional increase in the potential for nonpoint source pollution of agricultural streams and their receiving waters by nutrients, particularly DIN, and compounds that can cause endocrine disruption in aquatic organisms.

  10. Cytoarchitecture, Proliferative Activity and Neuroblast Migration in the Subventricular Zone and Lateral Ventricle Extension of the Adult Guinea Pig Brain.

    PubMed

    Jara, Nery; Cifuentes, Manuel; Martínez, Fernando; Salazar, Katterine; Nualart, Francisco

    2016-10-01

    In the mouse brain, neuroblasts generated in the subventricular zone (SVZ) migrate to the olfactory bulb (OB) through the rostral migratory stream (RMS). Although the RMS is not present in the human brain, a migratory pathway that is organized around a ventricular cavity that reaches the OB has been reported. A similar cavity, the lateral ventricle extension (LVE), is found in the adult guinea pig brain. Therefore, we analyzed cytoarchitecture, proliferative activity and precursor cell migration in the SVZ and LVE of 1-, 6- and 12-month-old guinea pigs. In young animals, we used confocal spectral and transmission electron microscopy to identify neuroblasts, astrocytes, and progenitor cells in the SVZ and LVE. Analysis of peroxidase diffusion demonstrated that the LVE was a continuous cavity lined by ependymal cells and surrounded by neuroblasts. Precursor cells were mostly located in the SVZ and migrated from the SVZ to the OB through the LVE. Finally, analysis of 6- and 12-month-old guinea pigs revealed that the LVE was preserved in older animals; however, the number of neurogenic cells was significantly reduced. Consequently, we propose that the guinea pig brain may be used as a new neurogenic model with increased similarity to humans, given that the LVE connects the LV with the OB, as has been described in humans, and that the LVE works a migratory pathway. Stem Cells 2016;34:2574-2586.

  11. Active and inactive phases of the South Pacific Convergence Zone and changes in global circulation patterns - A case study

    NASA Technical Reports Server (NTRS)

    Huang, H.-J.; Vincent, D. G.

    1988-01-01

    A set of FGGE Level III-b analyses produced at the NASA Goddard Laboratory for Atmospheres (GLA) is used to examine changes that occur in the global-scale circulation features during the period, January 10 - February 13,1979. In the first two weeks of this period, the South Pacific Convergence Zone (SPCZ) and its convective cloud band were observed to be dominant features of the circulation. Subsequent to January 24, there were marked changes in the global-scale circulation, particularly in the Southern Hemisphere tropics. Concomitant with these changes was the disappearance of the SPCZ and its cloud band. The primary purpose of this study is to compare some general circulation parameters, which frequently correspond to deep convection, for two 15-day periods: January 10-24, when the SPCZ was very convectively active, and January 28 - February 11 when it was inactive. Daily variations of some parameters are also shown. It is seen that distinct changes occur in each parameter by the end of the first period, particularly in the vicinity of the SPCZ. Suggestions are offered regarding mechanisms which might be responsible for the observed changes.

  12. A high affinity RIM-binding protein/Aplip1 interaction prevents the formation of ectopic axonal active zones

    PubMed Central

    Siebert, Matthias; Böhme, Mathias A; Driller, Jan H; Babikir, Husam; Mampell, Malou M; Rey, Ulises; Ramesh, Niraja; Matkovic, Tanja; Holton, Nicole; Reddy-Alla, Suneel; Göttfert, Fabian; Kamin, Dirk; Quentin, Christine; Klinedinst, Susan; Andlauer, Till FM; Hell, Stefan W; Collins, Catherine A; Wahl, Markus C; Loll, Bernhard; Sigrist, Stephan J

    2015-01-01

    Synaptic vesicles (SVs) fuse at active zones (AZs) covered by a protein scaffold, at Drosophila synapses comprised of ELKS family member Bruchpilot (BRP) and RIM-binding protein (RBP). We here demonstrate axonal co-transport of BRP and RBP using intravital live imaging, with both proteins co-accumulating in axonal aggregates of several transport mutants. RBP, via its C-terminal Src-homology 3 (SH3) domains, binds Aplip1/JIP1, a transport adaptor involved in kinesin-dependent SV transport. We show in atomic detail that RBP C-terminal SH3 domains bind a proline-rich (PxxP) motif of Aplip1/JIP1 with submicromolar affinity. Pointmutating this PxxP motif provoked formation of ectopic AZ-like structures at axonal membranes. Direct interactions between AZ proteins and transport adaptors seem to provide complex avidity and shield synaptic interaction surfaces of pre-assembled scaffold protein transport complexes, thus, favouring physiological synaptic AZ assembly over premature assembly at axonal membranes. DOI: http://dx.doi.org/10.7554/eLife.06935.001 PMID:26274777

  13. Spermidine Suppresses Age-Associated Memory Impairment by Preventing Adverse Increase of Presynaptic Active Zone Size and Release

    PubMed Central

    Gupta, Varun K.; Pech, Ulrike; Fulterer, Andreas; Ender, Anatoli; Mauermann, Stephan F.; Andlauer, Till F. M.; Beuschel, Christine; Thriene, Kerstin; Quentin, Christine; Schwärzel, Martin; Mielke, Thorsten; Madeo, Frank; Dengjel, Joern; Fiala, André; Sigrist, Stephan J.

    2016-01-01

    Memories are assumed to be formed by sets of synapses changing their structural or functional performance. The efficacy of forming new memories declines with advancing age, but the synaptic changes underlying age-induced memory impairment remain poorly understood. Recently, we found spermidine feeding to specifically suppress age-dependent impairments in forming olfactory memories, providing a mean to search for synaptic changes involved in age-dependent memory impairment. Here, we show that a specific synaptic compartment, the presynaptic active zone (AZ), increases the size of its ultrastructural elaboration and releases significantly more synaptic vesicles with advancing age. These age-induced AZ changes, however, were fully suppressed by spermidine feeding. A genetically enforced enlargement of AZ scaffolds (four gene-copies of BRP) impaired memory formation in young animals. Thus, in the Drosophila nervous system, aging AZs seem to steer towards the upper limit of their operational range, limiting synaptic plasticity and contributing to impairment of memory formation. Spermidine feeding suppresses age-dependent memory impairment by counteracting these age-dependent changes directly at the synapse. PMID:27684064

  14. Crustal Structure Across the Okavango Rift Zone, Botswana: Initial Results From the PRIDE-SEISORZ Active-Source Seismic Profile

    NASA Astrophysics Data System (ADS)

    Canales, J. P.; Moffat, L.; Lizarralde, D.; Laletsang, K.; Harder, S. H.; Kaip, G.; Modisi, M.

    2015-12-01

    The PRIDE project aims to understand the processes of continental rift initiation and evolution by analyzing along-axis trends in the southern portion of the East Africa Rift System, from Botswana through Zambia and Malawi. The SEISORZ active-source seismic component of PRIDE focused on the Okavango Rift Zone (ORZ) in northwestern Botswana, with the main goal of imaging the crustal structure across the ORZ. This will allow us to estimate total crustal extension, determine the pattern and amount of thinning, assess the possible presence of melt within the rift zone, and assess the contrasts in crustal blocks across the rift, which closely follows the trend of a fold belt. In November 2014 we conducted a crustal-scale, 450-km-long seismic refraction/wide-angle reflection profile consisting of 19 sources (shots in 30-m-deep boreholes) spaced ~25 km apart from each other, and 900 receivers (IRIS/PASSCAL "Texan" dataloggers and 4.5Hz geophones) with ~500 m spacing. From NW to SE, the profile crosses several tectonic domains: the Congo craton, the Damara metamorphic belt and the Ghanzi-Chobe fold belt where the axis of the ORZ is located, and continues into the Kalahari craton. The record sections display clear crustal refraction (Pg) and wide-angle Moho reflection (PmP) phases for all 17 of the good-quality shots, and a mantle refraction arrival (Pn), with the Pg-PmP-Pn triplication appearing at 175 km offset. There are distinct changes in the traveltime and amplitude of these phases along the transect, and on either side of the axis, that seem to correlate with sharp transitions across tectonic terrains. Initial modeling suggests: (1) the presence of a sedimentary half-graben structure at the rift axis beneath the Okavango delta, bounded to the SE by the Kunyere-Thamalakane fault system; (2) faster crustal Vp in the domains to the NW of the ORZ; and (3) thicker crust (45-50 km) at both ends of the profile within the Congo and Kalahari craton domains than at the ORZ and

  15. Soil Moisture Active Passive (SMAP) Mission Level 4 Surface and Root Zone Soil Moisture (L4_SM) Product Specification Document

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf H.; Ardizzone, Joseph V.; Kim, Gi-Kong; Lucchesi, Robert A.; Smith, Edmond B.; Weiss, Barry H.

    2015-01-01

    This is the Product Specification Document (PSD) for Level 4 Surface and Root Zone Soil Moisture (L4_SM) data for the Science Data System (SDS) of the Soil Moisture Active Passive (SMAP) project. The L4_SM data product provides estimates of land surface conditions based on the assimilation of SMAP observations into a customized version of the NASA Goddard Earth Observing System, Version 5 (GEOS-5) land data assimilation system (LDAS). This document applies to any standard L4_SM data product generated by the SMAP Project. The Soil Moisture Active Passive (SMAP) mission will enhance the accuracy and the resolution of space-based measurements of terrestrial soil moisture and freeze-thaw state. SMAP data products will have a noteworthy impact on multiple relevant and current Earth Science endeavors. These include: Understanding of the processes that link the terrestrial water, the energy and the carbon cycles, Estimations of global water and energy fluxes over the land surfaces, Quantification of the net carbon flux in boreal landscapes Forecast skill of both weather and climate, Predictions and monitoring of natural disasters including floods, landslides and droughts, and Predictions of agricultural productivity. To provide these data, the SMAP mission will deploy a satellite observatory in a near polar, sun synchronous orbit. The observatory will house an L-band radiometer that operates at 1.40 GHz and an L-band radar that operates at 1.26 GHz. The instruments will share a rotating reflector antenna with a 6 meter aperture that scans over a 1000 km swath.

  16. Response of the turbidity maximum zone in the Yangtze River Estuary due to human activities during the dry season.

    PubMed

    Chen, Xiaofeng; Shen, Zhenyao; Yang, Ye

    2016-09-01

    The interaction between a river and the sea results in a turbidity maximum zone (TMZ) within the estuary, which has a great impact on the local ecosystem. In the Yangtze River Estuary, the magnitude and extent of the TMZ vary with water discharge. In this study, the cumulative human activity altered the water discharge regime from the river to the estuary. In the post-Three Gorges Dam (TGD) period, water discharge increased by 35.10 % at Datong in February compared with that in the pre-TGD period. The effects of water discharge variation on the characteristics of the TMZ were analyzed during spring and neap tidal periods using the three-dimensional environmental fluid dynamic code (EFDC) model. The area of the TMZ decreased by 3.11 and 17.39 % during neap and spring tides, respectively. In addition, the upper limit of the TMZ moved 11.68 km seaward during neap tide, whereas the upper limit of the TMZ in the upstream and downstream areas moved seaward 9.65 and 2.34 km, respectively, during spring tide. These findings suggest that the area and location of the TMZ are more sensitive to upstream runoff during spring tide than during neap tide. These changes in the TMZ will impact the biochemical processes in the Yangtze River Estuary. In the foreseeable future, the distribution characteristic of TMZ will inevitably change due to variations in the Yangtze River discharge resulting from new human activities (i.e., new dams), which are being constructed upstream in the Yangtze River system.

  17. Control of biologically active degradation zones by vertical heterogeneity: Applications in fractured media. 1998 annual progress report

    SciTech Connect

    Colwell, F.S.; Smith, R.; McKinley, J.P.; Fredrickson, J.K.; Onstott, T.C.; Reysenbach, A.L.

    1998-06-01

    'The objective of this research is to determine the relationship between biologically active contaminant degradation zones in a fractured, subsurface medium and vertical geological heterogeneities. The research is being performed on samples collected from the Test Area North (TAN) site at the Idaho National Engineering and Environmental Laboratory (INEEL) where a dissolved trichloroethylene (TCE) plume is migrating in the basalts and interbed sediments of the Eastern Snake River Plain (ESRP) aquifer. Results are leading to an enhanced understanding of the constraints placed on the activities and distribution of TCE-degrading organisms by the geochemical and hydrological environment. This understanding allows better decisions to be made regarding the use of remedial technologies such as natural attenuation and in-situ bioremediation at geologically complex waste sites. Through this research, investigations conducted by the DOE Subsurface Science Program at TAN have been extended in order to develop a mechanistic understanding of the coupled geomicrobial and hydrogeochemical processes that are necessary to predict field-scale intrinsic degradation rates of TCE. The research objective is being accomplished by characterizing paired cores and water samples from boreholes located in differing geochemical and flow environments within the plume. Analysis of these samples will allow the determination of the spatial correlation between microbial degradation and preferred flow paths for the contaminant and required electron donors and acceptors. A combination of traditional microbiological methods (e.g., enrichments) and molecular tools are being used to characterize the indigenous microbial communities. This report summarizes work conducted after 1.5 years of a three year project.'

  18. Activity-dependent endogenous taurine release facilitates excitatory neurotransmission in the neocortical marginal zone of neonatal rats.

    PubMed

    Qian, Taizhe; Chen, Rongqing; Nakamura, Masato; Furukawa, Tomonori; Kumada, Tatsuro; Akita, Tenpei; Kilb, Werner; Luhmann, Heiko J; Nakahara, Daiichiro; Fukuda, Atsuo

    2014-01-01

    In the developing cerebral cortex, the marginal zone (MZ), consisting of early-generated neurons such as Cajal-Retzius cells, plays an important role in cell migration and lamination. There is accumulating evidence of widespread excitatory neurotransmission mediated by γ-aminobutyric acid (GABA) in the MZ. Cajal-Retzius cells express not only GABAA receptors but also α2/β subunits of glycine receptors, and exhibit glycine receptor-mediated depolarization due to high [Cl(-)]i. However, the physiological roles of glycine receptors and their endogenous agonists during neurotransmission in the MZ are yet to be elucidated. To address this question, we performed optical imaging from the MZ using the voltage-sensitive dye JPW1114 on tangential neocortical slices of neonatal rats. A single electrical stimulus evoked an action-potential-dependent optical signal that spread radially over the MZ. The amplitude of the signal was not affected by glutamate receptor blockers, but was suppressed by either GABAA or glycine receptor antagonists. Combined application of both antagonists nearly abolished the signal. Inhibition of Na(+), K(+)-2Cl(-) cotransporter by 20 µM bumetanide reduced the signal, indicating that this transporter contributes to excitation. Analysis of the interstitial fluid obtained by microdialysis from tangential neocortical slices with high-performance liquid chromatography revealed that GABA and taurine, but not glycine or glutamate, were released in the MZ in response to the electrical stimulation. The ambient release of taurine was reduced by the addition of a voltage-sensitive Na(+) channel blocker. Immunohistochemistry and immunoelectron microscopy indicated that taurine was stored both in Cajal-Retzius and non-Cajal-Retzius cells in the MZ, but was not localized in presynaptic structures. Our results suggest that activity-dependent non-synaptic release of endogenous taurine facilitates excitatory neurotransmission through activation of glycine

  19. Tonic activation of GLUK5 kainate receptors decreases neuroblast migration in whole-mounts of the subventricular zone

    PubMed Central

    Platel, Jean-Claude; Heintz, Tristan; Young, Stephanie; Gordon, Valerie; Bordey, Angélique

    2008-01-01

    In the postnatal subventricular zone (SVZ), neuroblasts migrate in chains along the lateral ventricle towards the olfactory bulb. AMPA/kainate receptors as well as metabotropic glutamate receptors subtype 5 (mGluR5) are expressed in SVZ cells. However, the cells expressing these receptors and the function of these receptors remain unexplored. We thus examined whether SVZ neuroblasts express mGluR5 and Ca2+-permeable kainate receptors in mouse slices. Doublecortin (DCX)-immunopositive cells (i.e. neuroblasts) immunostained positive for mGluR5 and GLUK5–7-containing kainate receptors. RT-PCR from ∼10 GFP-fluorescent cell aspirates obtained in acute slices from transgenic mice expressing green fluorescent protein (GFP) under the DCX promoter showed mGluR5 and GLUK5 receptor mRNA in SVZ neuroblasts. Patch-clamp data suggest that ∼60% of neuroblasts express functional GLUK5-containing receptors. Activation of mGluR5 and GLUK5-containing receptors induced Ca2+ increases in 50% and 60% of SVZ neuroblasts, respectively, while most neuroblasts displayed GABAA-mediated Ca2+ responses. To examine the effects of these receptors on the speed of neuroblast migration, we developed a whole-mount preparation of the entire lateral ventricle from postnatal day (P) 20–25 DCX-GFP mice. The GABAA receptor (GABAAR) antagonist bicuculline increased the speed of neuroblast migration by 27%, as previously reported in acute slices. While the mGluR5 antagonist MPEP did not affect the speed of neuroblast migration, the homomeric and heteromeric GLUK5 receptor antagonists, NS3763 and UB302, respectively, increased the migration speed by 38%. These data show that although both GLUK5 receptor and mGluR5 activations increase Ca2+ in neuroblasts, only GLUK5 receptors tonically reduce the speed of neuroblast migration along the lateral ventricle. PMID:18565997

  20. Altered Active Zones, Vesicle Pools, Nerve Terminal Conductivity, and Morphology during Experimental MuSK Myasthenia Gravis

    PubMed Central

    Patel, Vishwendra; Oh, Anne; Voit, Antanina; Sultatos, Lester G.; Babu, Gopal J.; Wilson, Brenda A.; Ho, Mengfei; McArdle, Joseph J.

    2014-01-01

    Recent studies demonstrate reduced motor-nerve function during autoimmune muscle-specific tyrosine kinase (MuSK) myasthenia gravis (MG). To further understand the basis of motor-nerve dysfunction during MuSK-MG, we immunized female C57/B6 mice with purified rat MuSK ectodomain. Nerve-muscle preparations were dissected and neuromuscular junctions (NMJs) studied electrophysiologically, morphologically, and biochemically. While all mice produced antibodies to MuSK, only 40% developed respiratory muscle weakness. In vitro study of respiratory nerve-muscle preparations isolated from these affected mice revealed that 78% of NMJs produced endplate currents (EPCs) with significantly reduced quantal content, although potentiation and depression at 50 Hz remained qualitatively normal. EPC and mEPC amplitude variability indicated significantly reduced number of vesicle-release sites (active zones) and reduced probability of vesicle release. The readily releasable vesicle pool size and the frequency of large amplitude mEPCs also declined. The remaining NMJs had intermittent (4%) or complete (18%) failure of neurotransmitter release in response to 50 Hz nerve stimulation, presumably due to blocked action potential entry into the nerve terminal, which may arise from nerve terminal swelling and thinning. Since MuSK-MG-affected muscles do not express the AChR γ subunit, the observed prolongation of EPC decay time was not due to inactivity-induced expression of embryonic acetylcholine receptor, but rather to reduced catalytic activity of acetylcholinesterase. Muscle protein levels of MuSK did not change. These findings provide novel insight into the pathophysiology of autoimmune MuSK-MG. PMID:25438154

  1. Activated carbons derived from coconut shells as high energy density cathode material for Li-ion capacitors.

    PubMed

    Jain, Akshay; Aravindan, Vanchiappan; Jayaraman, Sundaramurthy; Kumar, Palaniswamy Suresh; Balasubramanian, Rajasekhar; Ramakrishna, Seeram; Madhavi, Srinivasan; Srinivasan, M P

    2013-10-21

    In this manuscript, a dramatic increase in the energy density of ~ 69 Wh kg⁻¹ and an extraordinary cycleability ~ 2000 cycles of the Li-ion hybrid electrochemical capacitors (Li-HEC) is achieved by employing tailored activated carbon (AC) of ~ 60% mesoporosity derived from coconut shells (CS). The AC is obtained by both physical and chemical hydrothermal carbonization activation process, and compared to the commercial AC powders (CAC) in terms of the supercapacitance performance in single electrode configuration vs. Li. The Li-HEC is fabricated with commercially available Li₄Ti₅O₁₂ anode and the coconut shell derived AC as cathode in non-aqueous medium. The present research provides a new routine for the development of high energy density Li-HEC that employs a mesoporous carbonaceous electrode derived from bio-mass precursors.

  2. Activated carbons derived from coconut shells as high energy density cathode material for Li-ion capacitors

    PubMed Central

    Jain, Akshay; Aravindan, Vanchiappan; Jayaraman, Sundaramurthy; Kumar, Palaniswamy Suresh; Balasubramanian, Rajasekhar; Ramakrishna, Seeram; Madhavi, Srinivasan; Srinivasan, M. P.

    2013-01-01

    In this manuscript, a dramatic increase in the energy density of ~ 69 Wh kg−1 and an extraordinary cycleability ~ 2000 cycles of the Li-ion hybrid electrochemical capacitors (Li-HEC) is achieved by employing tailored activated carbon (AC) of ~ 60% mesoporosity derived from coconut shells (CS). The AC is obtained by both physical and chemical hydrothermal carbonization activation process, and compared to the commercial AC powders (CAC) in terms of the supercapacitance performance in single electrode configuration vs. Li. The Li-HEC is fabricated with commercially available Li4Ti5O12 anode and the coconut shell derived AC as cathode in non-aqueous medium. The present research provides a new routine for the development of high energy density Li-HEC that employs a mesoporous carbonaceous electrode derived from bio-mass precursors. PMID:24141527

  3. Modeling of complex antibody elution behavior under high protein load densities in ion exchange chromatography using an asymmetric activity coefficient.

    PubMed

    Huuk, Thiemo C; Hahn, Tobias; Doninger, Katharina; Griesbach, Jan; Hepbildikler, Stefan; Hubbuch, Jürgen

    2017-03-01

    A main requirement for the implementation of model-based process development in industry is the capability of the model to predict high protein load densities. The frequently used steric mass action isotherm assumes a thermodynamically ideal system and, hence constant activity coefficients. In this manuscript, an industrial antibody purification problem under high load conditions is considered where this assumption does not hold. The high protein load densities, as commonly applied in industrial downstream processing, may lead to complex elution peak shapes. Using Mollerup's generalized ion-exchange isotherm (GIEX), the observed elution peak shapes could be modeled. To this end, the GIEX isotherm introduced two additional parameters to approximate the asymmetric activity coefficient. The effects of these two parameters on the curvature of the adsorption isotherm and the resulting chromatogram are investigated. It could be shown that they can be determined by inverse peak fitting and conform with the mechanistic demands of model-based process development.

  4. Activated carbons derived from coconut shells as high energy density cathode material for Li-ion capacitors

    NASA Astrophysics Data System (ADS)

    Jain, Akshay; Aravindan, Vanchiappan; Jayaraman, Sundaramurthy; Kumar, Palaniswamy Suresh; Balasubramanian, Rajasekhar; Ramakrishna, Seeram; Madhavi, Srinivasan; Srinivasan, M. P.

    2013-10-01

    In this manuscript, a dramatic increase in the energy density of ~ 69 Wh kg-1 and an extraordinary cycleability ~ 2000 cycles of the Li-ion hybrid electrochemical capacitors (Li-HEC) is achieved by employing tailored activated carbon (AC) of ~ 60% mesoporosity derived from coconut shells (CS). The AC is obtained by both physical and chemical hydrothermal carbonization activation process, and compared to the commercial AC powders (CAC) in terms of the supercapacitance performance in single electrode configuration vs. Li. The Li-HEC is fabricated with commercially available Li4Ti5O12 anode and the coconut shell derived AC as cathode in non-aqueous medium. The present research provides a new routine for the development of high energy density Li-HEC that employs a mesoporous carbonaceous electrode derived from bio-mass precursors.

  5. Density Functional Study of the Structure, Stability and Oxygen Reduction Activity of Ultrathin Platinum Nanowires

    SciTech Connect

    Matanovic, Ivana; Kent, Paul; Garzon, Fernando; Henson, Neil J.

    2013-03-14

    We used density functional theory to study the difference in the structure, stability and catalytic reactivity between ultrathin, 0.5–1.0 nm diameter, platinum nanotubes and nanowires. Model nanowires were formed by inserting an inner chain of platinum atoms in small diameter nanotubes. In this way more stable, non-hollow structures were formed. The difference in the electronic structure of platinum nanotubes and nanowires was examined by inspecting the density of surface states and band structure. Furthermore, reactivity toward the oxygen reduction reaction of platinum nanowires was assessed by studying the change in the chemisorption energies of oxygen, hydroxyl, and hydroperoxyl groups, induced by converting the nanotube models to nanowires. Both ultrathin platinum nanotubes and nanowires show distinct properties compared to bulk platinum. Single-wall nanotubes and platinum nanowires with diameters larger than 1 nm show promise for use as oxygen reduction catalysts.

  6. Cortical current density oscillations in the motor cortex are correlated with muscular activity during pedaling exercise.

    PubMed

    Schneider, S; Rouffet, D M; Billaut, F; Strüder, H K

    2013-01-03

    Despite modern imaging techniques, assessing and localizing changes in brain activity during whole-body exercise is still challenging. Using an active electroencephalography (EEG) system in combination with source localization algorithms, this study aimed to localize brain cortical oscillations patterns in the motor cortex and to correlate these with surface electromyography (EMG)-detected muscular activity during pedaling exercise. Eight subjects performed 2-min isokinetic (90 rpm) cycling bouts at intensities ranging from 1 to 5 Wkg(-1) body mass on a cycle ergometer. These bouts were interspersed by a minimum of 2 min of passive rest to limit to development of peripheral muscle fatigue. Brain cortical activity within the motor cortex was analyzed using a 32-channel active EEG system combined with source localization algorithms. EMG activity was recorded from seven muscles on each lower limb. EEG and EMG activity revealed comparatively stable oscillations across the different exercise intensities. More importantly, the oscillations in cortical activity within the motor cortex were significantly correlated with EMG activity during the high-intensity cycling bouts. This study demonstrates that it is possible to localize oscillations in brain cortical activity during moderate- to high-intensity cycling exercise using EEG in combination with source localization algorithms, and that these oscillations match the activity of the active muscles in time and amplitude. Results of this study might help to further evaluate the effects of central vs. peripheral fatigue during exercise.

  7. Comparison of polar cap electron density enhancement due to solar illumination and geomagnetic activity as measured by IMAGE/RPI

    NASA Astrophysics Data System (ADS)

    Nsumei, P.; Reinisch, B.; Song, P.; Tu, J.; Huang, X.

    2007-12-01

    Polar cap electron density (Ne) measurements made between the years 2000 - 2005 by the radio plasma imager (RPI) on board the IMAGE spacecraft are used to study the density enhancements resulting from changes in solar illumination and geomagnetic activity level. This study covers a geocentric distance, R = 1.4 - 5.0 RE and the polar cap is defined by an empirical boundary model that takes into account the dynamic nature of the location and size of the polar cap. The average polar cap electron density profile depends on geomagnetic activity level e.g., measured by the Kp index and solar illumination (solar zenith angle) at the footprints of the geomagnetic field lines. Our analysis of RPI Ne data shows that increase in geomagnetic activity leads to an enhancement in Ne. This enhancement in Ne is found to increase with altitude. At geocentric distance of R = 4.5 RE, an increase in the geomagnetic activity level from Kp < 2 to ~5 results in an Ne increase by a factor of ~5. On the other hand, a strong solar illumination control of Ne at lower altitudes, and not at higher is observed. At geocentric distance of ~ 2 RE, the average Ne is larger on the sunlit side than on the dark side by a factor of 3 - 4 both for quiet and disturbed conditions. At geocentric distance of about 2.5 RE the effects of these two factors on Ne appear to be comparable. Similar to previous polar cap density models, a functional representation of RPI Ne that takes the form of a power law is proposed. While in the previous Ne functional representations the power index is a constant, the power index in our representation of Ne distribution is found to correlate with (and hence is a function of) the Kp index and the solar zenith angle (SZA).

  8. Final Report - Montana State University - Microbial Activity and Precipitation at Solution-Solution Mixing Zones in Porous Media

    SciTech Connect

    Gerlach, Robin

    2014-10-31

    Background. The use of biological and chemical processes that degrade or immobilize contaminants in subsurface environments is a cornerstone of remediation technology. The enhancement of biological and chemical processes in situ, involves the transport, displacement, distribution and mixing of one or more reactive agents. Biological and chemical reactions all require diffusive transport of solutes to reaction sites at the molecular scale and accordingly, the success of processes at the meter-scale and larger is dictated by the success of phenomena that occur at the micron-scale. However, current understanding of scaling effects on the mixing and delivery of nutrients in biogeochemically dynamic porous media systems is limited, despite the limitations this imposes on the efficiency and effectiveness of the remediation challenges at hand. Objectives. We therefore proposed to experimentally characterize and computationally describe the growth, evolution, and distribution of microbial activity and mineral formation as well as changes in transport processes in porous media that receive two or more reactive amendments. The model system chosen for this project was based on a method for immobilizing 90Sr, which involves stimulating microbial urea hydrolysis with ensuing mineral precipitation (CaCO3), and co-precipitation of Sr. Studies at different laboratory scales were used to visualize and quantitatively describe the spatial relationships between amendment transport and consumption that stimulate the production of biomass and mineral phases that subsequently modify the permeability and heterogeneity of porous media. Biomass growth, activity, and mass deposition in mixing zones was investigated using two-dimensional micro-model flow cells as well as flow cells that could be analyzed using synchrotron-based x-ray tomography. Larger-scale flow-cell experiments were conducted where the spatial distribution of media properties, flow, segregation of biological activity and

  9. Homeobox NKX2-3 promotes marginal-zone lymphomagenesis by activating B-cell receptor signalling and shaping lymphocyte dynamics

    PubMed Central

    Robles, Eloy F.; Mena-Varas, Maria; Barrio, Laura; Merino-Cortes, Sara V.; Balogh, Péter; Du, Ming-Qing; Akasaka, Takashi; Parker, Anton; Roa, Sergio; Panizo, Carlos; Martin-Guerrero, Idoia; Siebert, Reiner; Segura, Victor; Agirre, Xabier; Macri-Pellizeri, Laura; Aldaz, Beatriz; Vilas-Zornoza, Amaia; Zhang, Shaowei; Moody, Sarah; Calasanz, Maria Jose; Tousseyn, Thomas; Broccardo, Cyril; Brousset, Pierre; Campos-Sanchez, Elena; Cobaleda, Cesar; Sanchez-Garcia, Isidro; Fernandez-Luna, Jose Luis; Garcia-Muñoz, Ricardo; Pena, Esther; Bellosillo, Beatriz; Salar, Antonio; Baptista, Maria Joao; Hernandez-Rivas, Jesús Maria; Gonzalez, Marcos; Terol, Maria Jose; Climent, Joan; Ferrandez, Antonio; Sagaert, Xavier; Melnick, Ari M.; Prosper, Felipe; Oscier, David G.; Carrasco, Yolanda R.; Dyer, Martin J. S.; Martinez-Climent, Jose A.

    2016-01-01

    NKX2 homeobox family proteins have a role in cancer development. Here we show that NKX2-3 is overexpressed in tumour cells from a subset of patients with marginal-zone lymphomas, but not with other B-cell malignancies. While Nkx2-3-deficient mice exhibit the absence of marginal-zone B cells, transgenic mice with expression of NKX2-3 in B cells show marginal-zone expansion that leads to the development of tumours, faithfully recapitulating the principal clinical and biological features of human marginal-zone lymphomas. NKX2-3 induces B-cell receptor signalling by phosphorylating Lyn/Syk kinases, which in turn activate multiple integrins (LFA-1, VLA-4), adhesion molecules (ICAM-1, MadCAM-1) and the chemokine receptor CXCR4. These molecules enhance migration, polarization and homing of B cells to splenic and extranodal tissues, eventually driving malignant transformation through triggering NF-κB and PI3K-AKT pathways. This study implicates oncogenic NKX2-3 in lymphomagenesis, and provides a valid experimental mouse model for studying the biology and therapy of human marginal-zone B-cell lymphomas. PMID:27297662

  10. Using a Differential Emission Measure and Density Measurements in an Active Region Core to Test a Steady Heating Model

    NASA Astrophysics Data System (ADS)

    Winebarger, Amy R.; Schmelz, Joan T.; Warren, Harry P.; Saar, Steve H.; Kashyap, Vinay L.

    2011-10-01

    The frequency of heating events in the corona is an important constraint on the coronal heating mechanisms. Observations indicate that the intensities and velocities measured in active region cores are effectively steady, suggesting that heating events occur rapidly enough to keep high-temperature active region loops close to equilibrium. In this paper, we couple observations of active region (AR) 10955 made with the X-Ray Telescope and the EUV Imaging Spectrometer on board Hinode to test a simple steady heating model. First we calculate the differential emission measure (DEM) of the apex region of the loops in the active region core. We find the DEM to be broad and peaked around 3 MK. We then determine the densities in the corresponding footpoint regions. Using potential field extrapolations to approximate the loop lengths and the density-sensitive line ratios to infer the magnitude of the heating, we build a steady heating model for the active region core and find that we can match the general properties of the observed DEM for the temperature range of 6.3 < log T < 6.7. This model, for the first time, accounts for the base pressure, loop length, and distribution of apex temperatures of the core loops. We find that the density-sensitive spectral line intensities and the bulk of the hot emission in the active region core are consistent with steady heating. We also find, however, that the steady heating model cannot address the emission observed at lower temperatures. This emission may be due to foreground or background structures, or may indicate that the heating in the core is more complicated. Different heating scenarios must be tested to determine if they have the same level of agreement.

  11. Regulation of invertase activity in different root zones of wheat (Triticum aestivum L.) seedlings in the course of osmotic adjustment under water deficit conditions.

    PubMed

    Königshofer, Helga; Löppert, Hans-Georg

    2015-07-01

    Osmotic adjustment of roots is an essential adaptive mechanism to sustain water uptake and root growth under water deficit. In this paper, the role of invertases (β-fructofuranosidase, EC 3.2.1.26) in osmotic adjustment was investigated in the root tips (cell division and elongation zone) and the root maturation zone of wheat (Triticum aestivum L. cv. Josef) in the course of osmotic stress imposed by 20% polyethylene glycol (PEG) 6000. The two root zones investigated differed distinctly in the response of invertases to water deprivation. In the root tips, the activity of the vacuolar and cell wall-bound invertases increased markedly under water stress resulting in the accumulation of hexoses (glucose and fructose) that contributed significantly to osmotic adjustment. A transient rise in hydrogen peroxide (H2O2) preceded the enhancement of invertases upon exposure to osmotic stress. Treatment with the NADPH oxidase inhibitor diphenylene iodonium (DPI) abolished the stress induced H2O2 production and suppressed the stimulation of the vacuolar invertase activity, whereas the activity of the cell wall-bound invertase was not influenced by DPI. As a consequence of the inhibitory effect of DPI on the vacuolar invertase, hexose levels and osmotic adjustment were also markedly decreased in the root tips under water deficit in the presence of DPI. These data suggest that H2O2 probably generated by a NADPH oxidase is required as a signalling molecule for the up-regulation of the vacuolar invertase activity in the root tips under osmotic stress, thereby enhancing the capacity for osmotic adjustment. In the root maturation zone, an early H2O2 signal could not be detected in response to PEG application. Only an increase in the glucose level that was not paralleled by fructose and a slight stimulation of the activity of the vacuolar invertase occurred in the maturation zone after water deprivation. The stress induced accumulation of glucose in the maturation zone was not

  12. Host density and human activities mediate increased parasite prevalence and richness in primates threatened by habitat loss and fragmentation.

    PubMed

    Mbora, David N M; McPeek, Mark A

    2009-01-01

    1. Habitat loss and fragmentation are the principal causes of the loss of biological diversity. In addition, parasitic diseases are an emerging threat to many animals. Nevertheless, relatively few studies have tested how habitat loss and fragmentation influence the prevalence and richness of parasites in animals. 2. Several studies of nonhuman primates have shown that measures of human activity and forest fragmentation correlate with parasitism in primates. However, these studies have not tested for the ecological mechanism(s) by which human activities or forest fragmentation influence the prevalence and richness of parasites. 3. We tested the hypothesis that increased host density due to forest fragmentation and loss mediates increases in the prevalence and richness of gastrointestinal parasites in two forest primates, the Tana River red colobus (Procolobus rufomitratus, Peters 1879) and mangabey (Cercocebus galeritus galeritus, Peters 1879). We focused on population density because epidemiological theory states that host density is a key determinant of the prevalence and richness of directly transmitted parasites in animals. 4. The Tana River red colobus and mangabey are endemic to a highly fragmented forest ecosystem in eastern Kenya where habitat changes are caused by a growing human population increasingly dependent on forest resources and on clearing forest for cultivation. 5. We found that the prevalence of parasites in the two monkeys was very high compared to primates elsewhere. Density of monkeys was positively associated with forest area and disturbance in forests. In turn, the prevalence and richness of parasites was significantly associated with monkey density, and attributes indicative of human disturbance in forests. 6. We also found significant differences in the patterns of parasitism between the colobus and the mangabey possibly attributable to differences in their behavioural ecology. Colobus are arboreal folivores while mangabeys are terrestrial

  13. New light on the Co-C bond activation in B 12-dependent enzymes from density functional theory

    NASA Astrophysics Data System (ADS)

    Andruniow, Tadeusz; Zgierski, Marek Z.; Kozlowski, Pawel M.

    2000-12-01

    Density functional theory (DFT) is applied to the calculation of activation of the Co-C R bond in models of vitamin B 12, B-[Co III(corrin)]-R. It is shown that there is a positive correlation of the bond lengths between the Co atom and the two axial ligands, B and R. The electron donation from axial ligands to the cobalt atom either by electron donating substituents or by a properly oriented external electric field caused by external electric charges is argued to be the main trigger for the activation of the Co-C R bond.

  14. Noncovalent intermolecular interactions between dehydroepiandrosterone and the active site of human dehydroepiandrosterone sulphotransferase: A density functional theory based treatment

    NASA Astrophysics Data System (ADS)

    Astani, Elahe; Heshmati, Emran; Chen, Chun-Jung; Hadipour, Nasser L.; Shekarsaraei, Setareh

    2016-04-01

    A theoretical study was performed to characterize noncovalent intermolecular interactions, especially hydrogen bond (HB), in the active site of enzyme human dehydroepiandrosterone sulphotransferase (SULT2A1/DHEA) using the local (M06-L) and hybrid (M06, M06-2X) meta-GGA functionals of density functional theory (DFT). Results revealed that DHEA is able to form HBs with residues His99, Tyr231, Met137 and Met16 in the active site of the SULT2A1/DHEA. It was found that DHEA interacts with the other residues through electrostatic and Van der Waals interactions.

  15. 78 FR 68026 - Foreign-Trade Zone 32-Miami, Florida, Authorization of Production Activity, Almod Diamonds, Ltd...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-13

    ..., Almod Diamonds, Ltd. (Jewelry and Precious Stones), Miami, Florida On June 21, 2013, the Greater Miami... the Foreign-Trade Zones (FTZ) Board on behalf of Almod Diamonds, Ltd., within FTZ 32--Site 1, in...

  16. 77 FR 59890 - Foreign-Trade Zone 92-Gulfport, MS; Authorization of Production Activity; Gulf Ship, LLC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-01

    ... Ship, LLC (Shipbuilding); Gulfport, MS On May 10, 2012, the Mississippi Coast Foreign-Trade